U.S. patent application number 15/494094 was filed with the patent office on 2017-08-10 for method for switching between predefined transmit power classes on a mobile telecommunications device.
The applicant listed for this patent is Google Technology Holdings LLC. Invention is credited to Thomas E. Gitzinger, Michael E. Russell.
Application Number | 20170230912 15/494094 |
Document ID | / |
Family ID | 38194552 |
Filed Date | 2017-08-10 |
United States Patent
Application |
20170230912 |
Kind Code |
A1 |
Russell; Michael E. ; et
al. |
August 10, 2017 |
METHOD FOR SWITCHING BETWEEN PREDEFINED TRANSMIT POWER CLASSES ON A
MOBILE TELECOMMUNICATIONS DEVICE
Abstract
In a method of controlling power level of transmit signals from
a wireless communication device that is communicating with a
plurality of wireless ad-hoc network nodes as part of an ad-hoc
network, a value of a usage parameter of a communication between
the wireless device and a first wireless ad-hoc network node of the
plurality of nodes is detected. A power level of a transmit signal
from the wireless device to the first wireless ad-hoc network node
is set to a level corresponding to the value of the usage
parameter. A device for adjusting a power level in a wireless
device includes a parameter detection circuit, that detects a
parameter indicative of a relationship between the wireless device
and a wireless ad-hoc network node, and a power selection circuit
that sets a transmit signal power level from the wireless device to
a level corresponding to the parameter detected by the parameter
detection circuit.
Inventors: |
Russell; Michael E.; (Lake
Zurich, IL) ; Gitzinger; Thomas E.; (Libertyville,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Google Technology Holdings LLC |
Mountain View |
CA |
US |
|
|
Family ID: |
38194552 |
Appl. No.: |
15/494094 |
Filed: |
April 21, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11320066 |
Dec 28, 2005 |
9635625 |
|
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15494094 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 52/281 20130101;
H04W 52/46 20130101; H04W 52/28 20130101; H04W 52/283 20130101;
H04W 28/18 20130101; H04W 52/288 20130101; H04W 52/16 20130101;
H04W 52/367 20130101; H04W 84/18 20130101 |
International
Class: |
H04W 52/28 20060101
H04W052/28; H04W 52/16 20060101 H04W052/16 |
Claims
1. A method for controlling power levels of a wireless device,
comprising: determining a first power level for transmitting
messages from a first wireless device to a second wireless device
in a plurality of wireless communication devices; determining a
second power level for transmitting messages from the first
wireless device to a third wireless device in the plurality of
wireless communication devices; and setting a power level of the
first wireless device to the second power level, different from the
first power level, while maintaining an active communication
connection with the second wireless device at the first power
level.
2. The method of claim 1, wherein the first power level is
determined based on a first usage parameter that indicates a
distance of the first wireless device to the second wireless
device.
3. The method of claim 2, wherein the distance of the first
wireless device to the second wireless device is determined based
on a signal received from the second wireless device.
4. The method of claim 2, further comprising: determining that the
distance of the first wireless device to the second wireless device
has changed to a second distance; and in response to determining
that the distance of the first wireless device to the second
wireless device has changed to the second distance, changing the
first power level to a third power level based on the second
distance.
5. The method of claim 4, wherein changing the first power level to
the third power level comprises switching from a first RF path
associated with the first power level to a second RF path
associated with the third power level.
6. The method of claim 1, wherein the first power level is a lowest
possible power level to maintain the active communication
connection with the second wireless device from a group of possible
power levels.
7. A system for controlling power levels of a wireless device, the
system comprising: a hardware processor that is programmed to:
determine a first power level for transmitting messages from a
first wireless device to a second wireless device in a plurality of
wireless communication devices; determine a second power level for
transmitting messages from the first wireless device to a third
wireless device in the plurality of wireless communication devices;
and set a power level of the first wireless device to the second
power level, different from the first power level, while
maintaining an active communication connection with the second
wireless device at the first power level.
