Recently data traffic in communication network is increasing so rapidly, in the near future, data traffic will exceed voice traffic. Since traditional that telephone networks are optimized for fixed rate voice traffice, it is very inefficient to provide data services using the existing telephone networks. Therefore, communication service provider are trying to deploy the integrated communication networks optimized for both voice and data traffics which include future multimedia traffic based on packet network structure.
In the mean time, a lot of studies for packet network adaptation of wireline voice service have been done so far. Examples are VoIP, RTP, H.323, MGCP etc.. However research about packet network adaptation of wireless mobile network has started in recent years.
Major research issues for packet network adaptation of wireless mobile network is mobility management and soft handoff. Current wireless mobile network uses the home location register (HLR) and the visited location register (VLR) for mobility management. Soft handoff is a method for performance improvement by macro diversity. We propose the placement of HLR and VLR or servers having the same ability as HLR and VLR in packet network.
In this thesis, we propose a soft handoff method in packet network for CDMA mobile station and three delay-constrained routing algorithms for this application that find a tree between multiple sources and multiple destinations when soft handoff occurs. First algorithm is a method that selects one core node and finds multicast tree between source nodes and destinaation nodes and combines two multicast trees. Second algorithm is a method that finds multicast trees between each source node and destination nodes and merges same links. Third algorithm is a method that finds multicast trees for souce nodes and destination nodes and find delayed-constrained minimum cost path bridging two trees.
The proposed algorithms, which provide guaranteed QoS services at the network layer, are also designed to find reduced-cost routing trees. These algorithms are based on one of multicast routing algorithms.
The proposed algorithms are verified by simulation, and three algorithm's performances are compared in view of total tree cost and maximum end-to-end delay.
