Scheduler

• US 20060056340A1
• Filed: 09/09/2005
• Published: 03/16/2006
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Hottinen, Ari, Karageorgos, Themistoclis, Heikkinen, Tiina, Yao, Alex
• Granted Patent: US 7,751,423 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• 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. 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 comprising:

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; and

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.

2. The scheduler of claim 1, wherein the delays factors vary for successive slots.

3. The scheduler 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 scheduler of claim 1, wherein the indication of the channel quality is a data transmission rate.

5. The scheduler of claim 4, 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.

6. The scheduler of claim 5, wherein the ratio is modified by applying a delay factor to each of the transmission rates.

7. The scheduler of claim 1, wherein the delay factors and the indications of channel quality are received from the user nodes.

8. The scheduler of claim 1, further comprising a policy unit for storing the predetermined delay factors.

9. The scheduler of claim 1, wherein the slot is a time slot.

10. The scheduler of claim 1, wherein the communication network comprising another communication channel which is distinguished from the communication channel using at least one of CDMA, FDMA, OFDM, OFDMA, SDMA, MIMO or a combination thereof.

11. The scheduler of claim 1, wherein the communication network is wireless communication network.

12. The scheduler of claim 1, wherein the communication network is an ad hoc network, wherein a scheduler is located within each user node of the network for performing decentralised scheduling.

13. A method for scheduling access to a slot of a communication channel which is shared by a plurality of user nodes, the method comprising:

receiving a first set of quality values each representing a quality of the communication channel for each of the 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 the slot based on a combination of the quality values and the delay factors.