| 摘要 |
PURPOSE:To change easily the line concentration ratio in accordance with increment of the traffic intensity, by assigning channels of subscriber-side highways fixedly to corresponding subscribers and assinging channels of channel-side highways variably to subscribers. CONSTITUTION:Plural subscriber terminals 11-1n are multiplexed successively on low-speed highways (HW) 31-3m and 41-4m and high-speed HWs 71 and 73 through subscriber's circuit units 21-2m and multiplexing and demultiplexing circuits 51 and 61. These HWs 31-3m, 41-4m, 71, and 73 have service channels (CH) assigned fixedly to corresponding subscriber terminals, and control CHs. HWs 71 and 73 are concentrated and connected to central station-side HWs 72 and 74 through a line concentrating switch 81 and are connected to the central station through multiplexing and demultiplexing circuits 52 and 62 and low-speed HWs 101-10l and 111-11l. HWs 72, 74, 101-10l, and 111-11l have CHs assigned veriably to subscribers. The connection control is performed through a buffer device 91, a scan memory 92, and a distributing circuit 93 by a controller which is not shown in figure. |
