Base station device, mobile station device, communication system and communication method

Abstract

A base station device which communicates with a mobile station device, comprising an uplink synchronization managing unit which manages uplink synchronization maintenance status of the mobile station device, and a transmitting unit which transmits a synchronization recovery request to the mobile station which is in the uplink synchronization maintenance status.

The invention claimed is: 
     
       1. A mobile station device which communicates with a base station device, the mobile station device comprising:
 a transmission/reception unit transmitter/receiver configured to
 transmit data to the base station device on dedicated channels assigned to the mobile station device, 
 receive a response from the base station device, and 
 retransmit the data on the dedicated channels in case that the response of the base station device for the data is a predetermined response; and 
 
 a random access performing sectionthe transmitter/receiver configured not to retransmit the data on dedicated channels but to perform random access on a random access channel that is a non-dedicated channel in case that the predetermined response is detected over predetermined times. 
 
     
     
       2. The mobile station device according to  claim 1 , wherein the predetermined response is a Negative Acknowledgment (NACK). 
     
     
       3. A communication method of a mobile station device, the communication method comprising:
 transmitting data to a base station device on dedicated channels assigned to the mobile station device; 
 receiving a response from the base station device; 
 retransmitting the data on the dedicated channels in case that the response of the base station device for the data is predetermined response; and 
 performing random access on a random access channel that is a non-dedicated channel, without transmission of the data on the dedicated channels, in case that the predetermined response is detected over predetermined times. 
 
     
     
       4. A communication method of a user equipment, the communication method comprising:
 detecting responses of a base station device for transmitting data to the base station device,
 wherein the data is transmitted on uplink to the base station device by the user equipment and the data is retransmitted by the user equipment in a case that a predetermined condition is not satisfied; and 
   performing random access on a random access channel to the base station device in a case that the predetermined condition is satisfied, wherein the random access is contention based random access.   
     
     
       5. The communication method according to claim 4 wherein, the communication method comprises:
 cancelling retransmission of the data in case that a positive response is detected; and   retransmitting the data in case that a negative response being other than the positive response is detected.   
     
     
       6. A user equipment which communicates with a base station device, the user equipment comprising:
 a receiver/transmitter configured to and/or programmed to detect responses of the base station device for transmitting data to the base station device,
 wherein the data is transmitted on uplink to the base station device by the user equipment and the data is retransmitted by the user equipment in a case that a predetermined condition is not satisfied; and 
   the receiver/transmitter configured to and/or programmed to perform random access on a random access channel to the base station device in a case that the predetermined condition is satisfied, wherein the random access is contention based random access.   
     
     
       7. The user equipment according to claim 6 wherein, the receiver/transmitter is further configured to and/or programmed to:
 cancel retransmission of the data in case that a positive response of the base station is detected; and   retransmit the data in case that a negative response of the base station being other than the positive response of the base station is detected.   
     
     
       8. A processing device that is mounted in a user equipment, the processing device comprising:
 a receiver/transmitter configured to and/or programmed to detect responses of a base station device for transmitting data to the base station device,
 wherein the data is transmitted on uplink to the base station device by the user equipment and the data is retransmitted by the user equipment in a case that a predetermined condition is not satisfied; and 
   the receiver/transmitter configured to and/or programmed to perform random access on a random access channel to the base station device in a case that the predetermined condition is satisfied, wherein the random access is contention based random access.