Note: Descriptions are shown in the official language in which they were submitted.
~7`~7~30
Description
PAGING RECEIVER WITH PROGRAMMABLE
AREAS OF RECEPTION
Technical Fieldo
The present invention relates to RF paging
receivers which receive pages comprised of either
numeric characters and/or alphanumeric characters and
convey the page to a person possessing the paging
receiver.
Backqround Art:
Paging ~ystems are in use throughout the world.
There are paging systems which transmit pages from
satellite transmitt~rs to different cities~ An example
of such a system is that operated by National Satellite
Paging which ~ransmits only numeric pages. A system
operated by Metrocast pPrmits pages to be transmitted
to any city within the system through dedicated
communication links between the cities. In the
Metrocast system, pages to be transmitted locally are
exclusively made by calling into the city where the
page i5 to be made by a local telephone call. A page
~o be made on a regional basis i~ called in by an 800
number telephonQ call to a central facility in San
Diego ~rom which the page is transmittad to the city
where the page is to be broadcast by the dedicated
communication link. The page i~ received from the
communication l:ink at the city where it is to be
broadcas~ and ~hen bro~dcasted locally by an existing
paging service to transmit the page to the person to be
paged.
;~: To date, there is no existing national paging
: ~ system which substantially covers the geographical
~ Unit-d States. Because of the cost of hardware, a
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1 -',07~30
system like the Metrocast system is not economical in
small cities or rural areas where the paging volume is
relatively low. Accordingly, while the objective of
achieving nationwide paging has been attempted for many
years, no existing system integrates local and national
paging substantially throughout the geographical United
States or throughout the world. The vast majority of
paging systems operate totally locally with each system
having a limited functionality because of its inability
to deliver regional paging. Most paging receivers are
tuned to receive only a single channel which inherently
limits usage in time frames when heavy paging
conditions ~xist in a local paging system and ~urther
prevent usage in other geographical locations where
other channel freguencies are used.
Typically each existing paging system has unique
specifications which prevents operation o~ one paging
receiver in other systems. For example, the paging
receiver ident1fication codes are not universal.
Furthermore, existing paging receivers will only
receive transmissions from a single type o~ transmitter
(analoy or digital) systems. As a result o~ paging
receiver~ dif~ering in design and operation, the cost
of paging receivers is higher as a result of smaller
manufacturing volumes than would be realized if a
single paging receiver was usable for a worldwide
network.
:Paging receivers in the Metrocast system
: cycliaally scan a plurality of closely spaced channel
~requencies to detect the presence of a page for the
paging receiver on any one of the closely spaced
frequencies. This paging receiver suffers from the
inherent disadvantage that the continual scanning of
3 1 307~30
the closely spaced frequencies requires a substantial
power consumption causing the batteries o~ the pager to
have a short life span. Short battery life increases
the cost of operation and can cau~e pages to be lost
when the batteries are not promptly replaced.
All paging systems currently issue a paging
receiver identification code to each of the paging
receivers for purposes of providing a unique
identification. There currently is no universal
standard for issuing identification numbers to pagers,
with the largest system having capacity for issuing
only 2,000,000 paging receiving identification codes.
Worldwide, there currently are over 12,000,000 pagers
in use with projected growth on an annual basis in th~
paging industry exceeding 20~. ~hus, current paging
systems do not permit a worldwide paging system to be
realized as a result of the actual and projected number
of pagers being far larger than the capacity of the
identification codes in the largest existing paging
system.
All pagers currently monitor the one or more
channel frequencies which they are designed to receive
to detect if a paging receiver identification code
accompanying a page on the one or more channel
frequencies on which they are designed to receive
matches a stored paging recei~er identification cods.
If a match exists, ~then a page is processed and an
alarm a~d a display of the message is made to alert the
~ wearer of the paging receiver o~ the message contained
;~ ~ 30 with the page~ These æystems transmit the pager
identification code in an order of decreasing
significance of the digits of the identification code.
In other words, if a paging receiver has the
identification code 12345, the transmitter precedes the
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4 1 301~30
transmission of the page with the sequence of digits
12345. Each pager which receives the channel frequency
on which the paging receiver identification code is
transmitted continually detects each of the successive
digits and maintains ~ts radio frequency receiver on
until a mismatch is found be~ween the transmitted and
stored paging receiver identification code digits. As
a result of the fact that many paging receivers have
identification codes in which their more significant
digits are common to other paging receivers within a
6ystem, a ~ubstantial amount o~ battary power is
consumed detecting i~ a page i8 intended for a
particular paging receiver. Each paging receiver which
receives the digits of the paging recei~er
identification ~ode : in an order o~ decreasing
: significance is statistically likely to have its radio
frequency receiver turned on ~or most of the
transmission of the digits o~ the paging receiver
identification code until the lasser significant digits
of the paging receiver identifiration code are received
for the reason that it is ths lesser significant paging
receiver identificaticn code digits whîch distinguish
one paging receiver from another and only tha least
~; significant digit which dis~inguishes the paging
receiver which is desired to recei~e a particular page
from all other paging receivers. Accordingly, the
transmission of the paging receiver identification code
: digi~s in an order of decreasing significance
substantially increases power consumption lessening the
life of the batteries of the paging receiver.
~ hroug~out tha world different fre~uency bands
have been adopted for transmitting pages. In th~
Unlted Stat~s j transmls ions are authorized on VHF and
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UHF bands. In the United States, the channel
frequencies of the VHF and UHF bands are separated by 5
KHz steps. Moreover, for each of these bands
transmitters are in existence which transmit pages by
frequency modulation of a digital carrier wave and
other transmitters which transmit pages by frequency
modulation of an analog carrier wave. Currently no
paging receiver exists which is compatible with
transmissions ~rom both analog and digital
transmitters. Furthermore, Europe has allocated VHF
frequencies for paging with individual channel
frequencies being separated by 6.25 KXz steps and Far
Eastern countries has allocated paging frequencies on a
280 ~Hz VHF band with individual channel frequencies
being separated by 2.5 KHz steps. Currently, no paging
receiv~rs exist which are operational on any more than
one of the above-identified frequency bands. The
inability of current paging receivers to recei~e pages
on the different ~requency bands allocated throughout
the world prevents worldwide paging to be received on a
single paging receiver.
; NonP of the com~ercially marketed paging receivers
is programmable by command to receive different channel
frequencie~ which severely restricts the paging
receivers to usage in limited geographical areas. In
the United States there are a large number of paging
frequencies in use in different geographical parts of
the country. Because of the fact that the existing
paging receivers cannot be programmed by command to
receive differPnt channel frequencies, it is impossible
to universally receive pages throughout the country
because of the fact that reception of channel
frequancies is limited to a single channel fr~quency
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~ixed upon obtaining the paging receiver ~rom the
paging service or to cyclically scan a group o~ closely
spaced channels such a~ with the paging receiver used
by the Me~rocast system. Neith2r approach leads
itself to being dynamically usable to accept pages in
another geographical araa where a different frequency
or ~requencies are in use. The prior art paging
receivers' inability to rapidly change the fre~uencies
which may be received severely limits the usage of
paging for business or other travel.
In the prior art as a consequence of paging
receivers being designed to receive only a single
channel in a particl~lar frequency band or to scan a
se~uence of closely spaced channel frequencies, antenna
yain has not been a problem in achieving reception of
pages with suf~icient ~ignal strength to permit proper
decoding and display o~ the page. Antenna tuning
systems have been used to tune a receiver's antenna in
military co~munication for maximum antenna gain prior
to receiving co~munication~. However, these systems do
not tune antenna gain dynamiaally during tha reception
of the communic~ation. When a paging receiver is used
: to accept multiple bande of ~requencies, snvironmental
characteristics such as variable inductance and
: 25 capacitance which vary with location, will tend to
prevent maximum antenna gain from being achieved
especially when the paging receiver iæ being carried by
: a person in motion.
~urrently, no paging system exists which truly
~ 30 permits paging on a national and international level.
:~ : This is a conse~uence of the inability o~ th~ paging
receivers to receive a large number of frequencies and
fur~her the de~iciency of the existing systems in
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having a universal paging receiver identi~ication code
which uniguely identi~ies each o~ the paging receivers
throughout the world with the possibility existing in
the current systems o~ several pagers having the same
paging receiver identification code. A universal
pa~ing receiver identi~ication code is needed having
the capacity to uni~uely identify all of the paging
receivers throughout the world.
Currently in the United States a relatively small
number of frequencies are used in the large
metropolitan areas where most o~ the paging tra~fic
occurs. As paging tra~fic increases in view of the
relatively small number of ~requencies predominantly in
use in metropolitan areas, there is thP likelihood that
message traffic during the three peaX paging periods
that occur each day will incraase to the point where
the predominantly used small number of ~requencies will
become so busy that it is impossible to rapidly
transmit pages to a paging receiver. B cause of the
2G fact that current paging reaeivers are not programmable
by remote command to receive pages on dif~erent channel
frequencies, existing networks do not have the ability
to dynamically switch channel frequencie~ in large
~ metropolitan areas, when one channel becomes so busy
:~ 25 that rapid paging is not possible, to another lesser
used channel to eliminate delays in transmitting pages
to a paging receiver. In fact, in large metropolitan
areas there currently are VHF and UHF mobile channels
that are curren~ly undQr utilized due to ~he current
cellular radio system which could be used as
: alternative paging channel ~requencies to receive
tra~ic on commonly used stations.
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8 1 3n733n
FM analog and digital paging protocols exist.
Existing protocols for the FM analog and digital paging
systems do not have a high efficiency in transmitting
data per transmitted code. Existing digital
transmitters modulate a digital FM tran~mitter with a
binary signal which utilizes frequency shift keying of
the basic carrier signal to transmit high levels of a
bit with a burst of the shifted ~requency and the low
level bit with the unshi~ted frequency of the carrier.
Thus, each identifiable digit of the transmission from
an FM digital paging transmitter can encode only two
distinct levels for each ~requency burst of the
carrier. Anal og ~M paging transmitters frequency
modulate a sinu oidal carrier with a total of 15 tones
to create a hexadecimal level transmitting system in
which no modulation of the basic carrier frequency is
considered to be the IlF" le~el and the remaining 15
dif~erent levels are encoded by modulating the FM
carrier with distinct tones. Paging receivers which
are designed to receive analog transmissions require
: substantial reception time of each tone to validly
~ detect each character. Thus, while the protocol o~ FM
: analog paging transmitters transmits a much higher
number of daka levels for each fre~uency burst, the
slowness of the paging receivers in detecting the
: discrete tones does not result in a high throughput
speed of transmitting charac~ers.
Existing paging ~y~tems which permit paging in
multiple cities suffer from the deficiency that a long
di~tance phone call is required to phone in a page
which is to be tran~mitted to a remote city. Because
of the fact that the long distance phone call is
charged to the person wi~h~ng to make the page or to
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the operator of the system (800 service), the expense
of using these paging systems is increased and may
discourage users ~rom maXing non-local pages. No
national or regional prior art paging system permits a
page to be initiated ~ro~ a geographic area outside the
area where the paging receiver is normally located by
the making o~ a local phone call and further for the
paging receiver to be programmed to re~eive the page on
a particular frequency found at the location where the
page is to be received.
Current paging receivers do not execute a
repertoire o~ commands permitting the functional
characteristics of the paging receiver to be programmed
dynamically by RF transmission. Current paging
receivers do respond to commands which provide an alarm
to the person wearing the paging recelver that a page
has been received such as activating a display and/or
providing an audio alarm. However, current paging
receivers do not ex cute a diversity o~ commands in
which the system influences operation and structure o~
the paging receiver, including commands activating khe
~ display to indicate if the page has originated locally
;;~ or from another region, causing the message transmitted
with the page to be stored in a particular memory
: 25 location in the paging receiver and programming the
channels on which the paging receiver is to receive
pages and permitting the pagihg receiver to serve as a
relay ~or pages ei~her to be ~ransmitted or received.
