Performance Analysis of Existing Location Management Scheme with its Variants in PCS Network

This paper is presenting a comparative study of existing location management scheme with its various variants in Personal Communication Services (PCS) network. The existing location management scheme is based on two tier database architecture; Home Location Register (HLR) and Visitor Location Register (VLR).In the existing location management scheme, there is a single HLR. In the HLR, profile of a Mobile Terminal (MT) is permanently stored. The VLR caches the profile of the MT from the HLR when it is providing the service to the mobile terminal. Mobile terminal, on move changes its location and comes under the Registration Area (RA) of new VLR. The MT profile should be removed from the VLR from where this MT is coming from and the HLR should have the information of current location of the MT. In the existing location management scheme this is done by the explicit deregistration scheme. In the existing call delivery procedure of PCS network, the HLR is always consulted to get the current location of the MT. This call delivery procedure supports an idea that is it necessary to inform the VLR that MT who was residing in its RA is now in the RA of another VLR? This paper has used other de-registration schemes as: Implicit deregistration, Polling de-registration, Timeout de-registration scheme and Group de-registration scheme in the variant of existing location management scheme. The single HLR architecture is prone to bottleneck and multi HLR architecture for PCS network is proposed for the efficient call delivery. Analysis done in this paper shows that we can significantly reduce the location management cost in the various variants of the existing location management schemes. This paper finally concludes that group de-registration scheme when implemented with the proposed multi HLR architecture gives better results.