• Journal of KIISE:Information Networking
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• v.29 no.2
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• pp.197-203
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• 2002

This paper proposes a new agent based mechanism called a Multicast Handoff Agent (MHA) to reduce handoff latency for IP multicast. The MHA acts as a proxy for an Internet Group Management Protocol (IGMP) of Mobile Nodes (MNs) at each Base Station (BS) and keeps information for members of multicast groups in a cell. When an MN moves to a next cell, the MHA immediately sends unsolicited reports without waiting for the IGMP query. The mechanism was evaluated through simulation and analysis and compared with the IGMPv2 for micro-mobility and the IGMP traffic. Simulation results show that handoff latency for micro-mobility can be largely reduced and the IGMP control traffic on the wireless links during the duration of membership can be eliminated. Thus, this mechanism is superior to the existing mechanism in both micro-mobility and battery duration, as the need not to reply to a query conserves battery power.

• Journal of KIISE:Information Networking
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• v.37 no.6
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• pp.444-452
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• 2010

To avoid a channel zapping delay, the device needs to predict a next channel and must download it. Previous researches suggest algorithms based on assumption by utilizing many data. How to select and download future channels is a main issue in IPTV system. Most proposal based on assumption do not guarantees complete performance of channel zapping. In this paper, we suggest an effective method to avoid a channel zapping time with a constant performance by using a number remote controller key information.