| 摘要 |
A broadcast television relay transmission system comprises a relay station (16) which receives (17, 18) a TV signal from a parent transmitter (14) and re-transmits it over a relay transmitter (20, 21). Local information e.g. a local weather map may be required to replace the signal from the parent transmitter. To this end a computer (22) has a non-volatile store (23) to store the various components of the weather map, background map and icons etc., and a local studio centre (30) transmits instructions identifying the required picture components and their desired locations. The signal may be transmitted by telephone link (32) and modem (34), or may be included in the signal transmitted by the parent transmitter (14) and downloaded via a receiver/decoder (26). It is thus not necessary to maintain a video bandwidth landline or similar link with the relay station. |
