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 do you mean by flow control, Q. What do you mean by Flow Control? ...

Q. What do you mean by Flow Control? - How much data sender is capable to transmit before receiving the ACK - Why flow control? - Limitation with receiver 1. Processin

Use of coaxial cable, Has a central core conductor covered in an insulating...

Has a central core conductor covered in an insulating sheath encased in an outer conductor of metal foil  RG numbers indicate physical specs such as thickness and type of insula

Mesh, Mesh It is of two dimensional network.  In this every processi...

Mesh It is of two dimensional network.  In this every processing elements are arranged in a two dimensional grid. The processor are in rows i and column j are denoted by PEi

Explain cross bar interconnection networks, Cross Bar : The crossbar networ...

Cross Bar : The crossbar network is simplest interconnection network. It has a double dimensional grid of switches.  It's a Non-blocking network and offers connectivity between out

What are routers, What are routers? Routers work to connect two or more...

What are routers? Routers work to connect two or more network segments. These are the most intelligent network devices that store information in its routing table like paths, h

State the fundamental principles of 3gpp security, Question : a) What ...

Question : a) What does association refer to in IEEE 802.11? b) State the fundamental principles of 3GPP security. c) Explain the term "binding" in Mobile IPv6 d)

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

Fiber optic extension, FIBER OPTIC EXTENSION:  The LAN extension using f...

FIBER OPTIC EXTENSION:  The LAN extension using fiber optic is given in the figure below:   Figure The fiber-modem translates digital data into pulses of light the

Introduction to operations research, explain the three classification of op...

explain the three classification of operation research

Distinguish between network devices computers and servers, The School of Co...

The School of Computing is planning to deploy a new network structure to accommodate the following scenario. Please make suggestions on how this LAN can be designed based on the fl

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