Extending mobile IP with adaptive individual paging

The tremendous demands from social market are pushing the booming development of mobile communications faster than ever before, leading to plenty of new advanced techniques emerging. With the converging of mobile and wireless communications with Internet services, the boundary between mobile personal telecommunications and wireless computer networks is disappearing. Wireless networks of the next generation need the support of all the advances on new architectures, standards, and protocols. Mobility management is an important issue in the area of mobile communications, which can be best solved at the network layer. One of the key features of the next generation wireless networks is all-IP infrastructure. This paper discusses the mobility management schemes for the next generation mobile networks through extending IP's functions with mobility support. A global hierarchical framework model for the mobility management of wireless networks is presented, in which the mobility management is divided into two complementary tasks: macro mobility and micro mobility. As the macro mobility solution, a basic principle of Mobile IP is introduced, together with the optimal schemes and the advances in IPv6. The disadvantages of the Mobile IP on solving the micro mobility problem are analyzed, on the basis of which three main proposals are discussed as the micro mobility solutions for mobile communications, including Hierarchical Mobile IP (HMIP), Cellular IP, and Handoff-Aware Wireless Access Internet Infrastructure (HAWAII). A unified model is also described in which the different micro mobility solutions can coexist simultaneously in mobile networks.

Handoff latency affects the service quality of real-time applications. In this paper we develop an analytical model to analyze the Mobile IP Fast Authentication protocol (MIFA) and compare it to Hierarchical Mobile IP (HMIP). The study compares the signaling costs of the protocols as well as the overall load for packet forwarding. Our study shows that MIFA minimizes the packet delivery cost compared to HMIP. Additionally, MIFA is more efficient when the arrival rate of the packets increases. Thus MIFA outperforms HMIP with respect to signaling cost. From the performance point of view MIFA performs similar to HMIP when the domain consists of two hierarchy levels only, and outperform HMIP otherwise. However, MIFA does not require a hierarchical network architecture as HMIP does.

Network protocols in cellular wireless data networks must update routes as a mobile host moves between cells. These routing updates combined with some associated state changes are called handoffs. Most current handoff schemes in wireless networks result in data loss or large variations in packet delivery times. Unfortunately, many applications, such as real-time multimedia applications and reliable transport protocols, adapt to long term estimates of end-to-end delay and loss. Violations and rapid fluctuations of these estimates caused by handoff processing often result in degraded performance. For example, loss during handoff adversely affects TCP performance [4], and high packet loss and variable delays result in poor real-time multimedia performance. In this paper, we describe a multicast-based protocol that eliminates data loss and incurs negligible delays during a handoff. The basic technique of the algorithm is to anticipate a handoff using wireless network information in the form of received signal strengths and to multicast data destined for the mobile host to nearby base stations in advance. This routing, combined with intelligent buffering techniques at the base stations, enables very rapid routing updates and eliminates data loss without the use of explicit data forwarding. We have implemented this protocol using IP Multicast and Mobile IP-like routing. In our implementation, handoffs typically take between 8 and 15 ms to complete and result in no data loss.

In Proxy Mobile IP (PMIPv6) networks, proxy-registrations are performed even for idle MNs, resulting in unnecessary signaling traffic. Although there have been many IP paging techniques aimed at reducing the unnecessary location update, they focus only on Mobile IP (MIP) since they had been developed before PMIPv6 was proposed. Thus, adopting existing IP paging support is not sufficient to support mobility in PMIPv6 networks. For more efficient support, we propose a dynamic multi-step paging scheme that pages an MN in multiple incremental steps instead of flooding paging messages to a whole paging area to significantly reduce the signaling traffic caused by the proxy location updates in the PMIPv6 networks. In addition, to improve the paging delay performance that may be deteriorated by the multi-step paging, the proposed scheme configures paging area dynamically to raise the efficiency of locating MNs. The size of a paging area is designed to be determined based on the speed of an MN. We also develop a thorough analytical model for evaluating the performance of the proposed scheme compared with a static paging scheme in terms of the signaling cost and the paging delay. Thorough analysis and simulation demonstrate that in the PMIPv6 network, our paging scheme can significantly reduce the signaling cost for IP paging, achieving a shorter paging delay, compared to that of a paging scheme with a fixed paging area.

