Note: Descriptions are shown in the official language in which they were submitted.
~ 3 ~
LOCATION-BASED ADAPTIVE RADIO CONTROL
Backqround of the Invention
This invention pertains to radios.
Two-way radios have a number of operating
parameters including, but not limited to, transmitting
power, operating frequencies (channel), operating band,
modulation type, modulation index, frequency deviation,
squelch setting, channel spacing, control channel (for
trunked communications), noise blanker characteristic,
and receive bandwidth. Of these parameters, some are
fixed, while others may be, to some degree, variable.
One example of a parameter which is usually, but not
2 always, fixed is the modulation type, such as FM or AM.
One example of a parameter which is usually, but not
always, varlable i9 the operating frequancy or
frequencies (channel).
At a given time, it may be desirabla to ad~ust
the operating parameters in response to the current
operating environment to obtain optimum performance. For
example, it may be desirable to minimize interference to
other users.
A significant factor in determining the current
3~ optimum operating parameters is the geographic location
of the radio. As an example, a particular radio
operating in a densely-populated area, such as downtown
3S
- 2 ~ ?~ CM-00239N
Los Angeles, California must contend with, among other
factor~, a relatively large number of other radios using
the same frequency spectrum. As a result, the available
frequencies (channels) may be limited. Alss, the radio
must limit its transmitting power to avoid interfering
with neighboring users. On the other hand, if this
identical radio were located in the middle of a
sparsely-populated area, such as Death Valley,
California, it would contend with few (if any) other
radios using the same frequency spectrum. A~ a result,
more channels are available and the transmitting power
may be increased to achieve greater range without
interfering with neighboring users.
For radios which are fixed in location, that is,
non-mobile, usually there are few parameters, if any,
which need to be varied during day-to-day operation. This
is because the operating environment is relatively
constant for the radio which is due, to a large extent,
to the fact that the location of the radio is fixed.
For radios whose location is not fixed (that is,
mobile), on the other hand, it is desirable for operating
parameters to be ad;usted whenever a change in the
location of the radio causes the operating environment to
change. For example, using our above example, if a
mobile radio initially selects an operating freguency
band and transmit power while it is located in downtown
Los Angeles, the radio may need to periodically adjust
(change) these freguency band and power settings as its
location constantly changes during the course of its
journey from the downtown area to a final destination of
Death Valley. Moreover, it also may be advantageGus to
change other operating parameters during the course of
such a journey.
Another situation where a mobile radio might need
to adjust operating parameters based on its location
arises in trunked radio systems. In such systems, many
subscriber units share a fixed (and typically smaller)
_ 3 _ ~ s~ ?3 CM-00239N
number of communication channels. In such systems, a
common control station uses a control channel to allocate
the shared channels amongst the subscriber units. When a
subscriber wishes to place a call, it first tunes to the
control channel and transmits a channel request message
to the control station. Upon receipt of this message
(and assuming an idle channel is available) the control
station reserves, or assigns, an idle channel for the
call. The control station then transmits the channel
assignment information to the requesting subscriber via
the control channel. Upon receipt of this channel
assignment message, the requesting subscriber unit tunes
to the assigned channel and procaeds to place its call.
A possible scenario which might arise in such
trunked systems is a mobile subscriber unit which travels
in geographic region A served by trunked system A with
associated control channel A, and which mobile subscriber
unit also travels in region B served by trunked system B
with associated control channel B. With present trunked
radio ystems, no convenient mechanism exists to allow
the subscriber unit to easily and readily change from one
trunked system to another when travelling in this way.
In general, then, it is desirable for a mobile
radio to have the ability to change operating parameters
based on its current location. Given this fact, the
question arisQs of how to effect the desired changes in
the operating parameters. While it is obvious the human
operator could manually adjust the operating parameters
to obtain optimum performance, this could also prove to
be risky. This is because, due to human error, the
operator may be mistaken as to either the present
location of the radio, or the current optimum operating
parameters for the present location of the radio, or
both.
