Effect of Tracking Area List overlapping in reducing overall signaling overhead in Long Term Evolution system

In Long Term Evolution (LTE) system the Tracking Area (TA) is a group of cells in which User Equipment (UE) may move freely without performing location update process. The TA scheme has many limitations such as ping-pong effect and massive mobility signaling congestion. To overcome the limitations of the TA scheme, Tracking Area List (TAL) scheme is introduced. TAL is a group of TAs and if a UE is registered to one TAL it will not perform TAL update. In LTE system mobility management techniques are used to keep track of the current location of the UE which are location update and paging techniques. These techniques induce system overhead in both system signals and bandwidth consumption. In this paper we will examine the effect of TAL design in reducing this signaling overhead, taking into account TAL overlapping which mean that a cell may be included in more than one TAL. For a given TA and TAL design the overall signaling overhead was calculated. Results obtained showed that the TAL scheme gives minimum signaling overhead when compared with the TA scheme.