Virtually centralized uplink scheduling

• US 20060182022A1
• Filed: 10/01/2004
• Published: 08/17/2006
• Est. Priority Date: 10/03/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Abedi, Saied
• Granted Patent: US 7,660,280 B2
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management

Abstract

A method of scheduling uplink transmissions from a plurality of source user equipments to a base station is disclosed. The method comprises the steps of determining the amount of data in the data buffer of each of the user equipments, comparing the amount of data in the data buffers of the user equipments to obtain, for each user equipment, a relative indicator, the relative indicator indicating how full that user equipment'"'"'s data buffer is in comparison to the data buffers of the other user equipments, and scheduling uplink transmissions in dependence on the relative indicators. In this way, each user equipment is given some knowledge of the state of the buffer in the other user equipments. The user equipments are therefore able to make more efficient scheduling decisions. This can improve the throughput and give lower packet delivery delays.

Claims

1. A method of scheduling uplink transmissions from a plurality of source user equipments to a base station, the method comprising:

determining the amount of data in the data buffer of each of the user equipments;

comparing the amount of data in the data buffers of the user equipments to obtain, for each user equipment, a relative indicator, the relative indicator indicating how full that user equipment'"'"'s data buffer is in comparison to the data buffers of the other user equipments; and

scheduling uplink transmissions in dependence on the relative indicators.

2. The method according to claim 1, wherein a plurality of relative indicators are determined for each user equipment.

3. The method according to claim 1, wherein the or at least one of the relative indicators is an indication of how full a user equipment'"'"'s buffer is in comparison to the average.

4. The method according to claim 1, wherein the or at least one of the relative indicators is an indication of how full a user equipment'"'"'s buffer is in comparison to the minimum.

5. The method according to claim 1, wherein the comparing is carried out by the base station.

6. The method according to claim 5, further comprising transmitting the or each relative indicator for each user equipment from the base station to that user equipment.

7. The method according to claim 1, wherein a user equipment determines an amount of data in its data buffer and transmits an indication of the amount of data to the base station.

8. The method according to claim 1, wherein a user equipment sends to the base station an indication of the total amount of data to be sent, and the base station determines the amount of data in the user equipment'"'"'s data buffer based on the indication of the total amount of data, and the amount of data already received by the base station from that user equipment.

9. The method according to claim 1, wherein each user equipment determines a rate and/or time at which it transmits data to the base station based on the or each relative indicator for that user equipment.

10. The method according to claim 9, wherein a user equipment which receives an relative indicator indicating that it has a relatively full buffer transmits data to the base station at a higher rate than would otherwise be the case.

11. The method according to claim 9, wherein a user equipment which receives a relative indicator indicating that it has a relatively empty buffer transmits data to the base station at a lower rate than would otherwise be the case.

12. The method according to claim 9, wherein the user equipment determines the time and/or rate at which it transmits data based additionally on a measurement of radio channel conditions.

13. The method according to claim 9, wherein the user equipment determines the time and/or rate of packet transmission based additionally on the actual amount of data in its data buffer.

14. The method according to claim 9, wherein the user equipment determines the time and/or rate of packet transmission based additionally on the type of service.

15. The method according to claim 1, wherein a user equipment which receives a relative indicator indicating that it has more data to transmit than other user equipments transmits data to the base station even if the amount of data in its data buffer is below a minimum buffer threshold.

16. The method according to claim 1, wherein uplink transmissions are scheduled using rate scheduling.

17. The method according to claim 1, wherein uplink transmissions are scheduled using hybrid rate-time scheduling.

18. The method according to claim 1, wherein the rate of uplink transmission is varied by adjusting the modulation and coding scheme level.

19. The method according to claim 1, wherein the rate of uplink transmission is varied by adjusting the intervals at which the uplink transmissions take place.

20. A base station for receiving data transmissions from a plurality of user equipments, the base station comprising:

determining unit which determines the amount of data in a data buffer of each of the user equipments;

comparing unit which compares the amount of data in the data buffers of the user equipments to obtain, for each user equipment, a relative indicator, the relative indicator indicating how full that user equipment'"'"'s data buffer is in comparison to the data buffers of the other user equipments; and

transmitting unit which transmits the relative indicator for each user equipment from the base station to that user equipment.

21. The base station according to claim 20, wherein the determining unit is arranged to determine, for each user equipment, an indication of how full that user equipment'"'"'s buffer is in comparison to the average.

22. The base station according to claim 20, wherein the determining unit is arranged to determine, for each user equipment, an indication of how full that user equipment'"'"'s buffer is in comparison to the minimum.

23. The base station according to claim 20, wherein the base station comprises a receiving unit which receives from a user equipment an indication of the amount of data that that user equipment has in its data buffer.

24. The base station according to claim 20, wherein the base station further comprises:

a receiving unit which receives from a user equipment an indication of a total amount of data to be sent by that user equipment; and

said determining unit determines the amount of data in the user equipment'"'"'s data buffer based on the indication of the total amount of data, and the amount of data already received by the base station from that user equipment.

25. A user equipment comprising:

a data buffer;

a transmitting unit which transmits to a base station information concerning an amount of data to be transmitted;

a receiving unit which receives from a base station a relative indicator, the relative indicator indicating how full the data buffer is in comparison to the data buffers of other user equipments served by that base station; and

a scheduling unit which schedules uplink transmissions to the base station in dependence on the relative indicator.

26. The user equipment according to claim 25, further comprising a determining unit which determines the amount of data in the data buffer, wherein the transmitting unit is arranged to transmit an indication of the amount of data in the data buffer to a base station.

27. The user equipment comprising according to claim 25, further comprising a determining unit which determines an amount of data to be transmitted in a call, wherein the transmitting unit is arranged to transmit an indication of the amount of data to be transmitted in the call.

28. The user equipment according to claim 25, wherein the scheduling unit is arranged to determine a rate and/or time at which data is to be transmitted to the base station based on the relative indicator.

29. The user equipment according to claim 28, wherein the scheduling unit is arranged such that data is transmitted to the base station at a higher rate than would otherwise be the case when the user equipment receives a relative indicator indicating that it has a relatively full buffer.

30. The user equipment according to claim 28, wherein the scheduling unit is arranged such that data is transmitted to the base station at a lower rate than would otherwise be the case when the user equipment receives a relative indicator indicating that it has a relatively empty buffer.

31. The user equipment according to claim 28, further comprising a measurement unit which determines a measurement of radio channel conditions, wherein the scheduling unit is arranged to determine the time and/or rate at which data is transmitted based additionally on a measurement of radio channel conditions.

32. The user equipment according to claim 28, wherein the scheduling unit is arranged to determine the time and/or rate of data transmission based additionally on the type of service.

33. The user equipment according to claim 28, wherein the scheduling unit is arranged to determine the time and/or rate of data transmission based additionally on the or a amount of data which is determined to be in its data buffer.

34. The user equipment according to claim 25, wherein the scheduling unit is arranged such that data is transmitted even when the amount of data in the data buffer is below a minimum buffer threshold, when the user equipment receives a relative indicator indicating that it has more data to transmit than other user equipments.