JungKyo Sohn

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User-generated content (UGC) also known as usercreated content (UCC) refers to various kinds of media contents that are produced by end users. A recent trend in the use of the Internet exhibits that data traffic from UGC is rapidly growing with the potential to create a huge amount of uplink traffic for wireless operators. As the reality of UGC’s scope and(More)
Increasing demand for high data-rate multimedia services has led to the emergence of high-speed data transfer features such as High-Speed Downlink Packet Access (HSDPA) for WCDMA networks. The role of the MAC-hs scheduler is vital in HSDPA in improving overall system performance. Using Opportunistic scheduling to exploit multi-user diversity for efficient(More)
High-Speed Downlink Packet Access (HSDPA) uses a shared forward link packet data channel that can achieve peak data rates up to 14.4 Mbps. The newly introduced features that are key to reaching such high rates are link adaptation, Hybrid ARQ (HARQ) and fast scheduling. The decision to admit new users is still taken by the Radio Network Controller (RNC);(More)
Digital watermarking is already used to establish the copyright of graphics, audio and text, and is now increasingly important for the protection of geometric data as well. Watermarking polygonal models in the spectral domain gives protection against similarity transformation, mesh smoothing, and additive random noise attacks. However, drawbacks exist in(More)
In this paper, we address the problem of access selection in multi-access networks. As admission and handover process durations are in the order of seconds and decentralized decisions are made over multiple cells spread over the network, such decisions have to be made quickly and in a distributed manner while keeping the network stable and its load(More)
CDMA 1x Ev-DO is an evolution of the CDMA2000 3G wireless standard to enable high rate packet data services up to 2.4Mbps in Rev 0, 3.1Mbps in Rev A, and 4.9Mbps in Rev B. To support such high data rates, CDMA 1x Ev-DO utilizes TDMA technology on the downlink allowing a single receiver per time slot. Accordingly, a scheduling algorithm is necessary to(More)
In multi access network environments, mobile stations may encounter multiple choices for selecting an access network. Carefully designed access selection schemes can provide not only mobile users with better services but also network operators with better resource utilizations. It is also envisioned that further improvements can be achieved by(More)
Increasing demand for high data-rate real time services has led to the use of shared channels in the forward link for real-time services in 3G wireless networks, such as HSDPA. Strict and differentiated QoS requirements for real-time services, along with time varying channel capacity impose a great deal of challenge on the MAC-hs scheduler. In this paper,(More)
In multi access network environments, mobile stations may encounter multiple choices for selecting an access network. Carefully designed access selection schemes can provide not only mobile users with better services but also network operators with better resource utilizations. It is also envisioned that further improvements can be achieved by(More)