WO2007125515A1

WO2007125515A1 - System and method for defining partitions for spectrum agile radios

Info

Publication number: WO2007125515A1
Application number: PCT/IB2007/051603
Authority: WO
Inventors: Yasser Alsafadi; Amjad Soomro
Original assignee: Koninklijke Philips Electronics, N.V.
Priority date: 2006-05-01
Filing date: 2007-04-30
Publication date: 2007-11-08
Also published as: AR060727A1; TW200814807A

Abstract

A method of establishing spectrum usage policies for wireless devices (400) includes defining a realm (1100) for governing the spectrum usage policies of the devices (400); providing a general ontology (1200) defining a virtual space (200) for spectrum usage by the devices; establishing partitions within the defined virtual space; and assigning spectrum usage policies (370) for devices operating within partitioned spaces (300). A corresponding method (500) of operating a wireless device includes: determining a partitioned space (300) within the virtual space defined by the general ontology in which the device (400) exists; selecting one or more spectrum usage policies for the device that is/are associated with the partitioned space in which it exists; determining a set of operating capabilities/needs (625) of the device; and comparing the set of operating capabilities/needs of the device against the selected spectrum usage policies (370) to identify any existing spectrum opportunities for device (400).

Description

SYSTEM AND METHOD FOR DEFINING PARTITIONS FOR SPECTRUM AGILE RADIOS

This invention pertains to the field of radio spectrum management for wireless communications, and more particularly to a system for partitioning a virtual space, assigning spectrum policy usage rules to points in these partitions; and providing devices that adhere to the policies set in these partitions.

There continues to be a proliferation of wireless communications systems and devices. Meanwhile, spectrum resources are limited.

In the past, regulatory bodies around the world (e.g., the U.S. Federal Communications Commission (FCC); the European Conference of Postal and Telecommunications Administrations (CEPT); etc.) have allocated parts of radio spectrum for the dedicated use of specific services and organizations. However, this model of spectrum allocation has proved to be inefficient in making use of precious spectrum resource. Therefore, there is, currently, active scientific research in defining policy, behaviors and protocols to develop next generation spectrum policies, systems and architectures.

Toward this end, for example, the FCC has proposed to allow unlicensed radio transmitters to operate within the broadcast television spectrum at locations where one or more of the allocated terrestrial television channels are not being used, so long as such unlicensed transmitters include safeguards that insure no interference with the reception of licensed terrestrial television signals. Various organizations are considering spectrum agile, or cognitive, radio communication technologies to take advantage of permitted unlicensed wireless device operations in licensed frequency bands.

However, the current definitions for agile spectrum usage management provided by regulatory bodies such as the FCC in the U.S.A. are global. That is, they don't define granular partitions. Therefore, inferring applicability of rules to a particular circumstance or condition is ad-hoc in nature and it does not lend itself to efficient machine interpretation. Furthermore, in the real world the boundaries of the partitions are constantly evolving due to a changing environment and the current definitions do not support temporal or situational changes. While some have proposed providing geographical partitioning by specifying spatial XY co-ordinates they may simply be not available for use, as in the case of inside buildings or they may be not enough to sufficiently describe the environment. The current knowledge focuses on describing domains of regulatory importance, but does not address specific use scenarios, particularly scenarios that are dependent upon time or other not location-dependent factors.

Accordingly, it would be desirable to provide a system and method for partitioning a logical space, and assigning spectrum policy usage rules to points in these partitions. It would further be desirable to provide wireless devices that adhere to the policies set in these partitions. In one aspect of the invention, a method of establishing frequency spectrum usage policies for wireless devices comprises: defining one or more realms for governing the spectrum usage policies of the wireless devices; providing a general ontology defining a virtual space for spectrum usage by the wireless devices; establishing partitions within the defined virtual space; and assigning spectrum usage policies for wireless devices operating within partitioned spaces defined by the partitions of the virtual space.

In another aspect of the invention, a method of operating a wireless device comprises: (a) determining a partitioned space within a virtual space defined by a general ontology in which the wireless device exists; (b) selecting one or more spectrum usage policies for the wireless device that is/are associated with the partitioned space in which it exists; (c) determining a set of operating capabilities and needs of the wireless device; and (d) comparing the set of operating capabilities and needs of the wireless device against the selected spectrum usage policies to identify any existing spectrum opportunities for a device to operate.

