Method and Apparatus for Contention-Based Granting in a Wireless Communication Network

• US 20110176500A1
• Filed: 01/14/2011
• Published: 07/21/2011
• Est. Priority Date: 01/15/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Enbuske, Henrik, Furuskär, Anders, Wager, Stefan, Meyer, Michael, Larmo, Anna, Lindström, Magnus
• Granted Patent: US 8,767,644 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

In one aspect of the disclosed teachings, associating a plurality of contention-based uplink grants with a range of uplink resource blocks allows one contention-based uplink grant message to signal the entire plurality of grants. As an example in the LTE context, the signaling load on the PDCCH is reduced by using a single contention-based uplink grant message to signal a plurality of contention-based uplink grants. The message indicates an allocated set of uplink resource blocks and the number of separate uplink resource grants represented by the set is known or signaled, such that user terminals recognize that separate subsets of uplink resource blocks within the set each correspond to a separate contention-based uplink grant. Information included in the contention-based uplink grant message, or otherwise signaled can be used to control the probability at which the user terminals attempt contention-based uplink transmissions and/or to control the MCS used for such transmissions.

Claims

1. A method in a wireless communication network node for signaling contention-based uplink grants to user equipments, said method comprising:

allocating a range of uplink resource blocks for use in making a plurality of contention-based uplink grants within a given scheduling interval, wherein the range of uplink resource blocks comprises different subsets of uplink resource blocks and wherein each contention-based uplink grant in the plurality of contention-based uplink grants maps to a subset of uplink resource blocks out of the different subsets within the allocated range of uplink resource blocks; and

transmitting a single contention-based uplink grant message that indicates the allocated range of uplink resource blocks.

2. The method of claim 1, further comprising processing uplink transmissions received on the different subsets of the allocated range of uplink resource blocks as separate user equipment transmissions, each of said uplink transmissions being responsive to and corresponding to a different one of the plurality of contention-based uplink grants mapped to the allocated range of uplink resource blocks.

3. The method of claim 1, wherein said step of allocating comprises allocating two or more different ranges of uplink resource blocks for use in making two or more different pluralities of contention-based uplink grants within the given scheduling interval, each said two or more different ranges of uplink resource blocks comprising different subsets of uplink resource blocks, and wherein the step of transmitting comprises transmitting a respective single contention-based uplink grant message for each plurality of contention-based uplink grants out of the two or more different pluralities of contention-based uplink grants.

4. The method of claim 3, wherein a size of the two or more different allocated ranges of uplink resource blocks, or a size of the different subsets of uplink resource blocks within each of the allocated two or more different ranges of uplink resource blocks, or both, differ between at least two of the two or more different pluralities of contention-based uplink grants.

5. The method of claim 1, wherein the wireless communication network node comprises an eNodeB configured for operation in a Long Term Evolution, LTE, network, and wherein said step of transmitting the single contention-based uplink grant message comprises transmitting the contention-based uplink grant message on an LTE Physical Downlink Control Channel, “

PDCCH”

, using Downlink Control Information, “

DCI”

, Format 0.

6. The method of claim 5, further comprising manipulating the Modulation and Coding Scheme, “

MCS”

, field that is defined for DCI Format 0 messages, to indicate different uplink transmission coding and multiplexing parameters for two or more of the contention-based uplink grants.

7. The method of claim 5, further comprising including signaling within the single contention-based uplink grant message that indicates one or more access probabilities to be used by the user equipments in determining whether or not to perform a contention-based uplink transmission corresponding to one of the plurality of contention-based uplink grants.

8. The method of claim 1, further comprising including in said single contention-based uplink grant message information indicating the number of contention-based uplink grants represented by the allocated range of uplink resource blocks.

9. The method of claim 1, further comprising, prior to said step of transmitting the single contention-based uplink grant message, transmitting information indicating the number of contention-based uplink grants represented by the allocated range of uplink resource blocks.

10. The method of claim 9, wherein said step of transmitting the information indicating the number of contention-based uplink grants comprises including the information indicating the number of contention-based uplink grants in system broadcast information, or in connection setup information that is signaled to each user terminal during Radio Resource Control, “

RRC”

, setup.

11. The method of claim 1, further comprising storing default size information for the contention-based uplink grants, which default size information commonly defines the size of the different subsets in terms of the number of uplink resource blocks to be included in each subset.

