The Cdma High-speed Real-time Streaming Network Handoff Algorithm

With the development of mobile communication technology, high-speed real-time multimedia service will become the most important part of mobile network services in forthcoming 3G times. So, researching in the handoff of this kind of data flow is very meaningful. Handoff is a particular function and a primary characteristic of mobile cell system. It has become a key to increase system capacity and improve communication quality. In end-to-end quality of service management of mobile communication network, the handoff block rate is a very important indicator.How to reduce handoff drop rate as well as to utilize system resource efficiently is a primary issue of wireless mobile network QoS and resource management all along. At first, several handoff algorithms which are often used in 2G network have been introduced. Through elaborate analysis of the advantages and disadvantages of these algorithms, the paper points out the fact that the granularity of resource reservation can impact the performance of traditional algorithms. In order to reduce these impacts, a dynamic resource reservation algorithm based on transient solutions for M/M/N queuing processes has been put forward. In the algorithm, the handoff block rate indicator is adjusted in term of statistic of real block rate, and through forecasting the future block rate, the call admission control of mobile terminal in cell can be carried through. This can reduce the influence to the algorithm's performance from the granularity of resource reservation.The process and character of soft handoff in CDMA system have been introduced, and randomicity and burst of CDMA system capacity have been analyzed. According to analyzing probability of using resource of the flow in different state in cell, a high-speed flow resource reservation dynamic handoff algorithm has been put forward. Because the move mode of mobile terminals in soft handoff area has been forecasted exactly, this algorithm can make system have lower original call block rate and higher resource using rate than which in hard handoff condition.In order to assure flow QoS request when assuring system handoff block rate lower enough. The property of flows in high-speed network has been analyzed and investigated elaborately. And the self-similarly flow queuing model of Norros has been expanded, a call admission control scheme of random access ON-OFF flows which have heavy-tail distribution alternation has been brought forward. On this condition, a self-similarly flow resource reservation dynamic handoff algorithm has been put forward. This algorithm has taken both system handoff block rate indicator and long-range dependence of flow into account.