Namhi Kang

Localized Proxy-MIPv6 with Route Optimization in IP-Based Networks

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 PMIPν6 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.

Mobility management based on proxy mobile IPv6 for multicasting services in home networks

Advances in broadband Internet access and enhanced performance of mobile devices have enabled seamless mobile IPTV service between indoor and outdoor. Mobile IPTV service is based on mobile multicasting to support efficient group communication. However, mobile multicasting has two constraints that we consider: a tunnel convergence problem and high handover latency. To reduce the two constraints, we propose a mobile multicasting model that is feasible for PMIPv6 domain. The proposed model removes tunnel convergence and reduces router processing. We then propose a fast handover scheme using a context transfer mechanism suitable for the proposed model. We also show that the proposed scheme outperforms previously proposed schemes in terms of packet delivery cost and handover latency.

Enhanced PMIPv6 Route Optimization Handover

Packet delivery in Proxy Mobile IPv6 (PMIPv6) relies on an anchor node called LMA. All packets sent by a source node reach a receiver node via LMA, even though the two nodes attach to the same MAG. In some scenarios, PMIPv6 results in high delivery latency and processing costs due to this unnecessary detour. To address this issue, several PMIPv6 route optimization schemes have been proposed. However, high signaling costs and excessive delays remain when handover is performed. For this reason, we propose an enhanced PMIPv6 route optimization (EPRO) scheme. In addition, we analyze the performance of the EPRO. Analytical results indicate that the EPRO outperforms previous schemes in terms of signaling overhead and handover latency.

Load-Balancing Proxy Mobile IPv6 Networks with Mobility Session Redirection

This letter presents a mobility session redirection scheme for Proxy Mobile IPv6 networks (PMIPv6-MSR), facilitating LMA changes in the middle of a mobility session for, e.g. load-balancing purpose. Analytical results confirm that the proposed PMIPv6-MSR shows lower blocking and dropping probability than PMIPv6 without load control (PMIPv6-NLC), as offered load increases.

Comprehensive performance evaluation of distributed and dynamic mobility routing strategy

In this paper, we conduct a comprehensive performance study of distributed and dynamic mobility management (DDMM). DDMM presents a new architectural paradigm for a sustainable mobile networking against an ever-increasing amount of Internet data traffic, providing IP mobility management with distributed deployment of mobility anchors and dynamic activation when mobility is needed. Such a distributed mobility management concept is generally and intuitively accepted in terms of effective distribution of mobile traffic when compared with centralized mobility management (CMM) approaches. Nevertheless, the routing strategy of DDMM has not yet been properly examined through performance studies, and especially the impact of potential mobility routing strategies on the user plane is an open question. We perform a mathematical analysis of DDMM and present numerical results aiming to identify in which conditions, by which factors, and how much, DDMM improves mobility performance. For comparison, Mobile IPv6, Proxy Mobile IPv6 (PMIPv6), and PMIPv6 localized routing (PMIPv6-LR) were considered as representative IP mobility protocols following CMM approaches. Analytical results demonstrate that DDMM generally achieves higher performance when compared with CMM-based protocols in terms of packet delivery cost, tunneling overhead, and throughput, but specific performance varies in function of multiple input parameters.

Multimedia push-to-talk service in home networks

We propose a distributed Push-to-Talk (PTT) system model to support a one-to-many multimedia content distribution service. We also present a home-monitoring service scenario as an example that demonstrates how a multimedia PTT service can be used in wireless mesh-formed home networks. The proposed system uses wireless mesh routers for a home network. Centralized server-based functionalities for SIP session control and PTT service management are distributed over a set of mesh routers in manner of peer-to-peer system. To realize this service system, the system model and the implementation architecture were proposed and verified by real implementation.

An Efficient QoS Control Mechanism for IMS based Convergence Network

In this paper, we propose a novel QoS control mechanism called IPFIX (class fixing in IP option header) which is intended to identify IMS user residing in conventional Internet for resources reservation in DiffServ core network. The work was motivated by the need of interoperability between QoS-enabled UMTS network and conventional Internet unable to support QoS for NGN (next generation network). IPFIX does not force user in Internet to be equipped with any resource reservation protocol such as PDP or RSVP. Instead it utilizes the option field of IP header that contains the minimum information of QoS. Our numerical analysis and implementation results show that IPFIX outperforms PDP and RSVP in terms of control overhead.

Secure and scalable routing protocol for mobile ad-hoc networks

This paper is intended to find an efficient way to support secure and scalable routing mechanism well suited for Mobile Ad hoc Networks (MANET). Support of secure routing protocol is prerequisite for launching a secure communication in the presence of adversaries. To do this, we first propose a zone networking architecture based on zone masters that allow ordinary nodes to discover a feasible route to the destination in a scalable manner. On the basis of the architecture, secure routing protocol is given. Moreover, we also propose to use short-lived key(s) to overcome the performance degradation caused by applying expensive digital signature to our scheme.

Heterogeneous routing protocol coordinator for mobile ad hoc networks

Lots of routing protocols have been proposed in the literatures to overcome several challenges in ad hoc networks. The fundamental point we consider in this paper is that most of such protocols are generally based on the assumption that mobile nodes are functionally equivalent to each other in computing power and memory space. Moreover, all of the mobile nodes are required to use a common routing protocol to communicate with each other. However, such assumptions do not reflect the real world, even further the future oriented ubiquitous world. The ubiquitous paradigm requires networking technologies to support the heterogeneity including various capabilities to compute, amounts of storage, radio interfaces, patterns of mobility and others. In real scenario, for instance, some nodes may not want to relay packets for others owing to their power constraints. Also there might be nodes employing different routing protocols in a single communication zone. To cover some of these cases, this paper proposes a simple but efficient approach called HRPC (Heterogeneous Routing Protocol Coordinator) that works well in our previously proposed MANET architecture. HRPC is not a stand-alone routing protocol but a coordinating module for support bridging functionality between heterogeneous routing protocols in MANET. This paper also gives HRPC implementation and its demonstration results, where DYMO and OLSR routing protocols are used as an exemplified scenario to evaluate the operability of HRPC.

Ubiquitous zone networking technologies for multi-hop based wireless communications

This positioning paper presents u-Zone (ubiquitous-Zone) based multi-hop wireless network architecture and its components. Several networking technologies to support reliability, enhanced scalability, heterogeneity, internet connectivity, and mobility are briefly presented.