Process and devices for selective collision detection
View Patent ↗The present invention concerns a method in a network including at least a first device and a second device, where the sending of a packet by two devices simultaneously generates a collision. The method includes the steps of emitting by the first device a packet comprising a first part, and a second part including at least an identification of a source and a destination of the packet, receiving the first part of the packet by the second device; and in the case of the second device detecting a collision during the reception of the second part of the packet, issuing a packet indicating collision detection by the second device.
1. Method in a network comprising at least a first device and a second device, where the sending of a packet by two devices simultaneously generates a collision, wherein it comprises, at the second device, the steps of:
receiving a packet comprising a first part and a second part, said second part comprising at least an identification of a source address and a destination address of the packet;
in the case of detecting a collision during the reception of the first part of the packet, not issuing a packet indicating a collision detection; and
in the case of detecting a collision during the reception of the second part of the packet, after having correctly receiving said first part of said packet, issuing a packet indicating a collision detection,
wherein said packet indicating a collision detection does not comprise any source or destination address.
2. Method according to claim 1 , wherein in the case of not detecting any collision during the reception of the packet, the method further comprises the step of issuing a packet indicating no collision detection, wherein said packet indicating no collision detection does not comprise any source or destination address.
3. Method according to claim 1 , wherein the step of receiving said first part of said packet comprises a step of identifying whether a collision detection field is present in said first part of the packet, and if said field is present, performing collision detection mechanism for said packet.
4. Method according to claim 1 wherein that said network is a wireless local area network.
5. Device intended to receive a packet, said packet comprising a first part with collision detection field and a second part containing at least an identification of a source and a destination of the packet, in a network where the sending of a packet by two devices simultaneously generates a collision, wherein said device comprising:
means for identifying collision detection field in said first part of said received packet;
means for detecting a collision during the reception of the second part of the packet;
means for issuing a packet indicating a collision detection in the case of detecting a collision during the reception of the second part of the packet, after having correctly received said first part of said packet without collision, and not issuing a packet indicating a collision detection in the case of detecting a collision during the reception of the first part of the packet, wherein said packets indicating a collision detection and no collision detection do not comprise any source or destination address.