Research On Location Management Technique In Mobile Networks

Mobile communication is one of the most active and fastest developing areas during the present time of communication areas, and also is one of the scientific areas that have great influences on social development and human activities. With the fast development of mobile communication service in the world, there is a higher and higher demand for various aspect of mobile communication technology. Techonlogy in mobile communication is maily involved in wireless access technology and mobility management technology. The main characteristic of wireless access is the mobility of communication in which the system guarantees the realiability and availability of communication by overcoming wireless interference and fading. The main characteristic of mobility management is roaming management in which system can offer service to subscribers when they randomly roam in wireless coverage areas. The mobility management comprises location management and handoff management technology. This paper maily investigates location management technology and contains following chapters:When a mobile user roams far away from his resident home location register (HLR), how the mobile system reduces the cost pressure on HLR and long distance signaling traffic produced by call delivery, registration and cancellation is proposed in Chapter 2. The proposed scheme can greatly reduce long distance signaling traffic and degree of HLR bottleneck and is very suitable for subscribers with low call-to-mobility ratio (CMR). According to our running experience, the probability that incoming calls to a user in her/his resident cell is higher than in non-resident cells. From this, Chapter 3 consider the ways to further improve paging algorithm to save wireless resources and reduce paging cost which is very suitable for operators with limited wireless frequency resources. The higher incoming calls rate in user's resident cell, the more efficient paging cost. At the same time, we use Residue Theorem to obtain performance under more general distribution assumption.Chapter 4 mainly investigates two call delivery schemes according to characteristic of residence times and incoming calls in corresponding visitor location register (VLR) coverage areas. Both proposed schemes can reduce call delivery delay, HLR bottleneck problem and improve the ability to resist HLR ruin. Local routing scheme is suitable for users with high locality of incoming calls. Improved per-user location cache algorithm is mainly used for users in their non-resident VLR coverage area. The higher locality the incoming calls, the higher performance improvement of both schemes.For our knowledge, previous or current researches on detach neglect the influence of detach interval on performance of system. The detach interval maily depends on wireless coverage quality and mobility attribute of user in practical running. The effect of detach interval on dynamic periodic location area update (PLAU) scheme is proposed in Chapter 5 and an analytic model is also presented in the Chapter.An authentication management algorithm in forwarding pointer is proposed in Chapter 6 when a user moves from one VLR coverage area to another in his/her non-resident VLR coverage area. The proposed scheme can perfect the forwarding pointer scheme and further reduce long way signaling traffic.Athough current researches on VLR overflow can provide service to newcomers, they may lead to fraudulence usage problem due to vicious clone users. Chapter 7 presents corresponding improved VLR overflow algorithm to detect potential fraudulence usage and presents an analytical model for performance analysis under general distribution assumption.Chapter 8 proposes an improved cache approach for supporting life-time number (CALN) scheme to hold lifetime number after a mobile user changes operator time after time in HLR/VLR strategy. The proposed scheme is realized efficiently by updating cache and plays an important role in mobile networks with two-tier database strategy.In order to verify and evaluate schemes propos...