In yet another aspect of the invention, a wireless device, comprises: a receiver front-end section; a signal processing block; memory; and a processor. The processor is configured to execute a method comprising the steps: (a) determining a partitioned space within a virtual space defined by a general ontology in which the wireless device exists; (b) selecting one or more spectrum usage policies for the wireless device that is/are associated with the partitioned space in which it exists; (c) determining a set of operating capabilities and needs of the wireless device; and (d) comparing the set of operating capabilities and needs of the wireless device against the selected spectrum usage policies to identify any existing spectrum opportunities for device to operate. FIG. 1 illustrates exemplary levels of ontology; FIG. 2 illustrates how a virtual space is defined by a general ontology; FIG. 3 illustrates a mapping between a partitioned space and associated spectrum policies; FIG. 4 is a high level block diagram of one embodiment of a wireless device;

FIG. 5 is a flowchart illustrating one embodiment of a method that may be employed to enable wireless device to adapt its use of radio spectrum to the real-time conditions of its current operating environment; and

FIG. 6 illustrates a range of spectrum opportunities identified by the method of FIG. 5.

We provide a system and method for defining variable levels of partitioning for spectrum agile radios. It enables managers of enterprises (hospitals, military compounds, hotels, etc.) to define parts of their enterprises at different granularities (temporal, spatial, conditional, etc.). Furthermore, they can assign spectrum usage statements to these partitions.

To facilitate defining partitions of the enterprise multiple levels of abstractions, are provided, such as (1) a Realm Ontology; (2) a General Level Ontology; and (3) a Domain Specific Ontology. The defining characteristics of these ontologies are described below. This approach provides flexible extensibility to add specific concepts in different application domains. These definitions can be assigned software-based spectrum usage policies. These policies can exploit the agility of devices and allow in-situ policy-based control of radio behaviors.

In general, an ontology is a specification of a conceptualization. More particularly, in the context of shared knowledge, an ontology is a description (like a formal specification of a program) of the concepts and relationships that can exist for an agent or a community of agents, where all of the agents commit to the ontology and follow its policies. For example, in this case an ontology is provided for managing frequency spectrum that describes the concepts that can exist in the management of frequency spectrum, a set of policies and relationships pertaining to frequency spectrum management, and devices, or agents, are provided that will commit to the ontology and adhere to its policies.

In the system and method described herein, partitions are defined as multiple levels of abstraction. FIG. 1 illustrates these exemplary levels of ontology 1000, in particular: a realm 1100, a general level ontology 1200, and domain specific ontologies 1300. These levels of abstractions can be modeled using the World Wide Web Consortium's Web Ontology Language (OWL). OWL can describe constraints on properties and classes, which helps to capture rich features of the objects. Furthermore, it exploits the defined relationships between objects, in a manner that allows a machine to make inferences and determine actions. Thus, these models can be realized in machine executable software. A realm 1100 is a granular partition that is defined by boundaries such as:

• Administrative 1120: where an administrator defines an enterprise and set the policies that will be accepted within this enterprise. For example, an enterprise could be a hospital and a group of affiliated clinics scattered throughout a region.

• Regulatory 1140: where bodies such as FCC, or Defense Advanced Research Projects Agency (DARPA) can define realm(s) and set the policies acceptable in these realms.

• Security 1160: A realm is defined by a location, a time, or a condition related to a security state. For example, at times of different threat alert levels (e.g., color-coded terrorism alert levels such as Blue, Orange, Red; defense condition (DEFCON) levels 1 through 5; etc.) different policies can be applied to different geographical areas, depending upon the current existing alert level.

• Weather 1170: A realm is defined by weather conditions such as temperature, humidity, particles in the air (sand or snow storm rain, ..). A general level ontology 1200 is a high-level ontology that provides general features pertaining to basic entities. It captures concepts 1210 such as space 1220, location 1230, time 1240, user 1250, security condition 1260, and activity 1270, to name a few. The high-level general concepts in turn can have more particular concepts. For example, within the concept "space" 1220, there are the more particular concepts of "indoor" 1222 and "outdoor" 1224. Similarly, within the concept "location" 1230 we have the concepts "city" 1232, "suburb" 1234, and "rural" 1236. The general level ontology 1200 can be thought of as general concepts 1210 that span space in //-dimensions, where N is the number of general concepts 1210 available in the particular general level ontology 1200. A domain specific ontology 1300 defines the details of general concepts and their properties in the domain. Different domains have different interpretations of the general level concepts in the general ontology 1200, such as a clinical domain ontology 1300a, an office domain ontology 1300b. For example, in an office domain, a "location" can be a MeetingRoom, a PrintingRoom, or a ConferenceRoom. In a clinical domain, a "location" can be a PatientRoom, an OperatingRoom 1304, or a RadiologyReadingRoom 1306, etc.

