Relay-station assignment/re-assignment and frequency re-use

• US 20080031197A1
• Filed: 08/02/2007
• Published: 02/07/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Maheswari, Shashikant, Boariu, Adrian, Wang, Shu-Shaw, Reid, Anthony, Bhatt, Tejas
• Granted Patent: US 8,165,073 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04B 7/15542 Selecting at relay station its transmit and receive resources selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 84/047 using dedicated repeater stations
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 92/20 : between access points

Abstract

A prospective relay station sends a report indicative of radio resource sets/preamble sequences used by its neighbors. Where the reported radio resource sets comprise less than all available radio resource sets, a radio resource set that is not indicated in the report is assigned; else where the reported radio resource sets comprise all available radio resource sets, a resource set indicated in the report is assigned. A message is sent to the prospective relay station indicates the assigned radio resource set and an identifier for use as an enabled relay station. The message may include signal strength and IDs. Apparatus, methods and computer programs are detailed for both a base station and the relay node. Radio resource set re-assignment, managed mode relay operations (where the base station schedules traffic among relays using the same radio resource set), and power control of relays and associated mobile stations are also described.

Claims

1. A method comprising:

receiving from a prospective relay station a report indicative of radio resource sets used by neighbors of the prospective relay station;

for the case a) where the reported radio resource sets comprise less than all available radio resource sets, assigning a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, assigning a resource set indicated in the report; and

sending to the prospective relay station a message indicative of the assigned radio resource set and an identifier for the prospective relay station to change the prospective relay station to an enabled relay station.

2. The method of claim 1, wherein each radio resource set comprises preamble segments and the message comprises a relay station configuration request message.

3. The method of claim 1, wherein for the case b) the relay station is enabled for a managed mode where traffic through the enabled relay mode is scheduled by a base station.

4. The method of claim 3, further comprising signaling another enabled relay station having the same assigned radio resource set to operate in the managed mode.

5. The method of claim 1, wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength.

6. The method of claim 1, wherein the enabled relay station comprises an enabled mobile relay station;

the method further comprising;

receiving from the enabled mobile relay station a measurement report indicative of neighbor preamble segments and an indication of which of the neighbor preamble segments was received with a lowest signal strength;

determining from the measurement report a preamble segment to reassign to the enabled relay station; and

using handover procedures to effect handover of all subscriber stations associated with the enabled mobile relay station from the assigned radio resources of the enabled mobile relay station to the reassigned preamble segment of the enabled mobile relay station at one of a predetermined time or a predetermined frame.

7. The method of claim 6, wherein using the handover procedures comprises switching all mobile stations attached to the enabled mobile relay station to switch to the reassigned preamble segment at a predetermined time via a mobile-base station handover request message.

8. The method of claim 1 further comprising;

receiving channel measurement reports from a plurality of subscriber stations;

grouping the subscriber stations according to the received measurement reports without regard to which relay station they are associated; and

sending power control messages to at least one of the subscriber stations in the group and associated with the enabled relay station to suppress co-channel interference with another of the subscriber stations in the group that is associated with a different relay station.

9. The method of claim 1, further comprising sending power control messages to the enabled relay station to reduce co-channel interference between the enabled relay station and another relay station and increase channel reuse probability in the relay stations.

10. An apparatus comprising:

a receiver adapted to receive from a prospective relay station a report indicative of radio resource sets used by neighbors of the prospective relay station;

a processor adapted, for the case a) where the reported radio resource sets comprise less than all available radio resource sets, to assign a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, the processor is adapted to assign a resource set indicated in the report; and

a transmitter adapted to send to the prospective relay station a message indicative of the assigned radio resource set and an identifier for the prospective relay station to change the prospective relay station to an enabled relay station.

11. The apparatus of claim 10, wherein each radio resource set comprises preamble segments and the message comprises a relay station configuration request message.

12. The apparatus of claim 11 comprising a base station, wherein for the case b) the relay station is enabled for a managed mode where traffic through the enabled relay mode is scheduled by the base station.

13. The apparatus of claim 12, wherein the transmitter is adapted to signal another enabled relay station having the same assigned radio resource set to operate in the managed mode.

14. The apparatus of claim 10, wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength.

15. The apparatus of claim 10, wherein the enabled relay station comprises an enabled mobile relay station;

wherein;

the receiver is adapted to receive from the enabled mobile relay station a measurement report indicative of neighbor preamble segments and an indication of which of the neighbor preamble segments was received with a lowest signal strength;

the processor is adapted to determine from the measurement report a preamble segment to reassign to the enabled relay station; and

the apparatus is adapted to use handover procedures to effect handover of all subscriber stations associated with the enabled mobile relay station from the assigned radio resources of the enabled mobile relay station to the reassigned preamble segment of the enabled mobile relay station at one of a predetermined time or a predetermined frame.

16. The apparatus of claim 15, wherein adapted to use the handover procedures comprises switching all mobile stations attached to the enabled mobile relay station to switch to the reassigned preamble segment at a predetermined time via a mobile-base station handover request message.

