Channel granting in telecommunication networks and methods therefor

A cellular telephone network provides cells P1,P2,P3... which serve the subscribers of more than one subscriber system; e.g. a GSM system and a micro-cellular system. In order to prevent subscribers from one of the systems using all the available channels in any cell at any time, thus blocking out the other system, information is pre-stored for each cell defining the average proportion of the number of bids for channels from subscribers to each of the systems which can be granted at any particular time having regard to the number of channels available at the time of each such bid. In response to a bid from a subscriber to a particular one of the systems, the stored information relating to that system, and in accordance with the number of channels available at the time of that bid, is accessed, and a decision whether or not to grant the bid is made so as to maintain the actual average porportion of bids granted substantially in agreement with the pre-stored value. For example, in response to each such bid a pseudo-random number can be generated: if the value of this number is less than the value pre-stored for the average proportion of bids which can be granted, the bid is granted; otherwise, the bid is blocked.