Scheduler

• US 7,751,423 B2
• Filed: 09/09/2005
• Issued: 07/06/2010
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Hottinen, Ari, Heikkinen, Tiina, Yao, Alex, Karageorgos, Themistoclis
• Primary Examiner(s): Mattis, Jason E
• Assistant Examiner(s): Chery, Dady
• Application Number:
  US11/221,786
• Publication Number:
  US 20060056340A1
• Time in Patent Office: 1,761 Days
• Field of Search: 370/330, 370/332, 370335-338, 370/342, 370/347, 370/436, 370/437, 370/478
• US Class Current: 370/437
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/56 implementing delay-aware scheduling
• CPC Class Codes: H04L 47/626 channel conditions
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A scheduler in a communication network comprising a communication channel which is shared by a plurality of user nodes, the communication channel having a succession of slots. The scheduler has a quality unit for receiving an indication of the quality of the communication channel for each user node. A delay unit for receiving a predetermined delay factor for each of at least some of the user nodes, the delay factor representing a level of tolerance to a time delay. A selection unit connected to the quality and delay units and being arranged to determine, for each slot, which of the user nodes is to use that slot based on the channel quality indication and the delay factors.

Claims

1. An apparatus, comprising:

a quality unit configured to receive an indication of the quality of a communication channel for each user node of a plurality of user nodes;

a delay unit configured to receive a predetermined delay factor for each of at least some of the user nodes, the delay factor representing a level of tolerance to a time delay; and

a selector configured to be operably connected to the quality and delay units and being configured to determine, for each slot of a succession of slots of the communication channel, which of the user nodes is to use that slot based on the channel quality indication and the delay factors,

wherein the indication of the channel quality is a data transmission rate, and

wherein proportion fair scheduling is performed by selecting, for each slot, which user node has the highest ratio of an instantaneous data transmission rate to an average data transmission rate.

2. The apparatus of claim 1, wherein the delay factors vary for successive slots.

3. The apparatus of claim 2, wherein if a user node having a predetermined delay factor is not selected for a slot, its delay factor is modified to indicate for the next slot that the user node is even less tolerant to a time delay.

4. The apparatus of claim 1, wherein the ratio is modified by applying a delay factor to each of the transmission rates.

5. The apparatus of claim 1, wherein the delay factors and the indications of the quality of the communication channel are received from the user nodes.

6. The apparatus of claim 1, further comprising a policy unit configured to store the predetermined delay factors.

7. The apparatus of claim 1, wherein the slot is a time slot.

8. The apparatus of claim 1, wherein the apparatus is in a communication network, the communication network comprising another communication channel which is distinguished from the communication channel using at least one of code division multiple access, frequency division multiple access, orthogonal frequency division multiplexing, orthogonal frequency division multiple access, space divisional multiple access, multiple input multiple output or a combination thereof.

9. The apparatus of claim 1, wherein the apparatus is in a wireless communication network.

10. The apparatus of claim 1, wherein the apparatus is in an ad hoc network, and wherein a scheduler is located within each user node of the ad hoc network for performing decentralized scheduling.

11. A method, comprising:

receiving a first set of quality values each representing a quality of communication channel for each of the user nodes of a plurality of user nodes;

receiving a second set of predetermined delay factors each representing a tolerance to a time delay of at least some of the user nodes;

selectively determining which of the user nodes is to be granted access to a slot of the communication channel based on a combination of the quality values and the delay factors,

where an indication of the channel quality is a data transmission rate, and

wherein proportional fair scheduling is performed by selecting, for each slot, which user node has the highest ratio of an instantaneous data transmission rate to an average data transmission rate.

12. The method of claim 11, wherein the delay factors vary for successive slots.

13. The method of claim 12, further comprising, modifying a delay factor of a user node to indicate for the next slot that the user node is even less tolerant to a time delay, if the user node having a predetermined delay factor is not selected for a slot.

14. The method of claim 11, further comprising modifying the ratio by applying a delay factor to each of the transmission rates.

15. The method of claim 11, wherein the receiving the first set of quality values further comprises receiving the first set of quality values from the user nodes, and wherein the receiving a second set of predetermined delay factors further comprises receiving the second set of predetermined delay factors from the user nodes.

16. The method of claim 11, further comprising storing the predetermined delay factors.

17. The method of claim 11, wherein the slot is a time slot.

18. The method of claim 11, further comprising:

distinguishing another communication channel from the communication channel using at least one of code division multiple access, frequency division multiple access, orthogonal frequency division multiplexing, orthogonal frequency division multiple access, space divisional multiple access, multiple input multiple output or a combination thereof.

19. The method of claim 11 wherein the method is implemented in a wireless communication network.

20. The method of claim 11, wherein a scheduler is located within each user node of an ad hoc network for performing decentralised scheduling.

21. An apparatus, comprising:

quality means for receiving an indication of the quality of a communication channel for each user node of a plurality of user nodes;

delay means for receiving a predetermined delay factor for each of at least some of the user nodes, the delay factor representing a level of tolerance to a time delay; and

selection means for determining, for each slot of a succession of slots of the communication channel, which of the user nodes is to use that slot based on the channel quality indication and the delay factors,

wherein an indication of the channel is a data transmission rate, and

where proportional fair scheduling is performed by selecting, for each slot, which user node has the highest ratio of an instantaneous data transmission rate to an average data transmission rate.