Scanning and Handover Operation in Multi-Carrier Wireless Communications Systems

Abstract

A comprehensive solution is provided for multi-carrier scanning and handover operations in OFDM wireless systems. A multi-carrier scanning is any scanning operation that involves multi-carrier radio frequency carriers. In one embodiment, a mobile station communicates with a serving base station over a primary carrier, and performs scanning over one or more determined carriers. A multi-carrier handover is any handover operation that involves multiple radio frequency carriers. In a first embodiment, a break-before-entry (BBE) handover procedure with fast synchronization is provided. In a second embodiment, an entry-before-break (EBB) handover procedure through unavailable intervals is provided. In a third embodiment, EBB handover procedures for both inter-FA and intra-FA using multiple carriers are provided. Finally, in a fourth embodiment, intra-BS handover procedures are provided. The multi-carrier handover procedures may be applied to 2 -to- 2 or N-to-N carriers handover situation. The overall scanning time and handover interruption time may be reduced through the provided procedures.

1 - 29 . (canceled) 
     
     
         30 . A method of operating a mobile station to handover from a serving base station to a target base station in a multi-carrier wireless communications system, the method comprising:
 (a) receiving a handover command from the serving base station via an original primary radio frequency carrier;   (b) disconnecting connections on the original primary radio frequency carrier from the serving base station;   (c) performing a ranging procedure with the target base station after the connections with the serving base station on the original primary radio frequency carrier are disconnected; and   (d) performing network reentry and thereby establishing data path with the target base station through a new primary carrier, and establishing data connections with the target base station over the new primary carrier and a secondary carrier.   
     
     
         31 . The method of  claim 30 , wherein the network reentry is performed using the original primary carrier. 
     
     
         32 . The method of  claim 31 , wherein the original primary carrier becomes the new primary carrier. 
     
     
         33 . A method of operating a mobile station to handover from a serving base station to a target base station in a multi-carrier wireless communications system, the method comprising:
 (a) receiving a handover command from the serving base station via an original primary radio frequency carrier;   (b) acquiring network reentry related parameters;   (c) disconnecting connections on the original primary radio frequency carrier from the serving base station;   (d) performing a ranging procedure with the target base station after the connections with the serving base station on the original primary radio frequency carrier are disconnected; and   (e) performing network reentry and thereby establishing data path with the target base station through a new primary carrier, wherein the network reentry related parameters is acquired before the connection with the serving base station is disconnected.   
     
     
         34 . The method of  claim 33 , wherein the network reentry in (e) is performed using the original primary carrier, wherein the downlink or uplink adjustments of the secondary carrier are reused by the original primary carrier for the network reentry, and wherein the original primary carrier becomes the new primary carrier. 
     
     
         35 . The method of  claim 33 , wherein the network reentry in (e) is performed using an original secondary carrier, and the original secondary carrier becomes the new primary carrier.