发明名称 |
DATA MODULATION ARRANGEMENT FOR SELECTIVELY DISTRIBUTING DATA |
摘要 |
A cable television distribution arrangement is supplied via optical fibers with additional digital signals which are delivered to customers via coaxial drop cables modulated at frequencies above those of the conventional analog television channels. A reduction in the required number of modulators is achieved, while delivering individually selected signals to individual customers, by supplying digital signals for a group of customers to a first modulator and a pseudo dam signal to a second modulator, and selecting between the outputs of the two modulators individually for each customer in the group. Switching between the outputs of the modulators is carried out during overhead information which is additionally supplied commonly to both modulators. |
申请公布号 |
EP0737403(B1) |
申请公布日期 |
1999.02.03 |
申请号 |
EP19950902019 |
申请日期 |
1994.12.07 |
申请人 |
NORTEL NETWORKS CORPORATION |
发明人 |
WARWICK, ALASTAIR, ANTHONY |
分类号 |
H04N7/16;H04N7/173;H04N21/61 |
主分类号 |
H04N7/16 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|