U.S. patent application number 11/614383 was filed with the patent office on 2008-06-26 for method and apparatus for cognitive radio policy change.
This patent application is currently assigned to MOTOROLA, INC.. Invention is credited to Ellis W. Glick, Michael D. Kotzin.
Application Number | 20080151856 11/614383 |
Document ID | / |
Family ID | 39542675 |
Filed Date | 2008-06-26 |
United States Patent
Application |
20080151856 |
Kind Code |
A1 |
Glick; Ellis W. ; et
al. |
June 26, 2008 |
METHOD AND APPARATUS FOR COGNITIVE RADIO POLICY CHANGE
Abstract
A method of operation of a cognitive radio in a hierarchical
group of cognitive radios, the hierarchy of cognitive radios
including at least one master cognitive radio that has a higher
position in the hierarchy than another of the cognitive radios in
the group, consistent with the present invention, involves
establishing a first operational policy for the group of cognitive
radios; determining that the operational policy is unsuitable for
use by at least one member of the group; and the master cognitive
radio dictating a change in the operational policy used by the
group to a second operational policy for use by the group.
Inventors: |
Glick; Ellis W.;
(Northbrook, IL) ; Kotzin; Michael D.; (Buffalo
Grove, IL) |
Correspondence
Address: |
MOTOROLA, INC.
1303 EAST ALGONQUIN ROAD, IL01/3RD
SCHAUMBURG
IL
60196
US
|
Assignee: |
MOTOROLA, INC.
Schaumburg
IL
|
Family ID: |
39542675 |
Appl. No.: |
11/614383 |
Filed: |
December 21, 2006 |
Current U.S.
Class: |
370/343 |
Current CPC
Class: |
H04B 1/0003 20130101;
H04W 16/14 20130101; H04W 8/245 20130101 |
Class at
Publication: |
370/343 |
International
Class: |
H04J 1/00 20060101
H04J001/00 |
Claims
1. A method of operation of a cognitive radio in a hierarchical
group of cognitive radios, the hierarchy of cognitive radios
including at least one master cognitive radio that has a higher
position in the hierarchy than another of the cognitive radios in
the group, comprising: establishing a first operational policy for
the group of cognitive radios; determining that the operational
policy is unsuitable for use by at least one member of the group;
and the master cognitive radio dictating a change in the
operational policy used by the group to a second operational policy
for use by the group.
2. The method according to claim 1, wherein the dictating comprises
determining a new operational policy for use by the group.
3. The method according to claim 1, wherein the dictated change in
operational policy comprises synchronizing timing of all cognitive
radios in the group and sending a the second operational policy to
the group of cognitive radios.
4. The method according to claim 2, wherein the determining
comprises downloading the second operational policy.
5. The method according to claim 1, wherein the determining
comprises querying a cognitive radio in the group to determine its
operational capabilities.
6. The method according to claim 1, wherein the second operational
policy comprises a prohibition of at least one radio from
communication.
7. The method according to claim 1, wherein the determining
comprises receiving a beacon from a cognitive radio in the group
indicating that the new operational policy is unsuitable.
8. A computer readable electronic storage medium storing
instructions that, when executed on a programmed processor, carries
out the process according to claim 1.
9. A master cognitive radio, comprising: a software configurable
transceiver; a control processor that executes program instructions
to implement: establishing a first operational policy for the group
of cognitive radios; determining that the operational policy is
unsuitable for use by at least one member of the group; and the
master cognitive radio dictating a change in the operational policy
used by the group to a second operational policy for use by the
group.
10. The master cognitive radio according to claim 9, wherein the
determination that the operational policy is not suitable comprises
determining that the operational policy based upon the received
policy information being beyond the capabilities of at least one of
the cognitive radios in the group.
11. The master cognitive radio according to claim 9, wherein the
determination that the operational policy is not suitable comprises
receiving a beacon signal from at least one of the cognitive radios
in the group.
12. The master cognitive radio according to claim 11, wherein the
beacon contains a description of the capabilities of the cognitive
radio.
13. The master cognitive radio according to claim 9, wherein at
least one of the first and second operational policies is obtained
by reference to a database within the master cognitive radio.
14. The master cognitive radio according to claim 9, further
comprising a digital signal processor that processes transmitted
and received data from and to the master cognitive radio's
transceiver respectively, and wherein establishing at least one of
the first and second operational policies further comprises
configuring the digital signal processor with parameters of the at
least one of the first and second operational policies.
15. The master cognitive radio according to claim 9, wherein the
dictated change in operational policy comprises synchronizing
timing of all cognitive radios in the group and sending a the
second operational policy to the group of cognitive radios.
16. The master cognitive radio according to claim 9, wherein the
second operational policy is downloaded from a server.
17. The master cognitive radio according to claim 9, wherein the
determining comprises querying a cognitive radio in the group to
determine its operational capabilities.
18. The master cognitive radio according to claim 1, wherein the
second operational policy comprises a prohibition of at least one
radio from communication.
19. A cognitive radio, comprising: a software configurable
transceiver; a control processor that executes program instructions
to implement: receiving policy information; determining that an
operational policy based upon the received policy information is
not suitable for use by the cognitive radio; and transmitting a
beacon requesting new policy information.
20. The cognitive radio according to claim 19, wherein the
determination that the operational policy based upon the received
policy information is not suitable comprises determining that the
operational policy is beyond the capabilities of the cognitive
radio.
