| 摘要 |
A digital cellular telecommunication network (30) uses transcoders (50) which vocode voice using a maximal lossy compression algorithm which conserves spectrum usage. A call path for an intercepted call is looped from an outer space satellite (32) network into an intercepting terrestrial gateway (34). Compressed call data for each of two half-calls in this call path bypass normal transcoders (50) through the use of rate adapters (80) which translate between data communication protocols that operate at different data rates without voice coding and decoding. After rate adaptation, the compressed call data are combined in a conference bridge (90), and routed to a monitoring center (60). A subscriber unit (36), a second device (48), and the monitoring center (60) all receive call data which has experienced only one compression/decompression cycle. |