Within a specific domain, the domain-specific ontology defines a number of properties. Examples of such properties are minimum transmission power, maximum transmission power, minimum operating frequency, maximum operating frequency, minimum bandwidth, maximum bandwidth, supported modulation types, supported Physical (PHY) layer types, supported Medium Access Control (MAC) layer types or other higher layer telecommunication protocols.

One example of a property described in OWL is:

Ξ hasMinPower Policy:Power

FIG. 2 illustrates how a general ontology defines a virtual space 200 within a realm. Axes 210 are shown for various concepts of a general ontology within an administrative realm, including location 210a, space 210b, room 210c, activity 21Od, time 21Oe, security level 21Of, user 21Og, and weather 21Oh. An example of a point in this virtual space 200 is:

{Location= NY city, Space=indoor, Room=OperatingRoom, Activity=Surgery, Time=daytime, Security Level = normal; user = physician} .

Each point in the space has properties defining the corresponding policy for spectrum usage. FIG. 2 illustrates two points in virtual space 200, where each point has its own individual policies defined. In general, the virtual space 200 is divided by partitions which define partitioned spaces within each of which common policies are applied to the various defined properties. For example, FIG. 3 illustrates a mapping between a partitioned space 300 and associated spectrum policies 370. In FIG. 3, at the administrative realm level 1120 a partition is defined for NYU Hospital 302. Partitions are also defined for the values assigned to various concepts, for example location 304 (NY City), space 306 (Indoor), room 308 (Operating Room), and Activity 310 (Surgery). These partitions define the partitioned space 300 having a plurality of properties 350, including a maximum power property 350a, a minimum frequency property 350b, a maximum frequency property 350c, and a transmission format property 35Od. In turn, the partitioned space 300 is mapped to a set of policies 370 for the various defined properties 350, for example, Power 370a (Max = 1 mW), Frequency 370b (Allowed Frequencies = 1 GHz - 2 GHz), and transmission format 370c (Allowed Format = Carrier Sense Multiple Access). Of course additional and/or different concepts and policies can be employed as desired. Policies may be permissive as shown in FIG. 3, but in other cases policies may be prohibitive, or a combination thereof. The person/entity (e.g., an administrator) in charge of managing the partitions of the virtual space 200 and assigning spectrum policies can create mappings between the properties of partitioned spaces 300 and their associated policies, as shown in FIG. 3. Creative user interfaces using diagrams, architectural layouts, animations, can be used to simplify the mapping process. Advantageously, by means of the ontology-based methods described above, an administrator can easily and flexibly redefine partitions and change policies that apply to various partitioned spaces.

Meanwhile, now that the ontology is provided to define the partitions in an environment, devices are needed to commit to that ontology and adapt to its partitions and policies. When we say that a device "commits" to the ontology, we mean to say that it is adapted to adhere to the conceptualization specified by the ontology.

FIG. 4 is a high level block diagram of one embodiment of a wireless device 400 for operating in conjunction with defined partitions and policies as described above. As will be appreciated by those skilled in the art, the various "parts" shown in FIG. 4 may be physically implemented using a software-controlled microprocessor, hard-wired logic circuits, or a combination thereof. Also, while the parts are functionally segregated in FIG. 4 for explanation purposes, they may be combined in various ways in any physical implementation. In general, wireless device 400 includes an antenna 410, a receiver front-end section 420, a signal processing block 430, a processor 440, memory 450, a user interface 460, one or more input/output ports 470, and transmitter 480. Of course wireless device 400 may include many other elements, or omit one or more of the aforementioned elements, depending on its particular function(s), but the elements above are exemplary and illustrative.

Beneficially, processor 440 is configured to execute one or more software algorithms in conjunction with receiver front-end section 420, signal processing block 430, memory 450, user interface 460, input/output ports 470, and transmitter 480 to provide the functionality of wireless device 400. Beneficially, processor 440 includes its own memory (e.g., nonvolatile memory) for storing executable software code that allows it to perform the various functions of wireless device 400. Alternatively, the executable code may be stored in designated memory locations within memory 450. FIG. 5 is a flowchart illustrating one embodiment of a method 500 that may be executed by processor 440 to enable wireless device 400 to adapt its use of radio spectrum to the real-time conditions of its current operating environment.