8. The system of claim 7, wherein the first power level is
determined based on a first usage parameter that indicates a
distance of the first wireless device to the second wireless
device.
9. The system of claim 8, wherein the distance of the first
wireless device to the second wireless device is determined based
on a signal received from the second wireless device.
10. The system of claim 8, wherein the hardware processor is
further programmed to: determine that the distance of the first
wireless device to the second wireless device has changed to a
second distance; and in response to determining that the distance
of the first wireless device to the second wireless device has
changed to the second distance, change the first power level to a
third power level based on the second distance.
11. The system of claim 10, wherein changing the first power level
to the third power level comprises switching from a first RF path
associated with the first power level to a second RF path
associated with the third power level.
12. The system of claim 7, wherein the first power level is a
lowest possible power level to maintain the active communication
connection with the second wireless device from a group of possible
power levels.
13. A non-transitory computer-readable medium containing computer
executable instructions that, when executed by a processor cause
the process to perform a method for controlling power levels of a
wireless device, the method comprising: determining a first power
level for transmitting messages from a first wireless device to a
second wireless device in a plurality of wireless communication
devices; determining a second power level for transmitting messages
from the first wireless device to a third wireless device in the
plurality of wireless communication devices; and setting a power
level of the first wireless device to the second power level,
different from the first power level, while maintaining an active
communication connection with the second wireless device at the
first power level.
14. The non-transitory computer-readable medium of claim 13,
wherein the first power level is determined based on a first usage
parameter that indicates a distance of the first wireless device to
the second wireless device.
15. The non-transitory computer-readable medium of claim 14,
wherein the distance of the first wireless device to the second
wireless device is determined based on a signal received from the
second wireless device.
16. The non-transitory computer-readable medium of claim 14,
wherein the method further comprises: determining that the distance
of the first wireless device to the second wireless device has
changed to a second distance; and in response to determining that
the distance of the first wireless device to the second wireless
device has changed to the second distance, changing the first power
level to a third power level based on the second distance.
17. The non-transitory computer-readable medium of claim 16,
wherein changing the first power level to the third power level
comprises switching from a first RF path associated with the first
power level to a second RF path associated with the third power
level.
18. The non-transitory computer-readable medium of claim 13,
wherein the first power level is a lowest possible power level to
maintain the active communication connection with the second
wireless device from a group of possible power levels.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/320,066, filed Dec. 28, 2005, which is
hereby incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to wireless communications
systems and, more specifically, to a system that manages the power
level of transmitted signals in an ad-hoc communications
system.
BACKGROUND
[0003] An ad-hoc network is a local area network or other small
network, especially one with wireless connections, in which some of
the communication devices form a somewhat informal impromptu
network, which is sometimes established for temporary communication
independent of a dedicated infrastructure, which can require a
degree of proximity depending upon the particular network. The
wireless device communication system known as Bluetooth.RTM. was
designed to allow wireless devices to interact with each other in a
more informal manner by providing a framework in which to establish
ad-hoc networks. In one configuration, a wireless device
communicates with a wireless ad-hoc network node. The
Bluetooth.RTM. specification is an open specification that is
governed by the Bluetooth.RTM. Special Interest Group (SIG), Inc.
The Bluetooth.RTM. SIG classifies Bluetooth.RTM. devices according
to three different power classes, as follows:
TABLE-US-00001 Power Class Maximum Output Power 1 100 mW (20 dBm) 2
2.5 mW (4 dBm) 3 1 mW (0 dBm)
[0004] Many portable Bluetooth.RTM. devices are in Power Class 1 or
2 due to cost and battery life issues. Typically, a Class 1 device
requires use of a power control to limit the transmitted power.
This will provide up to 100 m of range--sufficient for home
networking and other similar applications.
[0005] The majority of Bluetooth.RTM. devices currently in the
market have approximately a 10 meter range. This is sufficient for
many point to point communication applications, such as those
involving communications with headsets, handsfree car kits, PIM
transfers, etc., but as one starts to enter different personal area
networks within the home, business, and mobile world, a 10 meter
range may be insufficient for seamlessly transitioning between
these different environments. Some point to point scenarios (such
as communicating with a printer server) require a greater range.
