| 摘要 |
In conventional TDMA cellular mobile telephone systems, connections between one mobile station and the network conventionally utilise one time slot per TDMA frame and both the codec and the error control coding applied to the voice signal are based on a fixed number of bits. In areas of high interference, the user can request the enhancement of speech quality manually or by registering a permanent request. The network responds by allocating at least one further slot per TDMA frame to the connection. The same voice information is then spread over two slots while the additional capacity is utilised to implement a more powerful error control coding in addition to, or in place of, the regular error control coding. In a further embodiment, the additional capacity is utilised to apply an improved codec and so ameliorate the speech quality above that even of a fixed line. |
