# US 9,883,536 B2 · Radio base station and mobile station

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

- Number: US 9,883,536 B2
- Document ID: US9883536B2
- Status: Granted
- Kind: B2
- Application number: 14/760,128
- Filed: 2013-12-05
- Published: 2015-12-10
- Granted: 2018-01-30
- Earliest claimed: 2013-01-18
- Assignees: Ntt Docomo, Inc.
- Applicants: Ntt Docomo, Inc.
- Inventors: Tooru Uchino; Sadayuki Abeta; Kazuaki Takeda; Hiroyuki Ishii
- Web page: https://patentgrep.com/patent/US9883536B2

## CPC

- H04W 74/085: {collision avoidance}
- H04W 8/26: Network addressing or numbering for mobility support
- H04W 16/32: Hierarchical cell structures
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A system and method to prevent collision between mobile stations to which the same C-RNTI is allocated in a simple implementation while avoiding a problem of C-RNTI depletion in a phantom cell is disclosed. A radio base station includes an allocation unit configured to allocate multiple C-RNTIs to each of mobile stations, and the allocation unit performs adjustment such that collision of search spaces to which PDCCH resources are allocated does not occur among the multiple mobile stations.

## Claims

### Claim 1

A radio base station comprising an allocation unit configured to allocate a plurality of C-RNTIs to each of mobile stations,
wherein the allocation unit performs adjustment such that collision of search spaces to which PDCCH resources are allocated does not occur between the mobile stations,
wherein the allocation unit allocates:
a search space corresponding to a first C-RNTI of the plurality of C-RNTIs to a first mobile station of the mobile stations and a second mobile station of the mobile stations, and
a search space corresponding to a second C-RNTI of the plurality of C-RNTIs to the first mobile station of the mobile stations but not to the second mobile station of the mobile stations, and wherein the allocation unit performs the adjustment in consideration of a distance between the mobile stations.