# US 10,772,013 B2 · Radio terminal and base station

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,772,013 B2
- Document ID: US10772013B2
- Status: Granted
- Kind: B2
- Application number: 16/043,577
- Filed: 2018-07-24
- Published: 2018-11-15
- Granted: 2020-09-08
- Earliest claimed: 2016-01-25
- Assignees: KYOCERA Corporation
- Applicants: Kyocera Corporation
- Inventors: Masato Fujishiro; Chiharu Yamazaki; Kugo Morita; Noriyoshi Fukuta
- Web page: https://patentgrep.com/patent/US10772013B2

## CPC

- H04W 36/08: Reselecting an access point
- H04J 11/00: Orthogonal multiplex systems, {e.g. using WALSH codes}(H04J13/00 takes precedence)
- H04W 36/00692: {using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] (allocation of physical resources in CoMP or in CA H04L5/0035)}
- H04W 36/00725: {Random access channel [RACH]-less handover}
- H04W 56/0045: {compensating for timing error by altering transmission time}
- H04W 36/0077: {of access information of target access point}
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S)

## 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

### Claim 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.

### Claim 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.

### Claim 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.