21. The cognitive radio according to claim 19, wherein the beacon
contains a description of the capabilities of the cognitive
radio.
22. The cognitive radio according to claim 19, further comprising a
digital signal processor that processes transmitted and received
data from and to the cognitive radio's transceiver respectively,
and wherein establishing at least one of the first and second
operational policies further comprises configuring the digital
signal processor with parameters of the at least one of the first
and second operational policies.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to, in certain
embodiments, the field of software defined radios and cognitive
radios. More particularly, certain embodiments consistent with this
invention relate to methods and apparatus for establishing an
operational policy for such radios.
BACKGROUND
[0002] Radio communication technology has traditionally been based
upon fixed frequency or spectrum assignments and fixed modulation
techniques (as well as other regulatory agency established
parameters). For example, a particular local government agency such
as a police department might be assigned several frequencies for
its use using frequency modulation for voice communication.
Frequency spectrum could often be shared amongst groups of users in
order to more efficiently use the spectrum by, for example,
sub-audible digital or analog coding embedded in the transmitted
signals. Nevertheless, in such an environment, the assigned
frequencies are off limits for use by others and usage would rarely
approach full utilization. In fact, utilization might amount to
only a few percent of the available communication throughput. As a
result, frequency spectrum is inefficiently utilized, while
simultaneously demand for bandwidth is ever increasing.
[0003] A new paradigm for dealing with such a problem is emerging
in which a radio is provided with the intelligence to identify
underutilized or unutilized spectrum and change its operational
parameters to take advantage of the available spectrum while
minimizing potential for causing interference. Such radios are
commonly configurable and reconfigurable using software control and
posses the intelligence to obtain the needed situational awareness
to reconfigure in order to enhance spectrum utilization efficiency.
Such radios have been dubbed cognitive radios--a form of software
defined radio. Cognitive radios are envisioned to be able to cross
geographic boundaries and adapt to regulatory changes associated
therewith.
[0004] One issue that is to be addressed in producing a viable
working cognitive radio is the issue of adaptation to new policies
as a radio's situation or environment changes. This can happen, for
example, by virtue of changes in a geographically static
environment as well as changes resulting from geographical movement
of the radio (e.g., in an automobile or an airplane). The cognitive
radio should be able to competently adapt to such situations
BRIEF DESCRIPTION OF THE FIGURES
[0005] The accompanying figures, where like reference numerals
refer to identical or functionally similar elements throughout the
separate views and which together with the detailed description
below are incorporated in and form part of the specification, serve
to further illustrate various embodiments and to explain various
principles and advantages all in accordance with the present
invention.
[0006] FIG. 1 is an example block diagram of a cognitive radio in
accordance with some embodiments of the invention.
[0007] FIG. 2 is an example diagram illustrating a cognitive radio
network in accordance with some embodiments of the invention.
[0008] FIG. 3 is an example of another cognitive radio network in
accordance with some embodiments of the invention.
[0009] FIG. 4 is an example illustration of a change of domains of
a cognitive radio in accordance with some embodiments of the
invention.
[0010] FIG. 5 is another example illustration of a change of
domains of a cognitive radio in accordance with some embodiments of
the invention.
[0011] FIG. 6 is another example illustrating a change of domains
of a cognitive radio in accordance with some embodiments of the
invention.
[0012] FIG. 7 is a flow chart of an example hierarchical process
for changing policies of a cognitive radio in accordance with some
embodiments of the invention.
[0013] FIG. 8 is a flow chart of an example policy change process
of a cognitive radio in accordance with some embodiments of the
invention.
[0014] FIG. 9 is an example signal flow diagram between two
cognitive radios in accordance with some embodiments of the
invention.
[0015] FIG. 10 is an example communication flow diagram between
cognitive radios and a central/policy manager in accordance with
some embodiments of the invention.
[0016] FIG. 11 is a flow chart of a communication process using a
master cognitive radio in accordance with some embodiments of the
invention.
[0017] Skilled artisans will appreciate that elements in the
figures are illustrated for simplicity and clarity and have not
necessarily been drawn to scale. For example, the dimensions of
some of the elements in the figures may be exaggerated relative to
other elements to help to improve understanding of embodiments of
the present invention.
DETAILED DESCRIPTION
[0018] Before describing in detail example embodiments that are in
accordance with the present invention, it should be observed that
the embodiments reside primarily in combinations of method steps
and apparatus components related to the cognitive radio and related
processes. Accordingly, the apparatus components and method steps
have been represented where appropriate by conventional symbols in
the drawings, showing only those specific details that are
pertinent to understanding the embodiments of the present invention
so as not to obscure the disclosure with details that will be
readily apparent to those of ordinary skill in the art having the
benefit of the description herein.
[0019] In this document, relational terms such as first and second,
top and bottom, and the like may be used solely to distinguish one
entity or action from another entity or action without necessarily
requiring or implying any actual such relationship or order between
such entities or actions. The terms "comprises," "comprising," or
any other variation thereof, are intended to cover a non-exclusive
inclusion, such that a process, method, article, or apparatus that
comprises a list of elements does not include only those elements
but may include other elements not expressly listed or inherent to
such process, method, article, or apparatus. An element proceeded
by "comprises . . . a" does not, without more constraints, preclude
the existence of additional identical elements in the process,
method, article, or apparatus that comprises the element.
