Route optimization for network mobility is a key technique for providing a node in a mobile network (Mobile Network Node or MNN) with high quality broadband communications. Many schemes adding route optimization function to Network Mobility (NEMO) Basic Support protocol, the standardized network mobility management protocol from the IETF nemo working group, have already been proposed in recent years. One such scheme, a scheme using Hierarchical Mobile IPv6 (HMIPv6) aims to overcome micromobility management issues as well by applying a mechanism based on HMIPv6. The traditional scheme, however, suffers from a significant number of signaling messages as the number of MNNs and/or the number of their Correspondent Nodes (CNs) increase, because many messages notifying the MNNs' Home Agents (HAMNNs) and the CNs of the mobile network's movement are generated simultaneously each time the mobile network moves to the domain of another micromobility management router (Mobility Anchor Point or MAP). This paper proposes a scheme to overcome this problem. Our scheme reduces the number of signaling messages generated at the same time by managing the mobility of MNNs using multiple MAPs distributed within a network for load sharing. The results of simulation experiments show that our scheme works efficiently compared to the traditional scheme when a mobile network has many MNNs and/or these MNNs communicate with many CNs.

Proxy Mobile IPv6 (PMIPv6) is designed not only to avoid tunneling overhead over the air but also to manage the mobility of hosts that are not equipped with any mobility management software. However, PMIPv6 leads to increasing signaling cost as mobile nodes move frequently because the protocol is based on the global mobility management protocol. In this letter we propose Localized PMIPv6 with Route Optimization (LPMIPv6-RO). Our numerical analysis shows that the proposed scheme outperforms previously proposed mobility protocols in terms of both signaling and packet delivery cost.

Internet engineering task force (IETF) has proposed hierarchical mobile IPv6 (HMIPv6) in order to reduce a frequent location registration of a mobile node in mobile IPv6 (MIPv6). All traffics toward a mobile node must be transmitted through a MAP in HMIPv6. This brings unnecessary packet latency because of the increased processing cost of packet at the MAP. At this point, the processing cost of packet at the MAP is influenced by the packet arrival rate for a mobile node, cell mobility rate and the number of mobile nodes in MAP domain. In this paper, we analyze the MAP's performance considering the above elements. For this, we compare total cost of HMIPv6 with total cost of MIPv6 as MAP's capability after we define Markov chain model for performance analysis. Also, we define network's total profit as total cost of MIPv6 minus total cost of HMIPv6. Then, we can find optimal capability of MAP such that total profit has maximum value. Also, we use the blocking probability by the MAP's capability as performance estimation element. As a conclusion, we can observe both HMIPv6's performance by the MAP's capability and optimal capability of the MAP, and blocking probability form a relationship of trade off between them.

Micromobility management is a key issue for the deployment of broadband mobile communication services. The packet loss during handover and the handover latency need to be minimized to maintain the high quality of these services. We have previously proposed a mobility management scheme that addresses this issue in wide-area mobile networks that employed hierarchical multiple mobility management routers (Mobility Anchor Points or MAPs). Our scheme directs a Mobile Terminal (MT) to a suitable MAP to fully minimize packet loss during handover, and handover latency of the MTs. In our previous work, we confirmed the effectiveness of our scheme using a simple tree network. Actual networks however, always have densely meshed topologies to provide some redundancy for the elimination of single points of failure. In such networks, it is difficult to deduce the relationships between the MAPs, and this makes it difficult for our scheme to select a suitable MAP for an MT, because the selection is performed using both the MT's smoothed speed and the relationships existing between the MAPs located above the Access Router (AR), to which the MT is connected. In this paper, we propose a method to overcome this problem, by autonomously adjusting the selection criteria that are individually configured for use at a particular AR, and we evaluate this method using simulation experiments. The results show that our mobility management scheme works well in densely meshed networks using the proposed additional method.

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.

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.

In IP-based mobile networks, a few of mobility agents (e.g., home agent, foreign agent, etc.) are used for mobility management. Recently, Hierarchical Mobile IPv6 (HMIPv6) was proposed to reduce signaling overhead and handoff latency occurred in Mobile IPv6. In HMIPv6, a new mobility agent, called mobility anchor point (MAP), is deployed in order to handle binding update procedures locally. However, the MAP can be a single point of performance bottleneck when there are a lot of mobile node (MNs) performing frequent local movements. This is because the MAP takes binding update procedures as well as data packet tunneling. Therefore, it is required to control the number of MNs serviced by a single MAP. In this paper, we propose a load control scheme at the MAP utilizing an admission control algorithm. We name the proposed load control scheme proactive load control scheme to distinct from the existing load control schemes in cellular networks. In terms of admission control, we use the cutoff priority scheme. We develop Markov chain models for the proactive load control scheme and evaluate the ongoing MN dropping and the new MN blocking probabilities. As a result, the proactive load control scheme can reduce the ongoing MN dropping probability while keeping the new MN blocking probability to a reasonable level.

