摘要 |
<p>An information transmission system comprises a primary station and a number of secondary stations, information being transmitted from the primary station during traffic time periods which are interspersed in time with control time slots. The control time slots contain control data (CD) which contains a number of identifying indications (CMD1,CMD2,CMD3,CMD4) which each may include an address relating to a secondary station for which succeeding traffic information is intended. The identifying indications may be configured in a number of different ways, for example (E1), it may contain an address (A) and a traffic position identifier (XN). It may also contain, for example (E2), a channel identifier (CH). The information in the control slots allows secondary stations, which may be powered down for substantial periods of time, to prepare for reception of succeeding information if an address identifying that secondary station is included in the control data (CD). <IMAGE></p> |