The reduction of the signaling load associated with IP mobility management is one of the significant challenges to IP mobility support protocols. Hierarchical Mobile IPv6 (HMIPv6) aims to reduce the number of the signaling messages in the backbone networks, and improve handoff performance by reducing handoff latency. However, this does not imply any change to the periodic binding update (BU) to the home agent (HA) and the correspondent node (CN), and now a mobile node (MN) additionally should send it to the mobility anchor point (MAP). Moreover, the MAP should tunnel the received packets to be routed to the MN. These facts mean that the reduction of the BU messages in the backbone networks can be achieved at the expense of the increase in the signaling bandwidth consumption within a MAP domain. On the other hand, it is observed that an MN may habitually stay for a relatively long time or spend on using much Internet in a specific cell (hereafter, home cell) covering its home, office or laboratory, etc. Thus, considering the preceding facts and observation, HMIPv6 may not be favorable especially during a home cell residence time in terms of signaling bandwidth consumption. To overcome these drawbacks of HMIPv6, we propose a history-based auxiliary mobility management strategy (H-HMIPv6) to enable an MN to selectively switch its mobility management protocols according to whether it is currently in its home cell or not in HMIPv6 networks. The operation of H-HMIPv6 is almost the same as that of HMIPv6 except either when an MN enters/leaves its home cell or while it stays in its home cell. Once an MN knows using its history that it enters its home cell, it behaves as if it operates in Mobile IPv6 (MIPv6), not in HMIPv6, until it leaves its home cell; No periodic BU messages to the MAP and no packet tunneling occur during the MN's home cell residence time. The numerical results indicate that compared with HMIPv6, H-HMIPv6 has apparent potential to reduce the signaling bandwidth consumption and the MAP blocking probability.

This paper describes IP encapsulation technologies for the Mobile RSVP tunnel in next generation networks. Bandwidth is inherently a scarce network resource, and hence signaling overhead should be minimized as much as possible. However, because of duplicate RSVP messages, the existing RSVP tunnel-based mechanism suffers from bandwidth overhead and tunnel problems. The waste of network resources prevents low-cost network construction and the maximization of integrated network utility, which are the goals of next generation networks, and can lower the reliability of networks with the increase of service subscribers and resultant expansion of resource consumption. To solve these problems and to support end-to-end QoS efficiently, RSVP needs to be changed at a minimum degree. In this paper, a new IP encapsulation mechanism for saving of network resources in the Mobile RSVP tunnel (IPEnc-RSVP) is proposed. In order to compare the proposed mechanism and the existing RSVP tunnel-based mechanism in Mobile IP-based networks, we perform a comparative analysis of bandwidth consumption gain, throughput, mean packet delay, etc., and demonstrate the superiority of the proposed mechanism. In addition, we analyze several performance factors of RSVP protocols by applying the existing RSVP tunnel-based mechanism and the proposed mechanism, respectively.

There are two principal aspects of "mobility" in location-aware computing: (1) how to support mobility and (2) how to exploit it. This paper considers the latter, while many existing works only concentrate on the former. This work is trying to prove that the performance of location-aware systems will be greatly improved by understanding the user's movement. In this paper, we propose a novel location update protocol called state-based location update protocol (SLUP), which significantly minimizes the energy consumption of mobile client by exploiting a syntactic information of a user's movement. This concept is called mobility-awareness which is a kind of context-awareness. Moreover, there are three variations of the proposed protocol in terms of how to choose the optimal state: SLUP/BS, SLUP/UITR, and SLUP/IUT. Experimental results show that the proposed protocol outperforms the well-known existing protocols such as dead-reckoning and distance-based protocol, and that the SLUP/IUT approach can achieve different performance tradeoffs between energy efficiency and location accuracy by fine-tuning its algorithmic parameter Tiut.

This paper presents a novel analytical approach to evaluate the signaling load of Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6). Previous analytical approaches for IP mobility management have not provided a complete and general framework for the performance analysis; no consideration of either periodic binding refresh cost or extra packet tunneling cost from the viewpoint of IP mobility management, and no in-depth investigation with respect to various system parameters. In this paper, according to the proposed analytical approach, we derive the location update costs (i.e., the sum of binding update costs and binding refresh costs), packet tunneling costs, inside-domain signaling costs, outside-domain signaling costs, and total signaling costs, which are generated by a mobile node (MN) during its average domain residence time in case MIPv6 or HMIPv6 is deployed under the same network architecture, respectively. Moreover, based on these derived costs, we evaluate the impacts of various system parameters on the signaling costs generated by an MN in MIPv6 and HMIPv6. The aim of this paper is not to determine which protocol performs better, but evaluate the performance that can be expected for each protocol under the various conditions, broaden our deep understanding of the various parameters that may influence the performance, and provide insight for the deployment of the two protocols.

Although a lot of works for location management in wireless networks have been reported in the literature, most of the works have been focused on designing per-user-based strategies. This means that they can achieve the performance enhancement only for a certain class of mobile users with a specific range of CMR (call-to-mobility ratio). However, these per-user-based strategies can actually degrade the performance if a user's CMR changes significantly. Therefore, an efficient uniform location management strategy, which can be commonly applied to all mobile users regardless of their CMR, is proposed and analyzed in this paper. The motivation behind the proposed strategy is to exploit the concepts of the two well-known existing strategies: the location caching strategy and the local anchor strategy. That is, the location caching strategy exploits locality in a user's calling pattern, whereas the local anchor strategy exploits locality in a user's mobility pattern. By exploiting these characteristics of both strategies together with the profile management at the HLR (home location register), the proposed strategy can reduce the frequent access to the HLR, and thus effectively results in significant reduction in terms of the total location management cost. The analytical results also demonstrate that the proposed strategy can be uniformly applied to all mobile users, while always maintaining the performance gain over the IS-41 standard regardless of a user's CMR and the network traffic conditions.