摘要 |
A radio telecommunication system has radio channels, each radio channel including a plurality of slots generated by time division. The system encompasses a plurality of areas having a base station which sends a first signal over a predetermined slot of the slots. If the signal quality of the first signal received by a portable apparatus is less than a criterion, non-used at least one of the slots is designated. The portable apparatus sends a second signal over the predetermined slot and the designated slot. <IMAGE> |