For some point to point scenarios, a longer range can improve the
user experience by allowing greater freedom of mobility while
supporting and maintaining continued communication, even though as
the distance between communication participants decrease the
shorter Class 2 range would be sufficient for operation and even
preferred when battery power is low.
[0006] Existing wireless devices are often not configured to
dynamically adjust power level of the transmit signal, when the
range between the wireless device and the node with which it is
communicating changes, including instances in which the
appropriateness and/or suitability of a lower power level could be
detected. In absence of the capability to dynamically adjust power
levels, different applications will often set the level to the
maximum level supported by the application. By allowing the dynamic
adjustment of the power level, the power usage requirements for
supporting the communication can be reduced. This can result in
reduced time between battery charges. Also, transmitting an
unnecessarily high power level of the transmit signal from a
wireless device increases the likelihood that an eavesdropper will
be able to intercept the communication.
[0007] Consequently, a method that switches between different power
levels of the transmit signal according to the range (or other
parameter) in support of a communication between the wireless
device and another wireless ad-hoc network node would be
beneficial.
SUMMARY
[0008] The present invention provides for a method of controlling
power level of transmit signals from a wireless device that is
communicating with one or more other wireless communication
apparatus as part of an ad-hoc network. A value of a usage
parameter of a communication between the wireless device and the
one or more other wireless communication apparatus is detected. A
power level of a transmit signal from the wireless device to the
one or more other wireless communication apparatus is set to a
level corresponding to the value of the usage parameter.
[0009] In another aspect, the invention is a method of controlling
power level of the transmit signals from a wireless device that is
communicating with one or more other wireless communication
apparatus as part of an ad-hoc network. A first value of a usage
parameter of a communication between the wireless device and a
first one of the one or more other wireless communication apparatus
is detected. A power level of a transmit signal from the wireless
device to the first one of the one or more other wireless
communication apparatus is set to a first power level corresponding
to the first value. A second value of a usage parameter of a
communication between the wireless device and a second one of the
one or more other wireless communication apparatus is detected. A
power level of a transmit signal from the wireless device to the
second one of the one or more other wireless communication
apparatus is set to a second power level corresponding to the
second value, different from the first power level.
[0010] In another aspect, the invention is a method of applying a
power level of the transmit signal in a wireless communication
device that communicates with a wireless ad-hoc network node. A
value of a parameter corresponding to a range from the wireless
communication device to the wireless ad-hoc network node is
detected. A transmit signal is generated from the wireless
communication device. The transmit signal has a first predetermined
power level when the value of the parameter indicates that the
wireless communication device is within a first predetermined range
of the wireless ad-hoc network node and has a second predetermined
power level, higher than the first predetermined power level, when
the value of the parameter indicates that the wireless
communication device is outside the first predetermined range and
within a second predetermined range of the wireless ad-hoc network
node.
[0011] In yet another aspect, the invention is a device for
adjusting a power level in a wireless device that includes a
parameter detection circuit and a power selection circuit. The
parameter detection circuit detects a parameter indicative of a
relationship between the wireless device and a wireless ad-hoc
network node. The power selection circuit causes the wireless
device to generate a transmit signal so as to have a first power
level when the parameter detection circuit indicates that the
wireless device is within a first relationship to the wireless
ad-hoc network node and causes the wireless device to generate the
transmit signal so as to have a second power level, higher than the
first power level, when the parameter detection circuit indicates
that the wireless device is outside of the first relationship and
within a second relationship of the wireless ad-hoc network
node.
[0012] These and other aspects of the invention will become
apparent from the following description of the preferred
embodiments taken in conjunction with the following drawings. As
would be obvious to one skilled in the art, many variations and
modifications of the invention may be effected without departing
from the spirit and scope of the novel concepts of the
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is a schematic diagram showing a wireless device
interacting with one or more other wireless communication
apparatus, or wireless ad-hoc network nodes at different
ranges.
