Verifying availability of idle-mode mobile subscriber station in wireless access system

Abstract

A method of verifying availability of a mobile subscriber station that is in an idle-mode includes requesting to a base station by the mobile subscriber station to enter an idle-mode, wherein the base station is associated with a paging group comprising a plurality of base stations, and receiving from the base station an idle-mode response command to enter the idle-mode. The method also includes receiving from the base station a paging command comprising an action code associated with performing ranging while the mobile subscriber station is in the idle-mode to verify availability of the mobile subscriber station with respect to the base station, wherein if the ranging is not successfully performed with the base station during a predetermined period, the base station continues to transmit the paging command until a paging retrial count reaches a predetermined threshold.

1 . A communication method comprising:
 causing a first base station to transmit, to a mobile station, a first message comprising information on a paging cycle, wherein the first base station belongs to a group of base stations;   recognizing that the mobile station is in idle state;   causing every base station in the group to transmit a paging message at least based on the paging cycle;   determining that a predetermined period of time has passed without receiving a request message from the mobile station at any base station belonging to the group; and   in response to determining that the predetermined period of time has passed without receiving the request message from the mobile station, determining that the mobile station is unavailable for any base station in the group of base stations.   
     
     
         2 . The communication method of  claim 1 , further comprising causing the first base station to transmit, to the mobile station, a group identification information of the first group. 
     
     
         3 . The communication method of  claim 1 , wherein the paging message comprises information on downlink traffic. 
     
     
         4 . A communication apparatus comprising:
 a memory; and   a processor operably coupled to the memory,   wherein the processor, when executing program instructions stored in the memory, is configured to:
 cause a first base station to transmit, to a mobile station, a first message comprising information on a paging cycle, wherein the first base station belongs to a group of base stations; 
 recognize that the mobile station is in idle state; 
 cause every base station in the group to transmit a paging message at least based on the paging cycle; 
 determine that a predetermined period of time has passed without receiving a request message from the mobile station at any base station belonging to the group; and 
 in response to determine that the predetermined period of time has passed without receiving the request message from the mobile station, determine that the mobile station is unavailable for any base station in the group of base stations. 
   
     
     
         5 . The communication apparatus of  claim 4 , wherein the processor is further configured to cause the first base station to transmit, to the mobile station, a group identification information of the first group. 
     
     
         6 . The communication apparatus of  claim 4 , wherein the paging message comprises information on downlink traffic.