User equipment and base station in carrier aggregation system, and call admission control method for use with the user equipment and base station

Abstract

Disclosed are user equipment and a base station in a carrier aggregation system, and a call admission method thereof. The user equipment includes a plurality of physical layers, and the base station provides multiple component carriers. When messages for connection setup are transmitted and received between the user equipment and base station, the messages include information about what component carriers are selected by the physical layers, information about what component carriers are selectable by the physical layers, and information about calculations for uplink timing alignment, and call admission control and load balancing is performed based on the information included in the messages. Accordingly, in the carrier aggregation system, quicker call admission and load balancing are achieved.

1 - 20 . (canceled) 
     
     
         21 . A communication method for a user equipment (UE), the method comprising:
 transmitting a first random access preamble through a first carrier to a base station;   receiving, from the base station, a first random access response in response to the first random access preamble, wherein the first random access response includes first timing alignment information, the first timing alignment information allowing the UE to establish timing alignment with the first carrier;   after receiving the first random access response, receiving a first message through the first carrier from the base station, wherein the first message includes information indicating a second random access preamble;   transmitting, to the base station, the second random access preamble through a second carrier; and   receiving, from the base station, a second random access response in response to the second random access preamble,   wherein the second random access response includes second timing alignment information, the second timing alignment information allowing the UE to establish timing alignment with the second carrier, and   wherein the first timing alignment information is different from the second timing alignment information.   
     
     
         22 . The method of  claim 21 , further comprising:
 establishing timing alignment with the second carrier using the second random access response.   
     
     
         23 . The method of  claim 21 , further comprising:
 after receiving the first random access response, transmitting a connection request message to the base station; and   receiving a connection setup message from the base station.   
     
     
         24 . The method of  claim 21 , wherein the first carrier occupies a first frequency band and the second carrier occupies a second frequency band, and the first frequency band is not contiguous to the second frequency band. 
     
     
         25 . The method of  claim 21 , wherein the information in the first message uniquely identifies the second random access preamble. 
     
     
         26 . A communication method for a base station, the method comprising:
 receiving, from a user equipment (UE), a first random access preamble through a first carrier;   transmitting, to the UE, a first random access response in response to the first random access preamble, wherein the first random access response includes first timing alignment information, the first timing alignment information allowing the UE to establish timing alignment with the first carrier;   after transmitting the first random access response, transmitting, to the UE, a first message through the first carrier, wherein the first message includes information indicating a second random access preamble;   receiving, from the UE, the second random access preamble through a second carrier; and   transmitting, to the UE, a second random access response in response to the second random access preamble,   wherein the second random access response includes second timing alignment information, the second timing alignment information allowing the UE to establish timing alignment with the second carrier, and   wherein the first timing alignment information is different from the second timing alignment information.   
     
     
         27 . The method of  claim 26 , wherein the second random access response is used by the UE to establish timing alignment with the second carrier. 
     
     
         28 . The method of  claim 26 , wherein the first carrier occupies a first frequency band and the second carrier occupies a second frequency band, and the first frequency band is not contiguous to the second frequency band. 
     
     
         29 . The communication method of  claim 26 , wherein the information in the first message uniquely identifies the second random access preamble. 
     
     
         30 . A communication device, 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 the communication device to transmit a first random access preamble through a first carrier to a base station;   cause the communication device to receive, from the base station, a first random access response in response to the first random access preamble, wherein the first random access response includes first timing alignment information, the first timing alignment information allowing the UE to establish timing alignment with the first carrier;   cause the communication device to receive, after receiving the first random access response, a first message through the first carrier from the base station, wherein the first message includes information indicating a second random access preamble;   cause the communication device to transmit, to the base station, the second random access preamble through a second carrier; and   cause the communication device to receive, from the base station, a second random access response in response to the second random access preamble,   wherein the second random access response includes second timing alignment information, the second timing alignment information allowing the UE to establish timing alignment with the second carrier, and   wherein the first timing alignment information is different from the second timing alignment information.   
     
     
         31 . The communication device of  claim 30 , wherein the processor is further configured to cause the communication device to establish timing alignment with the second carrier using the second random access response. 
     
     
         32 . The communication device of  claim 30 , wherein the processor is further configured to cause the communication device to, after receiving the first random access response, transmit a connection request message to the base station; and
 receive a connection setup message from the base station.   
     
     
         33 . The communication device of  claim 30 , wherein the information in the first message uniquely identifies the second random access preamble.