Scheduling

Let us discuss the requirement of scheduling and proceed further by giving a proper definition of scheduling along with its classifications. First of all, what for we are doing the process of scheduling? Consider a wireless (or wired network) in which there are several nodes that transmit and receive packets of different size. If there is no scheduling, then there will be two problems. Primarily, each and every node will try to transmit the packets at the same time; this will lead to collision and re-transmission of lost packets, etc, which makes the network inefficient. Secondly, one node may try to monopolize the network by sending its own packets at any given time. This does not ensure fairness and hence there must be some regulating mechanism to control them all. In other words, if there are multiple packets competing for a single link, then scheduling becomes mandatory.