[0020] It will be appreciated that embodiments of the invention
described herein may be comprised of one or more conventional
processors and unique stored program instructions that control the
one or more processors to implement, in conjunction with certain
non-processor circuits, some, most, or all of the functions of the
cognitive radio described herein. The non-processor circuits may
include, but are not limited to, a radio receiver, a radio
transmitter, signal drivers, clock circuits, power source circuits,
and user input devices. As such, these functions may be interpreted
as a method to perform functions such as acquisition of a new
policy in accordance with certain embodiments consistent with the
present invention. Alternatively, some or all functions could be
implemented by a state machine that has no stored program
instructions, or in one or more application specific integrated
circuits (ASICs), in which each function or some combinations of
certain of the functions are implemented as custom logic. Of
course, a combination of the two approaches could be used. Thus,
methods and means for these functions have been described herein.
Further, it is expected that one of ordinary skill, notwithstanding
possibly significant effort and many design choices motivated by,
for example, available time, current technology, and economic
considerations, when guided by the concepts and principles
disclosed herein will be readily capable of generating such
software instructions and programs and ICs with minimal
experimentation.
[0021] Reference throughout this document to "one embodiment",
"certain embodiments", "an embodiment" or similar terms means that
a particular feature, structure, or characteristic described in
connection with the embodiment is included in at least one
embodiment of the present invention. Thus, the appearances of such
phrases or in various places throughout this specification are not
necessarily all referring to the same embodiment. Furthermore, the
particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments without
limitation.
[0022] The term "or" as used herein is to be interpreted as an
inclusive or meaning any one or any combination. Therefore, "A, B
or C" means "any of the following: A; B; C; A and B; A and C; B and
C; A, B and C". An exception to this definition will occur only
when a combination of elements, functions, steps or acts are in
some way inherently mutually exclusive.
[0023] For purposes of this document, the term "policy" or
"operational policy" is used to generically describe a rule or set
of rules that define a parameter or a collection of parameters that
specify a communication protocol and related specifications for use
in radio communication. Those rules, for example, determine the
type of waveforms used in modulation of information used for
communication. Such policies and parameters thereof may be
established or limited by convention, by agreement or by law.
Examples of policies and components of policies include, but are
not limited to, frequency or frequencies or frequency band, power
limits, application, location, situation, wave shape, spectral
characteristics, temporal characteristics, packet or other data
formats, modulation technique, operational mode, coding, bandwidth,
data throughput, encryption parameters and other communication
parameters that might be used to specify the operation of a radio
communication device.
[0024] A policy may be fully defined in some embodiments by a
policy identifier or policy code, while in other embodiments, a
policy may be identified by the specific parameters and
specifications. In still other embodiments, the policy may be
identified by a difference between two policies, or by a policy
identification with exceptions, or by compressed data explaining,
defining or labeling the policy. Any number of other techniques may
be devised to identify a policy without deviation from the
principles governing embodiments consistent with the present
invention.
[0025] For purposes of this document, the term "domain" or "policy
domain" is intended to mean a geographical region or other
operational constraint in which a particular policy is in
force--generally by virtue of regulations established by a
regulating authority (e.g., in the U.S., the Federal Communication
Commission is one such regulatory authority). It is noted that a
policy domain may include radio spectrum that is unregulated or is
nearly unregulated, and which can be utilized in accordance with
certain embodiments as well as licensed spectra.
[0026] For purposes of this document, the term "software defined
radio" (SDR) is intended to mean a radio communication device whose
operational parameters are established by software. Thus, an SDR
may be configured and reconfigured under software control to comply
with a particular set of operational parameters (i.e., a policy).
An example SDR may operate in multiple bands and in multiple
modes.
[0027] For purposes of this document, the term "cognitive radio"
(CR) is used to mean a configurable radio such as a software
defined radio that has the ability to configure itself for
operation based upon its operational environment. That is, a CR is
able to determine or seek out an operational policy applicable to
its capability, location, applicable policies, laws, regulations,
spectral congestion, likelihood of receiving or causing
interference, and/or similar considerations. A cognitive radio can
take many forms and have varying degrees of "situational awareness"
that permits the cognitive radio to select (or have selected for
it) an appropriate operational policy. The CR can then configure
itself (or be configured) and operate to carry out radio
communications according to the operational policy. The term "smart
radio" is also sometimes used to describe this type of radio.
[0028] "Situational awareness" implies that the cognitive radio is
aware of its operational environment to some degree. That
situational awareness may be obtained by virtue of the CRs
capability to sense parameters such as spectral utilization, or
sense or be made aware of position and movement of the CR (e.g., in
a car or plane by GPS signals or other means), or by virtue of
querying of or receipt of updates from other nearby cognitive
radios or other authorities to obtain such situational awareness.
This situational awareness is used by the CR in order to establish
or receive an appropriate operational policy for use in a given
situation in order to achieve efficient or reliable
communication.