:~oreover, the prior art paging receivers do not
control the scanning o~ channel frequencies in
:~ accordance with a program which automatically causes
: the RF receiver to monitor the channel on which the
last page was received for a predetermined time
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interval and if no carrier frequenay is detected on
that channel then scanning one or more additional
progran~ed channel ~requencies ~or a predetermined time
interval until either a carrier frequency is detected
on one o~ tAe channels being scanned in which case that
channel freguency is ~canned for the prPdetermined time
interval or in the absence o~ any carrier being
detected on the one or more channels being scanned
shutting down the RF receiver a~ter the predetermined
time interval. No prior ar paging ~ystem is known in
which a code i~ transmitted with the paging receiver
identi~ication code to restrict reception of pages in
particular geographic areas.
Cellular radio sy~tems dynamically assign
frequencies on which cellular radio re eiver~ are to
receiva telephone call~. To make or receive a
telephone call, a mobile cellular radio is locked onto
a set up channel through communications with th2
transmitter which are establish~d when the cellular
~0 radio receiver is turned on. ~he cellul~r system then
assigns the mobile cellular xadio to a ~pecific channel
while the mobile cellular radio is making or receiving
a telephone sall within a cell. As the ~ellular radio
: : receiver moves from one cell to another cell~ the
channel ~requency is dynamically changed ~rom one
requency to another ~requency to maintain a strong
signal ~requency. A cellular radio receiver does not
: ha~e a channel memory which ~tores channel ~requencies
which are to be scanned to establish if a call is forth
coming. The dynamic assignment o~ a channel ~requency
: is initiated by the transmitter ~or the sole purpose o~
establishing the channel ~requency over which ~oice
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communications are to be initiated or to be maintained
when moving ~rom one cell to another.
United State Patent No. 4,422,071 discloses a
system ~or programming an identification code of a
receiver by a radio ~requency communication between a
transmitter and the raceiver.
Disclosure of Invention-
The present invention provides the first paging
receiver which is compatible with all existing UHF and
V~F paging frequency band~ and existing paging system
FM analog and digital transmitterR found in the United
States, Japan and Europa. A paging receiver in
accordance with the present invention may be programmed
dynamically to receive ~requencies in multiple bands
including the VHF and UHF bands in the United States,
the VHF band in Europe and the 280 VHF Japanese band.
The dynamic programmability of channel frequencies of
the paging receiver o~ the present invention permits
operation in all of the geographi~ areas identified
above with a single paging receiver by programming the
paging receiver ~y a channel frequency changing command
to receive one or more ~requencies in,the geographic
: areas to which the pager will be transported. The
~; ~ transmitter tran~mitting the page in the area where the
~: : 25 paging reaeiver is to receive the page transmits the
page on a ~requency on which ~he paging receiver has
been dynamically programmed to receive the paga.
The paging receiver o~ the present invention and
its protocol is compatible with all exis~ing analog and
digital transmitters and permits page~ transmitted by
: either analog or digital paging transmittars to be
: ~ received by a single paging receiver with total
~: transparenay to the user of the paging receiver.
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12 1 ~"7~30
Furthermore, the adoption of a universal protocol in
which each code transmission by a FM digital
transmitter encodes a muItiple level of signals greater
than two achieves a high data throughput rate.
Moreover, the signal processing cir~uitry o~ the paging
receiver provides a rapid respons~ time to each
transmitted code ~rom either an analog or digital
transmitter which further permits the time duration of
transmission o~ each character to be shortened
providing a high data throughput. Finally, in
accordance with a preferr~d embodiment of the present
invention, a paging raceiver identification code format
is adoptad which permit~ 100, 000, 000 distinct paging
receivers to be used by the system enabling
international use.
The present invention substantially enhances the
battery li~e o~ batteria~ used to power the paging
receiver. In the ~irst place, each digit of the paging
receiver identification code is transmitted as a header
on each page in an order of increasiny significance of
the paging receiver identification code digits. The
paging receiver compares each recaived pagi~g receiver
~dentification code digit with the corresponding digits
of its unique stored paging receiver identi~ication
code to detect if a mismatch exists at which time the
paging rPceiver is turned off to conserve power until
it is ~urned on again under a control program of the
:~ main central processing uni~. The comparison o~ the
transmitted paging receiver identifi~ation code digits
~ 30 and the ~tored~ pagex receiver identification code
;~ digits continues sequentially until either a total
match is ~ound at which time the command and/or page
tranemitted with the paging receiver identification
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13 1,,'~7~30
code is processed or the paging receiver is shut down
to conserve power.
Furthermore, reception of pages by a particular
paging receiver may be restricted by use o~ a region
deaignation code. Each paging receiver contains a
memory ~or storing a de~tination code. Pages which are
to be received on an area ba~is by a paging receiver
are transmitted with the destination code being the
first digit of the transmission of the paging receiver
identification code. If a match i~ not ~ound between
the transmitted de~tination ~ode and any stored
destination code contained in the memory of the paging
receiver, th~ paging receiver is immediately shut down
to conserve power. If a match is found between a
transmitted destination code and any stored destination
code, the paging receiver then processes the
: su~sequently transmitted paging receiver identification
: code digit which are transmitted in an order o~
increasing significance of it~ digits as described
: 20 abovQ. The invention eliminates the problem of each
paging receiver which i~ to receive a national or
regional page ~rom re ponding to re~ident local paging
which con~umes substantial amounts of battery life.
Furthermore, in ar cordance with the invention,
~5 each paging receiver contains a memory for storing the
~: : last channel frequency on which a carrier frequency was
detected. The control program of the main central
processing unit for the paging receiver automatically
activates the paging receiver to receive the last
channel ~requency first because of the statistical
~ ~ probability that pages are more likaly to be ~ound on
: ~ ~ that channel than on additional channels s~ored in a
: channel frequency memory which are thereafter received
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07~30
by the paging receiver in an order determined by a
control program. Battery li*e is enhanced by ordering
the sequence in which channel frequsncies are to be
received such that the tatistically most likely
channel on which a transmission is likely to be
received i9 the first channel received when a plurality
of channel frequencies are to be scanned for the
presence of carrier frequency.
The diverse command repertoire o~ the paging
receiver further enhance~ its usage by permitting
programming of channal ~requencies, processing of
storage location of pages in memory, place of origin
display o~ pages, use of the paging receiver to relay
page~ to external devices and regional or group
speci~ic reception o~ page~.
A method for receiving a page in a remote area
when a paging re~eiver has been transported ~rom a
local area where the paging receiver has been
progra~med to receive pages on one or more channel
frequencies to the remote area in accordance with the
invention includes programming the paging receiver by
: one or mare channel fre~uency changing commands
: transmitted by an RF carrier from a transmitter located
in the local area while the paging receiver is located
in: the local area to receive one or more programmed
channel fre~uencies in the remote area; transporting
the paging receiver from the local area to the remote
: area where the page is to be received; and relaying ths
page from the local area to a transmitter located in
; 30 : the remote area and transmitting tha page from the
: transmitter in the remote area on one of the one or
more programmed channel ~requencies to the paging
receivGr. The paglng receiver has a channel memory ~or
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I 337~30
storing channel ~requencie~ on which the paging
receiver is to receive pages and a controller,
rasponsive to a channel frequency changing command for
decoding each channel rrequency changing command to
obtain a channel frequency to be stored in the channel
memory and causing storage in the channel memory of the
channel ~re~uency. The paging receiver xeceives a page
over one of the channel frequencies programmed by the
channel frequency changing command while located in the
remote area. Fur~her in accordance with the method, an
area destination code i~ s~ore~ in a ~emory o~ the
paging receiver to distinguish pages originating in khe
remote area and transmitted withn ths remote area and
pages originating in the local area~ relayed to the
transmitter in the remote area and transmitted by the
transmitter in the remote area to the paging rsceiver
: located in the remote area; and the paging receiver in
the remote area compares each transmission received on
the one or more programmed frequencies with the stored
destination code and turns o~ the paging recaiver upon
a match not being detected between the stored
destination code and a transmission on one o~ the one
~: or more programmed channel ~requencies. Further in
a~cordance with khe method, programming the memory of
the paging receiver with the destination code is
: accomplished with the channel ~requency changing
: command; and storage o~ the destina~ion code is in the
ahannel memory. The first Gharacter o~ each paga
~ransmitted by the transmi~ter in the remote area to
the paging receiver is the destination code stored in
the memoxy; and the paging receiver receives at least
: : one additional digi~ in a page i~ a match is detected
batween the transmitted and stored destination codes
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16 1 J07g30
and turns off immediately if a match is not ~ound. The
paging receivex is issued a unique paging receiver
identification code; the page transmitted by the
transmitter in the remote area is trAnsmitted with a
paging receiver identi~ication code immediately
~ollowing the destination code with digits of the
transmitted paging receiver identification code being
transmitted in an order o~ increasing significance;
when a match is detected between the transmitted and
stored destination code, tAe paging receiver compares
successive digits o~ the transmitted paging receiver
identification code and corresponding digits of the
stored paging receiver identification codes: the paging
receiver turns off immediately upon a match not being
detected betwsen a digit of the transmitted and stored
paging receiver identification codes; and the paging
receiver decodes a page following tha tran~mitted
paging receiver identification code if all o~ the
digits o~ the transmitted and received paging receiver
~0 identification codes match.
A method for receiving a page by a paging receiver
in a local axea on a channel ~requency on which other
paging receivers receive pages ind udes programming the
paging receiver by one or more channel frequency
changing commands transmitted by a RF carrier from a
transmitt~r located in the local area to the paging
receiver located in the local area with one or more
channel fre~uencies to be received in the local area
and programming a memory with a destination code 30 distinguishing pages to be received on the on~ or more
programmed ~requencies in the local area from a page to
be received by the paging receiver or a group of paging
receivers less than a total number of paging receivers
17 1 ~)0 7~30
within the local area that receive the one or more
programmed channel ~requencies; the paging receiver in
the local area comparing each transmission received on
the one or more programmed ~requencies with the stored
destination code and turning o~f the paging receiver
upon a match not being detected between the stored
destination code and a transmission received on one of
the programmed one or more programmed channel
~requencies, the channel ~requency changing command
programming the destination code; and storage of the
destination code and the one or more progra~med channel
~reguencies being in a channel memory. A first
character of each page to be transmitted to the paging
receiver is the destination code stored in the memory;
and the paging receiver receives at least one
additional code transmi~sion in a page if a match is
detected between the transmitted and stored destination
codes and turns off immediately i~ a match is not
found. The paging receiver is issued a unique paging
receiver identification code; the page is transmitted
with a paging receiver identi~ication code immediately
~ollowing the de~tination code with digits of the
paging rec~iver idsnti~ication code and corresponding
digits of the stored paging receiver identification
~: : 25 code being compared; the paging receiver turns off
: immediately upon a match not being detected ~etween a
digit of the transmitted and stored paging receiver
identific~tion codes; and the paging receiver decodes a
page following the transmitted paging receiver
identification code lf all of the digits of the
transmit~ed and received paging receiver identi~ication
codes match.
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1~ 1 )`~7S30
A RF paging re~eiver which is programmable by a
transmitted channel freque~cy changing command to
receive one or more channel frequencie~ in a plurality
of areas including one or more areas in which pages do
not originate and being programmable to control in
which of the plurality of areas pages may be received
by the paging receiver over the one or more channels,
for pages to be received in a first area, each page
containing a multidigit transmitted paging receiver
identification code which identifies a paging receiver
to receivQ a command in the first area o~er the one or
more channel frequencies and for pages to be received
in a second area each page containing an area
destination code distin~uishing the second area from
the first area which i8 transmitted prior to
transmission of the multidigit paging receiver
identification code in accordance with the invention
includes a RF receiver for receiving a channel
frequency on which pages are to be received: a channel
memory ~toring one or more channel ~reguencies to be
received by the RF receiver, the channel frequencies
being the one or more programmable channel ~requencies
which may be received in the fir~t area or the one or
more channel frequencies which ~ay be received in the
: 25 second area, the one or more channel ~re~uencies which
may be rece.iYad ln the second area containing the
destinatiQn code; a controller, re~pon~ive to the RF
; ~ receiver, for decoding each channel fre~uency changing
; command into a specifio frequency to be received by the
RF receiver, programming the channel mamory with a
~pecific frequency contained in the decoded command
~: : including destination code which i5 to be received,
decoding a first received character or digit of a
19 ~;''''7~30
transmission and comparing the first character or digit
recaived with the stored destination code, 1~ a match
exists between the first character or digit and the
destination code, the control means causing the RF
receiver to remain in an aativated s~ate ~o
sequentially receive one or more digits of the
transmission and if a match doe~ not exist between the
first digit and the destination code, the controller
causing the RF receiver to turn ofP.
