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

Medium earth orbiting satellite, Medium Earth Orbiting satellite is an orbi...

Medium Earth Orbiting satellite is an orbit which is located just above the few hundred miles to a few thousands above the earth surface. It is of higher advantage than Low orbit s

What is dos, What is DoS? A do, or Denial-of-Service attack, is an atte...

What is DoS? A do, or Denial-of-Service attack, is an attempt to stop users from being able to access the internet or any other network services. Such attacks might be come in

What is money laundering and how is money laundered, Question: a) (i)...

Question: a) (i) Describe the entire process of credit card processing, identifying the different steps and parties involved. (ii) What are the roles of the acquiring ban

Troubleshooting tcp/ip, I''m having trouble with understanding a diagram fo...

I''m having trouble with understanding a diagram for my assignment

Explain control frame of claim token, Control Frame: claim_token Co...

Control Frame: claim_token Consider first station turned on Station notices no tokens Sends claim_token No competitors, so makes a ring of just itself P

What is ring topology, What is Ring Topology? The physical ring topolog...

What is Ring Topology? The physical ring topology is a circular loop of point-to-point links. Every device connects directly to the ring or indirectly by and interface device o

Bandwidth and functionality, The performance of interconnection networks is...

The performance of interconnection networks is calculated on the given parameters. Bandwidth:  It is a calculated of maximum transmit rate among two nodes.   It is calculated i

Show the traffic profiles, Q. Show the Traffic profiles? Constant-...

Q. Show the Traffic profiles? Constant-bit-rate traffic - ADR=PDR No MBS Variable-bit-rate traffic ADR != PDR Small MBS Bursty traffic

Full form of httpd, Full form of HTTPd It stands for HTTP daemon. HT...

Full form of HTTPd It stands for HTTP daemon. HTTPd is the program run on a UNIX platform to establish a Web server. On other platforms, such as Microsoft Windows NT, the We

sorting circuit along with odd-even merging circuit, As we previously know...

As we previously know, the merge sort algorithm needs two circuits, i.e. one for merging and second for sorting the sequences. Thus, the sorting circuit has been derived from the a

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