Note: Descriptions are shown in the official language in which they were submitted.
WO94/13093 - 2 1 S 0 3 8 7 PCT~S93/11439
PAGING ~ M AND NETHOD WITH ACKNOW~EDGE T~ACK
SI~N~T-TtTG USING A RADIO TEL~hON~ SYSTEM
Field of the Invention
This invention relates in general to a combination
paging system and radio telephone system, and in
particular to a method and apparatus for paging with
acknowledge back signaling utilizing a radio telephone
system.
Background of the Invention
Selective call signaling systems (e.g., paging
systems) provide one-way radio frequency (RF)
c~mm-lnication of selective call messages, called pages,
from a message originator to a paging receiver. The
message originator contacts the paging system via the
public switched telepho~e network system or other input
interface means and provides the message information to a
paging terminal. The message information is encoded into
a conventional signaling protocol, modulated onto a
carrier signal, and transmitted as an RF signal to the
paging receiver. The paging receiver receives the signal,
demodulates and decodes the signal to recover the message,
and presents the message to the system subscriber who is
the user of the receiver.
Since selective call signaling is a one-way
commlln;cation system, the message originator is typically
unaware of whether the subscriber receives a message.
Acknowledge back (ack-back) signaling has been developed
to inform the system of the reception of a message by a
receiver. Yet, to avoid interference between the paging
signals and the ack-back signals either a commlln;cations
path or system air time must be reserved for the ack-back
signals. Air time is a precious commodity in selective
call signaling systems, particularly a wide area paging
WO ~t~093 21 S ~ ~ g PCT~S93/11~9
system with numerous subscribers. A selective call system
service provider wishes to provide service for a large
number of subscribers in order to obtain high revenue.
Therefore it is desirable that air time not be reserved
for ack-back signals.
Since selective call signaling systems are one-way
signaling systems, an ack-back c~mmnn;cations path would
involve costly investment by the service provider to
construct a commlln;cations path devoted to ack-back
signaling. Additionally, ack-back signals are infrequent
and typically reguire little air time. Therefore, a
devoted commllnications path would be inefficient and could
not provide the service provider a sufficient monetary
return for the added feature of ack-back.
Thus, what is needed is an ack-back signaling system
which does not take air time from the selective call
signaling system, while not requiring a devoted
cnmmlln;cations path.
Summary of the Invention
In carrying out the invention in one form, there is
provided a selective call receiver comprising a radio
frequency (RF) receiver for receiving paging signals
transmitted from a paging t~rm;n~l, a decoder coupled to
the RF receiving means for decoding the paging signals to
recover a page, a flagged page identifier for det~m;n;n~
whether the page is a flagged page requesting an
acknowledge back, and a controller for coupling to the
paging terminal via a radio telephone system and for
transmitting an acknowledge back signal thereby in
response to the flagged page identifier determ;n;ng that
the page is a flagged page.
In another form there is provided a method for
transmitting messages in a paging system to a combination
radio telephone and radio pager. The method comprises the
steps of receiving message information from a message
WO94/13093 2 1~ 0 3 8 7 PCT~S93/11439
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originator, determ; n; ng whether the message originator
wishes an acknowledge back signal in response to reception
of the message information by the radio pager, flagging
the message information as a flagged message requesting an
acknowledge back signal upon reception if the message
originator wishes an acknowledge back signal, and
transmitting the flagged message to the combination radio
telephon~ and radio pager. The method further comprises
the steps of coupling to the combination radio telephone
and radio pager via a radio telephone system, receiving
the requested acknowledge back signal via the radio
telephone system, and advising the message originator that
the message was received.
Brief Description of the Drawing
FIG. 1 is a diagram of a combination paging system
and cordless telephone system in accordance with the
preferred embodiment of the present invention.
FIG. 2 is a flow diagram of the operation of the
paging terminal in the combination paging system and
cordless telephone system of FIG. 1 in accordance with the
preferred embodiment of the present invention.
FIG. 3 is a block diagram of the combination radio
pager and cordless telepho~e transceiver of FIG. 1 in
accordance with the preferred embodiment of the present
nvention.
FIG. 4 is a flow diagram of the operation of the
paging message processor in the combination radio pager
and cordless telephone of FIG. 3 in accordance with the
preferred embodiment of the present invention.
Detailed Description of the Invention
Referring to FIG. 1, a selective call signaling
system combining a wide area paging system 10 and a radio
telephone system, such as a cordless telephone system 15,
WOg4t~0g3 PCT~S93/11~9
~ ~ 0 ~ ~ 4
uses the public switched tel~pho~ network (PSTN) 20 for
commlln;cation therebetween. The preferred embodiment of
the present invention utilizes a second generation
cordless telephone (CT-2) system, which is a less
expensive alternative to other radio telephone systems
such as cellular telephone systems. A message originator
utilizes a page entry device 25 to enter paging
information via the PSTN 20 for encoding and transmission
to a subscriber of the paging system 10.
Typically, the page entry device 25 is a telephone
for entry of voice or numeric information. The page entry
device 25 could also comprise a data processing device,
such as a computer terminal, for generation of paging
information comprising graphics, facsimile or alphAnllm~ric
information.
The message originator initiates a message
transmission sequence via the page entry device 25 by
entering a voice or data message in the form of a call to
the system access number of the specific paging device
(such as a radio pager/radio telepho~e 40) to be called.
The message originator is coupled to a paging t~rm;nAl 32
via a telephone network interface 30 of the paging system
10 and PSTN path 20a for processing by the paging terminal
32. When the incoming call is answered by the paging
t~rm;nAl 32, a pre-recorded message is played that
welcomes the message originator to the system 10, and
describes how the originator can enter a paging message
and request an optional acknowle~m~nt that the message
was received. The originator then responds by entering
the voice or data message and a special code signal to
indicate that an acknowle~m~nt of successful reception of
the message is desired.
In the paging t~rm;n~l 32, the message is initially
entered in a buffer memory. Then, after the originator
has ended the message entry sequence, the paging terminal
32 accesses a subscriber data base 34 to obtain a
subscriber address to associate with the paging
WO94tl3093 2 .~ ~ ~ 3 8 7 PCT~S93/11439
5
information to form a page. In accordance with the
present invention, if the originator has entered the
special code signal indicating an acknowl~m~nt is
desired, an acknowledge-back (ack-back) message flagger
portion 42 of the paging terminal 32 flags the message and
the terminal 32 places the flagged message into the paging
system queue 36 for later transmission. The ack-back
flagger 42 can, for example, flag the message by using an
address that is reserved for messages with acknowledge
re~uests, or it can attach an acknowle~m~nt request flag
to a general addressing functional portion of the message.
The pages stored in the paging system queue 36 are
retrieved se~uentially by the paging tPrm;n~l 32 and
provided to the paging transmitters 38 for transmission as
selective call signals therefrom.
Selective call signals transmitted from the paging
system lO are received by the combination radio pager and
radio telephone 40. The pager receives the selective call
signals. The radio telephone, such as a CT-2 cordless
telephone transceiver, couples to the PSTN 20 via the
radio telephone system 15 for com~lln;cation therewith.
In accordance with the preferred embodiment of the
present invention, the combination radio pager/cordless
telephone transceiver 40 receives selective call signals
broadcast by the paging system lO via the paging
transmitters 38. If a flagged message is received by the
combination radio pager/cordless telephone transceiver 40,
a cordless telephone link is established between the
combination radio pager/cordless telephone transceiver 40
and the cordless telephone system 15.
A call point transceiver 50, comprising a receiver
portion 50a and a transmitter portion 50b, receives the
acknowl~m~nt signal from the combination radio
pager/cordless telephone transceiver 40 along with
information identifying an access number for accessing the
paging system lO via the PSTN 20. The acknowle~m~nt
signal and the access information are provided to a call
WOS4/~093 ` PCT~S93/11~9
~ 6
point controller 52 which utilizes the access information
to call up the paging system l0 via a telephone network
interface 54 of the cordless telephone call point station
15. Once the call is established between the call point
controller 52 and the paging terminal 32 via path 20b
through the PSTN 20, the acknowled~m~nt signal indicating
"message received" is provided to the paging term;n~l 32.
The paging t~m;n~l 32, in response to reception of the
acknowle~m~nt signal, can generate a message received
response signal that is returned to the message originator
at the page entry device 25. This response signal to the
message originator can occur while the caller is holding
on the input telephone line at the telephone network
interface 30 or can be directed to a pager or other
commlln;cation device that is capable of receiving the
response signal.
Alternatively, the acknowle~gm~nt signal can
indicate the type of message that was received (i.e. a
voice, numeric or alphAnnm~ic message), the time the
message was received, whether or not the message was
received error free, or a personalized acknowle~gm~nt
signal. The paging t~rm;n~l 32 can provide the additional
information received to the message originator. In
addition, the acknowle~m~nt signal could also be used by
the paging terminal 32 to initiate retransmission of a
message that was received with errors.
Thus, in accordance with the present invention, the
paging system 10 need not have dedicated air time or a
dedicated ch~nnel to receive acknowle~m~nt signals from
radio pagers. The combination radio pager/cordless
tel~phon~ transceiver utilizes a cordless telephone link
to provide an acknowledgment signal to the paging system
10 for real time confirmation to a message originator that
~ a message was received.
