1.同步TDM:
同步时分复用(STDM),其中存在的每个设备都已指定了相同的时隙来传输数据。这不考虑设备是否包含数据。设备在其时隙到达时将其数据放置在链接上,而当任何设备不包含数据时,其时隙将保持为空。存在被组织成帧的各种时隙,并且每个帧由专用于每个发送设备的一个或多个时隙组成。
2.统计TDM:
统计时分多路复用(STDM)是一种用于通过一条传输电缆或线路同时传输几种类型的数据的技术。它通常用于管理通过局域网(LAN)或广域网(WAN)传输的数据。在这种情况下,通常会同时从网络上连接的任意数量的输入设备(包括计算机,打印机或传真机)传输数据。它也可以用于电话总机设置中,以管理同时打入或来自多条内部电话线的呼叫。
同步TDM与统计TDM之间的区别:
S.No. | Synchronous TDM | Statistical TDM |
1. | The data flow of each input connection is divided into units and each input control one output time slot. | The slots are allotted dynamically. Input line is given slots in output frame only if it has data to send. |
2. | In this, number of slots in each frame are equal to number of input lines. | In this, number of slots in each frame are less than the number of input lines. |
3. | The maximum bandwidth utilization is done when all inputs have data to send. | The volume of link is normally is less than the sum of the volume of each channel. |
4. | In this de-multiplexer at receiving end decomposes each frame, discards framing bits and draw out data unit in turn. This draw out data unit from frame is then passed to destination device. | In this de-multiplexer at receiving end decomposes each frame, by checking local address of each data unit. This draw out data unit from frame is then passed to destination device. |
5. | It uses synchronization bits at the beginning of each frame. | It does not used synchronization bits. |
6. | Slots in this carry data only and there is no need of addressing. | Slots in this contain both data and address of the destination. |
7. | In this, buffering is not done, frame is sent after a specific interval of time whether it has data to send or not. | In this, buffering is done and only those inputs are given slots in output frame whose buffer contains data to send. |