Spectrum assignment for networks over white spaces and other portions of the spectrum

• US 8,811,903 B2
• Filed: 05/28/2009
• Issued: 08/19/2014
• Est. Priority Date: 05/28/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Chandra, Ranveer, Moscibroda, Thomas, Murty, Rohan N., Bahl, Paramvir
• Primary Examiner(s): LIAO, HSINCHUN
• Application Number:
  US12/473,963
• Publication Number:
  US 20100304678A1
• Time in Patent Office: 1,909 Days
• Field of Search: 455/62, 455/68, 455/450
• US Class Current: 455/62
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/54 based on quality criteria

Abstract

Functionality is described by selecting a channel in an environment in which non-privileged entities have subordinate access rights to spectrum compared to privileged entities. The functionality operates by identifying spectrum that is available to all nodes involved in communication (where the nodes are associated with non-privileged entities). The functionality then generates a suitability assessment for each candidate channel within the available spectrum. The functionality selects a channel having the most desirable suitability assessment. The functionality can form a suitability assessment for a candidate channel of arbitrary width, e.g., by combining suitability assessments associated with constituent spectrum units within the candidate channel.

Claims

1. A method comprising:

generating local availability information that indicates first spectrum units within a spectrum that are available to a first node;

receiving other-node availability information that indicates second spectrum units within the spectrum that are available to a second node with which the first node seeks to communicate;

identifying, based on the local availability information and the other-node availability information, available spectrum units from the first spectrum units and the second spectrum units that can be used to communicate between the first node and the second node; and

selecting a channel using one or more of the available spectrum units for handling communication between the first node and the second node, wherein the channel is selected based on expected shares of the one or more available spectrum units for at least the first node or the second node, the expected shares being determined by taking maximums of residual airtimes and fair shares of airtimes for the one or more of the available spectrum units,

wherein the spectrum is used by privileged entities and the first node is a non-privileged entity having subordinate rights to the spectrum compared to the privileged entities, and

wherein at least the selecting is performed by a communication device.

2. The method of claim 1, wherein the spectrum comprises at least a portion of the TV spectrum, and the first spectrum units and the second spectrum units are in existing TV broadcast channels within the TV spectrum.

3. The method of claim 1, wherein said identifying is performed by taking a logical intersection of the local availability information and the other-node availability information.

4. The method of claim 1, wherein said other-node availability information indicates additional spectrum units that are available to additional nodes with which the first node seeks to communicate, and said identifying comprises identifying the available spectrum units from the first spectrum units, the second spectrum units, and the additional spectrum units.

5. The method of claim 1, wherein said selecting further comprises:

identifying suitability assessments for a plurality of candidate channels within the available spectrum; and

selecting the channel from the plurality of channels based on the suitability assessments.

6. The method of claim 5, wherein the suitability assessments reflect suitability from a perspective of the first node.

7. The method of claim 5, wherein the suitability assessments reflect suitability from a perspective of both the first node and the second node.

8. The method of claim 5, wherein the suitability assessments are based on current airtime utilization of the plurality of candidate channels.

9. The method of claim 5, wherein at least one candidate channel is composed of plural spectrum units, and wherein a suitability assessment for said at least one candidate channel is based on suitability assessments for the plural spectrum units.

10. The method of claim 1, wherein the method is initiated upon loss of a previous channel due to acquisition of the previous channel by an individual privileged entity.

11. The method of claim 1, wherein the method is initiated upon detection of a deterioration of a previous channel.

12. The method of claim 1, wherein the first node is an access point device, and the second node is a communication device that uses the access point device to access a network.

20. The method of claim 1, further comprising:

computing airtime utilizations for each of the one or more of the available spectrum units.

21. The method of claim 20, further comprising:

computing residual airtimes for each of the one or more of the available spectrum units using the airtime utilizations.

22. The method of claim 21, wherein the computing the residual airtimes comprises subtracting the airtime utilizations from 1.

23. The method of claim 22, further comprising computing the expected shares of the one or more of the available spectrum units for at least the first node or the second node.