[0029] An assumption to be used in considering the functioning of a
cognitive radio is that a common signaling and communication
mechanism should be available to all CRs (or at least all CRs in a
particular collection of CRs). This assumption permits the
cognitive radios to communicate at a basic level to permit
configuration of a group of cognitive radios for communication
among themselves and to exchange information contributing to
situational awareness to aid in optimizing communication. Two
possibilities are proposed for achieving this functionality. In the
first, an agreed upon standard protocol is established in which all
CRs possess the native ability to communicate. In the second,
cognitive beacons are provided which act as translators between
normally incompatible protocols to permit communication among
cognitive radios. In either case, however, the present document
presumes establishment and existence of such a common mechanism for
communication between CRs. At this writing an accepted protocol has
not been established, but it is clear that establishment of such a
protocol is a formality and a matter of national and/or
international regulatory agreement, convention, treaty, etc., with
no substantial technical barriers to be overcome. The presence of
agreements at this time on such a specified mechanism is not
necessary to the understanding of the present embodiments.
[0030] FIG. 1 depicts a simplified embodiment of a software defined
radio capable of operation as a cognitive radio 100. Such CR 100
incorporates a radio frequency (RF) transceiver 104 that is
configurable under software control by instructions received from a
control processor (e.g., a microprocessor or microcontroller) 108
in order to establish an air interface used by the transceiver 104
to carry out suitable communications. Received analog radio waves
are downconverted by the receiver section of the RF transceiver 104
and converted to digital by A/D converter 112 for processing by a
programmable digital signal processor (DSP) 116. Similarly, digital
data (which may include digitized voice) is passed from the DSP 116
to D/A 120 for transmission by the RF transceiver 104's
transmitter. Analog to digital and digital to analog conversion may
be bypassed in certain embodiments of digital communication
scenarios.
[0031] The programmable DSP 116 operates under control of control
processor 108 which configures the DSP for the particular policy in
use at the time. A user interface 124 provides audio or visual data
to and from a user of the cognitive radio 100. Control processor
108 has an associated memory (or other suitable storage) 130 that
stores instructions that are used to process the policy actions of
the cognitive radio 100. Memory 130 includes working memory 134
carrying programs and operating system and satisfies other such
storage requirements. A portion of memory 130 may also be reserved
for storage of parameters of a currently active policy at 138.
Another portion of memory 130 may be used to store policy templates
at 142, while still another part of memory 130 may store
situational awareness data at 146 used by the cognitive radio 100.
Situational awareness data can be received from many sources
including GPS data, data received via the receiver of RF receiver
104, user input, sensors, etc. For simplicity, this situational
data are represented as coming from block 150, but the presence of
a single block representing a source of this data should not be
construed to be limiting in any way. Situational awareness data
input are represented this way purely for conceptual convenience
without regard for the hardware which might be employed to produce
such data. A policy log 160 is also maintained according to certain
embodiments in order to facilitate reuse of prior policy decisions
that worked well in the past under similar or identical situations
(e.g., location).
[0032] Memory 130 further incorporates, in certain embodiments,
varying forms of policy selection algorithms 154 which depend upon
numerous factors including, but not limited to, situational
awareness data, reliability of situational awareness data, active
policy, policy templates, logged policy data, etc.
[0033] Implementing policy changes in a cognitive radio is a
complex issue involving many factors. In order to understand the
complexity of the problem, it is instructive to consider several
general operational considerations for a cognitive radio. First,
one should recognize that as this technology evolves and as new CRs
are developed and computing power available to the CR increases, a
variety of CRs may be in communication, with each having varying
knowledge, situational awareness, historical data and computing
power. As a result, a cognitive radio should be able to adapt
policy use decisions based upon a multitude of factors, not the
least of which might be the ability to take advantage of a more
powerful or more knowledgeable CR from which it can obtain valuable
information to be used in establishing a suitable policy for a
given situation.
[0034] Cognitive radios can be configured to operate in any number
of ways. Consider FIG. 2 for example. In this example, a first
cognitive radio CR-A (204) may directly communicate with a peer
cognitive radio CR-B (208) in a so-called "point-to-point" (P2P)
communication session. The CRs may establish a suitable policy for
use in this point-to-point environment via any number of techniques
including, but not limited to, the CRs' situational awareness,
negotiation with each other, consultation with other CRs in range,
or consultation with a central (or local or regional) policy
manager 212.
[0035] Another, more elaborate, example environment for cognitive
radio communication is depicted in FIG. 3 in which any number of
hierarchies may be utilized for obtaining the situational awareness
necessary for obtaining an appropriate operational policy.
Generally speaking, the depicted hierarchy of authority in policy
decision making increases from top to bottom in this illustration.
In this example, a peer-to-peer group 218 is depicted as having
three member cognitive radios--204, 208 and CR-M 220. In this
example, the group 218 may operate as an autonomous communication
group, or may utilize the services of a base station or repeater
224 in a more or less conventional manner once an appropriate
policy is established for such communication. The reader is
reminded that all CRs are presumed to be able to communicate using
a common signaling protocol in order to establish or change a
policy.
[0036] In communication group 218, one member may be established as
a "master" who can dictate policy to the others in the
communication group. In this case, assume that CR-M (220) is such a
master. If for any reason the master wishes to change policy
(either autonomously, or under user instruction) CR 220 can dictate
that change to the subordinate CRs 204 and 208 using appropriate
signaling. Envision, by way of example, that CR 220 is controlled
by a sheriff or military commanding officer, who deems that the
policy should be changed to permit communication with a broader
range of personnel operating together in an emergency situation or
to adapt to loss of communication with a member of the group.
