Communication system, communication apparatus and communication method

• US 9,900,059 B2
• Filed: 07/08/2015
• Issued: 02/20/2018
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Fujii, Kunihide, Morita, Tadashi, Arisawa, Shigeru, Takayama, Yoshihisa
• Primary Examiner(s): Nwugo, Ojiako
• Application Number:
  US14/794,582
• Publication Number:
  US 20150311958A1
• Time in Patent Office: 958 Days
• Field of Search: 340 104, 340 51- 58, 340 101- 105, 3405721-5729
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for a communication device includes determining whether a first radio frequency (RF) signal at a level of at least a first predetermined field threshold is detected. The method also includes generating a second RF signal at a level of at least a second predetermined field threshold greater than the first predetermined field threshold, when the communication device receives an instruction to generate the second RF signal and the determining determines that the first RF signal at the level of at least the first predetermined field threshold is not detected. The method further includes receiving a load modulated RF signal in response to the second RF signal.

Claims

1. An electronic device comprising:

circuitry configured to

receive a request command identifying a number of time slots;

generate a random number in response to the request command;

identify a time slot that matches the random number; and

control sending a response to the request command in the time slot that matches the random number.

2. The electronic device of claim 1, wherein

the circuitry is configured to generate the random number within a range set by the number of time slots.

3. The electronic device of claim 1, wherein

a unit of a time slot T_s is set as 256×

64/f_c.

4. The electronic device of claim 3, wherein

a delay time T_d is set as 512×

64/f_c, after an end of transmission of the request command.

5. The electronic device of claim 1, wherein

the response includes identification information of the communication device.

6. The electronic device of claim 5, wherein

the identification information includes a random number.

7. The electronic device of claim 1, wherein

the request command is a polling request command, and

the circuitry is configured to control not responding to the polling request command after sending the response to the polling request command.

8. A method performed by an electronic device, the method comprising:

receiving a request command identifying a number of time slots;

generating a random number in response to the request command;

identify a time slot that matches the random number; and

controlling sending a response to the request command in the time slot that matches the random number.

9. An integrated circuit (IC) chip configured for incorporation into a communication device, the IC chip comprising:

circuitry configured to

receive a request command identifying a number of time slots;

generate a random number in response to the request command;

identify a time slot that matches the random number; and

control sending a response to the request command in the time slot that matches the random number.