[Show abstract][Hide abstract] ABSTRACT: To enhance the handover performance of Mobile IP in heterogeneous wireless networks, we investigate the effects of L2 trigger in handover procedure, due to mobile speeds and cell sizes. We analyze throughput, packet loss, and network delay - with respect to handover timeliness and accuracy. We conducted extensive experiments through the ns-2 simulator by adopting the Mobile IPv6 and IEEE 802.21 Media Independent Handover (MIH) standards, where a mobile node (MN) moves around between the IEEE 802.16 and 802.11 networks.
[Show abstract][Hide abstract] ABSTRACT: The multiple choices of access networks offer different opportunities and overcome the limitations of other technologies. Optimal selection of interface is a big challenge for multiple interfaces supported mobile terminals to make a seamless handover and to optimize the power consumption. Seamless handover, resource management, and CAC to support QoS and multiple interface management to reduce power consumption in mobile terminal are the most important issues for the UMTS/WLAN overlaying network. The access of both interfaces simultaneously can reduce the handover latency and data loss in heterogeneous handover. The MN may maintain one interface connection while other interface can be used for handover process. But the access of both interfaces increases the consumption of power in MN. In this paper we present an efficient interface selection scheme including interface selection algorithms, interface selection mechanism and CAC considering battery power consumption for overlaying networks. MN's battery power level and provision of QoS/QoE in the target interface are considered as important parameters for our interface selection algorithm. The MIH is also introduced for interface selection.
[Show abstract][Hide abstract] ABSTRACT: The multi-radio interface MN (mobile node) has battery problem with power consumption from each interface. To reduce power consumption, we adopt that the power of the interface of the unused radio interface should be off. However, the MN can have network discovery problems. Therefore we propose the HSDPA interface sensitive AP (access point) and the power management procedure for the muti-radio interface MN using the WiFi interface and the HSDPA interface. We will show the reduction of energy consumption using the proposed AP and the power management procedure based on a power measurement experiment.
[Show abstract][Hide abstract] ABSTRACT: This paper initially shows ROHC and packet aggregation significantly improve the number of successful voice calls. However, the improvement does not include processor's processing overhead, which is identified by measuring ROHC processing time from Intel Pentium 4 and RouterBOARD, and applying the results into NS-2 simulations. Simulation results indicate the number of successful voice calls is seriously affected by the processing overhead. For the solution of the processing limitation, we propose a hardware model of the two algorithms and numerically analyze the model. Simulation results show the hardware model makes the number of successful voice calls approach the ideal (no-delay) case, and the numerical model exactly characterizes the hardware behaviors.
[Show abstract][Hide abstract] ABSTRACT: For seamless service, mobility should be supported in the NGN. For this, there have been many contributions, such as MIPv6, IP2, Q.MMF, IMS. In mobility area, handover latency time is the first parameter to consider. However, above all are not compared up to now. Therefore this paper presents the performance comparison of handover latency times. For this, we use NS-2 simulator. In simulation results, we shown that IP2 has minimum value as compared with other mechanisms about the handover latency time
[Show abstract][Hide abstract] ABSTRACT: IEEE 802.16 is one of broadband wireless access technologies and will become a key technology for growing wireless IP network. However, point-to-point oriented network such as IEEE 802.16 introduces some issues in applying conventional standard IPv6 neighbor discovery protocol (NDP). Following the previous 3GPP model for IPv6 NDP is not flexible in IPv6 link configuration since it assigns different network prefixes to each subscriber stations. We presents a mechanism which can allocate a common network prefix to all subscriber stations under the same IPv6 link. Through this mechanism, the standard IPv6 NDP can be applied to IEEE 802.16 networks without modifying conventional host-side operation
[Show abstract][Hide abstract] ABSTRACT: A variety of schemes for mobility are currently studied in ITU-T, 3GPP, IETF, and so on. The ITU-T (SG-19) considers Q.MMF, the 3GPP standardized IMS, the IETF currently uses mobile IP (MIP). For supporting mobility, there are many performance parameters, such as location registration delay, handover delay, packet delivery delay, signaling cost, location update cost, packet delivery cost. However the performance comparison of all existing schemes is not examined as yet. So, this paper investigates and compares the performance of MIPv6, IP2, Q.MMF, IMS to location registration. The time and cost of location registration are associated with the flow of messages between entities according to the procedure. We investigate the variation and performance comparison in the location registration time and cost using the performance metric