[0037] When base station 224 is in a position to assist with policy
decisions, such decisions may be implemented either by assistance
of the computing power available at the base station, or may be
dictated by the base station, operating in the role of a more
computationally powerful cognitive radio itself. Additionally, base
station 224 may operate in the capacity of a gateway that utilizes
either a private data network or the Internet 230 to obtain
additional assistance, or policy instructions from a local,
regional or master policy authority 234. Hence, a cognitive radio
may take advantage of numerous resources at its disposal, in
addition to any locally or internally generated situational
awareness data available to it in order to make policy
decisions.
[0038] Now consider the role of movement as depicted in FIG. 4-6 in
making policy decisions. In this example, a pair of CRs (again 204
and 208) are in communication with each other. In this example, the
CRs are depicted as traveling from left to right within or as a
part of an aircraft. This example could equally well have depicted
those CRs traveling in an automobile, train, military vehicle, etc.
CR 204 and 208 are shown to be currently operating within a domain
250 that uses policy R, but are approaching a domain 254 with
policy S. This is most readily visualized as representing travel
across the boundary from one nation to another wherein different
regulatory authorities establish the rules of radio communications
within their boundaries. Also depicted is a third CR 260 (CR-C)
traveling from domain 254 toward domain 250 from right to left.
Hence, CR 260 is operating under an appropriate policy S for domain
254. In this example, the CRs 204, 208 and 260 may modify their
policies in any number of ways. For example, the various CRs may
travel this route frequently and may therefore have stored in their
memory an appropriate set of policies and suitable information on
when and how to change those policies as they approach the new
domain. In other embodiments, the three CRs may query each other to
determine an appropriate policy for use.
[0039] It should be noted that three policies may be required as
the CRs make their way across the regulatory boundary into the
adjacent domain. While in domain 250, one policy may be used, while
in domain 254 another policy might be used and during their
transition between domains, a third commonly workable policy might
be used. Note that while a particular CR is near a border between
domains, it may have to accept a compromise policy that may be
undesirable for various reasons (e.g., congestion, poor throughput,
etc.), but since near the border transmissions have the potential
of causing interference the policy decision should take this into
account. Once a domain barrier has been crossed and the potential
for interference near the transitional region is gone or minimized,
the policy may be changed again in order to maximize
throughput.
[0040] The example of FIG. 4 is somewhat two dimensional, which may
be a realistic assumption when, for example, the cognitive radios
are transported via ground transportation, or when a border
involves only two domains or even when the transmitted power is
very low. This situation is further depicted in FIG. 5 in which the
altitude 270 is relatively low or the border between domains is
relatively isolated from other domain borders. However, consider
the depiction of FIG. 6 in which the altitude 274 is much higher
and more than two borders are involved. In this example, domains
250 and 254 are joined by domains 280 and 286 as being relevant to
the receipt of transmissions from CR 204. One can readily envision
areas, for example in Europe, where multiple boundaries converge in
which the scenario depicted is realistic and to be contended with.
Hence, the three dimensional aspect of the decision making for
establishing a communication policy for CR 204 comes into play. In
addition to compliance with regulatory issues associated with each
domain, an effective communication mechanism may be needed which
has suitable throughput for a particular application.
Simultaneously, creation of interference should be avoided. Hence,
geographical position in three dimensional space may need to be
taken into consideration in order to establish an appropriate
communication policy that meets a "least common denominator"
constraint on a selected policy.
[0041] Now consider an exemplary process for acquiring policy
related information as depicted as process 300 of FIG. 7 starting
at 304. When a cognitive radio is first activated, an initial
operational policy is established at 308. Such policy may be based
on policy templates stored in memory 130 at 312, as well as
historical data and any situational awareness data that might be
available. In certain embodiments, the initial startup may also
involve transmission of a beacon, a response to which may dictate
or suggest a policy or provide enhancements to existing situational
awareness. In any event, an initial communication policy is
established at 308 which is used until there is a determination at
316 that a policy change should be implemented. Such a
determination may be based upon a number of factors including:
time, 2 dimensional or 3 dimensional location, velocity and
direction of travel, interference, communication quality or
failure, data throughput, domain change, signal quality or strength
assesments, and other situational awareness data.
[0042] When a policy change is to be implemented at 316, an
exemplary hierarchical approach involves first querying neighboring
cognitive radios for policy information at 320. When this document
discusses a query of a neighbor (or any other entity) for policy
information, this should be interpreted to mean a broad range of
potential queries. For example, the query can involve one way or
two way communication of any or all of the following information:
capabilities or class of the querying radio, position of the
querying radio, velocity of travel or other information identifying
impending domain change, identification of present policy in use,
etc.
[0043] When this query is received by a neighbor CR, the neighbor
may reply in any number of ways. For example, the response may
involve communication of any or all of the following information: a
code representing a full set of policy information being used by
either the responding cognitive radio, a code representing a full
set of policy, information that is within the capabilities of the
querying radio, a set of suggested or dictated policy parameters, a
compressed set of suggested or dictated policy parameters, data
representing a policy difference (e.g.--a message stating that the
same policy can be used with power reduced from 5 watts to 1 watt),
information relating to spectral congestion or interference in the
domain being approached, a metric describing the reliability of
information being provided, capabilities of the responding radio,
situational awareness data, a radio identifier, etc.