In a first step 510, wireless device 400 determines a partitioned space 300 in which it is currently operating. This may be accomplished in a number of ways. A beacon transmitter may be employed near where wireless device 400 is located, broadcasting or otherwise transmitting a beacon signal or a solicited on unsolicited communication protocol frame including partition information to wireless device 400. As shown in FIG. 3, such partition information may include a realm (e.g., NYU Hospital), a location (e.g., NY City) a space (e.g., an operating room), an activity (e.g., surgery), and other parameters such as a security level (e.g., normal), a time (e.g., daytime), etc. In another case, partition information may be stored in memory in a peripheral device or "key device" (e.g., a USB dongle; a smartcard; etc.) that a user attaches to wireless device 400 according to its realm and/or location, etc. For example, a user may be required to attach a different key device to wireless device 400 for each different area in which the wireless device is moved. In that case, in a hospital setting, a first key device may be attached to wireless device 400 when it is located in a lobby or cafeteria, a second key device may be attached to wireless device 400 when it is located in a patient's room, a third key device may be attached to wireless device 400 when it is located in an operating room, etc.

In still another arrangement, wireless device 400 may obtain partition data to determine the partitioned space in which it operates by communication with its one or more peer wireless devices. Wireless device 400 may receive partition information through non- RF communications, such as ultrasound. Wireless device may receive partition information via a wired connection. In yet another embodiment, wireless device 400 may receive partition data in a signal transmitted in unregulated spectrum, which may be unconstrained by any policies for the partitioned space 300. In yet another embodiment, wireless device may determine partitions partly based on measurements of one or more positions of one or more celestial or astronomical bodies. Alternatively, wireless device 400 may include a global positioning system (GPS) receiver block 490 which advises wireless device 400 of its location. This locational information may be used in conjunction with other information that may be stored in memory 450 of wireless device 400, stored in a key device, received from a beacon, etc. to determine the partitioned space 300 in which wireless device 400 currently finds itself. In a step 520, wireless device 400 identifies and applies spectrum usage policies 350 that apply to its current partitioned space 300. A mapping between a partitioned space and corresponding spectrum usage policies may be stored in memory 440 of wireless device 400, may be stored in a "keycard" that is attached by a user to wireless device 400, may be communicated to device 400 by a beacon signal, or a solicited or unsolicited protocol frame, etc. Beneficially, the policies 350 may include a policy for permitted power levels, a policy for allowable operating frequencies, a policy for permitted transmission formats; etc.

In a step 530, wireless device 400 identifies its operating capabilities and the spectrum needs for a given application that is executed by wireless device 400. Such operating capabilities may include the minimum and maximum operating frequencies, a maximum transmission power, a minimum transmission power necessary for normal operation; a required transmission bandwidth; various parameters (e.g., bandwidths, modulation formats, data rates, power spectral density levels; etc.) associated with one or more transmission standards with which wireless device 400 may operate; etc. For example, wireless 400 may successfully operate with a power level of 1 mW if it can use a bandwidth of 1 GHz to spread its signal, but that it might require 10 mW if it is limited to only 100 MHz of available bandwidth. Countless other possibilities exist. The set of operating capabilities and needs for wireless device 400 may be stored within memory 450. Finally, in a step 540, wireless device 400 compares the capabilities and needs of device 400 against the prevailing spectrum usage policies 370 of its current partitioned space 300 to identify any existing spectrum opportunities for device 400 to operate. If there are no such opportunities, then device 400 is not permitted to transmit within its current partitioned space 300. Beneficially, wireless device 400 continuously repeats step 510 to identify any change in its partitioned space 300 so that it conforms its operation to the prevalent policies 370 as it moves from partitioned space 300 to partitioned space 300. Whenever it is determined that wireless 400 has transitioned to a new partitioned space 300, then steps 520-540 are also repeated. For example, when a security level is changed (e.g., lowered), wireless device 400 transitions to a new partitioned space 300. Thus, whereas wireless device 400 may have had no spectrum opportunities in one partitioned space 300, when a security level is reduced, wireless device 400 may find that it is now in a different partitioned space 300 with different policies 370, and that it now has some available spectrum opportunities in this new partitioned space 300. Wireless device 400 may move from one partitioned space 300 to another due to changes in any of the values of any of the concepts that define the virtual space 200, e.g., a new user, a change in location; a different time of day; moving to a different room, a change in activity (e.g., a surgery is now ended), etc.

FIG. 6 illustrates a range of spectrum opportunities identified by the method of FIG. 5. In a first case 610, the opportunities are defined by the intersection of the set of capabilities/needs 625 and the permitted policies 650. In a second case 660, the opportunities are defined by the portion of the set of the capabilities/needs 625 that is not intersected by the forbidden policies 675.

