Communication system, communication apparatus and method, and program

• US 20070026804A1
• Filed: 06/15/2006
• Published: 02/01/2007
• Est. Priority Date: 06/17/2005
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kubono, Fumio, Ishibashi, Yoshihito, Kusakabe, Susumu
• Granted Patent: US 7,693,174 B2
• Time in Patent Office: Days
• US Class Current: 455/63.100
• CPC Class Codes: H04W 74/0825 with collision detection

Abstract

A communication system equipped with a communication apparatus for transmitting a transmission signal to another communication apparatus via a communication medium, includes: transmission means for transmitting the transmission signal to the other communication apparatus via the communication medium; detection means for detecting a propagation signal propagated through the communication medium each time a predetermined amount of the transmission signal is transmitted from the transmission means; signal collision judgment means for judging from the propagation signal detected by the detection means whether a signal collision occurs on the communication medium between the transmission signal transmitted from the transmission means and another signal transmitted from the other communication apparatus; and control means for controlling transmission of the transmission signal from the transmission means in accordance with a judgment result by the signal collision judgment means.

Claims

1. A communication system equipped with a communication apparatus for transmitting a transmission signal to another communication apparatus via a communication medium, said communication apparatus comprising:

transmission means for transmitting said transmission signal to said other communication apparatus via said communication medium;

detection means for detecting a propagation signal propagated through said communication medium each time a predetermined amount of said transmission signal is transmitted from said transmission means;

signal collision judgment means for judging from said propagation signal detected by said detection means whether a signal collision occurs on said communication medium between said transmission signal transmitted from said transmission means and another signal transmitted from said other communication apparatus; and

control means for controlling transmission of said transmission signal from said transmission means in accordance with a judgment result by said signal collision judgment means.

2. A communication apparatus for transmitting a transmission signal to another communication apparatus via a communication medium, said communication apparatus comprising:

transmission means for transmitting said transmission signal to said other communication apparatus via said communication medium;

detection means for detecting a propagation signal propagated through said communication medium each time a predetermined amount of said transmission signal is transmitted from said transmission means;

signal collision judgment means for judging from said propagation signal detected by said detection means whether a signal 3 collision occurs on said communication medium between said transmission signal transmitted from said transmission means and another signal transmitted from said other communication apparatus; and

control means for controlling transmission of said transmission signal from said transmission means in accordance with a judgment result by said signal collision judgment means.

3. The communication apparatus according to claim 2, wherein said detection means detects said propagation signal each time one bit of said transmission signal is transmitted from said transmission means.

4. The communication apparatus according to claim 2, wherein said signal collision judgment means compares said propagation signal detected by said detection means with said transmission signal transmitted from said transmission means, and if features of said propagation signal and said transmission signal are not coincident, judges that said signal collision occurred.

5. The communication apparatus according to claim 2, wherein said control means controls said transmission means to stop transmission of said transmission signal, if said signal collision judgment means judges that said signal collision occurred.

6. The communication apparatus according to claim 2, wherein if said signal collision judgment means judges that said signal collision occurred, said control means controls a transmission timing of said transmission signal from said transmission means in a next transmission event, in accordance with a value of said transmission signal transmitted from said transmission means when said signal collision occurred.

7. The communication apparatus according to claim 6, wherein said control means controls said transmission timing earlier or later, if the value of said transmission signal transmitted from said transmission means when said signal collision occurred is a predetermined value.

8. The communication apparatus according to claim 2, wherein if said signal collision judgment means judges that said signal collision occurred, said control means controls to increase the number of time slots corresponding to a transmission timing of said transmission means more than the number of present time slots, in a next transmission event.

9. The communication apparatus according to claim 2, wherein said transmission means transmits said transmission signal in one of two time slots corresponding to prepared transmission timings.

10. A communication method for a communication apparatus for transmitting a transmission signal to another communication apparatus via a communication medium, said method comprising:

a transmission step of transmitting said transmission signal to said other communication apparatus via said communication medium;

a detection step of detecting a propagation signal propagated through said communication medium each time a predetermined amount of said transmission signal is transmitted under control of a process of said transmission step;

a signal collision judgment step of judging from said propagation signal detected under control of a process of said detection step whether a signal collision occurs on said communication medium between said transmission signal transmitted under control of the process of said transmission step and another signal transmitted from said other communication apparatus; and

a control step of controlling transmission of said transmission signal from said transmission means in accordance with a judgment result by said signal collision judgment step.

11. A program for making a computer execute a process of transmitting a transmission signal to another communication apparatus via a communication medium, said program comprising:

a transmission step of transmitting said transmission signal to said other communication apparatus via said communication medium;

a detection step of detecting a propagation signal propagated through said communication medium each time a predetermined amount of said transmission signal is transmitted under control of a process of said transmission step;

a signal collision judgment step of judging from said propagation signal detected under control of a process of said detection step whether a signal collision occurs on said communication medium between said transmission signal transmitted under control of the process of said transmission step and another signal transmitted from said other communication apparatus; and

a control step of controlling transmission of said transmission signal from said transmission means in accordance with a judgment result by said signal collision judgment step.