24. The method according to claim 1, further comprising computing the fair shares based on a number of competing entities that are contending for the one or more of the available spectrum units.

25. The method according to claim 1, wherein the local availability information identifies portions of the spectrum that are not occupied by individual privileged entities from the perspective of the first node.

26. The method according to claim 25, wherein the other-node availability information identifies portions of the spectrum that are not occupied by the individual privileged entities or other privileged entities from the perspective of the second node.

27. The method according to claim 1, wherein the communication device is the first node.

28. The method according to claim 27, wherein the channel is selected based on the expected shares for the first node and not the second node.

29. The method according to claim 27, wherein the channel is selected based on the expected shares for the first node and the second node.

13. One or more computer readable storage devices storing computer readable instructions, the computer readable instructions providing a channel assignment module when executed by one or more processing devices, the computer readable instructions comprising:

logic configured to identify a channel suitability assessment for a candidate channel, the channel suitability assessment identifying suitability of the candidate channel for conducting communication,

the candidate channel being composed of plural spectrum units, the channel suitability assessment for the candidate channel being based on plural spectrum unit suitability assessments reflecting airtime utilization of the plural spectrum units and competing entities that are contending for use of the plural spectrum units,

wherein the logic is further configured to;

combine the plural spectrum unit suitability assessments to determine an expected share of the candidate channel, and

scale the expected share of the candidate channel by a channel capacity of the candidate channel to obtain the channel suitability assessment for the candidate channel.

14. The one or more computer readable storage devices of claim 13, wherein the expected share of the candidate channel is based on a product of the plural spectrum unit suitability assessments.

15. The one or more computer readable storage devices of claim 13, wherein an individual spectrum unit suitability assessment of an individual spectrum unit is based on a number of the competing entities that are contending for use of the individual spectrum unit.

16. The one or more computer readable storage devices of claim 13, wherein individual spectrum unit suitability assessments for individual spectrum units are given by:

17. The one or more computer readable storage devices of claim 16, wherein the channel suitability assessment for the candidate channel is given by:

30. The one or more computer readable storage devices of claim 13, wherein the channel capacity corresponds to a width of the candidate channel.

18. A system comprising:

a channel assignment module comprising;

logic configured to access local availability information that indicates first spectrum units that are available to a first node, the first spectrum units being within a spectrum that comprises a plurality of channels;

logic configured to access other-node availability information that indicates second spectrum units that are available to a second node with which the first node seeks to communicate, the second spectrum units also being within the spectrum;

logic configured to identify, based on the local availability information and the other-node availability information, available spectrum units from the first spectrum units and the second spectrum units that can be used to communicate between the first node and the second node;

logic configured to identify suitability assessments for the plurality of channels of the spectrum, the suitability assessments reflecting expected shares of the available spectrum units for at least the first node or the second node, wherein;

the expected shares are determined in some instances using residual airtimes for the available spectrum units, and

the expected shares are determined in other instances using fair shares of airtimes for the available spectrum units; and

logic configured to select an individual channel from the plurality of channels based on the suitability assessments; and

one or more processing devices configured to execute the channel assignment module.

19. The system of claim 18, wherein at least one of the plurality of channels comprises plural spectrum units.

31. An access point device comprising:

at least one processing device; and

at least one memory device or media device storing instructions which, when executed by the at least one processing device, cause the at least one processing device to;

obtain local availability information that indicates first spectrum units within a spectrum that are available to the access point device;

obtain other availability information that indicates second spectrum units within the spectrum that are available to a node device other than the access point device;

identify, based on the local availability information and the other availability information, available spectrum units from the first spectrum units and the second spectrum units that can be used to communicate between the access point device and the node device;

determine expected shares of the available spectrum units by taking maximums of;

residual airtimes for the available spectrum units, and

fair shares of airtimes for the available spectrum units; and

based on the expected shares of the available spectrum units, select a channel that uses one or more of the available spectrum units for handling communication between the access point device and the node device,

wherein the spectrum is used by one or more privileged entities and the access point is a non-privileged entity having subordinate rights to the spectrum compared to the one or more privileged entities.