Method of operating relay station in wireless communication system

• US 20100035541A1
• Filed: 05/11/2009
• Published: 02/11/2010
• Est. Priority Date: 08/11/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Byoung-Hoon, Seo, Hanbyul
• Granted Patent: US 8,761,690 B2
• Time in Patent Office: Days
• US Class Current: 455/9
• CPC Class Codes: H04B 7/15557 Selecting relay station operation mode, e.g. between amplify and forward mode, decode and forward mode or FDD - and TDD mode
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

A method of operating a relay station in a wireless communication system is provided. The method comprises the steps of determining a relay mode and transmitting a signal, received from a source station, to a destination station in the determined relay mode, wherein the relay mode is determined based on at least one of requirements for quality of service (QoS) of traffic, the number of times in which attempts are made to transmit a packet, and an amount of packets stored in a buffer of the relay station.

Claims

1. A method of operating a relay station in a wireless communication system, the method comprising the steps of:

determining a relay mode; and

transmitting a signal, received from a source station, to a destination station in the determined relay mode,

wherein the relay mode is determined based on at least one of requirements for quality of service (QoS) of traffic, the number of times in which attempts are made to transmit a packet, and an amount of packets stored in a buffer of the relay station.

2. The method of claim 1, further comprising informing at least one of the source station and the destination station of the determined relay mode.

3. The method of claim 1, wherein the relay mode includes an amplify and forward (AF) mode and a decode and forward (DF) mode.

4. A method of determining a relay mode in a wireless communication system, the method comprising the steps of:

receiving a list of operable relay modes;

determining one of the modes included in the list as a relay mode; and

informing a relay station of the determined relay mode,

wherein the relay mode is determined based on at least one of requirements for quality of service (QoS) of traffic, the number of times in which attempts are made to transmit a packet, and an amount of packets stored in a buffer of the relay station.

5. The method of claim 4, wherein the list of the relay modes includes an AF mode and a DF mode.

6. A method of operating a relay station in a wireless communication system, the method comprising the steps of:

selecting one of an AF mode and a DF mode based on requirements for QoS of traffic; and

transmitting a signal, which is received from a source station, to a destination station in the selected relay mode.

7. The method of claim 6, wherein the requirements for QoS of the traffic include requirements for time delay of the traffic.

8. The method of claim 7, wherein if the traffic requires low time delay, the AF mode is selected, and if the traffic allows high time delay, the DF mode is selected.

9. A method of operating a relay station in a wireless communication system, the method comprising the steps of:

transmitting a packet, which is received from a source station, to a destination station in an AF mode;

receiving a re-transmission request message with respect to a packet from the source station or the destination station; and

retransmitting the packet to the destination station in a DF mode.

10. The method of claim 9, further comprising the step of, after the packet is transmitted to the destination station in the AF mode, preparing to retransmit the packet to the destination station in the DF mode.

11. A method of operating a relay station in a wireless communication system, the method comprising the steps of:

receiving packets from source stations;

transmitting the packets to destination stations in a DF mode; and

if packets received from the source stations are stacked in a buffer to a certain amount, transmitting all or some of the packets to the destination station in an AF mode.

12. The method of claim 11, wherein, in the case in which some of the packets are transmitted to the destination station in the AF mode, some of the packets are decided based on at least one of a priority of traffic, a channel status, QoS requirements and delay time in the buffer of the relay station.

13. A method of operating a relay station in a wireless communication system, the method comprising the steps of:

receiving packets from source stations;

transmitting the packets to destination stations in a DF mode; and

if packets received from the source stations are stacked in a buffer to a certain amount, transmitting a relay mode switchover request message to the source station or the destination station.

14. The method of claim 13, further comprising the steps of:

receiving a relay mode switchover message, instructing that all or some of the packets be transmitted in an AF mode, from the source stations or the destination stations; and

transmitting all or some of the packets to the destination stations in the AF mode in accordance with the relay mode switchover message.

15. A relay station of a wireless communication system, comprising:

a first buffer for storing packets received from source stations;

a decoder for decoding the packets stored in the first buffer;

an encoder for encoding the packets decoded through the decoder; and

a second buffer for storing the packets encoded through the encoder in order for the packets to be transmitted to a destination station,

wherein the first buffer comprises a buffer controller, and the buffer controller dynamically decides a relay mode in consideration of an amount of packets stored in the first buffer.