ASAK All, I need some help in simulation and optimization of the CSMA/CD algorithm. The problem is essentially the same as the CSMA/CD standard itself but for optimization's sake I have introduced an optimization parameter "q" in the following manner :
## Start Problem Statement ## Let there be "n" number of transmitters operating over an Ethernet cable-type broadcast channel. While transmitting, if a transmitter Ti senses a collision, it abandons transmission immediately on sensing the collision. Transmitter Ti then waits for a random amount of time "Tau" and senses the channel again. "Tau" will represent an exponential random variable with rate 1 msec-1. ->If it senses the channel to be busy at that time, it will continue to wait until the channel is free and then for another"Tau" for the channel to recover. ->If it senses the channel to be free, it attempts transmission with a probability "q", by tossing a coin with a "transmit" face having a probability q. If the coin tossing fails to decide "transmit," the transmitter will wait for another "Tau" amount of time and sense the channel again to determine if it should toss the q coin. ## End Problem Statement ## I am getting stuck in simulating more than one Transmitters at the same time i.e. How can I send/sense data from a second transmitter while the code for 1st transmitter is being run (since Matlab or any other languages have sequential control flow). Moreover , what mechanism can be used for detecting collision ?? Would setting of flags (similar to semaphors for IPC in Operating Systems) would do it..? In matlab , I am unsure if I can "run" more than one transmitters simoultenously due to its sequential command execution nature.. This is just for Simulation , I can take care of Optimization but I am having a real hard time putting it to implementation. If any of you knw similar implementations in Matlab or C/C++ I'd greatly appreciate it .. wussalam zeeshan ----------------------- More Info? ------------------------ NED's Official Website: http://www.neduet.edu.pk NEDian.ORG.PK : http://nedian.org.pk NED Alumni USA : http://NED-ALUMNI.org ECN List: http : http://nedian.org.pk/ecn/ecn.html List Archives : http://www.mail-archive.com/[email protected] ECN Members' Blurbs : http://nedian.org.pk/ecn/blurbs.html ---------------- http://nedian.org.pk ---------------------
