Congestion control in a communication network based on the CSMA/CA protocol

A communication device for a communication system supporting layered radio channel structure for enabling communication between at least the communication device and another communication device, the layered structure comprising at least a physical layer and a medium access layer, the communication system offering a first type of service with a first priority order and a second type of service with a second priority order with messages comprising a preamble and a payload can be transmitted between devices, each physical layer and medium access layer message being separated by at least a period corresponding to a minimum allowable period between two messages, the communication device comprising:

• a physical layer message generator configured to generate a physical layer message pertaining to the first type of service;
• a radio channel detector configured to sense the radio channel idle for at least a period corresponding to the minimum allowable period between two messages;
• and
• a transmitter configured to transmit the physical layer message comprising a preamble indicative of the type of service the message pertains, wherein the content of the preamble is arranged to be detected by the other communication device within a communication range even if the payload of the transmitted physical layer message is corrupted by interference.

A congestion control method for a communication system supporting layered radio channel structure for communication between at least a first communication device and a second communication device, the layered structure comprising at least a physical layer and a medium access layer, the communication system offering a first type of service with a first priority order and a second type of service with a second priority order with messages comprising a preamble and a payload transmitted between devices, each physical layer and medium access layer message being separated by at least a period corresponding to a minimum allowable period between messages, the method comprises the following acts performed by the first communication device:

• generating a physical layer message pertaining to the first type of service;
• sensing the radio channel idle for at least a period corresponding to the minimum allowable period between messages;
• and
• transmitting the physical layer message comprising a preamble indicative of the type of service the message pertains, wherein the content of the preamble is arranged to be detected by the second communication device within a communication range irrespective of the decoding state of the payload of the transmitted message,
• wherein the preamble further comprises an indication to the second communication device to refrain from any transmissions of messages pertaining to the service of the second type and to backoff with the maximum contention window size.

A congestion control method for a communication system supporting layered radio channel structure for communication between at least a first communication device and a second communication device, the layered structure comprising at least a physical layer and a medium access layer, the communication system offering a first type of service with a first priority order and a second type of service with a second priority order with messages comprising a preamble and a payload transmitted between devices, each physical layer and medium access layer message being separated by at least a period corresponding to a minimum allowable period between messages, the method comprises the following acts performed by the first communication device:

• generating a physical layer message pertaining to the first type of service;
• sensing the radio channel idle for at least a period corresponding to the minimum allowable period between messages;
• and
• transmitting the physical layer message comprising a preamble indicative of the type of service the message pertains, wherein the content of the preamble is arranged to be detected by the second communication device within a communication range irrespective of the decoding state of the payload of the transmitted message,
• wherein the preamble further comprises an indication for the second communication device to transmit a warning message to a third communication device for preventing the third communication device from transmitting messages pertaining to the second type, wherein the warning message is a medium access control layer message.

A communication device for a communication system supporting layered radio channel structure for enabling communication between at least the communication device and another communication device, the layered structure comprising at least a physical layer and a medium access layer, the communication system offering a first type of service with a first priority order and a second type of service with a second priority order with messages comprising a preamble and a payload transmitted between devices, each physical layer and medium access layer message being separated by at least a period corresponding to a minimum allowable period between two messages, the communication device comprising:

• a physical layer message generator configured to generate a physical layer message pertaining to the first type of service;
• a radio channel detector configured to sense the radio channel idle for at least a period corresponding to the minimum allowable period between two messages;
• a transmitter configured to transmit the physical layer message comprising a preamble indicative of the type of service the message pertains, wherein the content of the preamble is arranged to be detected by the other communication device within a communication range irrespective of the decoding state of the payload of the transmitted physical layer message;
• and
• a medium access control message generator configured to generate a warning message upon reception of the message pertaining to the first type of service.