| 摘要 |
A method and apparatus enabling operation of a dual mode TDNA portable telephone unit (12) are disclosed. The first mode (20) of operation enables synchronous communication up to 75 kilometers. In the second mode (22) of operation, the portable telephone unit (12) operates according to a frame structure (24) enabling synchronization between the portable telephone unit (12) and the base station (10) for ranges greater then 75 kilometers. This increased range is achieved by moving the transmission timeslot (24c) within the frame structure (24) of a TDMA transmission in the second mode (22) to a later timeslot than in the frame structure (24) of the first mode (20). |