A RF paging receiver ~or receiving pages on a
channel fraquency which are to be received ~eleGtively
within on~ or more area~ within a plurality o~ areas in
which pages are transmitted on the channel frequency
with each page being transmitted with a predetermined
protocol in which a destination code controlling in
which o~ the areas the paging receiver is to receive
the page when reception of a page in leRs than all of
the plurality of area~ is desired followed by a
multidigit paging receiver identification cod
identifying the paging receiver which is to receive the
page in accordance with the invention includes a RF
raceiver ~or receiving the channel frequency on which
the pages are to be transmitted; a me~ory for storing ~
unique multidigit paging receiver identification code
~5 of tha paging recelver; a memory for storing the
destination code controlling areas ln which the paging
raceiver is to receiver pages on the channel frequency;
and a ~ontroIler, re ponsive to the RF receiver,
decoding;a ~ir t character or digit of a page received
:~30 on the channel frequency and comparlng the stored
~:~ destination code with the first character or digit in
: response to matc~ not b~ing ~ound turning o~ th~ RF
~ receiver. The controllex, in response to a match being.
: :
:: :
1 3~7~,3(~
2n
found between the stored area destination code and th
first character or digit of th~ received transmission
on the channel ~requency, maintains the RF receiver in
an activated state for receiving the txansmitted paging
receiver identification code ~equentially diglt by
digit and comparing each decoded digit sequentially
with corresponding digit~ o~ the stored unique paging
recaiver identi~ication code to determine if a match
exists and i~ a match of all digits of the transmitted
and stored digits of the paging receiver identification
code~ is found, processes the page and when a ~atch is
not ~ound during the s~guential comparison of digits of
the stored and transmitted paging receiver
identification oodes, turns off the RF receiver. The
protocol of the transmission o~ the paging receiver
identi~ication code i~ with the digits transmitted in
an order o~ increasing ~ignificance, and the controller
compares the transmitted paging receiver identification
code digits with the ~tored paging receiver
identification coda digit~ in the order of increasing
significance until a match i8 not found betwean one of
the stored and transmitted digits o~ the paging
: receiver identi~ication codeæ at which time the
: ~ ~controller deacti~ates thQ RF receiver or a complete
: 25 match is ~ound between the stored and transmitted
digits of the paging receiv~r identi~ication codes at
which;time the message is processed by the controller.
A channel memory is provided which i~ programmable to
~: store one or more channel ~requenaie~ to be received by
~:: ; 30 ~ the RF receiver and wherein the paging receiver
: : recaive~ channel freguency changing commands each
speci~ying a particular channel frequency to be
recei~ed from a number of possible channel frequencies
:::
: ::: :
~:: :
:
21 1 3~7g30
which may be programmed to be received and a
destination code to be stored in the memory for storing
the destination code if reception in less than all of
the plurality of areas is desired; and the controller
is responsive to each channel frequency changing
command to store in the channel memory the channel
frequency to be receiv~d and to store in the memory for
stoxing the destination cods any destination code
transmitted with a channel frequency changing command
and the controller actiYates the RF receiver to receive
one or more of the progra~med channel ~re~uencies. The
controller sequentially activates the RF receiver to
receive the stored channel frequencies in the channel
memory in a predetermin~d order in the absence of
detection of a carrier frequency from all of the stored
channel frequencies by the RF receiver. The activating
the RF receiver to receive ~equentially the stored
channel frequencies in a predetermined order ic
repeated cyclically for a predetermined channel
receiving time interval in the absence of detection of
a carrier frequency on all of the stored frequencies
and causes activation of the RF r~ceiver to rsceive
stored channel frequencies in the predetermined order.
: The controller in response to the detection of the
carrier frequency being received by the RF receiver
~; activates the RF receiver cyclically during a
: predetermined channel receiving time interval to cause
~ ~ the RF receiver to cyclically receive the carrier
: ~ frequency. During each cycle of receiving the carri~r
:30 ~requency ~y the RF receiver, the controller activates
the receiver to receive the channel frequency for a
~: first predetsrmined tim2 interval and monitors the RF
: receiy~ to determine lf the channel frequency carrier
22 1 7`li7~30
is received during the ~irst predetermined time
interval and if the channel fre~uency carrier is
received, the controller continues the activation of
the RF receiver to cause the sequential reception and
decoding of digit~ of a transmitked paging receiver
identification code specifying a particular paging
receiver to receive the channel ~requency changing
command and compares the re~eived digit~ sequentially
with corre~ponding digits of a paging receiver
identification code stored in the memory ~or storing
the paging receiver identification ~ode of the paging
receiver in an order of increasing ~ignificance of the
digits of the stored paging receiver identification
code. When the controller detects a complete match
between the transmitted digits of the paging receiver
identification code and the stored digits o~ the paging
receiver identification code, the controller further
decodes the channel frequency changing command and
programs the channel memory with the decoded channel
frequency to be received. The controller stores in an
operating channel section o~ the channel memory the
channel frequency of the last channel on which the RF
receiver detected a channel carrier frequency and upon
turning on o~ the paginy receiver, thQ channel
frequency ~tored in the operating channel sectisn is
received by the RF receiver. The controller causes
storage o~ channel ~requencie~ which are to be
: programmed to be received by channel ~requency changing
commands in an area channel memory section o~ the
channel memory and the controller activate~ the RF
receiver to receive the channel freguencies in a
: predetermined order first from the operating channsl
~ : section and then sequentially ~rom the area channel
23 1 337~30
section of the channel memory. The controller
sequentially activates the RF receiver to receive the
channel fre~uencies ~tored in the channel memory in
response to detection o~ a channel frequency carrier
from any one o~ the programmed channel frequencies,
stores the ~requency of the detected channel frequency
in the operating channel section and activates the RF
receiver to recsive the channel fre~uencies stored in
the operating channel ~ection. A plurality of tuners
each for receiving channel frequencies from a band of
frequencies which have been programmed to be received
by the channel frequency changing command i8 provided~
only one of the tuners being activated at any one time
to receive a programmed channel frequency and a power
controller is provided, ~oupled to the controller and
to the plurality of tuners, for controlling the
activation of the plurality of tuners by the selective
application o~ power to only the tuner which is to
raceive a programmed channel ~requency and wherein the
controller proYides the power controller with a signal
identifying ~rom which band of *requencies a channel
frequency is from whiah one of the plurality of tuners
is to receive. ~he controller ~equentially activa~es
: ~ one:or more of the individual tuners to receive channel
: 25 frequencie~ stored in the channel memory under the
: ~ control of a control program. The control program of
:control of a control program. The control program of
the controller se~uentially activates one or more of
the plurality of tuners to receive channel frequencies
stored in the channel memory in a predetermined order
when a channel carrier frequency from any one of the
stored channel frequencies is not detected by any one
of the tuners.
24 ~ 7~ 30
A RF paging receiver which ig programmable by a
command to receive pages over one or more ~requencies
and is further programmable by a command with a
destination code to enablQ reception of the pages on
th~ one or more programmable frequencies by a
designated group, which are not to be received by all
other paging receivers receiving the one or more
fre~uencies being transmitted with the destination code
in accordance with the invention includes a memory for
storing the destination code; a memory for storing the
channel ~ra~uencies on which the paging receiver is to
receivP pages; a RF recQiver for receiving a command
for programminy the memory *or storing channel
frequencies with one or more frequencies on which pages
are to be received and a command for programming the
memory for storing the destination code; and a
controller, responsive to the RF receiver, for decoding
commands to raceive pages on the particular frequencies
and commands ~pecifyiny a destination and storing in
the memory ~or storing channel frequencies the one or
more ~requencies on which page~ are to be recei~ed and
storing a de~tination code in the memory ~or storing
the group destination code, and comparing a first
received character o~ a paye on one of the programmed
~25 channel ~requencies wikh any programmed destination
:~ codes stored in the memory storing the destination code
and i~ a match does not exist, turning of~ the RF
: receiver. The destination code is transmitted as a
irst part o~ each page which is to be received by a
paging recaiver as part of the designated group and the
controller turn~ o~f the RF receiver immediately upon
not detecting a match between a stored destination code
a transmitted destination code. Each channel frequency
~.
25 1 Jij7~30
and associated destination code are programmed by a
channel frequency changing command; and the controller
decodes each channel changing command to obtain a
channel frequency to ba received and any de~tination
code to be associated with thak channel ~requency for
receiving pages by the paging receiver. A single
ahannel memory is used ~or storing the programmed
channel frequencies and any as~ociated destination
codes.
Brief Description of Drawin~s:
- Fig. 1 is a block diagram of a preferred
embodiment of a paging receiver in accordance with the
present invention.
Fig. 2 is a diagram of the channel memory used for
I5 storing channel frequencies to be received.
Fig. 3 is a ~unctional block diagram of the
operation o~ a paging receiver in accordance with the
present invention in processing:signals from analog and
: digital transmitters.
: 20 Fig. 4 is a diagram illustrating the order of
transmis~ion o~ the digits of the paging receiver
~ identi~ication code.
: Fig. 5 is a diagram illuætrating the order of
transmiæsion of a destination code and the digi~s of
25 ~ the paging recelver identification code.
Fig. 6 is a flowchart illustrating the ord~r of
scanning the channels of the channel memory and
proces~ing o~ the destin~tion code and the paging
receiver identi~ication code.
30~ Fig. 7 is a circuit schematic of the antenna
circuit 14 of Fig. 1.
:~ Fig. 8 is a circuit schematic o~ the am?li~ier and
:~ mixer 18 of Fiy. 1.
.. ~
1 7`'~7~3~)
26
Fig. 9 is a circuit schematic of the amplifier and
mixer 22 of Fig. 1.
Fig. 10 is a circuit schematic of the amplifier
and mixer 20 of Fig. 1.
Figs. llA-C are a circuit schematic of the voltage
controlled oscillator 30 o~ Fig. 1.
Fig~ 12 i~ a circuik ~chematic o~ the phase lock
loop 28 of Fig. 1.
Fig. 13 is a circuit schematic of the IF
processing circuit 34 of Fig. 1.
- FigsO 14A~B ar~ a circuit schsmatic o~ the tone
decoder 56 of Fig. 1.
Figs. 15A-B are a circuit schematic of the main
CPU 24 of Fig. 1.
Fig. 16 i~ a circuit schematic of the ASIC
circuit A2 of the antenna controller 44 of Fig. 1.
Figs. 17 is a circuit schematic of the buffer
amplifier 50 and low pass filter 52 of Fig. 1.
FigO 18 is a circuit schematic o~ the powsr
controller 26 of Fig. 1.
: ~igs. l9A-B are a circuit schematic of the antenna
controller 44 of Fig. 1 without the ASIC circuit of
Fig~ 16.
: Fig. 20 is a circuit schematia o~ the LCD display
driver 62 o~ ~ig. 1.
Fig. 21 illu~krates the opera~ion of the present
: invention in making a page to a remote area.
