Method for controlling a communications channel shared by several stations

• US 20030050083A1
• Filed: 09/04/2002
• Published: 03/13/2003
• Est. Priority Date: 12/13/1999
• Status: Active Grant

• Current Assignee: Cassidian Limited (Airbus SE)
• Original Assignee: EADS Secure Networks
• Inventors: Le Gal, David, Metais, Jean-Pierre
• Granted Patent: US 7,136,663 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication system able to provide multiple path communication between a plurality of stations operating on a single channel. The stations are synchronized and a cyclically repeating series of time slots is defined. One time slot in each cycle is reserved for the transmission of synchronization information by a station designated the master station for reception by the other stations, designated slave stations, and maintaining synchronization therein. Another time slot is reserved for any slave station to transmit a message that it requires to communicate to another station, such indication preferably being by transmitting its own pre-assigned address code. The remaining time slots are used for transmitting address information and data. The slave stations operate in a low power condition except during one of the other time slots when they may receive their own address, or except when they need to transmit data.

Claims

1. A method for controlling a channel shared by several transmitting/receiving stations, comprising at least one phase of use of the channel by a station participating in a communication, in the course of which said station transmits traffic information on the channel, followed immediately by a phase of retention of the channel by said station, in the course of which said station transmits signaling information authorizing each other station participating in the communication to transmit in turn traffic information on the channel, the phase of retention of the channel by said station continuing, so long as the communication is in progress, until another phase of use of the channel by a station participating in the communication.

2. The method as claimed in claim 1, in which, in the phase of use of the channel, said station furthermore transmits signaling information requesting each other station participating in the communication not to transmit traffic information.

3. The method as claimed in claim 2, in which said station operates in the phase of use of the channel according to a first frame structure comprising at least time intervals for the transmission on the channel of the traffic information and time intervals for the transmission on the channel of the signaling information, and in which said station operates in the phase of retention of the channel according to a second frame structure comprising at least time intervals for the transmission on the channel of the signaling information and time intervals for the reception of signals originating from another station participating in the communication and beginning to transmit traffic information on the channel, the reception of said signals ending the phase of retention of the channel by said station, replaced by a phase of use of the channel by said other station.

4. The method as claimed in claim 3, in which the first and second frame structures furthermore comprise time intervals for the reception of signals originating from stations not participating in the communication.

5. The method as claimed in any one of the preceding claims, in which said signaling information comprises data for identifying the stations participating in the communication.

6. The method as claimed in any one of the preceding claims, in which said signaling information comprises data indicating a level of priority of the communication.

7. The method as claimed in any one of the preceding claims, in which said signaling information comprises a reference for identifying the communication.

8. A station for transmitting/receiving on a shared channel, comprising:

means of use of the channel in master mode in the course of a communication, which are designed to transmit traffic information on the channel;

means of retention of the channel in master mode in the course of a communication, which are designed to alternately transmit signaling information on the channel and to listen to the channel, said signaling information authorizing each other station participating in the communication to transmit in turn traffic information on the channel;

means of reception in slave mode for receiving traffic and signaling information transmitted in master mode by another station participating in the communication; and

means of control for activating the means of use of the channel in master mode in response to a request for use when signaling information authorizing the transmission of traffic information has been received by the means of reception in slave mode, so as to activate the means of retention of the channel in master mode in response to a deactivation of the means of use of the channel in master mode, and to activate the means of reception in slave mode in response to the reception of signals originating from another station participating in the communication by the means of retention of the channel in master mode listening to the channel.

9. The transmitting/receiving station as claimed in claim 8, in which the means of use of the channel in master mode are designed to transmit, furthermore, signaling information requesting each other station participating in the communication not to transmit traffic information.

10. The transmitting/receiving station as claimed in claim 9, in which the means of use of the channel in master mode operate according to a first frame structure comprising at least time intervals for the transmission on the channel of the traffic information and time intervals for the transmission on the channel of the signaling information, and in which the means of retention of the channel in master mode operate according to a second frame structure comprising at least time intervals for the transmission on the channel of the signaling information and time intervals for channel listening.

11. The transmitting/receiving station as claimed in claim 10, in which the first and second frame structures furthermore comprise time intervals for the reception of signals originating from stations not participating in the communication.

12. The transmitting/receiving station as claimed in any one of claims 8 to 11, in which said signaling information comprises data for identifying the stations participating in the communication.

13. The transmitting/receiving station as claimed in any one of claims 8 to 12, in which said signaling information comprises data indicating a level of priority of the communication.

14. The transmitting/receiving station as claimed in any one of claims 8 to 13, in which said signaling information comprises a reference for identifying the communication.