[0044] Once the policy data are received at 322, a decision is made
(unless the policy is dictated) as to the policy changes that are
to be made. The policy is then updated and verified at 324 to
assure suitable functionality of the new policy. A policy update
counter can then be incremented at 328 in order to keep track of
attempts at establishment of an operative policy. At 332, if the
policy is verified as suitable, the policy is logged to the policy
log along with data identifying appropriate situations for its use
(e.g. time, position, velocity, etc.) at 336. Normal communication
functions then ensue at 340 and the update counter is reset.
Control then returns to 316 to await the next policy change.
[0045] However, in the event the policy is not verified at 332, the
count of the update counter is compared with a threshold at 344. If
the established threshold for number of attempts to update the
policy with a viable policy has not been reached, either the
process can return to 320 to find a new peer neighbor radio with
better information (not shown for ease of illustration), or the
policy request can be escalated to a network node (as depicted in
this example) at 348. Hence, at 348, a network node (or similar
higher level authority) is queried (e.g., a local base station or
master or through a local base station or via point-to-point
communication).
[0046] Policy information is then received at 350 and a new policy
decision can be made. The policy is then updated and verified at
352 and the update counter is incremented at 356. If the new policy
is verified at 360, control passes back to 336. Otherwise, control
passes to 366 for another inspection of the policy update counter.
If the threshold count has still not been reached at 366, then
control passes to 370 where a higher level authority can be sought
and selected to request new policy data. The process then repeats
starting at 352. (In a similar manner, multiple neighbor peer
radios can be repeatedly queried until a count is exceeded--this
process has been omitted to simplify the flow diagram).
[0047] When an update count exceeds (or meets) the threshold value,
control passes to 380 where a policy request is sent to the highest
level server node that can be reached. Policy data are then
received at 382 and a new policy decision made. The policy is then
updated at 386 and if verified at 390, control passes to 336. If
this policy cannot be verified at 390, an error condition is
presumed to exist at 394. This can result in any number of
corrective actions including a full software reset of the radio
and/or presentation of alerts or other error messages.
[0048] As previously implied, a cognitive radio CR should quickly
identify the policies that apply to it based on its current
location, movements and time of day, for example along with other
parameters. This is particularly important for rapidly-moving
radios, such as is found in aircraft traversing multiple countries
or governing authorities. The radio should determine in real time
whether it can transmit, and under what conditions should be used
for transmission at its current location and time. The CR
establishes a usage policy (for example by download from a database
in an associated network, or by the process just outlined). A
particular policy may only be valid for a certain geographic area.
Hence, the cognitive radio can predict when a new policy will be
needed as a function of its current location (in two or three
dimensional space), signal propagation and a speed and direction of
movement. Based upon this data an approximate expiration time can
be calculated based on its current location and speed. Also, by
sensing its altitude along with its known latitude/longitude (or
other location coordinates), the CR can estimate transmit (Tx)
propagation and thus decide how often to request a policy
update/download.
[0049] As noted earlier, policy updates can either be downloaded
from the network, or the CR can query neighboring CR's to obtain
policy updates (in various formats such as a compressed, difference
format). This latter approach is presumed to provide a much quicker
update compared to downloading the entire policy from the network.
Using the location, time, and propagation estimates, the CR chooses
the most viable frequency and protocol (etc.) to use and verify
that the defined policy is available/unused. It maintains a history
log with policy, location, and interference info to assist in
quickly determining how to best communicate (i.e. skip propagation
estimate and/or policy update request if CR has already traveled
this path before), using coarsely-quantized locations to save
storage space. If a new policy is needed but one is not available
for this location from either the network or neighboring radios,
the CR will compare the last-used policy with a cached policy for
the closest location to determine which subset of policy rules to
apply. If after a policy change no valid data can be received
(i.e., the policy is not verified), the policy used by the
transmitter may be beyond this CR's capability, or their policies
may be out of sync; the CR then transmits a trouble beacon signal
to all. The network detects the beacon and attempts to resync all
CR's with a policy usable to all (i.e. least-common denominator of
usage capabilities).
[0050] Thus, in accordance with certain embodiments, the CR takes
advantage of its location, capabilities, and info from neighboring
CRs to rapidly determine the best policy for the geographic region.
Local caching and decision-making may often eliminate the need to
support frequent, large policy downloads.
[0051] An exemplary flow chart of a process 400 of FIG. 8 starting
at 404 depicts an example implementation of the procedures
described above that may be utilized in certain embodiments. At
408, the current movement, time and location data including
altitude, speed, direction, latitude, longitude, GPS coordinates,
etc. are fetched. By reference to a database of logged policy
information, the CR can then determine if this path or something
close has been previously logged at 412. If so, the policy data can
simply be retrieved from the CRs internal database in order to
establish a likely functional policy for use at 416. A protocol,
frequency, etc. (policy parameters) can then be selected for use in
communication at 420.
[0052] However, if traveling in a new or unlogged area at 412, a
policy can be requested by transmission of a query beacon at 424. A
download can be received (e.g., as in FIG. 7) at 428 and a policy
can be selected and implemented at 420. At 440, the policy is
verified and if verified at 444, communication is established at
448. The policy and location and movement information can then be
logged to the database at 452. However, if not verified, a trouble
beacon can be transmitted at 476 and a negotiation for appropriate
policy can be carried out at 480 in order to obtain an appropriate
communication policy. Once communication is established at 448 and
appropriately logged at 452, the cognitive radio's internal
processor 108 can estimate a distance of propagation of the
transmitted signal at 456. The CR can then estimate at 460 how long
the present policy can remain active before another domain is
approached by its propagated signal, and thus establish an
expiration time estimate based on speed, path and geographical
data. Such expiration time may slightly precede the actual last
time frame that the policy can remain in use in order to permit
acquisition of a new policy in time for a smooth transition between
policies. Of course, such an estimate is just that--an estimate.
