# US 12,184,359 B2 · Communication device and method for controlling same and non-transitory computer-readable storage medium

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

- Number: US 12,184,359 B2
- Document ID: US12184359B2
- Status: Granted
- Kind: B2
- Application number: 17/508,777
- Filed: 2021-10-22
- Published: 2022-02-10
- Granted: 2024-12-31
- Earliest claimed: 2019-04-26
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Makoto Umehara
- Web page: https://patentgrep.com/patent/US12184359B2

## CPC

- H04B 7/024: Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
- H04B 7/0413: MIMO systems
- H04B 7/2656: {for structure of frame, burst}
- H04B 7/2687: {Inter base stations synchronisation}
- H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)}
- H04W 16/28: using beam steering
- H04W 28/16: Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
- H04W 56/0015: {one node acting as a reference for the others}
- H04W 84/12: WLAN [Wireless Local Area Networks]
- Y02D 30/70: in wireless communication networks
- H04B: TRANSMISSION
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

The invention provides a mechanism for reducing residual frequency differences in distributed MIMO using a slave trigger, and increasing synchronization precision between APs. The communication device, which constitutes a wireless network by cooperating with another communication device, has a transmission unit for transmitting a frame for synchronization to the other communication device to cooperate with the other communication device. The transmission unit includes: a setting unit that sets a value exceeding 4 as a repetition number for an EHT Long Training Field (EHT-LTF) in a preset position of an EHT Signal Field (EHT-SIG-A) of a frame for synchronization; and a generation unit that generates a frame for synchronization, the frame including EHT-LTFs whose quantity is the set repetition number. The transmission unit transmits the generated frame to the other communication device.

## Claims

### Claim 1

A master access point (AP) which constitutes a wireless network by cooperating with a slave AP, comprising:
one or more processors; and
one or more memories that store computer-readable instructions for causing, when executed by the one or more processors, the master AP to perform:
a generation of a synchronization frame whose repetition number for a Long Training Field, in a case of transmitting the synchronization frame for performing communication by Distributed multiple input and multiple output (MIMO), is larger than a repetition number for a Long Training Field in a case of transmitting a frame other than the synchronization frame for performing communication by Distributed MIMO; and
a transmission of the generated synchronization frame to said slave AP to cooperate with said slave AP.

### Claim 2

A method for controlling a master access point (AP) which constitutes a wireless network by cooperating with a slave AP, the method comprising:
generating a synchronization frame whose repetition number for a Long Training Field in a case of transmitting the synchronization frame for performing communication by Distributed multiple input and multiple output (MIMO), is larger than a repetition number for a Long Training Field in a case of transmitting a frame other than the synchronization frame for performing communication by Distributed MIMO; and
transmitting the generated synchronization frame to said slave AP to cooperate with said slave AP.

### Claim 3

A non-transitory computer-readable storage medium storing a computer program that is read and executed by a processor in a master access point (AP) that constitutes a wireless network by cooperating with a slave AP, wherein the program causes the master AP to execute:
a generation of a synchronization frame whose repetition number for a Long Training Field, in a case of transmitting the synchronization frame for performing communication by Distributed multiple input and multiple output (MIMO), is larger than a repetition number for a Long Training Field in a case of transmitting a frame other than the synchronization frame for performing communication by Distributed MIMO; and
a transmission of the generated synchronization frame to said slave AP to cooperate with said slave AP.