Method and apparatus for controlling a relay station in a multi-hop relay network

1. A method for controlling communication in a cell of a multi-hop relay network including a base station, a plurality of relay stations, and a plurality of mobile stations, the plurality of relay stations being configured to operate as a master station or a slave station with respect to each other in the cell, the method comprising:

during a downlink sub-frame, when the relay station operates as the slave station, controlling the relay station, in accordance with a one-way propagation delay between the master station and the relay station in the cell, a first period required for the slave station to make a first transition from a transmit state in which the slave station is configured to transmit signals to a receive state in which the slave station is configured to receive signals and a second period required for the slave station to make a second transition from the receive state to the transmit state, so that the slave station ends a first transmit zone at least a third period before the master station starts a second transmit zone and the slave station starts a third transmit zone subsequent to the first transmit zone at least a fourth period after the master station ends the second transmit zone, the slave station being configured to transmit signals to one or more other slave stations in the first and third transmit zones, the master station being configured to transmit signals to the slave station in the second transmit zone, wherein

the one-way propagation delay is variable, and

when the first period is greater than the one-way propagation delay, the third period is equal to the first period minus the one-way propagation delay and the fourth period is equal to the second period plus the one-way propagation delay.

2. The method of claim 1 , wherein, when the first period is less than the one-way propagation delay, the third period is equal to zero and the fourth period is equal to the second period plus the one-way propagation delay.

3. The method of claim 1 , wherein the one-way propagation delay between the master station and the relay station is determined by the one-way propagation delay between the master station and the relay station within a cell that is the farthest away from the master station.

4. A method for controlling communication in a cell of a multi-hop relay network including a base station, a plurality of relay stations, and a plurality of mobile stations, the plurality of relay stations being configured to operate as a master station or a slave station with respect to each other in the cell, the method comprising:

during an uplink sub-frame, when the relay station operates as the slave station, controlling the relay station, in accordance with a one-way propagation delay between the master station and the relay station in the cell, a first period required for the slave station to make a first transition from a transmit state in which the slave station is configured to transmit signals to a receive state in which the slave station is configured to receive signals and a second period required for the slave station to make a second transition from the receive state to the transmit state, so that the slave station ends a first receive zone at least a third period before the master station starts a second receive zone and the slave station starts a third receive zone subsequent to the first receive zone at least a fourth period after the master station ends the second receive zone, the slave station being configured to receive signals from one or more of other slave stations the master station in the first and third receive zones, the master station being configured to receive signals from the slave station in the second receive zone, wherein

the one-way propagation delay is variable, and

when the first period is greater than the one-way propagation delay, the third period is equal to the second period plus the one-way propagation delay and the fourth period is equal to the first period minus the one-way propagation delay.

5. The method of claim 4 , wherein, when the first period is less than the one-way propagation delay, the third period is equal to the second period plus the one-way propagation delay and the fourth period is equal to zero.

6. The method of claim 4 , wherein the one-way propagation delay between the master station and the relay station is determined by the one-way propagation delay between the master station and the relay station within a cell that is the farthest away from the master station.

7. A relay station configured to operate in a cell of a multi-hop relay network including a base station, a plurality of other relay stations, and a plurality of mobile stations, the relay station and the plurality of other relay stations being configured to operate as a master station or a slave station with respect to each other in the cell, the relay station comprising:

a controller configured to control the relay station during a downlink sub-frame, when the relay station operates as the slave station, in accordance with a one-way propagation delay between the master station and the relay station, a first period required for the slave station to make a first transition from a transmit state in which the slave station is configured to transmit signals to a receive state in which the slave station is configured to receive signals and a second period required for the slave station to make a second transition from the receive state to the transmit state, so that the slave station ends a first transmit zone at least a third period before the master station starts a second transmit zone and the slave station starts a third transmit zone subsequent to the first transmit zone at least a fourth period after the master station ends the second transmit zone, the slave station being configured to transmit signals to one or more of other slave stations in the first and third transmit zones, the master station being configured to transmit signals to the slave station in the second transmit zone, wherein

the one-way propagation delay is variable, and

when the first period is greater than the one-way propagation delay, the third period is equal to the first period minus the one-way propagation delay and the fourth period is equal to the second period plus the one-way propagation delay.

8. The relay station of claim 7 , wherein, when the first period is less than the one-way propagation delay, the third period is equal to zero and the fourth period is equal to the second period plus the one-way propagation delay.

9. The relay station of claim 7 , wherein the one-way propagation delay between the master station and the relay station is determined by the one-way propagation delay between the master station and the relay station within a cell that is the farthest away from the master station.

10. A relay station configured to operate in a cell of a multi-hop relay network including a base station, a plurality of other relay stations and a plurality of mobile stations, the relay station and the plurality of other relay stations being configured to operate as a master station or a slave station with respect to each other in the cell, the relay station comprising:

a controller configured to control the relay station during an uplink sub-frame, when the relay station operates as the slave station, in accordance with a one-way propagation delay between the master station and the relay station, a first period required for the slave station to make a first transition from a transmit state in which the slave station is configured to transmit signals to a receive state in which the slave station is configured to receive signals and a second period required for the slave station to make a second transition from the receive state to the transmit state, so that the slave station ends a first receive zone at least a third period before the master station starts a second receive zone and the slave station starts a third receive zone subsequent to the first receive zone at least a fourth period after the master station ends the second receive zone, the slave station being configured to receive signals from one or more of other slave stations in the first and third receive zones, the master station being configured to receive signals from the slave station in the second receive zone, wherein

the one-way propagation delay is variable, and

when the first period is greater than the one-way propagation delay, the third period is equal to the second period plus the one-way propagation delay and the fourth period is equal to the first period minus the one-way propagation delay.

11. The relay station of claim 10 , wherein, when the first period is less than the one-way propagation delay, the third period is equal to the second period plus the one-way propagation delay and the fourth period is equal to zero.

12. The relay station of claim 11 , wherein the one-way propagation delay between the master station and the relay station is determined by the one-way propagation delay between the master station and the relay station within a cell that is the farthest away from the master station.