• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.12C
• /
• pp.208-217
• /
• 2001

In mobile Internet environment, providing multicast requires much more complex mechanism comparing with the unicast Mobile IP routing protocol. This is because multicast datagrams are sent to a group address that do not belong to a specific network. The IETF Mobile IP suggested two approaches for mobile multicasting, namely remote subscription and hi-directional tunneling. In remote subscription, a mobile node may join a group via a local multicast router on the visited subnet. Therefore remote subscription may cause much datagram loss while reconstructing the delivery tee. In bi-directional tunneling, a mobile node may join a group via a hi-directional tunnel to its home agent. Bi-directional tunneling may suffer from inefficient routing. In this paper, we proposed a new mobile multicasting protocol, Mobile If Multicast using Local Broadcast(MIMLB) which can receive multicast datagrams as fast as possible and optimize routing path for multicast delivery. The MIMLB protocol uses hi-directional tunneling to receive multicast datagrams. And the MIMLB protocol can resolve datagram duplicated problem and optimize routing path by using local broadcast. Simulation results show that MIMLB reduces delivery path length and optimizes multicast routing path when a mobile nod? moves into a foreign network.

• 한국ITS학회:학술대회논문집
• /
• 2003.11a
• /
• pp.100-104
• /
• 2003

• Journal of KIISE:Information Networking
• /
• v.32 no.5
• /
• pp.603-614
• /
• 2005

The wireless LAN environment using Mobile IP is constructed and managed to be connected with Ethernet based wired networks. However, there have been many problems with wireless networks using Mobile IP. Some important facts on network performance have not been considered when introducing wireless LAN by Mobile IP to wired networks. In this paper, we suggest schemes which can solve problems on Handover latency caused by the asymmetrical connectivity of the Access Router at applying the HMIPv6 and on binding updates due to the MN frequent movement. Our proposed schemes can reduce network latency by using the HMIPv6 architecture with a virtual router layer, and reduce communication overhead by interchanging information of the MN movement between routers. Our schemes are expected to assist in constructing a more real and effective wireless LAN environment based on the HMIPv6 and FMIP.

• The KIPS Transactions:PartC
• /
• v.12C no.2 s.98
• /
• pp.267-280
• /
• 2005

In this paper, we implement and verify XMIP integrating IETF Mobile IP and the Explicit Multicast mechanism for a great number of small group multicast communications. U a source node sends Xcast packets explicitly inserting destination nodes into the headers, each Xcast router decides routes and forwards the packets toward each destination node based on unicast routing table without the support of multicast trees. n is a straightforward and simple multicast mechanism just based on a unicast routing table without maintaining multicast states because of the inheritance from the Explicit Multicast mechanism. This research modifies and extends the functionality of IETF Mobile IP's mobility agents, such as HA/FA to HA+/FA+ respectively, considering interworking with Xcast networks. Xcast packets captured by HA+ are forwarded into X-in-X tunnel interfaces for each FA+ referred to the binding table of HA.. This X-in-X tunneling mechanism can effectively solve the traffic concentration problem of IETF Mobile IP multicast services. Finally WLAN-based testbed is built and a multi-user Instant messenger system is developed as a Xcast application for finally verify the feasibility of the implemented XMIP/Xcast protocols.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.3
• /
• pp.309-316
• /
• 2016

Recently, the voice service over a mobile communication system tends to be provided based on the packet-based technology. Even though the sufficient transmission rate is supported by LTE mobile communication system, the quality of VoIP service that is experienced by the user can be degraded by the change in the transmission conditions and the terminal mobility. This paper has established an environment on which experiments are conducted for the different values of the major parameters that represent the transmission conditions. The result can contribute to the decision of the requirement that the mobile system should meet for maintaining the quality of VoIP service.

