Radio communication apparatus and method for preventing hidden terminals from interrupting communications

• US 5,754,947 A
• Filed: 03/14/1995
• Issued: 05/19/1998
• Est. Priority Date: 03/15/1994
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Co. (Panasonic Holdings Corporation)
• Inventors: Takai, Hitoshi, Tanabe, Takumi, Asano, Hiroaki
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US08/404,047
• Time in Patent Office: 1,162 Days
• Field of Search: 370/85.11, 370/85.2, 370/85.3, 370/524, 455/33.1, 455/34.1, 455/54.1, 455/54.2, 455/56.1, 455/58.2, 455/67.1, 455/63, 455/9, 455/68, 455/69
• US Class Current: 455/515
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A radio communication method for transmitting and receiving data between a first terminal and a second terminal comprises the following two steps. A step of establishing a connection between the first terminal and the second terminal when the first terminal and the second terminal have detected that a signal has not been transmitted on a predetermined channel, and the other step of starting data communications between the first terminal and the second terminal which have established the connection, and transmitting the predetermined signal on the predetermined channel from both the first terminal and the second terminal throughout the data communications.

Claims

1. A radio communication method for transmitting and receiving data between a first terminal and a second terminal, wherein each terminal may not be able to hear signals sent by all other terminals, said method comprising the steps of:

establishing a connection between the first terminal and the second terminal when the first terminal and the second terminal have detected that any signal has not been transmitted on a predetermined channel, wherein each of the first terminal and the second terminal is assigned a data channel provided for connection establishment and data transmission and a control channel, said predetermined channel being the control channel, the connection establishment step comprising the steps of;

detecting a presence or absence of said signal transmitted on said predetermined channel, by the first terminal;

transmitting a first control signal from the first terminal to the second terminal in a case where the absence of said signal transmitted on said predetermined channel has been detected by the first terminal;

detecting a presence or absence of said signal transmitted on said predetermined channel, by the second terminal, when the second terminal has received the first control signal;

starting a transmission of said signal on the control channel from the second terminal, at a predetermined time point after a completion of detecting the presence or absence of said signal transmitted on the control channel by the second terminal;

transmitting a second control signal from the second terminal to the first terminal in a case where the absence of said signal transmitted on said predetermined channel has been detected by the second terminal;

receiving the second control signal by the first terminal; and

transmitting said signal on the control channel from the first terminal concurrently with a transmission of the first control signal from the first terminal; and

starting data communications between the first terminal and the second terminal which have established the connection, and simultaneously transmitting a predetermined signal on said predetermined channel from both the first terminal and the second terminal and continuing to transmit the predetermined signal throughout the data communications.

2. A radio communication apparatus for transmitting and receiving data to and from a desired radio communication apparatus, wherein each radio communication apparatus may not be able to hear signals sent from all other apparatus, the radio communication apparatus comprising:

a connection establishment means for detecting a presence or absence of any signal transmitted on a predetermined channel, and for establishing a connection with said desired radio communication apparatus when the absence of said signal transmitted on said predetermined channel has been detected;

a data communication means for starting data communications with said desired radio communication apparatus, responding to the connection establishment; and

a signal transmission means for transmitting simultaneously with the data, a predetermined signal on said predetermined channel from both the radio communication apparatus and said desired radio communication apparatus and continuing to transmit the predetermined signal throughout the data communications;

wherein said connection establishment means comprises;

a detection means for detecting a presence or absence of said signal transmitted on said predetermined channel;

a control signal transmission means for selectively transmitting one of a first control signal and a second control signal;

a control signal reception means for receiving the first control signal and the second control signal; and

a control means for controlling said control signal transmission means to transmit the first control signal when said detection means has detected the absence of said signal transmitted on said predetermined channel in a case where the radio communication apparatus is a transmitting terminal, and for, in a case where the radio communication apparatus is a receiving terminal, controlling said control signal transmission means to transmit the second control signal to said desired radio communication apparatus after the first control signal has been received by said control signal reception means and said signal has been detected to be absent on said predetermined channel by said detection means, the control means comprising;

a receiving terminal signal transmission control means for controlling the signal transmission means to start a transmission of the predetermined signal on a control channel at a predetermined time point after a detection of the absence of said signal transmitted on the control channel and before a commencement of the data communications, in a case the radio communication apparatus has received the first control signal; and

a transmitting terminal signal transmission control means for controlling said signal transmission means to continue the transmission of the predetermined signal on the control channel while said control signal transmission means is transmitting the first control signal;

wherein said control signal transmission means transmits the first control signal and the second control signal on the data channel, said data communication means performs data communications on the data channel, and said predetermined channel is a control channel provided apart from the data channel.