Referring next to FIG. 2, a flowchart of the
operation of the call reception routine of the paging
terminal 32 (FIG. 1) begins upon the paging system being
wo 94/13093 ` 2 1 5 0 3 ~ ~ PCT/USg3/ll439
put into service 100. Processing then awaits reception of
an incoming call 102 from a message originator. When an
incoming call is received 102, via the telephone network
interface 30 (FIG. 1), the call is answered 104 and the
paging term;nAl provides a voice prompt 106 requesting the
caller (message originator) to enter the message via the
page entry device 25 (FIG. 1). As the message is entered,
it is stored 108 in a buffer memory of the paging terminal
32 (FIG. 1) until the end of message is detected 110.
When the end of message is detected 110, it is determined
whether an ack-back signal is requested 112. If no ack-
back signal is requested 112, the message is recalled from
the temporary message memory 42 by the paging terminal 32
and placed in the paging system queue 36 such that the
message is queued for paging transmission 114. Processing
then returns to await the next incoming call received 102.
If ack-back signaling is requested 112, the message
is recalled from the message memory 42 and provided to the
paging system queue 36 (FIG. 1) such that the message is
queued for paging transmission on a priority basis 116. A
recording is then played 118 to the caller asking the
caller to wait for an acknowle~gm~nt (ack-back) signal.
Processing then awaits for the ack-back signal to be
received 120 or for the time out limit to be reached 122.
The time out limit is a predetermined time which the
system will keep the caller on the line to await reception
of an ack-back signal. When a time out limit is reached
122, a message is played to the caller that no response
has been received 124 the paging t~rm;n~l 32 hangs up 126,
and processing returns to await the next incoming call
received 102. If an ack-back signal is received 120
within the time out limit, the ack-back cignal is e~m;ne~
to see if a predetermined security identification (ID)
~ -- code is received 127. If the security ID code is not
received 127 with the ack-back signal, processing returns
to await reception of another ack-back signal 120 or time
out 122. The security ID code prevents falsing by
W094/~093 ` I ' PCT~S93/11~9
2~ q~ 8 ~
verifying that the ack-back signal originated in response
to the caller's message. It is desirable that a hospital,
for example, receives a verified acknowledgement that a
doctor has been paged. If the security ID code is
detected 127, the ack-back response, either a st~n~rd
message (e.g. "No Acknowle~m~nt Signal Received") or a
message generated by the pager user is relayed to the
caller 128. The paging t~rm;n~l 32 then hangs up 126 and
processing returns to await reception of the next incoming
call 102.
Referring to FIG. 3, the combination radio pager and
cordless tel~phon~ transceiver 40 (FIG. 1) according to
the preferred e-m-bodiment of the present invention
comprises a paging receiver section 200, a cordless
telephone transceiver section 205, and a message and
display controller section 210. The paging receiver
section 200 includes an antenna 212 for receiving
selective call signals, a paging _hannel radio frequency
(RF) receiver 214 coupled to the antenna for demodulating
the selective call signals, and a selective signaling
decoder 216 for decoding the demodulated signal to recover
the page transmitted thereon.
The decoded page is provided to a message processor
~and display controller 220 for processing thereby. In
accordance with conventional paging operations, the
decoded page is stored in a message memory 222 and the
user (subscriber) is alerted via an alert device 224 that
a page has been received. The user can activate user and
display controls 226 to retrieve the page from the message
memory 222 and display the page on a message display 228.
The controls 226 can manipulate the message display 228 or
alter receiving parameters in a m~nner well known to those
skilled in the art.
' In accordance with the present invention, certain
paging address codes or "flag" signals appended to a
message cause the message processor 220 to initiate a
telephone call via the cordless telepho~e transceiver
WO94/13093 - ~ ~ 5 ~ 3 8 7 PCT~Sg3/ll439
-
section 205 when the unit is within range of a cordless
telephone call point station 15 (FIG. 1). Therefore, when
the alert signal is generated, the alert device 224 alerts
the user that a message has been received, and, depending
on the desired operation, can either indicate that a
return acknowle~m~nt signal has been requested so that
the user can initiate the response, or it can
automatically generate the return acknowle~m~nt signal.
The acknowle~m~nt signal is generated by activating the
cordless telephone transceiver section 205 of the
combination radio pager/cordless telephone transceiver 40.
Operation of the cordless telephone section 205 is
controlled by a telephone control logic device 230. An
antenna 232 is utilized for transceiving signals for
conventional transceiver operation. The antenna 232 is
coupled to a transmit-receive switch 234 which operates
under the control of the telephone control logic 230. The
transmit-receive switch 234 in one position couples the
antenna 232 to a telephone channel RF receiver 236 for
processing received RF signals and providing the signals
to the telephone control logic 230. In a second position,
the transmit-receive switch 234 couples the antenna 232 to
a telephone ch~nn~l transmitter 240 which processes
signals received from the telephone control logic 230 for
transmittal as an RF signal from the antenna 232.
