Modeling And Cost Analysis Of Location Management In Long Term Evolution

In mobile communication network, location management (LM) is responsible for tracking the location of user equipment (UE), so the network can successfully deliver the incoming call to UE. LM includes two operations:location update and paging. Location update is based on the change of user's location dynamically to update the location information which is stored in the network. Paging is the process that the network searches the UE and establish a communication connection through the location information which stored in the network when an incoming call arrives.In the Long Term Evolution (LTE), it adopts a location management scheme that called tracking area list (TAL)-based scheme. In this theme, the TAL is comprised of several tracking area (TA). When UE moves into a new cell and the TA which contain this cell is not in the allocated TAL, UE need to perform a tracking area update (TAU).For the insufficiency existing study of the TAL-based location scheme failed to consider the call holding time and simply adopt parallel paging scheme, this thesis take call holding time into account. In order to establish the location management model of UE, we need to consider the call inter-arrival time and call holding time. By analyzing the location update process of UE under the two conditions, this thesis improves the original embedded Markov chain model, utilize sequential paging and derive the close-form formulas of the signaling cost between two continuous incoming calls. We verify the accuracy of the analytical results by simulation, conclude that compared the other scheme that this scheme can effectively reduce the signaling cost of location management, analyze the influence of call inter-arrival time, call holding time and other parameters on the TAL-based location management scheme, and obtain the signaling cost which close to the actual situation.For the local anchor based location management which apply to small cell network does not consider the call holding time and analyze the impact of call plus location update and call without location update these two call handling models on the scheme, this thesis derives the location management signaling cost close-form formulas of these two models by the embedded Markov chain model. We check the accuracy and analyze the influence of these two models on the scheme. Through the close-form formulas results compared with the literature of this scheme, concluded that it is a special case of this thesis. At the same time because of the local anchor based scheme will significantly increase the system complexity, by comparing the signaling overhead and paging delay with the TAL-based scheme in this thesis, it can conclude that when this scheme applied in small cell networks, we can achieve the cost performance as the local anchor based scheme by select an appropriate TA size, obtain the lower call processing time delay and improve the system performance by adopt the CPLU model.