~ 3 ~. ~ c ~ , CM-00239N
SummarY of the Invention
Therefore, it is an object of the present
invention to vary one or more operating parameters of a
mobile radio automatically, and without human
intervention, based on the location o~ the radio.
According to the invention, a method is provided, and an
apparatus described, whereby one or more operating
parameters of a mobile radio may be varied automatically,
and without human intervention, based on the location of
the radio.
Brief DescriPtion of the Drawinqs
Fig. 1 depicts the location-based adaptive radio
control arrangement.
Fig. 2 depicts a flow diagram illustrating the
steps of the invention.
Detailed Descri~tion of the Invention
The invention may be used with any location
determining device or system (101), such as LORAN,
satellite global positioning systems, or dead reckoning,
and with any mobile radio having adjustable operating
parameters. Such location determining systems are well
understood and need not be described here in any further
detail. (In the context of this invention, "mobile"
refers to a non-fixed location radio, and includes both
vehicle mounted and personally carried radios.)
The invention (100) is shown in Fig. 1.
Switch 1 (102) is arranged to select the
operating frequency band of the radio. When switch 1 is
in position designated "A", the radio operates on the 800
MHz band (103). When switch 1 is in the position
designated "B", the radio operates on the 30 MHz band
(104).
- 5 - ~ rls~ CM-00239N
Switch 2 (105) is arranged to select the output
power level of the transmitter. When switch 2 is in the
position designated "A", the output power is 10 Watts
(106). When switch 2 is in the position designated "B",
the output power is lO0 Watts (107).
Switch 3 (108) is arranged to select the control
channel oP the radio. When switch 3 is in the position
designated "A", the control channel selected is channel A
(109). When switch 3 is in position designated "B", the
control channel selected is channel B (110).
The mobile radio (120) is equipped with a
location determining device (101) which, ln turn, is
arranged to control the position of switch l (102),
switch 2 (105), and switch 3 (108). In this embodiment,
the location determining device (lOl) is capable of
determining whether the radio is located in location A
(the urban area) or location B (the rural area).
When the location determining device (lOl)
determines the radio i9 located in location A, it causes
switch l (102) to reside in position "A", thereby causing
the radio to operate on the 800 MHz band. Also when the
location determining device (lOl~ determines the radio is
located in location A, it causes switch 2 (105) to resids
in position ''Atl, thereby causing the radio to transmit at
lO Watts power output. Finally, when the location
determining device (lOl) determines the radio i5 located
in location A, it causes switch 3 (108) to also reside in
position "A", thereby causing the radio to use channel A
as a control channel.
When the location determining device ~lOl)
determines the radio is located in location B, it causes
switch l (102) to reside in position "B", thcreby causin~
the radio to operate on the 30 MHz band. Also when the
location determining device (lOl) determines the radio is
located in location B, it causes switch 2 (105) to reside
in position "B", thereby causing the radio to transmit at
lO0 Watts power output. Finally, when the location
-- 6 - 3 3 ~ CM-00239N
determining device (101) determines the radio is located
in location B, it causes switch 3 (108) to reside in
position "B", thereby causing the radio to use channel B
as a control channel.
Fig. 2 shows the flow diagram (200) of the steps
of the invention.
The process starts with the radio determining its
location (201). If the radio determines it is located in
a first predetermined location, such a~ location A (the
urban area), the radio operates on the 800 MHz band
(202), adjusts the transmitter to 10 Watts of output
power (203), and uses channel A as a control channel
(204). The radio then returns (220) to its initial
determining step (201), and makes a new determination of
its location.
In this embodiment, if the radio determines it is
located in location B (the rural area), the radio
operates on the 30 MHz band (212), adjusts it~
transmitter to 100 Watts o~ output power (213), and uses
channel B as a control channel (214). The radio then
returns (220) to its initial determining step (201), and
makes a new determination of its location.
