Call set-up in a transmission trunking radio system

Claim 2

A call control method in a transmission trunking radio system, comprising the steps of: sharing M traffic channels by simultaneous on-going calls of N mobile stations in maximum according to a transmission trunking method, N and M being positive integers and N>M; requesting traffic channel for each call transaction by said mobile stations via a control channel during said calls; allocating to any one of said N mobile stations requesting a traffic channel any one of said M traffic channels, if available, for a duration of a call transaction, and deallocating said traffic channel and commanding said one mobile station to return onto said control channel after completion of said call transaction; registering collision of call transactions, if the radio system, due to a lack of available traffic channels, fails to immediately allocate any one of said M traffic channels to any one of said N mobile stations requesting a traffic channel; collecting data about collisions of call transactions of different calls on said M traffic channels; and automatically adjusting the allowed maximum number N of simultaneous calls in accordance with the collected data.

Claim 3

The method of claim 1, further comprising the steps of: initiating the call transaction by activating a pressel in the mobile station; and terminating the call transaction by releasing the pressel in the mobile station.

Claim 4

The method of claim 1, further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with the number of collisions of call transactions.

Claim 5

The method of claim 3, further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with the frequency of collisions of call transactions.

Claim 6

The method of claim 3 further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with a ratio of such channel allocation attempts which have caused collisions to the total number of allocation attempts in a time unit.

Claim 7

The method of claim 1, further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with the frequency of collisions of call transactions.

Claim 8

The method of claim 6, further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with the ratio of such channel allocation attempts which have caused collisions to a total number of allocation attempts in a time unit.

Claim 9

The method of claim 1, further comprising the step of: adjusting the allowed maximum number N of simultaneous calls in accordance with a ratio of such channel allocation attempts which have caused collisions to the total number of allocation attempts in a time unit.

Claim 10

The method of claim 1, wherein said step of adjusting comprises, in connection with every channel allocation attempt, the further steps of: measuring a time elapsed since a previous collision; integrating the maximum number N of simultaneous calls downwards if the allocation attempt causes collision of call transactions; and integrating the maximum number N of simultaneous calls upwards if the allocation does not cause collision of call transactions.

Claim 11

Transmission trunking radio system, comprising: a plurality of base station sites; a plurality of mobile stations; at least one of said base station sites having at least one control channel and at least M traffic channels for shared use of simultaneous on-going calls of N mobile stations in maximum according to a transmission trunking method, N and M being positive integers and N>M; said N mobile stations being arranged to request traffic channel for each call transaction via said control channel during said calls; a call control unit arranged to allocate to any one of said N mobile stations requesting a traffic channel any one of said M traffic channels, if available, for a duration of a call transaction, and to deallocate said traffic channel and to command said one mobile station to return onto said control channel after completion of said call transaction; means for collecting data on collisions of call transactions of different calls on said M traffic channels, a collision of call transactions being detected, if said call control unit, due to a lack of available traffic channels, fails to immediately allocate any one of said M traffic channels to any one of said N mobile stations requesting a traffic channel; and means for automatically adjusting the allowed maximum number of simultaneous calls in accordance with the collected data.

Claim 12

Transmission trunking radio system, comprising: a plurality of base station sites; a plurality of mobile stations; at least one of said base station sites having at least one control channel and at least M traffic channels for shared use of simultaneous on-going calls of N mobile stations in maximum according to a transmission trunking method, N and M being positive integers and N>M; said N mobile stations being arranged to request traffic channel for each call transaction via said control channel during said calls; a call control unit arranged to allocate to any one of said N mobile stations requesting a traffic channel any one of said M traffic channels, if available, for a duration of a call transaction, and to deallocate said traffic channel and to command said one mobile station to return onto said control channel after completion of said call transaction; means for collecting data on collisions of call transactions of different calls on said M traffic channels, a collision of call transactions being detected, if said call control unit, due to a lack of available traffic channels, fails to immediately allocate any one of said M traffic channels to any one of said N mobile stations requesting a traffic channel; and means for automatically adjusting the allowed maximum number of simultaneous calls in accordance with the collected data.