International Journal of Computer Applications
"The obstruction in cellular network involves the problem when a mobile user travels from one cell to another during a call. As adjacent cell do not use the same radio channels, a call must be transferred from one radio channel to another when a user crosses the line between the adjacent cells. The process of handover takes place that transfer an ongoing call from one cell to another cell as the user moves through the coverage area of a cellular network. There are several different reasons needed to be known to determine whether a handover is required."