An Introduction to my Project

With the growing popularization of wireless networking, there is a need for studying the efficiency of multimedia communication over such a network. My project specifically deals with studying and analyzing the transmission of voice packets over a wireless network. In short, I will be establishing a point-to-point communication between two computers and observe the quality and strength etc. of the voice transmissions between them.

Procedure:

Initially, I will be installing a communication software on two computers. This application should be able to transmit and detect voice transmissions much like an Internet Phone. The RAT (Robust Audio Tool), an open source software was installed and run on the two computers (with Linux Operating System).
The next task was to write perl scripts for a client and a server, with functionality similar to a phone exchange service. The client would send a request to the server for the IP address of the intended call receiver and place the call by initiating RAT with the provided IP address. The server would have a directory with the name and IP address of every registered client. Hence, the two computers could communicate and the voice packages sent by the caller would be successfully routed to the intended receiver.
Once, a healthy communication is established between two machines, we test the efficiency of the communication and conduct several useful experiments with the voice signals. For instance, we trace the path (number of hops) taken by the voice packets to reach the receiver in the network, observe the number of packets that were lost on course of the transmission etc.

Background Information:

To successfully implement this project it was necessary to study some useful concepts or terms involved in wireless networking. To understand the transmission of packets across a network, one needs to know the steps it takes to reach the intended destination. Firstly, our workstation establishes a connection to the nearest access point in the network. Then, our message is sent in the form of small packets, through several routers, to the destination. Every packet transmitted carries with it certain header information such as the source IP address, Destination IP address, port number etc which enables it to be routed in the right direction. This entire task of transmitting information across a network is performed in five stages or layers. First, the Application layer where the message is created through a computer application like the web (emails) etc. Second, the transport layer where the port number of the source and destination application is attached to the message as a header. Third, the Network layer where the source and destination IP addresses are added to the header. Fourth, the MAC layer where the system identifies the path to be taken for successful transmission and the fifth layer, the physical layer, where the information is physically transmitted.




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