A computer network is a set of devices connected by communication links that allow sharing of resources and information. The transmission media can be divided into two broad categories: wired and wireless. Wired media include twisted-pair cable, coaxial cable, and fiber-optic cable. Wired networks are an interconnection of remote nodes through physical infrastructure of wires and cables. It provides advantages of fast, reliable, secure and long haul communications. On the other hand, wireless media is free space and Wireless Local Area Network (WLAN) links two or more devices using some wireless distribution method like free space, IF and RF.