Best Mode for Car~yi ~ Out The Invention:
I. Paginq Receiver A~hitecture
FigO 1 illustrates a block diagra~ o~ paging
receiver 10 in accordance with the invention. Actual
circuits for implemenking the various blocks of the
block diagram of Fig. 1 are set forth below in
~: :
'
,
27 1 307~,30
Figs. 7-20. An internal antenna 12 functions to
receive a total of 10,600 possible channels ~rom the
three discrete ~requency bands referred to above in
the Description of tha Prior Art. Because of the large
number o~ possible channel ~requencies which may be
received in the distinct three frequency bands, the
antenna 12 has a broad band characteristic. In the
paging receiver of the present invention, the antenna
12 is designed to be resonant as close as is reasonably
possible in all o~ th~ three frequency bands which it
is designed to receive. In other words, an -optimum
impedance match ic deslred. ~owever, the e~fects of
the environment in which the antenna 12 is disposed
during operation (a paging receiver is typically
clipped to the belt of a person) cause a variation in
the degree of resonance a~ a consequence of variable
inductance and capacitance cau~ed by a person's body
etc. in the environment oP the antenna. Thus, the gain
of the antenna 12 is subjeat to substantial variation
as a consequence o~ the person on which the pager is
located and tha physical environment in which the pager
is located both of which can ubstantially degrade the
gain of tha received page applied to antenna circuit
:14. The antenna cirouit 14 is a tuner containing
variable Gapa~itance dioda~ to which is applied an
ANTENNA TUNING SIGNAL to maximize the gain of the
antenna 12 ~or the particular channel frequency that RF
: ~ tuner 16 is tuned to receive. A circuit schematic of
:~ ~ : the antenna circuit is illus~rated in Fig. 7. The
3:0 ~ antenna circuit 14 i8 tuned by the ANTENNA TUNING
SIGNA~ which ~unc~ions to tune the antenna 12 to
achieve maximum gain in a manner d~cribed below in
detail.~ The RF tuner 16 is comprised o~ three separate
~: :
2~ 1 3~7~30
radio frequency ampli~iers and mixers 18, 20 and 22
which respectively receive UHF and 2 8 0 MHz VHF and VHF
channel ~re~uency bands. A circuit schematic of the
UHF ampli~ier and mixer oircuit 18 is illustrated in
Fig. 8; a circuit schematic of the 280 VHF amplifier
and mixer circuit 20 i8 illustrated in ~ig. 10; and a
circuit schematic of the VHF ampli~ier and mixer
circuit 22 is illustrated in Fig. 9. Only one of the
amplifiers and mixers 18, 20 and 22 is energized during
reception of any of the channel ~requencies which cuts
- down on pow~r consumption. A main CPU 24 controls the
activation of a power controller 26 which selectively
activates one o~ the ampllfi~r and mixer circuits 18,
20 and 22 depending upon in which o~ the UHF, 280 VHF
and VXF frequency bands a page i5 to bP received. The
digital RECEIVER TUNXNG SIGNAL outputked by the main
CPU 24 speci~ies one of the 10,60Q possible channel
~requencies to be received by the preferred embodiment
which are stored in ROM 58 as diGcussed below. The
RE~EIVER TUNING SIGNAL iB applied to phase lock loop 28
: ~ which frequency locks voltage controlled oscillator 30
on the particular channel frequency specified by the
~ECEIVER TUNING SIGNA~. When a particular frequency is
: to be received by the RF tuner 16, the main CPU 24
digitally commands tha power controller 26 to activata
a particular one of the amplifier and mixer circuits
~ ~ 18, 20 and 22 which is to receive the channel frequency
:~ to be received. By deactivating the remaining two
ampli~ier mixer circuits power is con~erved over that
whlch~would be consumed if all three ampli~iers and
: mixer circuits 18, 20 and 22 were simultaneously
activated. A circuit schematic of the main CPU 24 is
illu~trated in Fig. 15; a circui~ schematic of the
~: :
29 1 307~30
power controller circuit is illustrated ln Fig. 18; a
circuit schematic of the phase lock loop circuit 28 is
illustrated in Fig. 12; and a circuit ~chematlc of the
voltage controlled o~cillator 30 iB ilIu~trated in
Fig. 11. The voltage controlled o~sillator 30 produces
an output frequency which is ~ixed with the signal
being received by on~ of the amplifier and mixers 18,
20 and 22 to produce a 21.4 ~Hz output signal. The
21.4 ~Hz oukput signal is ~lltered by a 21.4 MHz filter
32 . The output o~ the 21. 4 MHz filter 32 is applied to
- . an IF proces~ing ~ignal circuit 34 to produc:e th~ IF
signal of 450 k~z. The output ~ignal f:rom the mixer
oscillator 36 is applied to an IF amplifier 38 which
amplifies the IF ~ignal to a level sufficierlt for
15 discrimination by ~ discriminator ~::irc:uit 40. A RSSI
circuit ~received signal ~trength indicator) 42
produces an output signal having a magnitude directly
proportional to the lev~l of the output signal from the
discriminator 40. A circuit sahematic of the IF
processing circuit 3~ is illustrated in Fig. 13. The
RSSI signal outputted by the RSSI circuit 42 is applied
to an antenna controller circuit 44. The antenna
control circuit 44 contains an analog-to digital
con~erter 46 which converts the analog RSSI ~ignal into
digital format suitable ~or processing by a dedicated
ASIC microprocessor. The antenna controller 44
contains an ASIC microprocessor based control circuit
which executes a computer program conta1ned in a ROM in
tha ASIC circuit. The ASIC circuit ~unctions to
produce a wobble ~ignal which iA ou~put~ed as a
variable digital value which is applied to
digital-to-analog convert~r ~8 to produce the ANT~NNA
: TUNING SIGNAL having a variable analog value which
3~ c~g3c~
causes the antenna circuit 14 to be tuned variably
through a frequency band for the purpose of continually
locking on the point of maximum gain as a channel
frequency is being received. The variation in signal
amplitude caused by the wobbling of the tuning
frequency o~ the antenna circuit 14 is detected by the
RSSI circuit 42 so that the antenna controller circuit
44 continually outputs an ~NTENNA TUNING SIGNAL which
tunes the antenna circuit 14 to achieve ~aximum gain
~or the antenna 12. The ANTENNA TUNIN~ SIGNAL
co~pensates for en~ronmental factors which change the
gain of the antenna 12 during reception such as
variable inductanca and capacitance caused by a
person's body. A circuit æchamatic of the antenna
controller 44 is illustrated in Fig. 16. The
discriminator circuit 40 outputs either no signal
(level F) or one of fifteen discrete sinusoidal
frequencies each of which encodes a diferant signal
level received ~rom either an analog or digital FM
paging receiver transmittar as describ~d below. A
buffer amplifier 50 amplifies the sinu~oidal output
signal from the discri~inator cirauit 40 to a level to
cxeate a square wave having a period e~ual to the
period of the sinusoidal signal outputted by the
discriminator 40. The squ~re wave outputted by the
bu~fer amplifier 50 is ~iltared by low pass filter 52
: to attenuate frequencie below 400 hertæ. A circuit
schematic of the buffer amplifier and low pass ~ilter
is illustrated in Fig. 17. The output of the low pass
filter 52 is applied to high pass ~ilter 54 which
: ~: attenuates frequencie above 3000 hertz. A tone
decoder circuit 56 converts the discrete tones
contained within the 400 to 3000 hertæ pass band
'
:
.
31 1 7rl7~3~
defined by the low pass ~ilter 52 and high pass filter
54 as described below in Fig~ 3 to produce an output
level signal indicative of 16 possible levels. The
main CPU 24 processes successive coded transmissions of
data by combining thPm into a two-digit decimal number
and decoding the two-digit number into alphanumeric
characters. A table correlating the decimal values
with their corresponding characters is set forth
below. The control program for the main CPU 24 is
stored in ROM 58. The ROM 58 also stor~s the possible
channel frequencies which may be received, which in ~he
preferred embodiment are 10,600, a command structure
table used for decoding each o~ the com~ands discussed
below, as well as th~ diæplay control for the LCD
di play 64. Variable data i~ stored in R~M 60. The
RAM 60 has separate memory ~ection~ tor storing pages
i~cludin~ specifiG memory sections which are
addressable by command, the channel frequencies which
are programmed to be received by the channel frequency
changing command including any regional de~ignation for
restricting the place o~ reception o~ pages or a group
: o~ paging receiv~rs to receive a page in a geographical
~:~ area in a channel ~emory and the paging receiver
idanti~ication. In th~ preferred embodiment there are
: 25 15 separate memory section~ which ~tor~ page~ with
sections 11-14 bQing addre~ able by com~and and
:~ : :: sections 1-10 and 15 not being addressable by command.
: The~ main CPU 24 controls a liquid crystal display
driver circuit 62. A cixcuit sch2matic o~ the liquid
~: 30:; orystal;display driver i~ ilIustrated in Fig. 20. The
liquid crystal driver circuit 62 drives a liquid
~ crystal di~play 64 described below in Fig~ 3. An
:~: external data port ~7 is used to relay the output
,
32 ~ O7~30
signal from the discriminator 52 to another data
processing or storage device when the main CPU 24
executes an external data command discussed below. A
port 68 i8 coupled to the main CPU 24 for driving an
external printer. A port 69 is provided for
establishing necessary communications between the main
CPU 24 and an external printer. A display switah 70 is
used for activating the display 64. A light switch 71
is used ~or activating baak lighting o~ the
display 64. The ~witches 70 and 71 may also be used
~or inpu~ting da~a when suitable displays are made on
~he display 54 by the control program of the main
CPU 24. Port 72 is aonnected to the paging receiver
battery (not illustrated) ~or providing power. Port 73
is provided for activating an audio alarm contained in
the paging receiver and port 74 permits connection to
an external antenna which may be used when the paging
receiver is connected to an external devic~ ~uch as a
printer.
A com~ercial embodiment of the paging receiver 10
:illu~trated in Fig. 1 has 10,600 discrete channel
requencies stored in ROM 58 ~rom the three discrete
bands which may be reaeived by the amplifier and mixers
18, 20 and 22 as described above. The main CPU 24 is
respon ive to a channel frequency changing command,
described be:low with reference to the commands which
: the main CPU 24 executes, to dynamically tune tha RF
~ ~: tuner 16 to discrete channels. Each channel fre~uency
: : ~changing com~and is decoded by the main CPU 24 to
:30 extract a channel ~requency, ~rom the 10,600 possible
: channel frequencies stored in ~OM 58, to be stored in a
channeI memory section 62 of the random access memory
60 de crLbed below with re~erence to Fig. 2.
~ ,
33 ~ 307~30
II~ Channel Memory
Fig. 2 illustrates the channel memory 62 which is
comprised of an operating channel section 64 storing a
single channel frequency and an area channel section 66
5 storing up to 15 discrete channel frequPncies to be
scanned sequentially by the RF tuner 16 under the
control of the operating program of the main CPU 24.
Illustrated below the operating channel section 64 and
the area channel section 66 is an arrow indicating the
10 order of channel reception by the RF tuner 16 when
channel frequencie~ are being ~canned to detect a
carrier frequency. The control program of the main
CPU 24 change~ the channel frequency stored in the
operation channel section 64 to automatiaally have the
15 frequency of the last received carrier frequency
: received by the RF tuner 16 stored therein. The
~requency 3tored in the operation channel section 64 is
one of the frequencies that the c:hannel memory 62 of
: the RAM 60 has been progxammed to receive by the
: 20 channel frequency changing command. It should be
understood that while 15 possible discrete channel
~: : frequencies may be stored in the area channel
~: section 66, it i6 only reguired that the area channel
sec~ion 6 6 be programmed with only one channel
25: fr~quency which is typiaally the case when the paging
receiver i o operated locally to receive only a
slngle channel. ~ In khat case, the operating channel
section 64 automatically E;tores the only channel
:frequency that the RF r~ceiver 16 will rec~ive upon
30 activation by the main CPU 24 and reception of the
: ~: carrier ~ignal. Furthermore, it ~hould be understood
that any number of charmels may be utilized in
practicing the invention. Each time the control
:' ' . . '
34 1 7~0 7g30
program o~ the main CPU 24 outputs a channel frequency
from the channel memory ~2 to be received hy the RF
tuner 16, the main CPU 24 applies the RECEIVER TUNING
5IGNAL in the form o~ a digital signal to the phase
lock loop 28 which activates the voltage controlled
oscillator 30 to produce a 21.4 MHz signal ~rom the
single activated ampli~ier and mixer circuit 18, 20 and
22. The control program of the main CPU 24 analyzes
the signal which is outputted ~rom the channel memory
62 and applie~ a contxol ~ignal to the power controller
26 which sel~ctively applies power ~rom the power
circuit 66 to only the particular one of the RF
amplifier and mixers 18, 20 and 22 which is to receive
the frequency specified by the RECEIVER TUNING SIGNAL
thereby saving power consu~ption o~ the battery.
