| 摘要 |
<p>A communication system includes a base station, called a ''Controller'' and one or more remote or satellite stations, each called a ''Communicator''. The controller arbitrates, controls and communicates with the communicators which are in range to receive its transmissions. The communicators receiving a particular controller's transmission form a network for that controller for the period in which reception occurs. The controller is the only generator of electromagnetic radiation which it modulates with information relating to its own identity, transactions it undertakes and information it transfers. Each communicator modulates and re-radiates the received transmission using back-scatter. Back-scatter re-radiation keeps the communicator design simple and allows for very sensitive receiver design in the controller. In operation, the controller initiates communication with each communicator by establishing, through a handshake exchange, the unique communications channel it will maintain with that communicator. Once channels are established, the controller repetitively polls each communicator for a sequential, cumulative interchange of data. The controller continually looks out for new communicators entering its network and de-activates polling of communicators whose transactions are complete. Whenever a network is not active because there are no communicators present, or any in need of a transaction or data interchange, the controller polls at a reduced rate.</p> |
