Dong-Jun Lee

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—A new signal-to-interference ratio (SIR)-based call admission control (CAC) scheme is proposed in DS-CDMA systems. In this scheme, a new call is accepted by a base station (BS) if the SIR's at that specific BS and its nearby, not necessarily adjacent, BS's can be guaranteed to be higher than some threshold value after accepting the new call. The SIR's of(More)
—Code-division multiple-access (CDMA) cellular systems use soft handoff. Although the capacity of CDMA systems is interference-limited in nature, channel shortages may occur because soft handoff uses several channels simultaneously. To cope with this problem, we propose an improved handoff method that borrows channels from stationary calls participating in(More)
—The Intermational Mobile Telecommunications IMT-2000 system uses a microcell concept to provide multimedia services and to support increasing number of users. However, in a microcell system, the number of handoffs is greatly increased. To solve this problem, a multitier cellular structure is proposed, in which high-speed mobile terminals (MTs) are serviced(More)
Abstmcr-CDMA cellular systems use soft handoff. Although the capacity of CDMA systems is interference-limited in nature, channel shortages may occur because soft handoff uses several channels simultaneously. To cope with this problem, we propose an improved handoff method which borrows channels from stationary calls participating in soft handoff and(More)
— When the cells in a location area are paged sequentially based on the specific information such as last registered area or mobile speed, paging load may be non-uniformly distributed among the cells. This non-uniform paging traffic causes additional paging delay due to the increase of waiting time in the cell with high paging load. In this paper, we(More)