Yu-Chul Kim

Upper layer enhancements for fast call setup in cdma2000 revision D

Fast call setup (FCS) technology, a recent enhancement in revision D of cdma2000/sup /spl reg// in 3rd generation partnership project 2 (3GPP2), is a set of mechanisms for reducing call setup latency. FCS technology comprises MS tracking mechanisms, channel assignment procedures, paging mechanisms, and traffic channel initialization procedures. The combination of these techniques contributes to the improvement of the overall call setup delay. This article discusses the functional aspects of these enhancements, and their quantitative and qualitative performance.

WLC10-2: Analytic Optimization of Hybrid ARQ Performance in Wireless Packet Data Systems

We propose an analytical framework that optimizes the performance of various Hybrid Automatic Repeat reQuest (HARQ) schemes in wireless packet data systems. The optimization framework lends itself to maximizing the user throughput without assuming a specific HARQ scheme, a target packet error rate, and a mapping of signal-to-interference-noise ratios (SINR) into modulation and coding scheme (MCS) sets. Thus, a user selects an optimal amount of redundancy bits used for retransmissions, an optimal packet error rate, and an optimal SINR-MCS mapping such that the user throughput would be maximized. We show that there exists an optimal redundancy block size of incremental redundancy (IR) scheme when the number of retransmissions is limited, while as small as possible redundancy size is optimal when the number of retransmissions is unlimited. Our analytical results are verified through extensive simulations of the IEEE 802.16e system.

Enhanced Slotted Mode Operation Considering Call Inter-arrival Time Distribution in cdma2000 Networks

In this paper, a new slotted mode operation in a cdma2000 wireless system is proposed. The proposed operation is designed to support emerging services such as push-to-talk (PTT) that require low paging delay and low power consumption. The proposed operation tries to minimize the paging delay and maximize battery life while using the same amount energy as that of legacy reduced slot cycle mode with the assumption that the inter-arrival time of a PTT call follows an exponential distribution. In the performance analysis, it is shown that the average paging delay can be reduced or battery life can be reduced