Alternatively, a speaker 238 can be coupled to the
receiver 236 and a microphone 242 can be coupled to the
transmitter 240 for conventional cordless telephone
operation. In the alternative embodiment, the receiver
236 would provide audio portions of the signals to the
speaker 238 and digital portions of the signals to the
telephone control logic 230. The transmitter 240 would
process audio signals received from the microphone 242 and
digital signals received from the telephone control logic
` 35 230 for transmission from the antenna 232. In addition, a
microphone 242 could allow a user to provide a
WO94/13093 ` PCT~S93/11439
3~ lo
personalized acknowle~gm~nt response to a message
originator.
In accordance with the present invention, when the
cordless telephone transceiver section 205 is activated in
an "acknowledge" mode, the receiver 236 searches for a
signal from a cordless telepho~e call point station 15
(FIG. 1). When the receiver 236 determines that the
co-m~bination radio pager/cordless telephone transceiver 40
is within range of a call point station 15, the telephone
control logic 230 activates the transmitter 240 to place a
call through the call point station 15 to the paging
t~rm;n~l 32 (FIG. 1). When the paging t~rm;n~l 32 answers
the acknowle~gm~nt call, the processor 220 provides a
special code thereto that identifies the specific radio
pager 40 that is calling and a message received
acknowle~gm~nt signal. The acknowle~gm~nt signal can
optionally indicate the type of message that was received
(i.e. a voice, numeric or alp~nllm~ric message), the time
the message was received, whether or not the message was
received error free, or a personalized acknowle~gm~nt
signal. In addition, the acknowle~gm~nt signal could also
be used by the paging terminal 32 to request
retransmission of a message that was received with errors.
Referring next to FIG. 4, the operation of the
paging message processor 220 in accordance with the
preferred e-mbodiment of the present invention starts 300
upon powering up of the combination radio pager and
cordless telephone transceiver 40. Processing of messages
awaits reception of a message having a paging address code
assigned to the radio pager 40.
When an assigned paging address code is received
302, processing determines if an acknowle~m~nt (ack-back)
signal is requested 304. If the message is a flagged
message, having been flagged by the ack-back message
flagger 42 (FIG. 1), an acknowle~gm~nt signal is requested
304. Also, a predetermined assigned paging address code
WO94/13093 2 1 ~ 0 3 8 7 PCT~US93/ll43g
11
could indicate that an acknowle~m~nt signal is requested
304.
If an acknowle~m~nt signal is not requested 304,
the message is stored 306 for subsequent retrieval by the
user in accordance with conventional pager operation and
an alert is generated 308 to notify the user that a
message has been received and stored. Processing then
returns to await reception 302 of a next message having an
assigned paging address code.
If an acknowle~m~nt signal is requested 304, the
message is stored 310 and an alert is generated 312. In
accordance with the present invention, the acknowle~m~nt
signal response is generated 314 including a security ID
code assigned to the pager. The acknowle~m~nt signal can
be automatically generated or can allow for
personalization by the user through activation of the
controls 226 or through entry of a voice message via the
microphone 242 (FIG. 3). In addition, a particular
response requesting retransmission could be generated by
the processor 220 in response to detection of sufficient
errors in the received message to indicate that the
message may not have been correctly received. The
security ID code authenticates the acknowle~m~nt signal,
verifying that the acknowl~m~nt signal originated from
the pager/cordless telephone 40.
After generation of the acknowle~m~nt signal 314,
the processor 220 activates the cordless telepho~e
transceiver section 205 in the acknowledge mode 316. Upon
activation 316 of the transceiver section 205, the
receiver 236 searches for a call point station 318. When
a call point station signal is detected 318, a cordless
telephone link is established between the transceiver
section 205 and a call point station. The processor 220
signals the telephone control logic 230 to call up 320 the
. .
paging terminal 32 (FIG. 1). When the transceiver section
205 is coupled to the paging terminal 32 via the cordless
telephone link, the generated acknowl~m~nt signal is
WO94/13093 ~ 12 PCT~S93/11439
provided 322 to the paging t~rm;nAl 32. The call is then
term;nAted 324 and processing returns to await the next
.message received having an assigned paging address code
302.
Therefore, in accordance with the present invention,
paging messages transmitted from a paging t~rm; n~ 1 and
received by the radio pager can be acknowledged via a
cordless telephone link between a transceiver coupled to
the radio pager and the paging terminal.
By now it should be appreciated that there has been
provided an ack-back signaling system which does not take
air time from the selective call signaling system, while
not requiring a devoted commlln;cations path.