While preferred embodiments are disclosed herein, many variations are possible which remain within the concept and scope of the invention. Such variations would become clear to one of ordinary skill in the art after inspection of the specification, drawings and claims herein. The invention therefore is not to be restricted except within the spirit and scope of the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A method of establishing frequency spectrum usage policies for wireless devices (400), comprising: defining a realm (1100) for governing the spectrum usage policies of the wireless devices (400); providing a general ontology (1200) defining a virtual space (200) for spectrum usage by the wireless devices (400); establishing partitions within the defined virtual space (200); and assigning spectrum usage policies (370) for wireless devices (4000 operating within partitioned spaces (300) defined by the partitions of the virtual space (200).

2. The method of claim 1, wherein providing the general ontology (1200) includes providing a set of concepts (1210) that span the virtual space (210).

3. The method of claim 2, wherein the concepts (1210) include location (210a), activity (21Od), security condition (21Of), weather (21Oh), user (21Og), time (21Oe), and space (210b).

4. The method of claim 1, wherein establishing partitions (300) within the defined virtual space (200) includes providing a domain specific ontology (1300) defining a plurality of properties (350).

5. The method of claim 4, wherein the spectrum usage policies (370) apply to the properties (350) defined by the domain specific ontology (1300).

6. The method of claim 4, wherein the properties (350) include a transmission power level (350a) and an operating frequency (350b, 350c).

7. The method of claim 6, wherein the policies (370) include one or more of: (A) a range of forbidden transmission power levels (675) and a range of forbidden operating frequencies (675); and (B) a range of permitted transmission power levels (650) and a range of permitted operating frequencies (650).

8. A method (500) of operating a wireless device (400), comprising:

(a) determining (510) a partitioned space (300) within a virtual space (200) defined by a general ontology (1000) in which the wireless device (400) exists;

(b) selecting (520) one or more spectrum usage policies (370) for the wireless device (400) that is/are associated with the partitioned space (300) in which it exists;

(c) determining (530) a set of operating capabilities and needs (625) of the wireless device (400); and

(d) comparing (540) the set of operating capabilities and needs (625) of the wireless device (400) against the selected spectrum usage policies (370) to identify any existing spectrum opportunities for the wireless device (400) to operate.

9. The method of claim 8, wherein determining (510) the partitioned space (300) in which the wireless device (400) exists comprises the wireless device (400) receiving a beacon signal containing partitioning data, or a solicited or unsolicited communication protocol frame.

10. The method of claim 8, wherein determining (510) the partitioned space (300) in which the wireless device (400) exists comprises attaching an external peripheral device to the wireless device (400), the external peripheral device including memory for storing partitioning data.

11. The method of claim 8, wherein determining (510) the partitioned space (300) in which the wireless device (400) exists comprises at least one of: (1) receiving a global positioning system (GPS) locational signal; (2) communication with one or more peer devices; (3) receiving a signal via a wired connection; (4) receiving a signal through unregulated spectrum; (5) receiving a signal through non-RF communications; and (6) measurements of one or more positions of one or more celestial or astronomical bodies.

12. The method of claim 8, wherein the spectrum usage policies (370) include one or more of: (A) a range of forbidden transmission power levels (675) and a range of forbidden operating frequencies (675); and (B) a range of permitted transmission power levels (650) and a range of permitted operating frequencies (650).

13. The method of claim 8, wherein determining (530) a set of operating capabilities and needs (625) of the wireless device (400) includes retrieving the set of operating capabilities and needs of the wireless device from memory (450) in the wireless device (400).

14. The method of claim 8, further comprising preventing transmission by the wireless device (400) when the set of operating capabilities and needs (625) of the wireless device (400) are inconsistent with the selected spectrum usage policies (370) such that no spectrum opportunities exist.

15. The method of claim 8, further comprising repeating step (a) until a new partitioned space (300) in determined, and then repeating steps (b) through (d).

16. A wireless device (400), comprising: a receiver front-end section (420); a signal processing block (430); memory (450); and a processor (440) configured to execute a method (500) comprising the steps:

17. The wireless device (400) of claim 16, further comprising an input/output port (480) for receiving partitioning information for the wireless device (400).

18. The wireless device (400) of claim 16, wherein the processor (440) is further configured to disable wireless transmission when the set of operating capabilities and needs (625) of the wireless device (400) are inconsistent with the selected spectrum usage policies (370) such that no spectrum opportunities exist.

19. The wireless device (400) of claim 16, further comprising a global positioning system, (GPS) receiver (470) adapted to provide location information to wireless device (400).

20. The wireless device (400) of claim 16, wherein the spectrum usage policies (370) are stored in the memory (450).