The indiYidual channels o~ the area channel
section are programmed at the time that the paging
receivsr identification code is sent to the paging
receiver identification code memory described below
when the pager is issued to a customer and further are
also reprogrammed when the customer desires to "roam"
~ to another service area such as during business travel
: in which it may b esired to recei~e page~ on the same
frequencies that the paging receiver is currently
: 25 programmed to receive in which case a destination code
: will be added by the fre~uency channel changing command
: or to receive di~ferent freguencies in which case
dif~erent frequencie will be programmed. The
programming of channels may also be accomplished
dynamically during local paging to switch the paging
receivPr to channels which are not as busy as a channel
~requency that the paging receiver is currently
programmed to receive. A5 1~ apparent i'rom Fig. 2,
.
~'
'' ' ' ', -
.
1 7,~7~,3~
during channel scanning for the purpose o~ finding achannel frequency on which at least one carrier
~requency is present, channel frequencies to be
recei~ed are selectively outputted ~rom the operating
channel section 64 first and then ~rom the successive
section 66 of the area channel sectionO Each of these
frequencies causes the phase lock loop 28 to lock the
voltage controlled oscillator 30 to a ~requency
necessary to produce the 21.4 megahertz signal from the
10a~tivated RF ampli~ier and mixer circuits 18, 20 and 22
which i~ to receive tha particular channel ~re~uency.
The control program causes the channel ~requency which
is stored in the operating channel section 64 to be
cyclically r~ceived ~or a predetermined time interval,
such as but not limited to 15 minute~, by activating
the RF tuner 16 once every 900 milliseconds, or other
appropriate frequency, to sample th~ channel freguency
for the presence of a carrier signal and if carrier
signal is present to compare the paging receiver
identification code discussed below transmitted-with
: the page in the order of increasing significance of the
digits until a micmatch between the trans~itted paging
receiver identi~ication code digits and the digits of a
paging receiver identification code stored in the
random access me~ory 60 is detected at which time the
RF tuner 16 i8 shut of~ to conserve power.
III. Universal Reception of Pages From Either
Analoa or Digital Transmitters
: Fig. 3 illustrates a detailed block diagram
: 30 o~ the bu~fer amplifier 50, low pa~s filter 52, high
:pass filter 54 and tone deooder 56 of the present
invention for unlYersally processing signals
tran~mitted fro= ~ither analog or digital F~ paging
1 7`,)7~,30
36
transmitters. The preferred form of the signal
protocol of the present invention utilizes the
following tones to encode 16 discrete signal levels as
stated in a hexadec~mal nu~bering system as follows:
5600 Hz. = 0; 741 Hz. = 1; 882 Hz. = 2: 1023 Hz. = 3:
1164 Hz. = 4; 1305 Hz. - 5: 1446 Hz. - 6; 1587 Hz. = 7;
1728 Hz. = 8: 1869 Hz. = 9; 2151 Hz. = A; 2435 Hz. = B;
2010 Hz. = C; 2295 Hz. a D; 4059 Hz. - E; and no tone
(absence of modulated carrier signal) = F. Any
10existing analog ~ paging ~ransmitter can be used ~o
output a carrier wave having a fre~uency which is
frequency modulated with the above-described tones.
Similarly, any exi~ting digital FM paging transmitter
can be used to output a square wave signal having a
15period modulated with the above-des~ribed frequencies
encoded thereon. ~he output from the frequency
discriminator 40 is applied to a sine wave to square
wave converter 50 which amplifies the sinu~oidal input
signal to convert it to a square wave having a period
20equal to a period of the sinusoidal input signal. The
output of the sine wave to square wave converter is
applied to a noise debouncer circuit 70 ~hich removes
jitter from the input ~quare wave signal ~o provide
preci e period information on it~ output. The output
25~rom the noise debouncer circuit 70 is applied to a
shift register 72 having a nu~ber o~ stages requiring a
; :pradetermined t~me duration of the input square wave
outputted by the noise debouncer circuit 70 to be
applied to produce an output. The hift register 72 is
30reset each time the ~ignal l~vel from the sine wave to
: square wave converter 50 ls zero or changes frequency.
~he function of the shift register 72 is to eliminate
transicnt signals whioh ar- not valid signal levols.
'' '
.
37 1 3~7~ ,0
The number of stages is chosen to be suf~icient to
produce an output when an actual tone used for encoding
valid information is received while blocking
transmission of invalid transient shorter duration
tones. Output signals having a duration less than the
time required to fill up the shift register 72 are not
applied to a group of 15 digital filt~rs 74. Each of
the digital ~ilters has a pass band centered around a
different one of the tones ~et forth above. When a
sguare wave having a ~requency falling wikhin the pass
band o~ any one o~ the fift~en dlgi~al ~ilters is
applied to the ~ifteen digital filters 74, an output
square wave signal i8 produced ag inputted to the
fifteen digital filter from the shi~t register 72. A 4
M~z. oscillator 76 applies a 4 MHz. internal ref~rence
signal to an AND ga~e 8a to which the output of the
fi~teen digital filters 74 is also applied. The high
~requency of the oscillator 76 permits a large number
of samples to be taken for each high level state of the
output of the fifteen digital filters 74. By providing
the high level sampling ~requency, it i~ possible to
precisely determine the freguency of the ~ifteen tones
used for encoding signal levels with a high degree of
; accuracy over a single cyd e. The ability to datect
: 25 accurately the ~requency over a ~ingle cycle provides
an extremely high throughput o~ in~ormation when a
single cy~le is used to encode sixteen possible data
: levels. The sampled output from the ~i~teen digital
filters 74 is passed by AND gate 80 to a countar 82
: 30 which counts the number of samples of the output o~ the
digital filters 14 which have a high state during a
fixed tim~ period of sampling by AND gate 80. The time
interval during which the counter 82 counts the number
38 1 ~) 7(~30
o~ high level state~ pas~ed by the AND gate 80 is not
critical but should be chosen to be long enough to
permit a high number of possible samples to be taken
from a single cycle o~ the lowest frequency of the
15 tones identified above to permit a high degree of
accuracy in the detection of the encoded frequencies
transmitted with each page to encode charactsr
information. The output of the counker 82 is connected
to a range comparator 84 which has an associated
ROM 86. Ths ROM 86 has ~ifteen di~crete address ranges
stored therein with each a~dresc ranga being associated
with a single one of the 15 tones. Each of the
addresses within each range is addressed by a count
applied fxom the counter 82. The range comparator 84
compares the output from counter ~2 with addresses nf
the fifteen discrete ranges contained in the ROM 86 and
passas the count ~rom counter 82 to the look-up ROM 88
if a match occurs between the count outputted by the
counter 82 and an address of one of the fifteen ranges
stored in the ROM 86. I~ a match does not occur, the
count from counter 82 is not pa~sed to the look-up
ROM 88. ~he range comparator 8~4 r2sets the countsr 82
: either upon the elapging of the predetarmined time
interval during which the count from the counter 82 has
been outputted to the look-up ROM 86 or when there is
no match from between the count from the counter 82 and
an address contained in one of the ranges stored in the
: ROM 86. The look-up RO~ 88 outputs one of sixteen
different numerical values which are representative of
the sixteen possi~le signal 1QVe1S which ~ay be encoded
with each hexadecimal digit transmitted by eikher an
analog ox digital paging transmitter. The output of
the look-up ROM 88 is applied to a signal duration
... ...
.
39 1 ~07~30
comparator 90 which outputs one of the 16 numerical
values (0-15) stored in the look-up ROM 88 to the main
CPU 24 when the output o* the look-up ROM is present
for a duration for a time interval such as 10 milli-
seconds or longer. The purpose of the signal durationcomparator 90 is to remove transient conditions which
are not indicative of the true transmisRion of a
hexadecimal level by an analog or digital transmitter.
The output numerical values from a signal duration
comparator 90 are combined by the main CPU 24 in
accordance with its operating program to- produce a
two~digit decimal number which is decoded to characters
in accordance with the ~ollowing convexsion table.
CONVERSION TABLE
Two Digit
Addre~s Character
01~ !
02 ll
03 #
04 $
05
06 &
07
03
09
1 0 *
11 +
12
13
: ~30 14
16 o
17
1 307~30
Two Digit
Address Character
18 2
19 3
21 5
22 6
~3 7
24 8
2S 9
26
27
2~ ~ -
29
31 ; ?
3 2 : O
3 3 ,~
3 4 B
20 ~ ~ ~ 35
3 6 D
3 7 E
3 8 ~ F
3 9 ~ G
25~ - 40~
42: ~ J:
43 K
4,~ L
;3~0 ~ 45 ~ M
4 6 ; ~ N
,8 P
~: ` :
.. ,.,. ,.. ,,, .~, ... . .
. . .
~1 1 307~30
Two Digit
Address Character
49 Q
R
51 S
52 T
53 U
54 V
W
56 X
57 Y
58 Z
59
~0 ~/ ''
61 ]
62 A
: ~3 f
64
a
20: 66 b
6 7 c
68: d
69 ~
7 0 f
25 ~ 71 g
7 2 h
7 3
7 4
7 5 X
30~: ~ 76
77 m
78 n
79 o
~:~: ::
... . ....
42 1 307~30
Two Digit
Address Character
~o ' P
81 q
82 r
83 ~
84 t
u
86 v
87 w
88 x
89 Y
z
91 {
~:: 15 92 1 1
~: ~ 9 3 }
9 4 ~ :
~: : 95
: 97 ~
98 1i
he decoded: charaaters are applied by the main
CPU 24 :~ to the random access memory 60 in ASCII
25 ~ :character :encoding forma~ and to the LCD driver 62
whi h~provides power ~and logiG for their di~play on the
LCD display :64. ~he ~ D display 6~ is of a dot matrix
: type~ and~ has~ a~d1spl~y~ area 64 which ltime mul~iplexes
displays~ as follows. W~en a page is rec:~ived, the main
30 ~ control program causes the display 64 to flash with the
addre~s location in ~memory whare the page is stored.
In response: to the~ flashing o~ the display as described
above, the ~wearer of the : paging receiver presses
~,
: . .
43 1 ~C7~30
switch 70 which causes the location header to be
displayed on area 64. The location headers are "LOCAL"
indicating i~ the page originated in the same area
where the paging receiver normally xeceives pages or
i'NATIONAL" or "REGIONAL" indicating that the page did
not originate in the area where the paging recaiver has
received the message. In response to the location
header, tha wearer of the paging receiver presses
switch 70 which causes the page to be displayed on
display 64 which i8 stored in the memory area of RAM 60
which was flashed initially. It should be understood
that alternati~ely separate di~play areas for the
memory location header, location header, and page
displays may be provided.
: 15 IV. Battery Savina
The paging receiver 16 has predetermined
scanning time interval~ necessary for detecting the
: presence of the carrier signal, the presence of
individual code transmissions (tones3 and to cyclically
scan up to the 15 possible channel freguencies in the
: channel memory 62. In the embodiment of Fig. 1, the
scanning time necessary to detect only the presence of
the carrier of the channel frequency is 315
~: milliseconds for all 15 channels which may be received
if the area channel section 66 is completely
: programmed. It takes approximately 10 milllseconds for
~: the phase lock loop 28 to respond to a channel
: frequency to be received and another approximately 11
: milliseconds for the amplifier and mixers 18, 20 and 22
: 30 : to respond to the presence or absence of the channel
: frequency. When a carrier frequency is detected, it
takes approximately 33 millisecondA for it to be
received by the RF euner 16 and processed by the main
44 1 307~30
CPU 24 ko determine its identity and to compare it with
the stored paging receiver identification code as
described below. When the channel ~requencies of the
channel memory 6~ are cyclically scannad, the RF
tun~r 16 in the embodiment o~ Fig. 1 is powered up once
every 900 m.s. for a perlod of 15 minutes at which time
the reception by the RF tuner is stopped under the
control program.
