Asynchronous or statistical time division multiplexing, Computer Networking

Assignment Help:

Asynchronous or Statistical Time Division Multiplexing

As we  have seen  synchronous  TDM does not  guarantee that the full capacity of a link in sued. In fact it is more likely  that only  a portion of the  time slots are in use at a given  instant. Because  the time  slots  are reassigned and  fixed whenever a connected device is not  transmitting, the  corresponding  slot is empty and that much   capacity of the path  is wasted. For  example imagine that we have multiplexed the output of 20 identical computer onto a single line. Suing synchronous TDM the speed  of that line must be at  least 20 times the speed of each input line. But  what  if only 10 computers  are in use at a time ? half of the capacity  of the line  is wasted.

Statistical  time  division  multiplexing is designed to avoid this type of waste. As with  the term  synchronous. The term  asynchronous means some  things   different  in multiplexing  that it  means  in other  areas of data communications. Here it  flexible  or not  fixed.

Like synchronous TDM asynchronous TDM allows  a number of lower  speed  input  lines  to be  multiplexed  to a single  higher speed  line. Unlike  synchronous  TDM however in asynchronous TDM the total  speed of the input  can be greater than  the capacity  of the path. In a synchronous systems if we have in  input  lines. The frame contains a fixed number of a least m time  slots. In  an asynchronous systems. If  we have  n input line the  frame contains no more  than  m slots with m less than n. In  this way asynchronous TDM supports  the same  number of input lines as synchronous TDM with a lower capacity  link or given the same  link. Asynchronous TDM can support more  devices  than  synchronous TDM.

1558_Asynchronous or Statistical Time Division Multiplexing.gif

figure Asynchronous TDM

The number  of time  slots in an asynchronous TDM fame is based on a statistical analysis of the number  of input lines that are likely to be transmitting at any given  time. Rather than being reassigned each slot  is available to any  of the attached input lines  that has data  to seen. The  multiplexer scans the input lines accept portions of data until a frame is felled and then sends the frame across the link. If  there are not enough data to  fill all the  slot s in a frame the frame a transmitted only partially filled thus full link capacity  may not be used 100 percent   of the time. But  the ability to allocate time slots  dynamically coupled with  the lower  ration of the slots  to input  greatly reduces the likelihood and degree  of waste.

 

 


Related Discussions:- Asynchronous or statistical time division multiplexing

What is mesh network, What is mesh network? A network in which there ar...

What is mesh network? A network in which there are many network links among computers to provide multiple paths for data to travel.

Define unicast - multicast and reserved addresses, Q. Define Unicast - Mult...

Q. Define Unicast - Multicast and Reserved Addresses? Unicast, Multicast, and Reserved Addresses Unicast address - identifies a specific device Multicast address

State the specification of high-end server, State the specification of high...

State the specification of high-end server A mid-range or high-end server with the following specifications would be sufficient for a medium to large organisation: A Pentiu

What security risks present on the networks, Security risks present on the ...

Security risks present on the networks Lots of risks are present everywhere on Internet as well as on Intranet, if it is not known what is being done. Every day a number of

Explain about star backbone network, Q. Explain about Star Backbone network...

Q. Explain about Star Backbone network? - Collapsed or switched backbone - Backbone is just one switch that connects LANs - Utilized as distribution backbone inside a bui

What do mean by tunnel mode, What do mean by tunnel mode? This is a mod...

What do mean by tunnel mode? This is a mode of data exchange wherein two communicating computers do not use IPSec themselves. Instead, the gateway that is linking their LANs to

Write down short note on frame-relay dlci, DLCI- Data Link Connection Iden...

DLCI- Data Link Connection Identifier. A frame-relay service provider usually assigns DLCI values that are used by frame-relay to distinguish among different virtual circuits on th

Database management, University of Wolverhampton School of Technology 6CI00...

University of Wolverhampton School of Technology 6CI007 Database Server Management Resit Assessment Hand in December 14th 2012 In this assignment you will build a small database t

Define the term - frame and packets, Define the term - frame and packets ...

Define the term - frame and packets Frames sum up packets. When a packet arrives at data link layer, the complete packet, header, data and remaining all, is used as data field

Network topology and design, Question 1: The following is a dump of a T...

Question 1: The following is a dump of a TCP header in hexadecimal format: 00CD0018 00000EF1 00000D5D 502200D1 01BF0010 Please answer the following two parts of questions

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd