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In a medium access control (MAC) protocol for a wireless communications network, communications between a control point and other nodes are coordinated by a repeated superframe. This superframe contains in sequence a contention-free period (CFP1), a contention-based period, and second contention-fre

In a medium access control (MAC) protocol for a wireless communications network, communications between a control point and other nodes are coordinated by a repeated superframe. This superframe contains in sequence a contention-free period (CFP1), a contention-based period, and second contention-free period (CFP2). Prior to CFP1 a node hops from one channel frequency to another. CFP2 in a superframe is used for initial transmission of isochronous data (such as voice signals); CFP1 of the following superframe is used for retransmission of any such data which were not correctly received at the first attempt, after the frequency hop at the start of that following superframe. This arrangement minimises delay before retransmission of data, and improves the robustness of the system.

대표청구항 ▼

In a medium access control (MAC) protocol for a wireless communications network, communications between a control point and other nodes are coordinated by a repeated superframe. This superframe contains in sequence a contention-free period (CFP1), a contention-based period, and second contention-fre

In a medium access control (MAC) protocol for a wireless communications network, communications between a control point and other nodes are coordinated by a repeated superframe. This superframe contains in sequence a contention-free period (CFP1), a contention-based period, and second contention-free period (CFP2). Prior to CFP1 a node hops from one channel frequency to another. CFP2 in a superframe is used for initial transmission of isochronous data (such as voice signals); CFP1 of the following superframe is used for retransmission of any such data which were not correctly received at the first attempt, after the frequency hop at the start of that following superframe. This arrangement minimises delay before retransmission of data, and improves the robustness of the system. slot of a frame having predetermined quality requirements and a pseudo-random sequence, and the system for distributing radio channels is adapted to allocate a channel to an incoming call, or to a foreseen incoming call, or to a call in process, the system for distributing radio channels comprising: a) means for setting-up a list of radio channels occupied with calls in process based on said quality requirements; b) means for analyzing the quality requirements of a call to which it is desired to allocate a channel; c) means for comparing said analysis with said list in order to find on said list an occupied radio channel in accordance with a predetermined selection criterion; d) means for releasing said occupied radio channel of said time slot; and e) means for allocating to said call the released radio channel within said time slot. 12. The system for distributing radio channels according to claim 11, wherein the means for setting-up a list of radio channels occupied with calls in process are included in said fixed unit. 13. The system for distributing radio channels according to claim 11, wherein the means for releasing an occupied radio channel are included in said fixed unit. 14. The system for distributing radio channels according to claim 13, wherein said means for releasing an occupied radio channel generate an initiation message for a handover procedure. 15. The system for distributing radio channels according to claim 11, wherein the means for allocating a channel to said call are included in said fixed unit. 16. The system for distributing radio channels according to claim 11, wherein the means for analysing the quality requirements are incorporated in said fixed unit. 17. The system for distributing radio channels according to claim 11, wherein the system is applied to CDMA communications systems. 18. A fixed unit for distributing radio channels among a plurality of remote units in a radio-communications system, said fixed unit, wherein a radio channel corresponds to a time slot of a frame having predetermined quality requirements and a pseudo-random sequence, and the fixed unit is adapted to allocate a channel to an incoming call, or to a foreseen incoming call, or to a call in process, the fixed unit comprising: a) means for setting-up a list of radio channels occupied with calls in process based on said quality requirements; b) means for analyzing the quality requirements of a call to which it is desired to allocate a channel; c) means for comparing said analysis with said list in order to find on said list an occupied radio channel in accordance with a predetermined selection criterion; d) means for releasing said occupied radio channel of said time slot; and e) means for allocating to said call the released radio channel within said time slot. 19. The fixed unit according to claim 18, wherein the means for releasing said occupied radio channel orders a remote unit using said occupied channel to execute a handover procedure.