Each paging receiver is issued a unique paging
receiver identification code. A pre~erred for~ of the
paging rec~ivsr iden~i~ication code is de~cribad belov
in Fig. 4 with reference to a memory map o~ the paging
receiver identification code memory which-is located
within the random acce memory 60. It should be
understood that the invention i8 not limited to the
number o~ digits as described below in the preferred
form o~ the paging ~receiver identi~ication code and
: further that is used herein "digit" means any number in
: any numbering base with the preferred nu~bering base of
the present invention for paging receiver
: identification code~ being base 10. ~lth respect to
~: Fig. 4, each paging receiver identification code 90 is
::~ comprised of a group of ~hree most significant digits
92 which have regional signi~icance and are referred to
as an "area designation code'Y. In a preferred form of
: the pr~sent invention, these digits are th~ telephone
area code of the location where the person normally
wearing the paging receiver resides. For international
u~e, the country code may al o be added as an area
30~ designation ood~0 Five addi~ional digits 94 of
decraasing significance are used to distinguish each
bearer of a paging receiver in the particular area
~ identifled by the aroa designation code 92. In a
,.:~, .. .
1 3()7~30
preferred form of the invention, a command is issued by
the local channel transmitter to which the paging
receiver is normally tuned to receive messages ~or
programming the eight digit paging receiver
identification coda 90 for storage in the RAM 60. An
eight digit paging recei~er identification code 90 was
chosen in the preferred embodiment of the present
invention for the rea~on that it permlts a total of
100,000,000 paging receivers to be uniquely identified
in a base ten numbering sy~tem. In the preferred form
of the present invention, while individual characters
are sent by successive tone modulations o~ a ~requency
modulated carricr with ~ixteen possible levels per
~requency tone~ the paging receiver identification
codes are issued in a base ten nu~bering system ~or the
reason that it is easier ~or mo~t users to understand a
base ten numbering sy~tem than a base sixteen numbering
system.
A significant feature o~ the present invention
in prolonging battery life in the individual paging
receiver is that the paging raceiver identi~ication
code identifying the paging receiver to which a page i~
: directed i~ sent with the digits in an order to
: increasing significanca. With reference to Fig. 4, the
right-most least signi~icant digit is sent first
followed by digits of increasing =ignificance as
identified by the circled numbers in each of the
individual digits of the paging r2ceiver identification
co~e 90 and the arrow above the individual digits
3 O labelled "ORDER OF ID DIGIT TRANSMIS5ION" . The paging
receiver iden~ification code is proc~ssed by the paging
receiver in the order o~ increasing significance o~ the
digits as described with respect to Fig. 4.
~6 1-/`C7~30
In a system with 1,000 paging recelvers, the
following example demonstrate~ the battery life saving
achievsd by the present invention for paging receivers
having identification codes 93110000 through 93110999
with thP present invention as contrasted with the prior
art~ I~ the paging receiY2r identi~ication code digits
are sent in the order of decreasing signi~icance as in
the prior art, which is the opposite o~ the order
illu~trated in Fig. 4, each paging receiver will
respond to the fir~t flve digits. As~u~ing three pages
per day, per paging receiver, the paging receiver will
turn on RF tuner 16 3000 times per day. I~ it assumed
that each cycle of turning on the ~F tunex 16 consumes
300 milliseconds of on time, then each paging r~ceiver
will have its RF tuner 16 on for fifteen minutes per
day. With the pres~nt invention, when the paging
receiver identification code is sent in an order of
increasing signiflcance of the digits, as illustrated
in Fig. 4, 900 paging receivers will immediately turn
: 20 off aXter the transmi~sion of the first diyit because
there will be no match between the first digit
transmitted with the page and the stored paging
receiver identi~ication code digit as illustrated in
FigO 4. Upon the trans~ission of the second digit,
ninety more paging receivers will turn o~. Upon the
transmission of the third digit nine more will turn
off. With the same 3000 page~ per day, ths average
time a pager will be on is only one minute per day.
This produces a 93.4% reduction in battery consumption
attributad to the tuxning on o~ the RF tuner 16 to
merely determine if a page i~ possibly to be received
on a channel ~requency to which the paging receiver has
; been program~ed to receive. I~ a system is expanded to
47
1 737~30
10,000 pages, the battery savings will be increased
with the on time in a system in accordance with the
prior art in which ths paging receiver identification
code digits are sent in the order of decreasing
significance being two and one-half hours per day
versus only ten minutes per day oX on time when the
digits of the paging receiver identificatlon code are
sent in the order as described in Fig. 4 with it being
assumed that the RF tuner 16 on time is tha same as
described above.
Y. ~g
The operation o~ the paging receiver in turning
on to detect the presence of a channel frequency on one
of the channel ~re~uencies which it is programm2d to
receive and the Rcanning o~ a plurality o~ channels of
the channel memo~y 6~ i8 de~cribed a~ follows. Upon
turning on of ~he paging receivex, the channel
fre~uency of the operating channel 64 is sampled ~or 15
minutes. If one of the amplifier mixer sections 18, 20
20 and 22 does not detect a tone fre~uency (a 0-9 tone of
6so milliseconds) o~ the operatiny chanrlel ection,
within 15 minutes, the paging receiver will scan the
c:hannel ~requenc:y stored in the operating channel
memory section 64. If thsre is no detection of any
2 5 receptions a~ter the 3 0 minutes o~ scanning, the
operating program of the main CPU 24 will turn of~ the
RF tuner 16 and display on the message portion 68 of
the display 64 "out of range" and activata a beeper.
In the embodiment of the invention illustrated
: 30 in Fig~ 1, when the paging receiver 10 is scanning the
: ~ channel frequencies ~tored in the memory 62, it is
searahing for the pre~ence o~ an RF carrier and the
paging receiver identif i~ation code . When no carrier
.
,
1 3n7~30
48
is present, the RF receiver 16 will turn on and detect
that no carrier is present in approximately 11 m.s, of
time and progresses to the next channel frequency
stored in the channel memory 62 ag indicated by the
"ORDER OF CHANNEL RECEPTION." When a last diyit of the
paging receiver identi~ication aode is detected ~or two
consecutive on intervals o~ the RF tuner 16, the paging
receiver will stay on that particular channel frPquency
for the duration of tha paging receiver identification
code which spans 1912 m$11iseconds in ~he preferred
a~bodiment. Each time carrier ~rom one o~ the channel
frequenaies is detected or the paging receiver
identi~ication code ls detected~ the fifteen minute
timer is reset. Thi~ allows the paging receiver to
remain on a channel frequency. The paging receiver
then samples the channei once every 900 milliseconds
for an 11 or 33 m.s. duration to respectively detect
if carrier frequen~y is present and7 if so, to identify
the code which was transmitted.
The full channel ~canning mode of the paging
receiver as described above with respect to Fig. 2
: requires a sampling time on eazh channel of
approximately 11 milliseconds to detact the carrier
:~ wave or 33 millisecond~ to fully detect a code
: 25 ~ ~ran~mission dependin~ upon the presencQ o~ a carrier
signal. I~ no carrier is pre6ent, the paging receiver
will detec~ the lack o~ a aarrier within 6 milliseconds
: ~ ~ and scan ~o the next channel. When a carrier is
~ detected, th~ pager will look for tones 0-9 during the
:~: 30 sampling time in~rval of approximately 33
; : mi}liseconds. If a tone is detected, it is stored in
the random acces~ memory 60 and sc~nning o~ the
channels in the full scanning mode a~ described with
: ::
:
49 1 7u7~30
respect to Fig. 2 above is continued. When the RF
receiver then again receives the same channel, a sample
is taken. If a tone is stlll present, and it is the
same tone stored in the random access memory 60 on the
previous sampling intarval, a match occurs with the
previous digit and sampling se~uentially occurs with
successive digits of th~ paging receiver identification
code until either a match is found in which case the
main CPU 24 executes one of the commands described
below or a match is not ~ound in which case the RF
tuner 16 is turned of~ and th~ cyclical sampli-ng every
900 milliseconds continues.
VI. National, Regional, Remote Area, Local,
Sublocal and Group Paqina _ _
15When it is desir0d to program the paging receiver
10 to receive a fixed channel in a local area for
purely local operation, programming may be accomplished
manually or automatically. As used herein, "local"
identi~iee an area identified by ~he area designation
code 92. Automatic programming is done with the
channel fraquenay changing command AC with the desired
: operating channel being sent twice to the pager as
described below. The operating program for the main
CPU 24 rscogni~.es the sequential sending of tha same
:channel twlce by a channel frequency changing co~mand
;~ and stores the repeated frequency in the area channel
section 66 and operating channal sectlon 64. By
: ~storing only a single channel in the operation channel
: :saction 64 and the area ahannel 66, the paging rscei~er
; ~ 30 is ~orced to receive only a single channel which is
desirable ~or local operation.
~ Nationwide, regional, remote area, sublocal and
;~ group paging by the paging receiver is programmed as
'
.
1 ,07~30
follows. In order to di~ferentiate nationwide,
regional (a plurality of areas including one or more
areas outside the area identified by the area
designation code), remote area (an area other than the
area identified by the area designation code)~ sublocal
(a part of an area within an area .identified by the
operation channel section 64 and the area channel 66,
the paging receiver is forced to receive only a single
channel which is desirable for lo al operation.
Nationwide, regional, remote area, sublocal and
group paging by the paging recelver is programmed as
follows. In order to diPferentiate nationwide,
regional (a plurality o~ areas includlng one or more
areas outside the area identified by the area
designation code), xe~ote area ~an area oth~r than the
area identified by the area designation code), ~blocal
(a part o~ an area within an area identified by the
area designation code) and group (one or more paging
: receivers lo~ated within the local area) paying from
local paging, the paging signal contains a "destination
code" having one or more characters which precede the
paging receiver identification code that are not
recognized by a paging receivar as par~ of a local
: page. This ensures that only persons to receive
national, regional, remote area, sublocal and group
pages will be alerted when transmission occuxs. In a
preferred form of the invention, the "destination code"
: ~ is a letter, which is transmitted prior to the
transmission of the paging receiver identi~ication: ~ 30 code. Paging receivers which ~re to receive national,
regional, remote area, sublocal or group pages are
: programmed by the channel frequency changing co~mand to
tore a destination code as a header on the channel
.
1 ,~J`7'333
51
~requency. Thus, on a particular fre~uency where some
pages are transmitted with destination codes, only the
first digit of each page iR required to be compared
with the stored destination code to enable an
identification by a paging receiver programmed to
receive pages with destination codes if a page is
potentially directed to that paglny receiver. The
paging receiver which ha~ b~en programmed with a
destination code immediately turne o~f when a match is
not ~ound between the first digit of a page on a
received ~requancy and the stored de~tination code
thereby saving power required to compare the following
digits of the stored and transmitted paging receiver
identifioation code as described below.
Fig. 5 illustrates the order of transmission of
the destination code and the digits of the paging
receiver identification code for pages which are to be
received with use of the destination code. Like
reference numerals in Figsc 4 and 5 are used to
identify like parts. The first digit which is
: transmitted is the destinatio~ code 96. Thereafter the
individual digit~ of the paging receiver identification
code are transmitted in an order of increasing
: significance as descrihed with re~erence to Fig. 4.