[0014] FIG. 1B is a schematic diagram showing interaction between a
wireless device, trusted devices and attempted eavesdroppers at
different ranges.
[0015] FIG. 2 is a schematic diagram of one exemplary embodiment of
a circuit in a wireless device that may be used to change power
classes.
[0016] FIG. 3 is a flow diagram that may be used to control
selection of power classes.
DETAILED DESCRIPTION
[0017] A preferred embodiment of the invention is now described in
detail. Referring to the drawings, like numbers indicate like parts
throughout the views. As used in the description herein and
throughout the claims, the following terms take the meanings
explicitly associated herein, unless the context clearly dictates
otherwise: the meaning of "a," "an," and "the" includes plural
reference, the meaning of "in" includes "in" and "on."
[0018] In one representative embodiment, the invention includes a
system for adjusting a transmit signal power level from a wireless
device to a wireless ad-hoc network node that is part of an ad-hoc
network to correspond to a value of a usage parameter. The usage
parameter could be a measurable quantity, such as the power level
of a signal received from the wireless ad-hoc network node to the
wireless device. The wireless device then sets the power level of
the transmit signal from the wireless device to a level
corresponding to the value of the usage parameter. For example, if
the received signal is weak, indicating that the network node could
be far away, then the transmit signal would be set at a relatively
high power level; on the other hand, if the received signal is
strong, indicating that the network node could be near by, then the
transmit signal would be set at a relatively low power level. The
system could be configured to allow the wireless device to
communicate with a plurality of network nodes, with the transmit
signal to different network nodes being set at different power
levels. Thus, the system could facilitate the wireless device
making and breaking communications with different network nodes as
the wireless device transitions through different geographic
areas.
[0019] An example of the wireless device 102 transitioning through
different geographic areas is shown in FIG. 1A, in which in a first
transition cases (CASE 1) that is centered on the home 104, the
user's wireless device 102 is initially outside of the range 106a
of the home 104 network of devices. The user's wireless device 102
may even be communicating with a cellular node 108. At this point,
the user's device will operate with a Class 1 (100 meter) range. By
having this increased range, the home's network can route any
messages to the user locally, through the short range radio, rather
than through the cellular network, or other broadband system, and
can receive commands from the user (e.g., "turn on lights," "turn
on television, or "start stereo," etc.) using the local
communications system (versus a cellular network). Thus, the user
can have everything set up by the time he enters the house. Once
the user is situated in the home environment, his wireless device
102 can switch to a shorter range power class to reduce power
consumption. In the second transition case (CASE 2), the user is
leaving the home 104 and, upon leaving the power Class 2 (10 meter)
range, the device switches to the Class 1 range and can finish
transferring any data or issuing any commands before the user gets
out of the Class 1 range. As the user is leaving, the home network
can then transition back to an away mode and route any messages
through a cellular telephone network or broadband system.
[0020] The ranges of different power classes are shown in FIG. 1B.
(It should be noted that the ranges are not drawn to scale and are
not directed to a specific ad-hoc network technology.) As shown in
FIG. 1B, the user might wish to communicate simultaneously with
different trusted wireless ad-hoc network nodes 130, but there is a
likelihood that attempted eavesdropper nodes 132 could be
attempting to intercept communications between the user's device
102 and the trusted nodes 130. In this scenario, minimizing the
power level of the signal output by the user's device 102 for each
communication would reduce the probability that an attempted
eavesdropper 132 could intercept a communication. While a Class 1
(100 meter range) would be useful in the home and out in the world,
the longer range can increase the possibility of eavesdropping.
Many typical wireless devices include a means for encryption
involving a public link key and a private pin, but it is possible
that the communications could be intercepted and decrypted at a
later time; it is also possible for the user's link key to be
intercepted. By dropping the power level, the user can decrease the
range between the wireless device and a trusted device, thereby
preventing eavesdroppers from intercepting communications. In the
proposed implementation, due to the time slotted nature of
Bluetooth.RTM.-type nodes that have two RF paths, connections would
be allowed from one user to multiple devices using different power
levels for secure and non-secure transactions.