The estimate may be refined to account for speed changes, course
changes, weather and other situational awareness data, but once an
established or refined time for expiration of the policy (Test) is
reached, at 466, control returns to 408 where the process repeats.
Until such time as the expiration time is reached, the process
simply waits at 470.
[0053] Computation of a time estimate for expiration of the current
policy can be easily made once all of the appropriate data are
determined or estimated. For example, if the propagation distance
toward a new domain is four miles, and the speed of travel toward
the new domain is one hundred twenty miles per hour, the new domain
will be reached in 4/120 hour=2 minutes. Propagation estimates are
readily made by reference to known formula, tables and charts.
[0054] The above process is centric to a single CR. But, if after a
policy change no valid data can be received, the policy used by the
transmitter may be beyond this CR's capability, or their policies
may be out of sync. The CR can use transmission of a trouble beacon
signal to signal surrounding devices of the problem. The network or
other authority or neighboring devices can detect the beacon and
attempt to resyncronize all CR's with a policy usable to all (i.e.
least-common denominator of usage capabilities).
[0055] This concept can be expanded to incorporate a methodology to
induce change to an operational policy based on user/application
hierarchy. By way of an example: a chief police officer is in
location that his communication with the rest of group is failing
due to inadequacy of operational policy being used. He/his radio,
acting as a master cognitive radio in the group, will have
authority to change the current policy and request other members to
re-synchronize with the new policy. That is, an entity of higher
place in the hierarchy can demand a resynchronization and can
dictate the parameters of the re-synchronization, even including
dictating that certain radios (e.g., those that might fall into
enemy hands, are disabled or deauthorized).
[0056] In establishing a new policy, among a group of communicating
cognitive radios, in certain embodiments, a new policy is
implemented by first synchronizing timing of the radios and then
transmitting a new policy to all radios. In the event the new
policy is beyond the capabilities of a particular radio, it can
signal this fact by use of a trouble beacon. In response, the
master can query the radio as to its capabilities and change the
policy to one having capabilities common to all radios in the
group. In other circumstances, certain members of the group can be
excluded from the group (i.e., disabled) in order to establish a
policy with the remaining group members. The different members of
the group may be performing different roles, functions,
applications, services, etc. Also, each of the different members of
the group might be capable of only certain functions or
capabilities that might or might not be needed at a certain time.
There may thus be a need to provision communications on a temporary
or ongoing basis for only a subset of proximal users and/or nodes.
Thus, certain radios in the hierarchy could be temporarily disabled
(e.g., certain non-key members/applications) in order to create an
operational environment with adequate amount of resource for the
key individuals/applications.
[0057] Consider the embodiment described in connection with FIG. 9.
This represents a communication flow between two radios CR-A and
CR-B. This exchange begins at 504 with a query from CR-A to CR-B as
to whether CR-B is using a particular rule X. At 508, CR-B replies
"no" after which rule X is supplied to CR-B from CR-A at 512. It is
then up to CR-B to either acknowledge (ACK) or not acknowledge
(NAK) based upon whether or not the rule can be used based upon the
capabilities of CR-B at 518. A NAK message may be essentially the
same as a trouble beacon in some embodiments. Responsive to the
NAK, CR-A initiates a re-synchronization with a different policy at
522.
[0058] A similar policy management scenario can be implemented as
depicted in FIG. 10 wherein a local, regional or central policy
manager dictates the policy to be used. Such manager 540 may also
be another CR with a higher rank in a group's hierarchy. In this
embodiment, a policy may be dictated as depicted by transmission of
rule X (i.e., a new policy). If rule X does not work to establish
the communication link desired, a NAK (beacon) can be transmitted
in order to initiate a re-synchronization.
[0059] A process for a policy manager or master cognitive radio to
change a policy in accordance with certain embodiments is depicted
in FIG. 11 starting at 600 after which the master determines at 606
that there is a need for a new policy. Such decision can be based
upon any given motive including disabling certain radios or classes
of radios or inability of certain radios to communication. Once
this determination is made at 606, the master sends a new policy
directive is transmitted to all desired members of the
communication group at 610. Once the directive is received by the
radio group, the master listens for receipt of a NAK beacon from
any of the desired communication group members. If a NAK is not
received at 614, normal communication ensues at 618. However, if a
NAK beacon is received at 614, the master queries the radios that
sent the NAK beacon to determine their capabilities at 622. The
master then makes a determination of a suitable policy having
common communication abilities for all members of the desired group
at 630. Control then returns to 610 where the new policy is
transmitted as a directive to the communication group.
Implementation of the directed new policy may involve first
synchronizing all the radios followed by implementing the policy at
a specified time.
[0060] Thus, a cognitive radio (CR) quickly identifies the policies
that apply to it based on its current location and time of day,
even for rapidly-moving radios, such as is found in aircraft
traversing multiple countries or governing authorities. The radio
determines in real time whether it can transmit, and under what
conditions apply for its location and time. The CR downloads a
usage policy from a database in an associated network. The policy
is defined to be valid for a certain geographic area and timeframe,
and the user calculates an expiration time based on its current
location and speed. Also, by sensing its altitude along with its
known lat/longitude, the CR can estimate transmit (Tx) propagation
and thus decide how often to request a policy update/download.
