Communication system, communication terminal, and base station

Abstract

A communication system capable of a stable communication operation between a base station device and a communication terminal device. A UE is configured to communicate with an MeNB directly or through a SeNB. The UE is set to transmit, to the MeNB and the SeNB, transmission data addressed to the MeNB when an amount of the transmission data exceeds a predetermined threshold. The UE is set to transmit the transmission data not to the SeNB but to the MeNB when the amount is smaller than or equal to the threshold. The threshold is changed so that the transmission data is transmitted to the MeNB and the SeNB, when the SeNB is set to communicate with the UE with radio resources periodically allocated and the amount of the transmission data is smaller than or equal to the threshold.

1 . (canceled) 
     
     
         2 : A communication system comprising:
 a first base station;   a second base station; and   a communication terminal configured to perform radio communication with the first base station and the second base station, wherein   the communication terminal is configured to communicate with the first base station via a first path for direct communication with the first base station and via a second path for communication with the first base station through the second base station, and   the communication terminal is configured to:
 at a time when there is uplink data addressed to the first base station from the communication terminal, perform a first padding transmission to the second base station with radio resources that are periodically allocated to the second base station, and 
 at a time when there is no uplink data, perform a second padding transmission that is different from the first padding transmission to the second base station with the radio resources. 
   
     
     
         3 : The communication system according to  claim 2 , wherein the second base station is configured to release the radio resources that are periodically allocated to the second base station when the second base station detects the second padding transmission consecutively a predetermined number of times. 
     
     
         4 : A communication terminal configured to perform radio communication with a first base station and a second base station, wherein
 the communication terminal is configured to communicate with the first base station via a first path for direct communication with the first base station and via a second path for communication with the first base station through the second base station, and   the communication terminal is configured to:
 at a time when there is uplink data addressed to the first base station from the communication terminal, perform a first padding transmission to the second base station with radio resources that are periodically allocated to the second base station, and 
 at a time when there is no uplink data, perform a second padding transmission that is different from the first padding transmission to the second base station with the radio resources. 
   
     
     
         5 : A base station configured to perform radio communication with a communication terminal, wherein
 the communication terminal is configured to communicate with another base station via a first path for direct communication with the other base station and via a second path for communication with the other base station through the base station,   the communication terminal is configured to:
 at a time when there is uplink data addressed to the other base station from the communication terminal, perform a first padding transmission to the base station with radio resources that are periodically allocated to the base station, and 
 at a time when there is no uplink data, perform a second padding transmission that is different from the first padding transmission to the base station with the radio resources, and 
   the base station is configured to release the radio resources that are periodically allocated to the base station when the base station detects the second padding transmission consecutively a predetermined number of times.