: 25 When it is de~red to program a paging receiver to
~: recei~e page~ with use of the destination code, the
individual channels o~ the area channel section 66 of
memory 62 ar~ progr3mmed by the channel frequency
: changing command as described below. However, the
: 30 first digit o~ the channel frequencie~ which are to be
programmed to be received by th~ channel frequency
: changing comm~nd con~ain the des~ination coda 96
character cuah as the latter A, B, C, etc., which is
52 ~ 7 ~3 3 0
not reaognized as part o~ a paging recelver
identification code, which preferably are base ten
numbers~ When a paging receiver receives the ~irst
digit of the paging receiver identifiaation code, that
digit is compared with the ~Eirst dis~it oP the channel
frequencies stored in the area channel section 66. If
a match occurs, the operating program of ~he main CPU
24 causes the RF tuner 16 to stay in an on state to
compare the subsequent digits of the received paging
receiver identification code with the stored paging
receiver identification code. IiE there is no match
between the first digit of the transmitted page and the
destination code, then the paging receiver RF tuner 16
is immediately turned off to save battery power. By
turning off the paging receiver immediately upon the
detection of no match between the destination code 96,
when the paging receiver i transported to a remot~
area its on ti~e to receive page will not be
influenced by pages 3~10cal~ to the remote area for the
reason that the first digit mismatch which must occur
when any page originating ~ro~ an area into which the
paging receiver has been transported will immedi~tely
be detected as a mismatch causing the RF tuner 16 to be
: : ~ turned off.
: 25 Fig. 6 illustrates a flow chart illustrating the
operation o~ the control program of ths main CPU 24 in
canning channels including the processing of pages
: transmit~ed with destination codes. The program starts
at point 100 where the channel frequency o the
operation channel section 64 is scanned by ths RF
reGeiving section 16. If channel freguency carrier is
: ~ not present, the RF tuner 16 turns of ~ ~or 900 milli-
soconds and then aqain c~ecks if carrier is present.
53 1 707(~30
If carrier is present, the operating program proceeds
to point 102 where a determination is made whether or
not the program is in the scanning mode in which the
channels of the operating channel section 94 and area
5 channel section 96 are sequentially scanned for an
interval of 30 minutes as illustrated in Fig. 2. If
the program is not in the scanning mode, which is
indicativa of only the operation channel section
channel 94 fre~uency ~eing scanned, the program
proceeds back to point 100. If the an~wer is yes at
point 102, the program proceeds to point 104 to chQck
if the channels of the area channal section 66 have
been checked. If the answer is no, the program
proceeds back to point 105 where the channel
frequencies of the area channel section are scanned.
The program then proceed back to point 100. If the
answer is yes at point 104, the program proceeds to
point 106 to determine if a destination code 96 is
present on the channel being received. If the answer
: 20 is no, the program branches to point 108 whera the next
channel in the area channel section 66 is scanned. The
: program proceed~ from poin~ 108 to point 100. If the
answer is ye~ at point 106 that a destination code 96
i9 detected, the program proceeds to point 110 where a
comparison is made between the transmitted destination
code and any destinakion code which is stored in the
channels of ~he area channel section 6~. If the answer
is no at point I10, the program proceeds to point 112
where the next channel within the area channel section
66 i~ received. If the answer is yes at point 110, the
: program proaeeds to point 114 to compare the first
: : digit of the paging recaiver identi~ication code
transmitted on the channel frequency with th2 stored
~:
:
54
1 -'07~30
paging rsceiver identification code. If there is no
match at point 114, the program proceeds to point 116
where the next channe1 of ~he area channel section ~6
is scanned. If the answer is ye~ ak point 114, the
program proceeds to point 118 where the remaining
digits of the paging receiver identiPication code are
compared. If the answer ie no at the comparison of any
one of the remaininy digits o~ the paging receiver
identification code at point 118, the program proceeds
to point 120 to scan the next channel o~ the area
channel ~ection 66. I~ th~ answer is yes at point 118,
the paging receiver lock~ on the channel frequency at
point 122 by setting the phase lock loop 28 to continue
to receive that channel and the fo11Owing com~and is
decoded by the operating program of the main CPU 24 and
exeauted.
VII. Commands
An important part of the present in~ention is the
command structure which permits the functionality of
the paging receiver to be changed dynam1ca11y by the
transmitter in a manner not achieved by the prior art.
~11 commands which are executed by the main CPU 24 are
sent according to a protoco1. An exampl~ of the paging
pxotocol i~ ~et forth below with a nationwide telephone
: 25 number page to paging receiver ID 789 12345 with
: te1ephone number 424, 6464 and a warb1e tone.
: FF- 5--B4 BE 321 BE 937 A7 424 DE 6464 A~A
NOTES 1 lA 2 2 3 4 5
FF - provides 66 m.~. of silence prior to page.
~ NO~E 1- is the last digit of the paging
recQiver ldentlfication code which
1 31~7~30
is sent first as the preamble. I:f
the page is a group page, a C may
be substituted ~or the 5.
NO~E lA - When a "B" appears arter the preamble
digit, the person receiving the page will
be alerted that a "batchedl' page i5
occurring to be ~ent to a group o~ paging
receivers .
- NC3T~: 2 - The BE's ar~ received by the pagirly
receiver and ignored and provide
time spa~ing.
NOTE 3 - A7 . The A ~ignif ia~ th~t a command
sequence follows. ~rhe 7 in~iaates
the ~essage is numerlc, and
il luminates the nation~ide origin
: ~ display and telephone
~nessages.
NOTE 4 - DE ' s are . ~ sent during the data
portion of the transmission to
allow overlay operation.
NOTl: 5 - AXA or AE Indicates the end of
transmi~sion and the type og alert
tone to use e . g. warble .
The: operatins~ program of the main CPU 24 is
2 5 programmed to respond ~o a colDmand repertoire explained
~: : as follows. A command ~equenoe immediately follow the
pager receiver identi~ication c:ode and always begins
with a tone "A" ~ollowed by the command tone. Se~
1 3a7~30
56
~orth below is a command table explaining the command
structure .
CO~D TABLE
A0 BATTERY S~VE
Al REPEAT
A2 PROGRAM ID
A3 LOCAL & ~UMEP~IC (16 NU~qBERS)
A4 L{~CA~ & ~ESSAGE - ALP~A (511 CHAR)
A5 NATIONAL & NU~ERIC ( 16 NUNBER5 ~
A6 NA~IONAL & MESSAGE - A.LP:EIA (511 C}IAR. )
A7 ALP~ FIXED M13MO:IRY I OCA:rION
A~8 RESE3~VED
A9 EXT DATA (OPENS AUDIO TO EXIT ~ACK)
AA DO NO~ USE ~
A:E3 OUT OF SERVICE
AC C~NN~5L PROGRAM
AD SUBLOCAL PAOERS FROM RESTRICTED AREAS
OR GROUPS OF PAGING REC:EIVERS
AE DO NOT IJSE !
2 0 AO_Battery Save
The battery save command i~ followed by a two
digit decimal format indlGatlng how many seconds the
paging receiver should sleep be~ore beginning it
hannel sampling. It is ~ollowed by an AE message
25 ter~nina~or with no tone alert necessary. The two diyit
number represents the number of 10 second increments to
sleep with a maximum of 990 seconds (16 ~ 5 minutes~ .
A022AE = 220 ~econd ~leep period
A099AE = 990 ~econd sleep period
3 0 ~ ~
The repeat aommand indicates tha~ the page being
sent is a repeat ~of the previous page. The previous
message :: display wil} be used, and the numeric or
~: :
: -
1 307~30
57
alphanumeric page should match a previous page which
has been stored in the random acces~ memory 60 during
the execution o~ the A3-A6 commands which cause a page
to be stored in the random access memory. If a page
match is detectad by the paging receiver, the page is
discarded. If the ~ir~t page was not received, the
page should be stored in the random access memory 60
and the wearer of ths paging receiver alerted. The
status display will ~how "RPT" indicating a repeat page
and the first page was not ~ound in ~emory, i.e.,
Al~ A3 424DE6464AE REPEAT 424-6464 (local,
numeric, which is the execution of command A3 described
below)
A2 Proqram ID
The program ID com~and is used to send a new
paging receiver iden~ification code to the paging
receiver. The previous paging recei~er identification
code will be overwritten by this command. No tone
alert is necessary, but the paging receiver should
display the new paging receiver identificakion code as
a page, i.e.,
CHANGE 789 12345 TO ID 789 45678
A2789DE4567DE8~E (NEW ID)
A3 Local ~ Numeric ~16 Diaits!
The A3 command saquentially illuminates the
~ display 64, indicating the page is of local origin, and
: a numeric telephone number display as a page. This
: command is used by a local transmitter to transmit
pages origina~ing within the area identified by the
;~ 30 area designation code. ~he main CPU 24 will receive
the page as single digit.~, i.e.,
A3956DE1030AE TEL # 956-1030
The maximum numeric message length is 16 digitsa
:
1 3~7~3Q
5~
A4 Local & Messaae ~Alphanumeric)
The A4 command seguentially illuminates the
display 64 indicating the page is of local origin and
an alphanumeric display as a page. The alphanumeric
format is sent with each character belng encoded as a
two digit number as explained above. The message
length will be 511 characters or les~, This command is
used by a local transmitter to transmit pages
originating within t~e area iden~ified by the area
designation code 92.
The message length when in ~he alphanumeric mode
will be 511 charac~ers in length. ~he display will
flash, indicating the message is 511 characters long,
i.e.,
IBM STOCK $124 3/4
(18 CEAR~CTER MESSAGE)
A4 73 66 DE 77 32 DE 83 84 D~ 79 67
1 B M S~ S T O C
DE 75 3 a DE 36 49 DE
K SP $
50 52 DE 32 51 DE 47 52 A~
2 4 SP 3 / 4 (56 CHAR~CTER 1.848
SEC.)
A5 National & Numeric (16 Diqits~
25~he A5 command sequentially illuminates the
~ :display ~4 indicating that tha orîgin of the page is
: :~ : not local and a numeric m~ssage a~ a page. This
command is used by a local paging sarvice, within the
: area identified by ~he area designation code, which
30~: relays a page to a transmitter located at a remote area
where a paging r~ceiver is to xeceive a page
:~ trsnsmitted by the transmitt~r located at the remoCe
, . .
5g 1 307~30
area. The digits are sent in a single digit format,
e.g.,
TEL # 956 1001
A6956DElOElAE (NOTE: REPEAT DIGIT FOR
5SECOND ZERO)
A6 National ~ Messa~e ~511 Char.~
The A6 command sequentially illuminates the
display 64 indicating that tha origin of the page is
not local and alphanumeric ~ssage as a page. This
10command is used by a local pag~ng æervic~, within the
area identi~ied by the arQa designation code, which
relays a page to a transmitter located at a remote area
where a paging rec~l~ex is to receive a page
transmitted by the tra~smitt~r located at the remote
15area. The page which is ~ent in a two digit decimal
: order with the number field being 01-9~ in the same
~anner as explained a~ove.
The maximum me~sage l~ngth is 511 characters. The
example is identical to th~ A4 command discussed above
: 20wi~h ~he firs~ ~wo tone~ being A~.
~: A7 AlPh-anumeric S~eci~ic ~essaqe Memory
: The A7 command permits a suhset of co~mands ko
~ollow. The digit immediately following the A7 command
; will indicate in whiah ~ection of addxessable sections
25of:the random acce~s memory 60 to place the messagP.
: a message exis~s in this memory location of the
: random acc~ss memory, it will automatiaally overwrite
the message memory. Th~ command subset will be 1-4
indlcating memory locations 11-14~ An ordinary message
30 ~: will not ov~rwrite the 11-14 mes~age locations. The
massage will i~madiately follow:
A7 1
7 2
: :
.:,
6~ 1 307~30
~7 3
~7 4
The message locations 11-14 will only be
overwritten by messag~s with the same command
5 (e . g. memory location 11 will only be overwritten by
the A7 (1) command) or erased by the user. Th~ messagP
type will always be "Special Call" and will be sent as
an alphanumeric message.
A8 Reserved
9 Ext~rnal Date M~3~ssage
- . The A9 ~o~nand alert~ the person being paged that
the audio must be routed to the external data ; ack 67
for remote processing. The paging receiver will
~orward the audio to the external data jack 67 until
the AE message is received, indiaating end of data
- transmission, i.e. A9~ ATA---AE.
AA Inval id
The AA command cannot be used, as it would be
processed by the main CP~ 24 a~ an AE (end of file)
20 command.
AB Out o~ Service
The AB command will illuminate an out o~ service
display on the memory section 68 of tha display 64 and
may or may not have numeric data following. This
: 25 command may be used wh~n syætem maintenance is
required, or to alert the wearer o~ thP paging service
tha~ service is being denied, until the bill is paid,
i.e. ABAE (illuminates out o~ service message upon turn
on and for two seconds).