[0061] Policy updates can either be downloaded from the network, or
the CR can query neighboring CR's to obtain policy updates (e.g.,
in a compressed, difference format). This latter approach provides
a quicker update compared to downloading the entire policy from the
network. Using the location, time, and propagation estimates, the
CR chooses the most viable frequency and protocol and/or other
policy elements to use and verify that the frequency is
available/unused. The cognitive radio maintains a history log with
policy, location, and interference info to assist in quickly
determining how to best communicate (i.e. skip prop estimate and/or
policy update request if already traveled this path before), using
coarsely-quantized locations to save storage space. If a new policy
is needed but one is not available for this location from either
the network or neighboring radios, the cognitive radio compares the
last-used policy with a cached policy for the closest location to
determine which subset of policy rules to apply. If after a policy
change no valid data can be received, the policy used by the
transmitter may be beyond this cognitive radio's capability, or
their policies may be out of sync; the CR then transmits a Trouble
Beacon signal to all. The network detects the beacon and attempts
to resynchronize all cognitive radio's with a policy usable to all
(i.e. least-common denominator of usage capabilities).
[0062] The CR takes advantage of its location, capabilities, and
information from neighboring CRs to rapidly determine the best
policy for the geographic region. Local caching and decision-making
eliminates the need to support frequent, large policy
downloads.
[0063] Thus, if after a policy change no valid data can be
received, the policy used by the transmitter may be beyond this
CR's capability, or their policies may be out of sync; The CR then
transmits a Trouble Beacon signal to all. The network detects the
beacon and attempts to resync all CR's with a policy usable to all
(i.e. least-common denominator of usage capabilities).
[0064] A computer readable electronic storage medium can be used to
store instructions that, when executed on a programmed processor,
carries out any of the processes described above.
[0065] Thus, A master cognitive radio consistent with certain
embodiments has a software configurable transceiver; A control
processor executes program instructions to implement: establishing
a first operational policy for the group of cognitive radios;
determining that the operational policy is unsuitable for use by at
least one member of the group; and the master cognitive radio
dictating a change in the operational policy used by the group to a
second operational policy for use by the group.
[0066] In certain embodiments, the determination that the
operational policy is not suitable comprises determining that the
operational policy based upon the received policy information being
beyond the capabilities of at least one of the cognitive radios in
the group. In certain embodiments, the determination that the
operational policy is not suitable comprises receiving a beacon
signal from at least one of the cognitive radios in the group. In
certain embodiments, In certain embodiments, the beacon contains a
description of the capabilities of the cognitive radio. In certain
embodiments, In certain embodiments, at least one of the first and
second operational policies is obtained by reference to a database
within the master cognitive radio. In certain embodiments, a
digital signal processor processes transmitted and received data
from and to the master cognitive radio's transceiver respectively,
and establishing at least one of the first and second operational
policies further involves configuring the digital signal processor
with parameters of the at least one of the first and second
operational policies. In certain embodiments, the dictated change
in operational policy comprises synchronizing timing of all
cognitive radios in the group and sending a second operational
policy to the group of cognitive radios. In certain embodiments,
the second operational policy is downloaded from a server. In
certain embodiments, the determining involves querying a cognitive
radio in the group to determine its operational capabilities. In
certain embodiments, the second operational policy includes a
prohibition of at least one radio from communication.
[0067] In another embodiment, a cognitive radio has a software
configurable transceiver. A control processor executes program
instructions to implement: receiving policy information;
determining that an operational policy based upon the received
policy information is not suitable for use by the cognitive radio;
and transmitting a beacon requesting new policy information.
[0068] In certain embodiments, the determination that the
operational policy based upon the received policy information is
not suitable comprises determining that the operational policy is
beyond the capabilities of the cognitive radio. In certain
embodiments, the beacon contains a description of the capabilities
of the cognitive radio. In certain embodiments, a digital signal
processor processes transmitted and received data from and to the
cognitive radio's transceiver respectively, and the process of
establishing at least one of the first and second operational
policies further comprises configuring the digital signal processor
with parameters of the at least one of the first and second
operational policies.
[0069] In accordance with certain embodiments, a method of
operation of a master cognitive radio in a hierarchical group of
cognitive radios, where the hierarchy of cognitive radios includes
at least one master cognitive radio that has a higher position in
the hierarchy than another of the cognitive radios in the group
involves: establishing a first operational policy for the group of
cognitive radios; determining that the operational policy is
unsuitable for use by at least one member of the group; and the
master cognitive radio dictating a change in the operational policy
used by the group to a second operational policy for use by the
group.
[0070] In the foregoing specification, specific embodiments of the
present invention have been described. However, one of ordinary
skill in the art appreciates that various modifications and changes
can be made without departing from the scope of the present
invention as set forth in the claims below. Accordingly, the
specification and figures are to be regarded in an illustrative
rather than a restrictive sense, and all such modifications are
intended to be included within the scope of present invention. The
benefits, advantages, solutions to problems, and any element(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential features or elements of any or all the
claims. The invention is defined solely by the appended claims
including any amendments made during the pendency of this
application and all equivalents of those claims as issued.
* * * * *