Wireless communication system, its base station and mobile station, communication synchronization management method and timer control program therefor

A wireless communication system which performs communication between a mobile station and a base station, wherein the base station comprises:

• a timer unit which sets a period for judging whether an uplink signal from the mobile station is synchronized;
• a timer control unit which determines the set period for each of a plurality of mobile stations and notifies the set period to each of the mobile stations;
• and
• wherein the mobile station comprises:
• a unit which judges whether an uplink signal to the base station is synchronized based on a set period which is determined for each of the mobile stations and notified to each of the mobile stations.

A method of a User Equipment (UE), the method comprising:

• receiving a first timer value of a timer and applying the first timer value,
• wherein the timer is used for uplink time alignment, and
• wherein the first timer value is common to one or more UEs in a cell;
• receiving a second timer value of the timer,
• wherein the second timer value is received after the first timer value is applied, and
• wherein the second timer value is transmitted from a base station to the UE dedicatedly;
• applying a Timing Advance Command and restarting the timer with the second timer value, in a case where the Timing Advance Command is received;
• and
• sending one or more uplink signals to the base station.

A User Equipment (UE) comprising:

• a memory;
• and
• a processor coupled with the memory,
• wherein the processor is configured to:
• receive a first timer value of a timer and apply the first timer value, wherein the timer is used for uplink time alignment, and wherein the first timer value is common to one or more UEs in a cell;
• receive a second timer value of the timer, wherein the second timer value is received after the first timer value is applied, and wherein the second timer value is transmitted from a base station to the UE dedicatedly;
• apply a Timing Advance Command and restart the timer with the second timer value, in a case where the Timing Advance Command is received;
• and
• send one or more uplink signals to the base station.