| 摘要 |
A multiframe structure is adapted to transmit narrowband telephony signals over a broadband cable link (BCL) carrying also video or television signals. The telephony transmission occurs according to classical telephony protocols such as the channel associated signalling (CAS) or the common channel signalling (CCS) protocols, which are mapped into the multiframe structure. The multiframe is transmitted according to the time division multiple access (TDMA) technique and each frame thereof has 40 time slots (TS00-TS39) carrying bursts of data. The frames include time slots carrying signalling bursts (S01-S30; S01-S04) of telephony signalling information and time slots carrying traffic bursts (D01-D30, C01-C36) of telephony traffic data. For the CCS, the time slots (TS00-TS03) carrying signalling bursts (S01-S04) are grouped within the frames so as to form a wideband common channel, whilst for the CAS, time slots (TS04, TS09, TS14, . . . , TS39) carrying signalling bursts are separated by four time slots carrying traffic bursts (D01-D30) and are distributed over all the frames of the multiframe structure on a periodic basis. The multiframe handling protocol is adapted to the above multiframe structure wherein at least one time slot (TS00-TS01; TS00-TS03) per frame carries a control burst of cable link operation signalling which is exchanged between a telephony access node (TAN) and subscriber stations (HOME) via the broadband cable link (BCL). The telephony access node (TAN) is adapted to load the address of a subscriber station into one of the time slots carrying control bursts and each subscriber station is adapted to recognize its own address in these time slots. When a subscriber station has recognized its own address in one of the time slots carrying control bursts, any kind of information may be exchanged between the telephony access node and the subscriber station through this one time slot.
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