Hierarchical Mobile IPv6 (HMIPv6) has been proposed to improve the performance capability of Mobile IPv6 at handover. In HMIPv6, local entities named Mobility Anchor Points (MAPs) are distributed throughout a network to localize the management of intra-domain mobility. In particular, multi-layered MAP has been proposed to improve performance. MAPs reduce the number of Binding Updates to the Home Agent and improve the communication quality at handover. These conventional methods that manage a multi-layered MAP cannot, however, select an appropriate MAP because they use the virtual mobility speed. As a result, they increase the signaling traffic in a multi-layered MAP. Moreover, they may cause the load to concentrate at a specific MAP. In this paper, we propose a location management method for Hierarchical Mobile IPv6 using the MN's mobile history. In this method, when a MN performs a handover, the Access Router calculates the area-covered rate of each upper MAP from the MN's mobile history and selects the MAP that best manages the MN in accordance with its rate. Thus, the proposed method reduces both the number of Binding Updates to the Home Agent and the signaling traffic because it reduces the frequency of changing the MAP. We evaluate the performance of the proposed method by simulation.

Three representative protocols are proposed to support mobility for IPv6 in IETF: Mobile IPv6, Hierarchical Mobile IPv6, and Fast Handovers for Mobile IPv6. Recently, IEEE 802.11 network has been widely deployed in public areas for mobile Internet services. In the near future, IPv6 mobility support over IEEE 802.11 network is expected to be a key function to actualize the pure IP-based mobile multimedia service. The IPv6 mobility support protocols have their characteristics in terms of signaling, handover latency, lost packets, and required buffer size. In this paper, we analyze the performance of the protocols over IEEE 802.11 network. We define a packet-level traffic model and a system and mobility model. Then, we construct a framework for the performance analysis. We also make cost functions to formalize each protocol's performance. Lastly, we investigate the effect of varying parameters used to show diverse numerical results.

In mobile multimedia environment, it is very important to minimize handoff latency due to mobility. In terms of reducing handoff latency, Hierarchical Mobile IPv6 (HMIPv6) can be an efficient approach, which uses a mobility agent called Mobility Anchor Point (MAP) in order to localize registration process. However, MAP can be a single point of failure or performance bottleneck. In order to provide mobile users with satisfactory quality of service and fault-tolerant service, it is required to cope with the failure of mobility agents. In, we proposed Robust Hierarchical Mobile IPv6 (RH-MIPv6), which is an enhanced HMIPv6 for fault-tolerant mobile services. In RH-MIPv6, an MN configures two regional CoA and registers them to two MAPs during binding update procedures. When a MAP fails, MNs serviced by the faulty MAP (i.e., primary MAP) can be served by a failure-free MAP (i.e., secondary MAP) by failure detection/recovery schemes in the case of the RH-MIPv6. In this paper, we investigate the comparative study of RH-MIPv6 and HMIPv6 under several performance factors such as MAP unavailability, MAP reliability, packet loss rate, and MAP blocking probability. To do this, we utilize a semi-Markov chain and a M/G/C/C queuing model. Numerical results indicate that RH-MIPv6 outperforms HMIPv6 for all performance factors, especially when failure rate is high.

Next-generation wireless/mobile networks will be IP-based cellular networks integrating Internet with the existing cellular networks. Recently, Hierarchical Mobile IPv6 (HMIPv6) was proposed by the Internet Engineering Task Force (IETF) for efficient mobility management. HMIPv6 reduces the amount of signaling and improves the performance of MIPv6 in terms of handoff latency. Although HMIPv6 is an efficient scheme, the performance of wireless networks is highly dependent on various system parameters such as user mobility model, packet arrival pattern, etc. Therefore, it is essential to analyze the network performance when HMIPv6 is deployed in IP-based cellular networks. In this paper, we develop two analytic models for the performance analysis of HMIPv6 in IP-based cellular networks, which are based on the random-walk and the fluid-flow models. Based on these analytic models, we formulate the location update cost and the packet delivery cost. Then, we analyze the impact of cell residence time and user population on the location update cost and the packet delivery cost, respectively. In addition, we study the variation of the total cost as the session-to-mobility ratio is changed and the optimal MAP domain size to minimize the total cost is also investigated.

Hierarchical Mobile IPv6 (HMIPv6) has been proposed to accommodate frequent mobility of terminals within the Internet. It utilizes a router, named Mobility Anchor Point (MAP), so that networks can manage mobile terminals without floods of signaling message. Note here that, particularly in a wide area network, such as a mobile communication network, it is efficient to distribute several MAPs within the same network and make the MAP domains cover overlapped areas. This enables the network to manage the terminals in a flexible manner according to their different mobility scenarios. The method described in the Internet-Draft at the IETF, however, lets mobile terminals select its MAP. This may cause load concentration at some particular MAPs and/or floods of signaling messages, because the terminals may not select a feasible MAP in a desirable manner. In this paper, a MAP selection method in distributed-MAPs environment is proposed. It reduces signaling messages to/from outside networks without load concentration at any particular MAPs. Finally, we show that the proposed method works effectively by simulation experiments.