A Distributed GLR Scheme for Mobile Networks

In the Universal Mobile Telecommunication System (UMTS) core network, an optional element Gateway Location Register (GLR) is introduced in visited networks to reduce location management signaling cost. In traditional GLR scheme, the GLR is usually centralized which may be a potential bottleneck due to the increase of number of roaming subscribers. In addition, the failure of GLR in the centralized GLR scheme will be fatal to the services for roaming subscribers. In this paper, a novel distributed GLR scheme is presented where the first visited VLR in visited network becomes the GLR for a roaming user to increase the ability to resist against failure of GLR and reduce the potential bottleneck. Analytic results show that the distributed scheme surpasses the traditional centralized GLR scheme in performance parameters such as robustness, resistance-bottleneck, database tracking cost and tracking-delay. In addition, the proposed scheme is easily realized since it only involves in software upgrade in corresponding network elements.