17. The apparatus of claim 10, wherein;

the receiver is adapted to receive channel measurement reports from a plurality of subscriber stations;

the processor is adapted to group the subscriber stations according to the received measurement reports without regard to which relay station they are associated; and

the transmitter is adapted to send power control messages to at least one of the subscriber stations in the group and associated with the enabled relay station to suppress co-channel interference with another of the subscriber stations in the group that is associated with a different relay station.

18. The apparatus of claim 10, wherein the transmitter is adapted to send power control messages to the enabled relay station to reduce co-channel interference between the enabled relay station and another relay station.

19. A program of machine-readable instructions embodied on a computer readable memory and executable by a digital data processor to perform actions directed toward assigning radio resources to a relay station, the actions comprising:

receiving from a prospective relay station a report indicative of radio resource sets used by neighbors of the prospective relay station;

for the case a) where the reported radio resource sets comprise less than all available radio resource sets, assigning a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, assigning a resource set indicated in the report; and

sending to the prospective relay station a message indicative of the assigned radio resource set and an identifier for the prospective relay station to change the prospective relay station to an enabled relay station.

20. The program of claim 19, wherein for the case b) the relay station is enabled for a managed mode where traffic through the enabled relay mode is scheduled by a base station.

21. The program of claim 19, wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength.

22. The program of claim 19, wherein the enabled relay station comprises an enabled mobile relay station;

the actions further comprising;

receiving from the enabled mobile relay station a measurement report indicative of neighbor preamble segments and an indication of which of the neighbor preamble segments was received with a lowest signal strength;

determining from the measurement report a preamble segment to reassign to the enabled relay station; and

using handover procedures to effect handover of all subscriber stations associated with the enabled mobile relay station from the assigned radio resources of the enabled mobile relay station to the reassigned preamble segment of the enabled mobile relay station at one of a predetermined time or a predetermined frame.

23. An apparatus comprising:

receiving means for receiving from a prospective relay station a report indicative of radio resource sets used by neighbors of the prospective relay station;

for the case a) where the reported radio resource sets comprise less than all available radio resource sets, processing means for assigning a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, the processing means is for assigning a resource set indicated in the report; and

transmitting means for sending to the prospective relay station a message indicative of the assigned radio resource set and an identifier for the prospective relay station to change the prospective relay station to an enabled relay station.

24. The apparatus of claim 23 comprising a base station;

wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength;

the receiving means comprises a receiver;

the processing means comprises a digital processor; and

the transmitting means comprises a transmitter.

25. A method comprising:

scanning neighbor nodes for radio resource sets in use by the neighbor nodes;

wirelessly sending a report indicative of the radio resource sets;

for the case a) where the reported radio resource sets comprise less than all available radio resource sets, selecting a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, selecting a radio resource set indicated in the report and grouping with the neighbor node using the selected radio resource set; and

thereafter

responsive to receiving a message indicative of the selected radio resource set and an identifier, relaying traffic using either the selected radio resource set or transparently relaying traffic without using a radio resource of any of the available resource sets.

26. The method of claim 25, wherein relaying traffic comprises relaying the traffic as scheduled by a base station.

27. The method of claim 25, wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength.

28. The method of claim 25, further comprising after receiving the message:

wirelessly sending a measurement report indicative of neighbor preamble segments and an indication of which of the neighbor preamble segments was received with a lowest signal strength; and

using handover procedures to effect a change from the selected radio resources to a reassigned preamble segment at one of a predetermined time or a predetermined frame.

29. The method of claim 25, wherein using the handover procedures comprises relaying to all associated mobile stations a handover message to switch to the reassigned preamble segment at a predetermined time.

30. An apparatus comprising:

a receiver adapted to scan neighbor nodes for radio resource sets in use by the neighbor nodes;

a transmitter adapted to wirelessly send a report indicative of the radio resource sets;

for the case a) where the reported radio resource sets comprise less than all available radio resource sets, a processor adapted to select a radio resource set that is not indicated in the report;

else for the case b) where the reported radio resource sets comprise all available radio resource sets, the processor is adapted to select a radio resource set indicated in the report and grouping with the neighbor node using the selected radio resource set; and

responsive to receiving at the receiver a message indicative of the assigned radio resource set and an identifier, the receiver and the transmitter are adapted to relay traffic using either the assigned radio resource set or to relay the traffic transparently without using a radio resource of any of the available resource sets.

31. The apparatus of claim 30, wherein relaying traffic comprises relaying the traffic as scheduled by a base station.

32. The apparatus of claim 30, wherein the report comprises an indicator of which radio resource set was received with a lowest signal strength.

33. The apparatus of claim 30, wherein after receiving the message:

the transceiver is adapted to wirelessly send a measurement report indicative of neighbor preamble segments and an indication of which of the neighbor preamble segments was received with a lowest signal strength; and

the transceiver and the processor are adapted to use handover procedures to effect a change from the assigned radio resources to a reassigned preamble segment at one of a predetermined time or a predetermined frame.

34. The apparatus of claim 33, wherein the transceiver and the processor are adapted to use the handover procedures by relaying to all mobile stations associated with the apparatus a handover message to switch to the reassigned preamble segment at a predetermined time.

35. The apparatus of claim 30 comprising a relay station.