Hsien-Ming Tsai

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The broadcast storm becomes a very serious problem for ad hoc networks to migrate into the overlay networks for the application of group communications. The main concept of virtual subnet technology is the capability to group users into broadcast domains, which divides a virtual subnet into logic, instead of physical, segments and reduces the traffic(More)
This paper proposes a radio channel assignment scheme called repacking on demand (RoD) for two-tier wireless local loop (WLL) networks. A two-tier WLL overlays a macrocell with several microcells. When a new call arrives at a two-tier WLL with RoD, if no idle channel is available in both the microcell and the macrocell, repacking is performed (i.e., a call(More)
To support real-time multimedia services in UMTS all-IP network, Third-Generation Partnership Project TR 25.936 proposed two approaches to support real-time serving radio network controller (SRNC) switching, which require packet duplication during SRNC relocation. These approaches significantly consume extra system resources. This paper proposes the fast(More)
To support real-time multimedia services in UMTS all-IP network, 3GPP TR 25.936 proposed two approaches to support real-time serving radio network controller (SRNC) switching, which require packet duplication during SRNC relocation. These approaches significantly consume extra system resources. This paper proposes the fast SRNC relocation (FSR) approach(More)
In mobile telecommunications networks, radio channels are limited resources that should be carefully allocated. To increase network capacity, channel assignment can be exercised in a hierarchical cellular network (HCN). By considering the speeds of MSs, we propose an HCN channel assignment approach called repacking on demand (RoD). A simulation model is(More)
In mobile telecommunications operation, radio channels are scarce resources and should be carefully assigned. One possibility is to deploy the hierarchical cellular network (HCN). This paper studies a HCN channel assignment scheme called repacking on demand (RoD). RoD was originally proposed for wireless local loop networks. We expend this work to(More)
A unicast video-on-demand (VOD) system is good at interactivity but bad at scalability. Many multicast schemes have been proposed to solve the scalability problem in recent years. However, the weakness of these schemes are lack of interactivity. Furthermore, most multicast schemes rely on a large number of buffer and bandwidth to prefetch a large portion of(More)