METHOD FOR CONTENTION RESOLUTION IN TIME-HOPPING OR FREQUENCY-HOPPING

摘要

The invention is related to a method of transmitting data, whereby a transmission channel towards an access point is shared among a plurality of users. The data is transmitted by using a multiple access frame divided in logical slots. According to the invention each data packet is divided into k units which are decoded by an (n,k) decoder, producing n−k redundant units. The n units are transmitted within a multiple access frame in n different slots according to a time-hopping pattern, a frequency-hopping pattern or a combination of both. Thereby, the positions of the n units composing a data packet are written in a header appended to each unit.;At the receiver side lost or corrupted data packets are recovered by using the redundant units, whereby the presence of a unit for each slot is detected. If a unit is present in a slot and has been transmitted without collisions, this unit is recovered. The recovered unit and its header are stored in a memory together with an index of the slot where they have been recovered. If a sufficient k+δ amount of units composing a data packet is recovered, the packet level decoder is used to recover the remaining n−k−δ units which experienced collisions in the respective slots.;According to the invention the interference caused by the n−k−δ units from the slots where they were transmitted is removed by using the information about the position of the units contained in the header of the recovered k+δ units. Afterwards, the units of other data packets which have experienced a collision with the n−k−δ units are recovered.