• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.3
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• pp.93-103
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• 2000

This paper describes Internet multicast routing protocols over MPLS (Multiprotocol Label Switching) networks. Internet multicast routing protocols are divided into 3 categories in terms of tree types and tree characteristics: a shortest path tree, a shared tree and hybrid tree types. MPLS should support various multicast mechanisms because of extremely different IP multicast architectures, such as uni-/bi-directional link, Flooding/prune tree maintenance mechanism, the existence of different tree types with the same group, etc. There are so many problems over MPLS multicast that the solutions can't be easily figured out. In this paper, we make a few assumptions on which the solutions of IP multicast routing protocols over MPLS networks are given. A broadcasting label is defined for the shortest path tree types. Cell interleaving problems of the shared tree types is solved by using block-based transmission mechanism. Finally, the existing hybrid-type multicast routing protocol is reasonably modified to support MPLS multicast.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.77-86
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• 2003

This paper describes the new method for Internet multicast routing protocols using MPLS (Multiprotocol Label Switching) networks. Internet multicast routing protocols are divided into three categories in terms if tree types and tree characteristics : a shortest path tree a shared tree and hybrid tree types. MPLS should support various multicast mechanisms because of extremely different IP multicast architectures, such as uni-/bi-directional link, Flooding/prune tree maintenance mechanism. the existence of different tree types with the same group, etc. There are so many problems over MPLS multicast that the solutions can't be easily figured out. In this Paper, we make a few assumptions on which the solutions of IP multicast routing protocols over MPLS networks are given. A broadcasting label is defined for the shortest path tree types. Cell interleaving problems of the shared tree types is solved by using block-based transmission mechanism. Finally, the existing hybrid-type multicast routing protocol is reasonably modified Shortest Path tree type to support MPLS multicast. It has been shown that these modifications give better performance (transmission delay) than the orignal method.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.137-140
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• 2001

In this paper, we propose a multicast routing scheme for an efficient and reliable support of multicast service to mobile hosts in IPv6 based networks. The purpose of this paper is to develop an algorithm to reduce both the number of multicast tree reconstruction and the multicast service disrupt time using the RSVP scheme. The proposed multicast routing scheme is a hybrid method using the advantages of the hi-directional tunneling and the remote subscription proposed by the IETF Mobile IP working group. The proposed scheme satisfies the maximum tolerable transfer delay time and supports the maximum tunneling service. The simulation results show that the proposed scheme has better performance in the number of multicast tree reconstruction and the time of multicast service disrupt than the previous schemes does.

• Journal of Internet Computing and Services
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• v.6 no.4
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• pp.115-124
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• 2005

The packet loss problem that occurs in the mobile multicast (MoM) protocol due to designated multicast service provider(DMSP) handoff is investigated through simulation experiments for several DMSP selection policies. Then, two enhanced DMSP schemes are proposed to minimize the packet loss of the MoM protocol with single DMSP. The first scheme uses a backup DMSP and greatly reduces the packet loss rate at the expense of the increased network traffic. The second scheme utilizes the extended DMSP operation and shows many desirable features such as the almost zero packet loss rate and relatively low network traffic.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1256-1264
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• 2011

MBS (Multicast Broadcast Service) is defined in WiBro networks for implementing multicast-based services. However, most of the WiBro networks currently used in Korea do not have the MBS functionality and it causes some difficulty in implementing multicast-based services. This paper evaluates the performance of VoIP-based group communication services when implementing using the following two cases: unicast-based and multicast-based group communication systems. The performance evaluation is done using QualNet for each case in terms of the amount of network resource for the service, the delay and delay jitter of packets, and the difference of the delay of members in a group. The simulation result shows that the number of groups and members in a group in a WiBro network is limited because the amount of network resource for the service is increased according to the number of members in a group, and so, the MBS service is required in a WiBro network for a fully-fledged service of VoIP-based group communications. The simulation result also shows that, when a packet bundling is used, the number of groups and members in a group that can be supported in a WiBro network can be increased due to the decrease of the amount of network resource for the service.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.133-136
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• 2003

In this paper, we propose a multicast routing protocol for the seamless delivery of multicast data to mobile hosts through the optimal route in IP based mobile networks. The proposed multicast routing protocol is a hybrid method employing the merits of the bi-directional tunneling and the remote subscription by considering the mobility of mobile hosts. The proposed protocol satisfies the bound of end-to-end delay and supports the seamless handoff. The simulation results show that the proposed protocol has better performance in the number of multicast tree reconstruction and tunneling length and packet loss time than the previous protocols.

• Journal of Internet Computing and Services
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• v.6 no.3
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• pp.85-95
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• 2005

Whereas the traditional multicast schemes based on Mobile IP can support a limited number of very large multicast groups, the Xcast protocol can support a very large number of small multicast groups, In the Xcast, the source node encodes the list of destinations in the Xcast header. Therefore, the maximum packet size in the network limits the number of destinations that a Xcast packet may have. In this paper, an enhanced Xcast protocol is proposed to solve the multicast group size limitation of the existing Xcast protocol in providing multicast service for mobile nodes. Moreover, the SIP (a very flexible control plane protocol) is integrated with the proposed multicast scheme to provide mobility awareness on the application layer. The simulation results verify that the proposed multicast scheme not only increases the packet delivery ratio and the data packet forwarding efficiency but also achieves low latency of packets in the network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.349-359
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• 2004

To provide multicasting service, several multicast protocols for mobile hosts have been proposed. But they include glitches such as a non-optimal delivery route, data loss when hosts move another network, therefore they have some insecure problems about multicast data transmission. In this paper, we consider these problems and propose a new reliable and efficient multicast routing protocol for Mobile If networks. The proposed protocol provides reliable multicast transmission by compensating data loss from the previous agent when a mobile host moves another network. Also it provides additional function that is directly to connect a multicast tree according to the status of agents. It provides more efficient and optimal multicast path. The performance of the proposed protocol is proved by simulation of various conditions.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10b
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• pp.1355-1358
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• 2001

IP Multicast can efficiently provide enormous bandwidth savings by enabling sources to send a single copy of a message to multiple recipients who explicitly want to receive the information. But due to the complexity of IP multicast and its fundamental differences from unicast, there are not very many tools available fer monitoring and debugging multicast networks, and only a few experts understand the tools that do exist. This thesis proposes a Multicast Routing Debugger (MRD) system that monitor the status of a multicast network. This system is aimed to multicast-related faults detection. In thesis, first, we define the set of information that should be monitored. Second, the method is developed to take out such information from multicast routers. Third, MRD system is prototyped to collect, process information from heterogeneous routers on a multicast network and to display the various status of the network comprehensively. The prototype of MRD system is implemented and deployed. We perform experiments with several scenarios. Experimental results show we can detect various problems as information that we define is monitored. The MRD system is simple to use, web-based and intuitive tool that can monitor the status of a specific multicast network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.208-213
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• 2011

Since the wireless technologies based on the IP have been developed recently, a variety of mobile services has been proposed. For broadcasting services to utilize network resources efficiently, there is a need to support handover of multicast traffic in mobile networks. In this paper, we add a network function block to solve the tunnel convergence problem, and propose a new fast handover scheme to reduce handover latency for PMIPv6 networks with multicast function. With the simulation result, we show that our fast handover scheme has better performance than the draft in the IETF in the viewpoint of handover latency and multicast service disruption.