12. The method of claim 1, further comprising determining an overall number of uplink resource blocks to be included in said allocated range of uplink resource blocks based on:

identifying a contiguous range of uplink resource blocks available for the given scheduling interval; and

determining a number of whole, non-overlapping subsets of uplink resource blocks that can be formed within the identified contiguous range of available uplink resource blocks, and setting the overall number of allocated uplink resource blocks to be included in said range of uplink resource blocks so that it includes the number of whole, non-overlapping subsets of uplink resource blocks.

13. A wireless communication network node configured to signal contention-based uplink grants to user equipments, said wireless communication network node comprising:

a transceiver configured to transmit downlink signals to said user equipments and receive uplink signals from said user equipments; and

a scheduling processor operatively associated with the transceiver and configured to;

allocate a range of uplink resource blocks for use in making a plurality of contention-based uplink grants within a given scheduling interval, wherein the range of uplink resource blocks comprises different subsets of uplink resource blocks and wherein each contention-based uplink grant in the plurality of contention-based uplink grants maps to a subset of uplink resource blocks out of the different subsets within the allocated range of uplink resource blocks; and

transmit, via said transceiver, a single contention-based uplink grant message that indicates the allocated range of uplink resource blocks.

14. The wireless communication network node of claim 13, wherein said wireless communication network node further comprises one or more receiver processing circuits that are configured to process uplink transmissions received on the different subsets of the allocated range of uplink resource blocks as separate user equipment transmissions, each of said uplink transmissions being responsive to and corresponding to a different one of the plurality of contention-based uplink grants mapped to the allocated range of uplink resource blocks.

15. The wireless communication network node of claim 13, wherein said scheduling processor is configured to allocate two or more different ranges of uplink resource blocks for use in making two or more different pluralities of contention-based uplink grants within the given scheduling interval, each said two or more different ranges of uplink resource blocks comprising different subsets of uplink resource blocks, and to transmit, via said transceiver, a respective single contention-based uplink grant message for each plurality of contention-based uplink grants out of the two or more different pluralities of contention-based uplink grants.

16. The wireless communication network node of claim 15, wherein a size of the two or more different allocated ranges of uplink resource blocks, or a size of the different subsets of uplink resource blocks within each of the allocated two or more different ranges of uplink resource blocks, or both, differ between at least two of the two or more different pluralities of contention-based uplink grants.

17. The wireless communication network node of claim 13, wherein the wireless communication network node is an eNodeB configured for operation in a Long Term Evolution, “

LTE”

, network, and wherein the wireless communication network node is configured to transmit the single contention-based uplink grant message on an LTE Physical Downlink Control Channel, “

PDCCH”

, using Downlink Control Information, “

DCI”

, Format 0.

18. The wireless communication network node of claim 17, wherein the wireless communication network node is configured to manipulate the Modulation and Coding Scheme, “

MCS”

, field that is defined for DCI Format 0 messages, to indicate different uplink transmission coding and multiplexing parameters for two or more of the contention-based uplink grants.

19. The wireless communication network node of claim 17, wherein the wireless communication network node is configured to include signaling within the single contention-based uplink grant message that indicates one or more access probabilities to be used by the user equipments in determining whether or not to perform a contention-based uplink transmission corresponding to one of the plurality of contention-based uplink grants.

20. The wireless communication network node of claim 13, wherein the wireless communication network node is configured to include in said single contention-based uplink grant message information indicating the number of contention-based uplink grants represented by the allocated range of uplink resource blocks.

21. The wireless communication network node of claim 13, wherein the wireless communication network node is configured to transmit information indicating the number of contention-based uplink grants represented by the allocated range of uplink resource blocks prior to transmitting the single contention-based uplink grant message.

22. The wireless communication network node of claim 21, wherein the wireless communication network node is configured to transmit the information indicating the number of contention-based uplink grants via signaling included in system broadcast information, or via signaling included in connection setup information that is signaled to each user terminal during Radio Resource Control, “

RRC”

, setup.

23. The wireless communication network node of claim 13, wherein the wireless communication network node is configured to use default size information for defining the size of the different subsets in terms of the number of uplink resource blocks to be included in each subset.

24. The wireless communication network node of claim 13, wherein the scheduling processor is configured to determine an overall number of uplink resource blocks to be included in said allocated range of uplink resource blocks based on being configured to:

identify a contiguous range of uplink resource blocks available for the given scheduling interval; and

determine a number of whole, non-overlapping subsets of uplink resource blocks that can be formed within the identified contiguous range of available uplink resource blocks, and set the overall number of allocated uplink resource blocks to be included in said range of uplink resource blocks so that it includes the number of whole, non-overlapping subsets of uplink resource blocks.

