Wireless communications network comprising multi-hop relay stations

Abstract

A method provides for conveying wireless communications in a radio network using OFDMA or multi-carrier technologies. The wireless network includes a first relay station and a subscriber station operative to communicate with that first relay station. The first relay station is operative to simultaneously transmit to or receive communications from at least two recipients along a shared frequency channel. The two recipients are wireless entities selected from among: the base station and a subscriber station; or another relay station and a subscriber station; or the base station and another relay station. The wireless communications network can further include a second relay station, which is operative to simultaneously transmit to or receive communications from at least two recipients selected from among: the first relay station and a subscriber stations, or a third relay station and a subscriber station, or the first relay station and a third relay station.

We claim: 
     
         1 . A method for conveying wireless communications in a wireless communications network comprising base stations, relay stations and subscriber stations, the method comprising:
 during a first time partition of a frame,   at a first base station (BS 1 ), transmitting a first downlink (DL) segment carrying base station DL traffic for a first relay station (RS 1 ), and transmitting a second DL segment carrying base station DL traffic for subscriber stations (SS 1 ) served by the BS 1 ;   at the RS 1 , receiving a first uplink (UL) segment carrying subscriber station UL traffic from subscriber stations (SS 2 ) served by the RS 1 ;   during a second time partition of the frame,   at the BS 1 , receiving a second UL segment carrying subscriber station UL traffic from subscriber stations (SS 1 ) served by the BS 1  and a third UL segment carrying relay DL traffic from RS 1 ; and   at the RS 1 , transmitting a third DL segment including relay DL traffic for the SS 2 ;   wherein each segment is allocated a group of frequency sub-channels.   
     
     
         2 . A method according to  claim 1 , wherein each sub-channel includes two or more sub-carriers. 
     
     
         3 . A method according to  claim 1 , wherein the group of frequencies used by the first DL segment is reused for the second DL segment. 
     
     
         4 . A method according to  claim 1 , wherein the group of frequencies used by the second UL segment is reused for the third UL segments. 
     
     
         5 . A method according to  claim 1 , wherein the group of frequencies used by the first UL segment in the first time partition is reused for the third UL segments. 
     
     
         6 . A method according to  claim 1 , wherein the first DL segment uses a first space-time coding (STC) mode for the base station DL traffic destined to the RS 1  and the second DL segment uses a second space-time coding (STC) mode for the DL traffic destined to the SS 1 . 
     
     
         7 . A method according to  claim 1 , wherein the second UL segment uses a STC mode for the base station UL traffic from SS 1  other than the STC mode used by the base station UL traffic from RS 1 . 
     
     
         8 . A method according to  claim 1 , wherein the RS 1  further receives, during the first time partition of the frame, a fourth UL segment including relay station traffic received from a next hop relay station (RS 2 ). 
     
     
         9 . A method according to  claim 8 , wherein the group of frequencies used by the first UL segment is reused by the forth UL segment. 
     
     
         10 . A method according to  claim 9 , wherein the first UL segment uses a STC mode for the relay station UL traffic received from RS 2  that is different from a STC mode used for the relay station UL traffic received from the SS 2   s.    
     
     
         11 . A method as claimed in  claim 1 , wherein the RS 1  further transmits, during the second time partition of the frame, a fourth DL segment including relay station traffic for a next hop relay station (RS 2 ). 
     
     
         12 . A method according to  claim 11 , wherein the group of frequencies used in the third DL segment is reused by the forth DL segment. 
     
     
         13 . A method according to  claim 9 , wherein the fourth DL segment uses a STC mode for the relay station UL traffic transmitted to RS 2  that is different from a STC mode used for the relay station UL traffic transmitted to the SS 2   s.    
     
     
         14 . A method as claimed in  claim 8 , wherein the group of frequencies used by the first UL segments and the fourth UL segment is reused for transmitting UL traffic from the SS 1  to the BS 1  during the first time partition of the frame. 
     
     
         15 . A method as claimed in  claim 14 , wherein the group of frequencies used by the third DL segment and the fourth DL segment in the second time partition of the frame is reused for transmitting DL traffic from the BS 1  to the SS 1 . 
     
     
         16 . A method as claimed in  claim 1 , wherein during the first time partition of the frame, RS 1  operates in a receiving mode and the BS 1  operates in a transmitting mode. 
     
     
         17 . A method as claimed in  claim 1 , wherein during the second time partition of the frame, RS 1  operates in a transmitting mode and the BS 1  operates in a receiving mode.