SYSTEM AND METHOD FOR WIRELESS RELAY FRAME STRUCTURE, PROTOCOL, AND OPERATION

• US 20110038284A1
• Filed: 04/21/2009
• Published: 02/17/2011
• Est. Priority Date: 04/21/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Bahceci, Israfil, Senarath, Nimal Gamini, Sun, Sheng, Zhang, Hang, Tong, Wen, Zhu, Peiying, Fong, Mo-Han, Yu, Derek
• Granted Patent: US 8,576,753 B2
• Time in Patent Office: Days
• US Class Current: 370/279
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 80/02 Data link layer protocols
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A relay station is provided for use in a wireless communication system. The wireless communication system includes a plurality of base stations communicatively coupled to a backhaul network and at least one mobile station. The relay station is shared by at least a first base station and a second base station. The relay station includes a transceiver, a controller and relay circuitry. The transceiver transmits signals to and receives signals both base stations and a mobile station. Signals transmitted to the base stations include a single preamble, MAP and FCH. The controller is electrically connected to the transceiver and is operable to measure a signal quality of the mobile station while connected to the first base station. The relay circuitry is electrically connected to the controller and is operable to conduct a phased handoff from the first base station to the second base station based on the signal quality.

Claims

1. A relay station for use in a wireless communication system, the wireless communication system including a plurality of base stations communicatively coupled to a backhaul network and at least one mobile station, the relay station shared by at least a first base station and a second base station, the relay station comprising:

a transceiver operable to transmit wireless signals to and receive wireless signals from the first base station, the second base station, and a mobile station, the wireless signals transmitted to the first base station and the second base including a single preamble, MAP and FCH;

a controller electrically connected to the transceiver, the controller operable to measure a signal quality of the mobile station, the mobile station communicatively connected to the first base station; and

relay circuitry electrically connected to the controller, the relay circuitry operable to conduct a phased handoff of the mobile station from the first base station to the second base station based on the signal quality.

2. The relay station of claim 1, wherein the phased handoff is conducted based on one of a relative signal quality and speed of the mobile station.

3. The relay station of claim 1, wherein the phased handoff includes:

performing a first intra-base station handoff between the first base station and the relay station;

performing a partial handoff from the first base station to the second base station, the partial handoff maintaining a connection between the relay station and the mobile station; and

performing a second intra-base station handoff between the relay station and the second base station.

4. The relay station of claim 3, wherein:

the first intra-base station handoff being performed responsive to determining that the signal quality of the mobile station is greater along a first path including the relay station and the first base station than the signal quality of the mobile station along a second path directly to the first base station;

the partial handoff being performed responsive to determining that the signal quality of the mobile station is greater along a third path including the relay station and the second base station than the signal quality of the mobile station along the first path; and

the second intra-base station handoff being performed responsive to determining that the signal quality of the mobile station is greater along a fourth path directly to the second base station than the signal quality of the mobile station along the third path.

5. The relay station of claim 3, wherein the communication system further includes a group of subordinate relay stations, the transceiver is further operable to transmit wireless signals to and receive wireless signals from the group of subordinate relay stations, the phased handoff further includes performing at least one partial handoff between subordinate relay stations of the group of subordinate relay stations.

6. The relay station of claim 1, wherein responsive to the first base station becoming disconnected from the network, the relay circuitry is further operable to communicatively connect the first base station to the second base station as an intermediate node.

7. The relay station of claim 6, wherein the second base station remains connected to the backhaul network, the relay station operates in a network access mode wherein the first base station has limited functionality.

8. The relay station of claim 7, wherein:

the transceiver is further operable to receive an emergency identifier from the first base station; and

the relay circuitry is further operable to;

establish sync with the first base station using one of a downlink preamble and a special uplink R-preamble; and

connect the first base station to the network through the second base station.

9. The relay station of claim 8, wherein the transceiver is further operable to:

receive data from the first base station in a downlink portion of a first frame; and

forward the data to the second base station using an uplink portion of a next frame.

10. The relay station of claim 6, wherein the second base station is also disconnected from the network, the relay station operates in a stand-alone mode connecting the first base station to the second base station to form a local network.

11. A relay station for use in a wireless communication system, the wireless communication system including at least one base station and at least one communication device, the relay station comprising:

at least one transceiver operable to transmit signals to and receive signals from a base station and a communication device;

at least two communication interfaces electrically connected to the at least one transceiver, each communication interface implementing a different communication protocol stack;

an interface translator electrically connected to the at least two communication interfaces, the interface translator operable to translate information between the communication interfaces from a first protocol stack associated with a first one of the communication interfaces to a second protocol stack associated with a second one of the communication interfaces; and

relay circuitry electrically connected to the at least one transceiver, the relay circuitry operable to relay signals between the base station and the communication device.

12. The relay station of claim 11, wherein the first protocol stack is 802.16 and the second protocol stack is one of 802.11 and 802.15.

13. The relay station of claim 11, wherein a wireless tunnel is communicatively coupled between the base station and the relay station, the wireless tunnel forwarding data between the base station and the relay station on a data link layer basis.

14. The relay station of claim 13, wherein the wireless tunnel operates using Relay Media Access Control.

15. The relay station of claim 13, wherein the wireless tunnel extracts quality of service information from an upper layer header associated with the data link layer and carries the quality of service information and tunnel information on a tunnel packet.

16. A relay station for use in a wireless communication system, the wireless communication system including at least one base station, at least one subordinate relay station, and at least one mobile station, the relay station comprising:

relay circuitry operable to relay wireless signals between the base station and the communication device, and between the base station and the subordinate relay station; and

a first transceiver electrically connected to the relay circuitry, the first transceiver operable to simultaneously receive a first wireless signal from the base station using a first frequency and transmit a second wireless signal to the subordinate relay station using a second frequency.

17. The relay station of claim 16, wherein the wireless signals include a frame structure having a transmission zone to a subordinate relay station and a receiving zone from one of a base station and a superordinate relay station, the transmission zone and the receiving zone overlapping.

18. The relay station of claim 16, wherein the first frequency and the second frequency are non-interfering.

19. The relay station of claim 16, further comprising a duplexer electrically connected to the first transceiver, the duplexer operable to combine the first wireless signal and the second wireless signal.

20. The relay station of claim 16, wherein the first frequency and the second frequency are interfering, the relay station further comprising:

a second transceiver, the second transceiver electrically connected to the relay circuitry, the second transceiver operable receive a first wireless signal from the base station using a first frequency and while the first transceiver transmits a second wireless signal to the subordinate relay station using a second frequency; and

isolation circuitry connected between the first transceiver and the second transceiver, the isolation circuitry operable to isolate the first wireless signal from the second wireless signal.