METHOD AND APPARATUS FOR DETERMINING AN APPROPRIATE LINK PATH IN A MULTI-HOP COMMUNICATION SYSTEM

• US 20080108369A1
• Filed: 10/18/2007
• Published: 05/08/2008
• Est. Priority Date: 11/06/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Baum, Kevin L., Cudak, Mark C., Visotsky, Eugene, Sartori, Phillippe J.
• Granted Patent: US 7,873,338 B2
• Time in Patent Office: Days
• US Class Current: 455/455
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A determination of link quality (C_SR) is made from the subscriber station to a relay station. A determination of link quality (C_RB) is made from the relay station to the base station, and a determination of link quality (C_SB) is made from the subscriber station to the base station. A quality of a first link path from the subscriber station to the base station that passes through the relay station is determined based on at least the link qualities (Csr, Crb). A quality of a second link path from the subscriber station to the base station that does not pass through the relay station is determined based on at least the link quality (Csb). Finally, a determination is made whether to utilize the first link path or the second link path from the subscriber station to the base station based on at least the quality of the first and second link paths.

Claims

1. A method for determining a link path from a subscriber station to a base station, the method comprising the steps of:

requesting channel quality information from a subscriber and a relay;

receiving an over-the-air transmission that contains channel quality information;

determining a link quality (C_SR) from the subscriber station to a relay station;

determining a link quality (C_RB) from the relay station to the base station;

determining a link quality (C_SB) from the subscriber station to the base station;

determining a quality of a first link path from the subscriber station to the base station that passes through the relay station based on the link qualities (C_SR, C_RB);

determining a quality of a second link path from the subscriber station to the base station that does not pass through the relay station based on the link quality (C_SB);

determining whether to utilize the first link path or the second link path from the subscriber station to the base station based on at least the quality of the first and second link paths.

2. The method of claim 1 wherein the step of determining the link quality (C_RB) from the relay station to the base station comprises the step of determining a link quality of a relay link path from the relay station to the base station, wherein the relay station link path passes through at least an additional intermediate relay station.

3. The method of claim 1 wherein the steps of determining C_SR, C_RB, or C_SB comprises the step of determining the link quality based on at least one of a data rate, a modulation-coding rate, an overhead-adjusted modulation-coding rate, a modulation-coding index, overhead -adjusted modulation-coding index, CNR, CINR, or a link capacity.

4. The method of claim 1 wherein the step of determining the link quality C_SR is performed after receiving a request to measure or report C_SR.

5. The method of claim 1 wherein the step of receiving the over-the-air transmission comprises the step of receiving an IEEE 802.16 MOB_SCN-REP message containing quality information.

6. The method of claim 1 wherein the step of requesting link quality measurements comprises the step of transmitting an IEEE 802.16 MOB_SCN-RSP message.

7. The method of claim 6 wherein the step of receiving the over-the-air transmission comprises the step of receiving an IEEE 802.16 MOB_SCN-REP message containing quality information.

8. The method of claim 1 further comprising the steps of:

determining a link quality (C_SR2) from the subscriber station to a second relay station;

determining a link quality (C_RB2) from the second relay station to the base station; and

wherein the step of determining whether utilize the relay station in forming the link path from the subscriber station to the base station is additionally based on comparing at least C_SR2 and C_RB2 to C_SR and C_RB.

9. A method for determining a link path from a subscriber station to a base station, the method comprising the steps of:

receiving an over-the-air transmission that contains channel quality information related to a subscriber station and a relay station;

determining a link quality (C_SR) from the subscriber station to a relay station;

determining a link quality (C_RB) from the relay station to the base station;

determining a link quality (C_SB) from the subscriber station to the base station;

determining a quality of a first link path from the subscriber station to the base station that passes through the relay station based on the link qualities (C_SR, C_RB);

determining a quality of a second link path from the subscriber station to the base station that does not pass through the relay station based on the link quality (C_SB);

determining whether to utilize the first link path or the second link path from the subscriber station to the base station based on at least the quality of the first and second link paths.

10. The method of claim 9 wherein the step of receiving the over-the-air transmission is in response to a MOB_SCN-RSP message sent to a mobile station.

11. The method of claim 9 wherein the step of determining the link quality C_BS further comprises the step of instructing the relay station to request the subscriber station to measure and report C_BS.

12. The method of claim 9 wherein the step of determining the link quality C_RS further comprises the step of sending a request to the relay station to measure/report link quality.

13. The method of claim 9 wherein the step of determining the link quality C_RS is further comprises the step of sending a request to the subscriber station to measure/report link quality.

14. A base station comprising:

a transmitter requesting channel quality information from a subscriber and a relay;

a receiver receiving an over-the-air transmission that contains channel quality information; and

logic circuitry determining a link quality (C_SR) from the subscriber station to a relay station, determining a link quality (C_RB) from the relay station to the base station, determining a link quality (C_SB) from the subscriber station to the base station, determining a quality of a first link path from the subscriber station to the base station that passes through the relay station based on the link qualities (C_SR, C_RB), determining a quality of a second link path from the subscriber station to the base station that does not pass through the relay station based on the link quality (C_SB), and determining whether to utilize the first link path or the second link path from the subscriber station to the base station based on at least the quality of the first and second link paths.

15. The base station of claim 14 wherein the the over-the-air transmission comprises an IEEE 802.16 MOB_SCN-REP message containing quality information.

16. The base station of claim 14 wherein request for link quality measurements comprises an IEEE 802.16 MOB_SCN-RSP message.

17. The base station of claim 16 wherein the over-the-air transmission comprises an IEEE 802.16 MOB_SCN-REP message containing quality information.

18. A base station comprising:

a receiver receiving an over-the-air transmission that contains channel quality information related to a subscriber station and a relay station; and

logic circuitry determining a link quality (C_SR) from the subscriber station to a relay station, determining a link quality (C_RB) from the relay station to the base station, determining a link quality (C_SB) from the subscriber station to the base station, determining a quality of a first link path from the subscriber station to the base station that passes through the relay station based on the link qualities (C_SR, C_RB), determining a quality of a second link path from the subscriber station to the base station that does not pass through the relay station based on the link quality (C_SB), and determining whether to utilize the first link path or the second link path from the subscriber station to the base station based on at least the quality of the first and second link paths.

19. The base station of claim 18 wherein the over-the-air transmission comprises an IEEE 802.16 MOB_SCN-REP message containing quality information.