| 摘要 |
In some communications systems such as the Terrestrial Trunked Radio (TETRA) system, it is not possible to use a standard receiver for monitoring the airwaves as the downlink channel needs to be demodulated and decoded to determine how the uplink channel is formatted with respect to interleaving, transmission slots encryption schemes and the like. The present monitor 36 therefore includes means 34 for receiving a downlink transmission and means for interpreting the received transmission to obtain the formatting information. This information can then be used to interpret uplink transmissions from the remote station 26. |
