If we divide a generic communication system into its most simple parts, we can distinguish four elements: a sender, a receiver, a message to communicate and a medium on which to do so. One of the problems that arises from establishing the communication is access to the medium. When there are multiple users or stations sharing the same communication medium or channel, access control is required to avoid two or more stations transmitting at the same time, which can cause interference and even make the communication impossible.
Cristian Garcia: Computer Engineer in the Teldat R&D department. Within this department he works as a software developer.