[0021] In the example shown, the user's wireless device 102 is
communicating with a plurality of trusted devices 130a-c as part of
an ad-hoc network. In the network, the power level of the transmit
signal from the user's wireless device 102 is set at a power level
that corresponds to the distance between the user's wireless device
102 and the specific trusted device being communicated with. This
has the advantage of limiting the opportunities for attempted
eavesdroppers 132a-c to intercept a given communication. For
example, while the user's wireless device 102 is communicating with
trusted device 130a, it transmits a signal having a power level
corresponding to the Class 3 range. Because of the limited transmit
power level; attempted eavesdroppers 132a-c would have a lower
probability of being able to intercept the transmitted signal.
While the user's wireless device 102 is communicating with trusted
device 130b, it transmits a signal having a power level
corresponding to the Class 2 range. At this power level, attempted
eavesdropper 132a would be within the normal range to monitor
communications, though it may still require an additional effort to
decrypt, while the potential for attempted eavesdroppers 132b-c to
intercept the signal would be greatly reduced.
[0022] One example of a circuit 200 to enable the present invention
is shown in FIG. 2. The circuit includes a chipset 210
corresponding to the network standard being used. The chipset 210
is responsive to communications signals 202 and control inputs 204.
One of the control inputs 204 is from a received signal power level
detecting circuit 206. The chipset 210 is in communication with a
power amplifier/low noise amplifier (PA/LNA) block 220 that
selectively amplifies the communications signal 214 (both the
outgoing signal and the received) to and from the chipset 210. The
PA/LNA block 220 is responsive to a pair of control signals 212
from the chipset 210, which determine whether the output signal 222
from the PA/LNA block has a Class 1 power level or a Class 2 power
level. The PA/LNA block 220 includes a first direction switch 244
and a second direction switch 246 that causes the communications
signal to be amplified by a power amplifier 240 and a band pass
filter 242 (optional) when transmitting and to pass through a low
noise filter 248 when receiving. The states of the first direction
switch 244 and the second direction switch 246 are controlled by
the pair of control signals 212.
[0023] A first bypass switch 252 and a second bypass switch 254
provide selective isolation of the PA/LNA block 220. A bypass
control circuit 256 controls the first bypass switch 252 and the
second bypass switch 254 via a pair of bypass control signals
257.
[0024] The standard chipset 210 may be selectively configured into
either a Class 3 power level or a Class 2 power level. (It should
be noted that when referring to different classes of power level,
the example used herein corresponds to a standard ad-hoc network
scheme. Thus, the Class 1 power level is the highest power level,
the Class 2 power level is the mid-range power level and the Class
3 power level is the lowest power level. It should be understood
that these power classes are given for illustration only and that
many other power level classification schemes may be used without
departing from the scope of the invention, as would be well
understood by those of skill in the communication systems art.)
When a Class 1 power level is desired, the chipset 210 is
configured into the Class 2 power level and the first bypass switch
252 and the second bypass switch 254 are set to cause the
communications signal 214 to go into the PA/LNA block 220. When a
Class 2 power level is desired, the first bypass switch 252 and the
second bypass switch 254 are set to cause the communications signal
214 to bypass the PA/LNA block 220. When a Class 3 power level is
desired, the second bypass switch 254 are set to cause the
communications signal 214 to bypass the PA/LNA block 220 and the
chipset 210 is configured into the Class 3 level.
[0025] A flow diagram 300 for system control is shown in FIG. 3, in
which the system initially detects 302 the received signal power
level (or another usage parameter, such as distance) of a
communication from a wireless ad-hoc network node and then sets the
power level of the signal transmitted signal from the wireless
device to a predetermined level corresponding to the usage
parameter, such as a communication parameter indicative of
communication integrity. To do this, the system determines 310 if
the received signal power level indicates that the system should be
in greater than a Class 3 mode. If not, the system sets 312 the
power level to Class 3. Otherwise, the system determines 314 if the
received signal power level indicates that the system should be in
greater than a Class 2 mode. If not, the system sets 316 the power
level to Class 2. Otherwise, the system sets 320 the power level to
Class 1.
