Radio terminal and base station

• US 10,772,013 B2
• Filed: 07/24/2018
• Issued: 09/08/2020
• Est. Priority Date: 01/25/2016
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Fujishiro, Masato, Yamazaki, Chiharu, Morita, Kugo, Fukuta, Noriyoshi
• Primary Examiner(s): Moore, Ian N
• Assistant Examiner(s): McCallum, Latresa A
• Application Number:
  US16/043,577
• Publication Number:
  US 20180332507A1
• Time in Patent Office: 777 Days
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04W 36/0069 in case of dual connectivity, e.g. decoupled uplink/downlink
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/0077 of access information of target access point
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/28 involving a plurality of connections, e.g. multi-call or multi-bearer connections
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time

Abstract

A UE (100) receives a handover command from a source cell to perform a handover to a target cell in response to the handover command. The handover command includes a notification indicating omitting a random access procedure during the handover. The UE (100) omits, in response to the notification, the random access procedure during the handover.

Claims

1. A method for dual connectivity performed by a first base station, a second base station, and a radio terminal, the method comprising:

acquiring, by the first base station, capability information indicating that the radio terminal supports a function of omitting a random access procedure in initial access to a base station;

transmitting, by the first base station to the second base station, an SeNB Addition Request message including the capability information;

transmitting, by the second base station, an SeNB Addition Acknowledgment message to the first base station, wherein the SeNB addition acknowledgment message includes an uplink grant indicating uplink radio resources allocated by the second base station to the radio terminal, a timing advance (TA) value to be applied to uplink transmission to the second base station, and information indicating that the radio terminal omit the random access procedure to the second base station;

transmitting, by the first base station, first message for notifying the radio terminal of the uplink grant, the TA value and the information;

omitting, by the radio terminal, the random access procedure to the second base station, based on the TA value and the information; and

performing, by the radio terminal, uplink transmission to the second base station by using the uplink radio resources indicated in the uplink grant.

2. A first base station configured to perform dual connectivity with a second base station and a radio terminal, the first base station comprising:

a processor and a memory coupled to the processor, the processor is configured to;

acquire capability information indicating that the radio terminal supports a function of omitting a random access procedure in initial access to a base station;

transmit an SeNB Addition Request message including the capability information to the second base station;

receive an SeNB Addition Acknowledgment message from the first base station, wherein the SeNB addition acknowledgment message includes an uplink grant indicating uplink radio resources allocated by the second base station to the radio terminal, a timing advance (TA) value to be applied to uplink transmission to the second base station, and information indicating that the radio terminal omit the random access procedure to the second base station; and

transmit first message for notifying the radio terminal of the uplink grant, the TA value and the information.

3. An apparatus to be provided in a first base station configured to perform dual connectivity with a second base station and a radio terminal, the apparatus comprising:

a processor and a memory coupled to the processor, the processor is configured to;

acquire capability information indicating that the radio terminal supports a function of omitting a random access procedure in initial access to a base station;

transmit an SeNB Addition Request message including the capability information to the second base station;

receive an SeNB Addition Acknowledgment message from the first base station, wherein the SeNB addition acknowledgment message includes an uplink grant indicating uplink radio resources allocated by the second base station to the radio terminal, a timing advance (TA) value to be applied to uplink transmission to the second base station, and information indicating that the radio terminal omit the random access procedure to the second base station; and

transmit first message for notifying the radio terminal of the uplink grant, the TA value and the information.