: 30 The paging r~ceiver still receives messages as
normal. The out of range di~play turns on. The LCD
display 64 displaya '~out o~ serviae" until the next
'
::
1 307~30
61
paye is allowed. The switching system will prevent any
massages from being sent to the pager.
AC Channel Pro~ramminq
The AC channel programming alerts the person
wearing the paging receiver that channel ~requency
programminy information is ~orthcoming. The
fre~uencies are stored in the channel memoxy 62
transmitted as ~our digit decimals numbers, each
separated by the DE delimeter. As explained above, up
to 15 channels may be loaded into the area channel
~ection 66 or the operation channel section ~4. A
preceding V indicates VHF, a U UHF, a J indi~at~s Japan
and an ~ indicates Europe.
Whan only one channel frequency i8 desired, such
as for local p ging, the channel is repeated at least
twice, to alert the paging racei~er that only one
channel fre~uency is desired to be programmed in the
area channel ~ection 66 o~ th~ channPl memory 62. All
previous channel frequencie~ in the area channel
section 66 of the channel memory 62 are erased. The
: memory cells havQ the new channel number entered to fix
: the paging receiver to receive a single channel. The
memory cells will remain programmed until the next
channel reprogramming of the paging xeceiver, i.e.
AC0123DE0123AE (CH.V 123 NO SCANNING)
~; A C O E 1 0 D E O 1 0 7 D ~ 0 2 1 0 D E 1 0 5 0 D E 7 A E A
(CHo~10~v107~u210~u50)~
~h~ channel programming sequence is as follows:
: 0001 - ODDD VHF 5 XHz steps
1001 - lDDD VHF 6.25 KHz teps (Europe)
2001 - 2DDD UHF 5 KHz step~
: 3001 - 3B2B 280 MHz 2.5 K~z steps (Japan)~
: ~ :
:: ::
: `
62 1 307~30
Channel codes 4001, 5001, 6001, 7001, 8001, 9001
are open for additional channels to be added. The
total upward reserve channel capacity in ROM 58 is
16,458 channels.
The following sub-commands are utilized for
instructing the main CPIJ 24 to perform functions
pertaining to the progra~ming of channel frequencies.
NO Command (Add One ~hannel)
When no sub-command is sent, one channel is to be
n added to the area channel ~ection 66 0 e . g. AC 0237 DE
7AE~ (add VHF channQl 237 to area channel s~ctisn 66).
Sub-command ~000 (TYpically~Reqional)
When 4000 is transmitted, it erase~ the entire
area channel section 66 and the operation channel
sectio~ 64 of the channel memory 6~ and cannot be used
in adjacent areas which mu~t be programmed with the
6000 ~ub command. e.g. AC 4000 DE 0156 DE 2132 DE
7AEA. This command erases and stored VHF 156 and
UHF 132 channel ~re~uencies in the area channel
saction.
Sub-co~mand 500Q
~hen 5000 is transmitted, the destination code is
programmed. This command erases the operating
channel 64 and the area channel section ~6 and forces
the reception o~ a particular channel. The command is
used for dynamic ~re~uency agility. The paging
receiver is fixed to rec~ive a ~ixed channel. e.g. AC
5000 DE 0171 DE 7AEA. This com~and era~es the
operating chann~l 64 and the area channel section 66
and forces the paging receiver to ~HF channels 171,
causing the operating channel section 64 to stor2 VHF
channel 171.
.
63 1 307~30
Sub-command 6000 (National)
This command is divided into the loading o~ the 15
possible destination codes 96 and the channel
~requencies.
ACB122 DE0200 DE0000 DE0000 DE0000 DE0212 DE0311
DE0408 DE2511 DE2139 DE7AEA
This repxesants tha 6000 national command followed
by the destination code 96 or local code for each of
the 15 possible fr~quencies in the area channel
section. The five channel~ follow and will be as
follows:
6122 National, ch~nnel 1 = A, channel 2 = B, channel 3
= B
0200 Channel 4 = local, channel 5 = B~ ~iller code
0000 Channel ~ iller code
0000 Channel 12-15, filler code
0212 VHF channel 212
0311 V~F channal 311
0408 V~F channel 408
: 20 2511 UH~ channel 511
: 2139 UHF channel 139
7AE~ Stop channel command.
Channel Pro~ramming Termination f7AE~)
The channel fre~uencies to be sent to the paging
:~ : 25 receiver are sent in the ~ollowing order:
: OXXX channels ~VHF) (ascending numerical order)
:~ lXXX channels (VHF Europe)
2XXX channels (UXF Europe)
3XXX channels (280 MHz).
~: :: 30 The last channel 6en~ is actually a terminate
message code. It ls 7AEA (7AAA).
The paging receiver will receive the last
frequenFy code and immediately tPrminate~ thP page.`
:; ::
1 3~7~30
64
The 7AEA terminate fxequency code is necessary at the
end of every AC channel program message. During the
transmission of channel codes, the AEA code may appear
(e.g. channel lAEA). In order to prevent termination
of the message, the AC command changes the AEA
termination command to 7AEA. 7AEA is an invalid
channel code.
AD Company COMMAND
The AD command allows a 32 alphanumeric character
company message to be sent to the paging receiver. ~he
message is alway~ alphanumeric, eOg. t AD 4247, DE 4637,
DE 5100, DE 4833, DE 3941, DE 4639, ~E Jones Paging.
When a company message is da~ired, it will be sent
after the paging receiver identification code has been
programmed, When the paging receiver is turned on, the
company message will be displayed instead of a self
test message which is typically used. If no company
message resides in the paging receiver, the self test
message will display.
The 32 character part of khe random access memory
60 is battery pro~ected to permit the message to
permanently reside in the paging receiver. It may be
ohanged by ~imply sending a new AD aommand and message
to the pager. This permits the company message to be
changed at will.
~: The AE command cannot ba used, a~ it cannot be
: encoded and also conflicts with the end of file
command.
End Of Paqe Command AE or AEA
All page~ require the end of page command. The
end of ~ page commzmd serves a two fold purpose
65 l 7~7~ 30
indicating the end o~ transmission and determinss the
type of tone alert.
AE = 2041 hertz - 50% duty cycle 2 ~econds
AEA = 2041 hertz - 25/75% duty cycle - 2 seconds
Certain co~mands do not send a tone alert. A
listing o~ the commands is as follows:
AO BA~TERY SAVE (NO ALERT)
Al REPEAT (NO ALERT) *
A2 PROGRAM ID ~ALERT) -
DISPLAY ID
A3 LOCAL ~ ~L NUNERIC tAhERT)
A4 LOCAL ~ SP ALPHA (ALERT)
A5 NAT. ~ ~L NUMERIC (AhERT)
A6 NA~. ~ ALPH~ (ALERT~
15 A7 ALP~ FIXED Mæ~ORY ~ALERT)
A8 UNASSIGNED (ALERT)
A9 SPECIAL & D~TA A~DIO (ALERT)
AB OUT OF SERVICE 5ALERT)
AC CHANNEL PROGRAM (A~ERT)
20 AD COMPANY ~ESSAGE (ALERT).
* AL will alsrt i~ ~irst page was not received or
if previou~ly erased.
VIII. Remote Area Paqinn
Fig. 21 illustrates the operation of the present
invention in receiving pages at a remote area. A local
transmitter 130 transmit one or more channel ~requency
: changing commands as described above which specify one
or more frequencies on which a paging receiver 132 is
: ~ to receive pages whilQ located at a remote area. The
ahannel ~requency changing commands ar~ received by the
paging receiYer 132 while it is located in transmission
distanca o~ th~ local transmitter 130. The one or more
channel fre~uency changing commands specifying tha one
'
66 1 3~7~)0
or more frequencies to be received in the remote
location also include the destination code 96 described
above used to differentiate pages to be received by the
paging receiver 132 whilP in the remote area from pages
originating in the remote area on the same one or more
programmed frequencies. The paging receiver 132 is
transported to the remote area as indicated by the
downwardly pointing vertical arrow in the right-hand
portion of Fig. 21. The downwardly pointing vertical
arrow in the left-hand portion of Fig. 21 illustrates
the relaying o~ a page originating at the local area or
relayed through the local area to a remote
transmitter 134 lo~ated in the remote area where the
page is transmitted by transmitter 134 and received by
the paging receiver 1320 The remote transmitter 134
sequentially in time transmits the destination code as
the f irst character which is trans~itted, the paging
receiver identification code digits in an order of
increasing significance and the actual page. The
20` paging receiver 132 while in tha remote area aompares
the first digit o~ each transmission on the one or more
channels that the paging recaiver i5 programmed to
receive with the stored destination code. I~ there is
a match between the ~irst character transmitted with a
page on the one or more frequenci~s that the paging
: receiver 132 is programmed to page and the de~tination
code, tha paging receiver 132 oompares the s~bsequent
digits of th~ transmitted paging receiver
identification code following the destination code in
an order of increasing significancs wlth the stored
: ~ paging receiver identi~ication code digits. The
RF tuner of the paging receiver is immediataly turned
~ off upon a mismatch o~ either the destination code or
:
.
67 1 J('7~30
one of the digits of the transmitted and stored paging
receiver identification code. If the transmitted and
received destination codes and paging receiver
identi~ication codes match, the page is displayed on
the di~play 64. It ~hould be noted that pages
originatir.g in the remote area will not cause the RF
tuner 16 to be tuxned on past the point in time of
transmission of the destination code because of the
mismatch which will occur ther~by saving the battery of
the paging receiver.
A method of ~he pre~ent invention in paging a
sublocal area within an area or a group within the
local area such as a company is as ~ollows. The paging
receiver is programmed with the channel frequency
changing command to receive one or more ~requencies.
The destination code is u~ed in the same manner as
described above with regard to Fig. 21 in identifying
pages to be received in a remote area except that it is
assigned to paging receivers within part of khe local
area (subarea) or to paging receiver~ belonging to a
group such as a company. The destination code is
transmitted with the channel ~requency changing command
to identify one or more frequencies on which pages on a
sublocal or a qroup level are to be detected.
~hereafter, the paging receiver which has been
pro~rammed to receive on the progra~med one or more
channel frequencies on a sublocal or a group basis
compares the ~irst digit o~ each transmission occurring
on the one or more programmed channel frequencies to
~30 detect i~ there is a match between the destination code
stored in the channel memory 62 and the first character
which is transmitted. If there is no match, the RF
~ euner l6 is i = ediately ohut of~ thereby ~aving the
:
,. :
' . '
. ' ' . '
6R I 3 0 7~ 3 0
battery of the paging receiver. If there is a match,
the paging receiver compares the transmitted digits of
the paging receiver identification code in an order of
increasing significance with the stored paging receiver
identification code digits. If there i~ a mismatch
be~ween any one o~ the paging receiver stored and
transmitted paging receiver identification code digits,
the RF tuner 16 i~ i~mediately shut off. If there is a
complete match between the destination code and the
stored and tran mitted paging receiver identification
code digits, the paging receiver processes the
subsequently transmitted page. Thu~, it i~ ~een that
paging receivers may be programmed on a sublocal or on
a group spcific basi within a local area to receive
pages on channel frequencies which are in widespread
use in a local paging system while achieving battery
savings by not turning on the paging receiver to
recaive subsequent digit~ of the paging receiver
identifica~ion code ~or every transmission occurring on
the programmed channels.
IX. Figs. 7~20
~ s has been explained above, Figs. 7-20 illustrate
circuit s~hematics for implementing the block~ of
: Fig. 1. Integrated circuits are identi~ied by their
ind~stry designation. It should be understood that
other implementations of the block~ of Fig. 1 may be
utilized in practicing the pre~ent invention.
While the invention has been de~cribed in terms of
its preferred embodiments, it should be understood that
numerous modifications may be made thereto without
departing from the spirit and scope of the invention as
defined by the appended claims. It is intended that
::
69 1-)07~3~
all such modifications fall within the scope of the
appended claims ~
: :
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