Mobile IP is the current standard supporting user mobility in wireless IP networks. Mobile IP regional registration is proposed by IETF to reduce the mobile IP location update cost by making the registration localized. A distributed regional registration scheme is also introduced to choose the GFAs dynamically. In the distributed scheme, the signaling burden is evenly distributed among the network and the regional network boundary is dynamically adjusted according to the mobile user's up-to-date mobility and traffic load. In this paper, we develop a system model to analyze the distributed scheme performance. We also propose an improved distributed scheme which is called improved distributed regional location management scheme in our paper. The analytical results show that the dynamic scheme can reduce the mobile IP mobility management cost effectively and the improved scheme can perform better.

Application of AI techniques for locating mobile terminals in mobile wireless cellular networks: A novel paging scheme

The Mobile IP standard for mobility management on the Internet enables transparent communication between mobile hosts (MHs) and their correspondent hosts (CHs). However, it suffers from triangular routing and prolonged handoff latency problems. Solutions such as route optimization and micro-mobility protocols either solve these problems partially or require costly modifications to the CHs. In this paper, we propose to use temporary home agent (TA) to address both problems without requiring any special support on CHs. TA exploits the locality of user movement observed in recent studies for PCS and wireless data networks. It does so by dynamically selecting a Mobile IP home agent based on the location of the user. The TA allocates a temporary home address, THAddr to the MH, which the MH may use as its source address. The underlying objective is to shorten the distance between a MH and its home agent, which is a critical factor in reducing handoff latency and improving routing efficiency. Our scheme is shown to outperform Mobile IP and is comparable to route optimization (RO) through both quantitative analysis and ns simulations. While our approach focus on improving the performance for sessions that are initiated by the MH, methods for optimizing traffic handling for sessions initiated by CHs are discussed.

The scarce radio resources available to any cellular radio network have to be shared between its revenue-generating voice- and data-carrying services, and non-revenue-generating management services. One of these management services is location management, crucial for the network to keep track of the location of its subscribers and to connect their incoming calls. Location management consists of the two activities, paging and location updating, both of which are structured around a subdivision of the network service area called the location area (LA). The ways in which the service area is partitioned therefore has a direct impact on the amount of radio bandwidth that has to be spent on location management. However, paging and location updating share an antagonistic relationship, and finding the optimal LA partitioning that strikes a balance between the two is a challenging design problem. In this paper, the problem of finding the optimal LA partitioning of a cellular radio network service area in order to minimise the total location management signalling cost is addressed. The choice of the decision variables used in the mathematical programming model results in an objective function that is conceptually easy to understand and a solution method that is simple and straightforward.

Mobile IP is a proposed standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher level protocols like TCP. Mobile IP (RFC 2002) is a standard proposed by a working group within the Internet Engineering Task Force; it allows the mobile node to use two IP addresses: a fixed home address and a care-of address that changes at each new point of attachment. The article presents the Mobile IP standard in moderate technical detail and points the reader toward a wealth of further information. Is also describes how Mobile IP will change with IP version 6, the product of a major effort within the IETF to engineer an eventual replacement for the current version of IP. Although IPv6 will support mobility to a greater degree than IPv4, it will still need Mobile IP to make mobility transparent to applications and higher level protocols such as TCP. There is a great deal of interest in mobile computing and apparently in Mobile IP as a way to provide for it. A quick Web search for items related to Mobile IP returned over 60,000 hits-impressive even given the notorious lack of selectivity for such procedures. Mobile IP forms the basis either directly or indirectly of many current research efforts and products. The Cellular Digital Packet Data (CDPD), for example, has created a widely deployed communications infrastructure based on a previous draft specification of the protocol. In addition, most major router vendors have developed implementations for Mobile IP.

This paper proposes the multiprotocol label switching (MPLS)-based hierarchical Mobile IP architecture to allow frequent and seamless location management It proposes that the label distribution protocol (LDP) can be applied to set up the label switched path (LSP) tunnels between the mobile agents (that is, foreign agents and home agents). It means that the IP-in-IP tunnels can be replaced by one or multiple LSP on the MPLS network. When a mobile node (MN) migrates to the adjacent subnet, it performs a regional registration and partial LSP re-establishment method. So our scheme can reduce LSP setup latency more than the existing integration of Mobile IP and MPLS. We also propose a multicast re-routing scheme to support smooth handover on the MPLS-based hierarchical Mobile IP network after analyzing several LSP re-routing schemes.