[0026] For multipoint personal area networks (PANs) to detect user
transitions and seamlessly handoff control between different zones,
a range of more than 10 meters may be desired. A 100 meter range
would be more ideal for detecting and moving a user's content or
automatically switching from a personal area network to different
modes. After the user is more centralized in this area the user's
mobile device can switch to the shorter range to save battery power
and increase device's battery life in the personal area
network.
[0027] Use of a Class 1 range is not necessary for all devices, but
it could increase the functionality and improve the user experience
by increasing the user's mobility. One area where having Class 1
range is very useful is for transitioning into and out of different
PAN's. By having up to 10 times greater range, handoffs and
synchronizations can be greatly improved when moving into and out
of different zones. When the user first comes into range of home
with the Class 1 range on, the user can cause the home computer to
take certain actions, such as: synchronize appointments with his
calendaring software on his computer, check sensor levels, turn on
the lights, set up the television to view their favorite program,
etc. Once he is within a 10 meter range of the connected devices,
the device can switch to the Class 2 power level and save battery
power on their mobile device. If the user begins to move out of the
10 meter range, the device can switch back to the 100 meter range
to finish whatever activity the user was doing and change the mode
of the network to being away. Switching between the 100 meter and
10 meter range also introduces an element of safety concerning user
data.
[0028] The electrical portion of this switching could be
implemented by adding another RF path to the device as can be seen
in FIG. 3. Many current Class 1 reference designs are implemented
using a Class 2 Bluetooth.RTM. chipset, with internal variable gain
amplifier and an external PA with a fixed gain. Some also include
an LNA on the receive path to increase receiver sensitivity and
improve the Class 1 to Class 2 link budget. This could also be done
using a variable gain amplifier for the PA and one RF path, but
having two RF paths allows the user to be connected to multiple
devices at different power levels because the second set of RF
switches can be used to change which RF power path is used for the
corresponding timeslot, similar to the TX/RX switching. For example
a phone could be connected to a stereo device using Class 1 range
and also connected to a Bluetooth.RTM. access point using Class 3
range to make a secure transaction. This implementation would allow
you to have a greater than 30 dBm difference in output power
between transmission timeslots.
[0029] The system detects a usage parameter, such as a power
condition (which could correspond to a received signal power level
or a detected range) or a security condition of a communication
between the wireless device and the wireless ad-hoc network node.
The system sets the power level of the transmit signal to a first
power level when the usage parameter indicates that the first power
level is indicated and sets the power level of the transmit signal
to a second power level when the usage parameter indicates that the
second power level is indicated. The power level may be set by
reducing power level of the transmit signal when a higher security
level is desired. This hampers attempted interception of a transmit
signal from the wireless device to the wireless ad-hoc network
node. Typically, the wireless device will be capable of
communicating simultaneously with a plurality of wireless ad-hoc
network node and the system will set the proper transmit power
level for each communication.
[0030] In one embodiment, the first power level (e.g., the Class 3
power level in a BlueTooth.RTM. embodiment) has a maximum output
power of 1 mW, the second power level (e.g., the Class 2 power
level in a BlueTooth.RTM. embodiment) has a maximum output power of
2.5 mW, and the third power level (e.g., the Class 1 power level in
a BlueTooth.RTM. embodiment) has a maximum output power of 100
mW.
[0031] The above described embodiments, while including the
preferred embodiment and the best mode of the invention known to
the inventor at the time of filing, are given as illustrative
examples only. It will be readily appreciated that many deviations
may be made from the specific embodiments disclosed in this
specification without departing from the spirit and scope of the
invention. Accordingly, the scope of the invention is to be
determined by the claims below rather than being limited to the
specifically described embodiments above.
* * * * *