25. A method in a user equipment for making contention-based uplink transmissions in a wireless communication network, said method comprising:

receiving a single contention-based uplink grant message that indicates a range of uplink resource blocks allocated to a plurality of contention-based uplink grants within a given scheduling interval, wherein the range of uplink resource blocks comprises different subsets of uplink resource blocks and wherein each contention-based uplink grant in the plurality of contention-based uplink grants maps to a subset of uplink resource blocks out of the different subsets within the allocated range of uplink resource blocks; and

selectively sending a contention-based uplink transmission on a particular subset of uplink resource blocks corresponding to one of the plurality of contention-based uplink grants.

26. The method of claim 25, wherein the user equipment is configured for operation in a Long Term Evolution, “

LTE”

, network.

27. The method of claim 25, wherein said step of selectively sending the contention-based uplink transmission comprises making a probabilistic decision on whether or not to transmit, whereby the user equipment does or does not transmit according to a defined probability.

28. The method of claim 27, wherein the contention-based uplink grant message includes an access probability control value, and said user equipment makes said probabilistic decision on whether or not to transmit by generating a random value and comparing it to the access probability control value and deciding whether or not to transmit in dependence on said comparison.

29. The method of claim 25, wherein the single contention-based uplink grant message includes parameter information indicating different coding and multiplexing parameters that are to be used for different contention-based uplink grants in the plurality of contention-based uplink grants, and wherein the step of selectively sending the contention-based uplink transmission comprises setting the uplink transmission coding and multiplexing parameters used for the contention-based uplink transmission in accordance with the parameter information.

30. The method of claim 25, further comprising determining the number of contention-based uplink grants that are represented by the indicated range of uplink resource blocks based on at least one of

receiving or otherwise storing information identifying the number of different subsets included in the indicated range of uplink resource blocks;

receiving or otherwise storing information identifying the number of uplink resource blocks that defines each subset of uplink resource blocks and calculating the number of different subsets that are included within the indicated range of uplink resource blocks;

or

receiving or otherwise storing information identifying both the size of each grant within the allocated range and the number of grants within the allocated range.

31. A user equipment configured to make contention-based uplink transmissions in a wireless communication network, said user equipment comprising:

a transceiver configured to transmit uplink signals to the wireless communication network and to receive downlink signals from the wireless communication network;

a receive circuit operatively associated with said transceiver and configured to receive a single contention-based uplink grant message that indicates a range of uplink resource blocks allocated to a plurality of contention-based uplink grants within a given scheduling interval, wherein the range of uplink resource blocks comprises different subsets of uplink resource blocks and wherein each contention-based uplink grant in the plurality of contention-based uplink grants maps to a subset of uplink resource blocks out of the different subsets within the allocated range of uplink resource blocks; and

a transmit circuit operatively associated with said transceiver and configured to selectively send a contention-based uplink transmission on a particular subset of uplink resource blocks corresponding to one of the plurality of contention-based uplink grants.

32. The user equipment of claim 31, wherein the user equipment is configured for operation in a Long Term Evolution, “

LTE”

, network.

33. The user equipment of claim 31, wherein said user equipment is configured to selectively send the contention-based uplink transmission based on being configured to make a probabilistic decision on whether or not to transmit, whereby the user equipment does or does not transmit according to a defined probability.

34. The user equipment of claim 33, wherein the contention-based uplink grant message includes an access probability control value, and wherein said user equipment is configured to make said probabilistic decision on whether or not to transmit based on generating a random value and comparing it to the access probability control value and deciding whether or not to transmit in dependence on said comparison.

35. The user equipment of claim 31, wherein the single contention-based uplink grant message includes parameter information indicating different coding and multiplexing parameters that are to be used for different contention-based uplink grants in the plurality of contention-based uplink grants, and wherein said user equipment is configured to set the uplink transmission coding and multiplexing parameters used for selectively sending the contention-based uplink transmission in accordance with the parameter information.

36. The user equipment of claim 31, wherein the user equipment is configured to determine the number of contention-based uplink grants that are represented by the indicated range of uplink resource blocks based on knowing or receiving information identifying the number of different subsets included in the indicated range of uplink resource blocks, or based on knowing or receiving information identifying the number of uplink resource blocks that defines each subset of uplink resource blocks and calculating the number of different subsets that are included within the indicated range of uplink resource blocks.