As portable devices are gaining more popularity, maintaining Internet connectivity anytime and anywhere becomes critical, particularly for mobile and vehicular networks. Network mobility (NEMO) and internet protocol mobility are gaining more and more importance. In this paper, we develop a session initiation protocol (SlP)-based mobile network architecture to support NEMO for vehicular applications. We propose to form a mobile ad hoc network (MANET) by the mobile hosts (MHs) inside a vehicle or a cluster of vehicles. The MANET is connected to the outside world via a SIP-based mobile network gateway (SIP-MNG), which is equipped with one or multiple external wireless interfaces and some internal IEEE 802.11 interfaces. The external interfaces of the SIP-MNG support Internet connectivity by aggregating user traffic to and from the Internet. In addition, exploiting the session information carried by SIP signaling, the SIP-MNG supports resource management and call admission control for the MHs. However, wireless access incurs charges, power consumption, and overhead of mobility management. So, it is desirable to allow the SIP-MNG to disconnect its external interfaces when necessary. To guarantee that users inside the mobile network will not lose any incoming request, we propose a push mechanism through short message service to wake up these wireless interfaces in an on-demand manner. We show the detailed signaling to support such a mechanism. The proposed system is fully compatible with existing SIP standards. Our real prototyping experience and some experimental results are also reported.

This paper introduces three hierarchical mobile IP schemes, i.e. hierarchical mobile IP (HMIP), dynamic HMIP, and distributed and dynamic HMIP to improve the handoff performance, and develops a model for cost analysis based on one-dimensional random walk of mobile host. Then the paper compares signaling transmission cost, packet delivery cost and total cost of the three schemes respectively, and discusses the effects of different home handoff thresholds and directional walk probabilities on these costs. Numerical results show that the DHMIP scheme has best performance among the three under small home handoff threshold.

In networks supporting Mobile IP (MIP), the address configuration of a Mobile Node (MN) is an important part of the handoff process, which is based on the detection of movement between different subnetworks. The movement detection in wireless IP network is usually performed by means of Router Advertisement (RA) messages which are sent with a fixed and constant period. The higher is the rate of these messages, the lower the handoff delay is and the higher is the bandwidth occupation on the wireless medium. To trade off these values, we propose a method to decrease the bandwidth occupation of movement detection messages while confining part of the L3 handoff setup latency under acceptable values, for instance 15 ms ÷ 40 ms. The benefit on the bandwidth occupation with respect to the constant rate technique is between 25% ÷ 40%, depending on the interval of advertisement messages. Our technique is based on the windowing of the RA messages trains, each window being placed at the predicted time instants of handoff arrivals.

Mobile IP is a mobility management protocol that has been designed to support mobile users in the Internet. As researchers are currently considering to use it in the third generation cellular system, it becomes clear that some kind of hierarchy is needed in Mobile IP to improve its scalability and its support for fast handoff control. Along this line, several proposals that separate the macro mobility management from the micro mobility management have been made recently. All these proposals agree that Mobile IP is a good protocol to support macro mobility but they all define their own micro mobility management protocol. As a result, a mobile host will need to understand the different micro mobility management protocols of the sites that it visits in order to stay connected. We argue that this approach is not practical and that a framework that allows the deployment of different micro mobility management protocol in different parts of the Internet while still providing seamless roaming to mobile users is needed. This paper present such a framework. We propose to decompose the Internet mobility management protocol into three components. The first one, the registration protocol, specifies the registration procedures between the mobile node and the domain it is attached to. It is standard and unique. The second one, the micro mobility protocol, manages local mobility and may differ from one domain to another. The third one, the macro mobility protocol, manages mobility across domains. We suggest to use Mobile IP as the macro mobility protocol.

Mobile IP presents an efficient solution to the wide-area host mobility problem in the Internet. Nevertheless, its home registration process introduces an overhead in the local-area mobility case. A mobile host is required to register with its possibly distant home agent, whenever it changes its point of attachment to the network. Foreign agent hierarchies have been introduced to perform regional mobile IP registration to minimize the home registration signaling overhead. We propose a novel configurable architecture to organize cooperating foreign agent hierarchies in the foreign domain. An attempt is made not to change the mobile host home registered care-of address as long as it is within the foreign domain. In such a manner, home registration signaling overhead is minimized, and the home agent is isolated from any local-area movement by the mobile host.