• The Journal of the Korea Contents Association
• /
• v.2 no.3
• /
• pp.119-126
• /
• 2002

The QoS(Quality of Service) guarantee mechanism is one of critical issues in the wireless network. Real-time applications like VoIP(Voice over IP) in All-IP networks need smooth handoffs in order to minimize or eliminate packet loss as a Mobile Host(MH) transitions between network links. In this paper, we design a new multicasting algorithm using DB(Dynamic Buffering) mechanism for Mobile-IPv6. A key feature of the new protocol is the concepts of the DB and MRA(Multicast Routing Agent) to reduce delivery path length of the multicast datagram. Particularly, the number of tunneling and average routing length of datagram are reduced relatively, the multicast traffic load is also decreased.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.10e
• /
• pp.433-435
• /
• 2002

All IP Mobile Network 하에서의 효율적인 멀티캐스트 전송의 필요성이 부각되고있다. Mobile IP프로토콜은 기본적으로 유니캐스트전송을 지원하며, 멀티캐스트 전송에 대해서는 효과적으로 정의하지 못하고 있다. 본 연구는 Mobile IP 망에 명시적 라우팅 프로토콜을 적용할 경우 기존 멀티캐스트 라우팅 도매인과의 연동을 하기 위한 미디어 게이트웨이(MGEM)를 설계하고 개발한다. 기존 멀티캐스트 트래픽을 1:N tunnel 의 특성을 가지는 명시적 멀티캐스트 전송방식을 사용하여 멀티캐스트 패킷을 이동단말들에 전송하기 위해서는 Mobile IP 홈에이젼트가 MGEM으로 확장되어야 하며, 이는 IGMP, SDP, 확장 HA 및 멀티캐스트 라우터 기능을 갖도록 요구된다.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.12 s.354
• /
• pp.89-94
• /
• 2006

In the Mobile IP, the movement of Mobile Host(MH) causes packets to be transmitted through a long route. A Correspond Node(CN) first communicate with a Home Agent(HA) when a Mobile Host moved from one subnet to another subnet. The HH-MIP algorithm reduces an inefficient transmission of packets by regarding a Foreign Agent(FA) near a mobile host as a Temporary Home Agent(THA). However, The algorithm costs the unnecessary signaling by measuring the distance of route between a FA and a THA for handover in the case that a Mobile host comes from a THA which a current FA never communicated. To solve this problem, we propose a scheme called Hierarchical Home Agent Handover in Mobile IP(HHH-MIP) algorithm. Our HHH-MIP algorithm only searches tables in a router by using the hierarchical structure between a FA and a THA. The simulation results show that the HHH-MIP algorithm reduces the additional signaling cost.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.1A
• /
• pp.24-35
• /
• 2008

We propose a tree-based integrated network of infrastructure network and mobile ad hoc network to effectively support Mobile IP for mobile ad hoc networks and also proposed a network management protocol for formation and management of the integrated network and a tree-based routing protocol suitable for the integrated network. The integrated network has fixed gateways(IGs) that connect two hybrid networks and the mobile nodes in the network form a small sized trees based on the mobile nodes that are in the communication distance with a IG. A new node joins an arbitrary tree and is registered with its HA and FA along tree path. In addition, the proposed protocol establishes a route efficiently by using the tree information managed in every node. We examined the effectiveness of the tree-based integrated network for some possible network deployment scenarios and compared our routing protocol against the Mobile IP supported AODV protocol.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.139-144
• /
• 2007

The mobile terminal's frequent changes to the access point introduce significant network overhead in mobile IP networks. To solve this problem, we introduce a hierarchical structure with consideration given to the dynamic value of neighbor scope in IP regional registration[1]. When a mobile terminal moves within the neighbor given by the scope value, it makes registration locally without registration with its home agent. We analyze the algorithm mathematically and show the numerical results. As a result, optimization of the scope value for the localized registration under the hierarchical structure makes the proposed scheme outperform the standard mobile IP protocol[2]. This can be explained from the fact that there is only local registration for terminal's movement within the scope region. Moreover, as the signaling cost for home agent increases, the proposed scheme becomes more advantageous.