Dong-ho Cho

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—Future mobile telecom systems will most probably consist of various radio access networks to utilize various merits. A typical scenario of these network integrations is an interworking between UMTS and WLAN network. UMTS network is one of most prevalent network that can cover wide area and wireless LAN (WLAN) network is a good and cheep solution for local(More)
In order to derive the suitable protocol architecture for IMT2000 systems, we evaluate the performance of signaling messages in the separated protocol layer and combined protocol layer recommended by W-CDMA and cdma2000, respectively. Also, we evaluate the performance of combined processing and sequential processing method in the case of handling(More)
– We analyzed four systems designed for high-data rate transmission such as IEEE 802.16d OFDMA, 3GPP TD-CDMA, 3GPP2 cdma2000 1xEV-DO, and IEEE 802.11a WLAN, and compared their efficiency, the number of VoIP user, and the normalized number of VoIP user per 1MHz. It is shown that the 802.16 system serves the most number of VoIP user, and the normalized number(More)
SUMMARY The capacity analysis of CDMA forward link is required to allocate high data-rate users. To solve this problem, we analyze the capacity of the CDMA forward link based on optimum power control. In a multi-cell environment, the intracell interference and intercell interference are derived. To show the capacity impact of high data-rate users, we(More)
SUMMARY A loop architecture of DQDB with slot reuse (LDQDB-SR) segmented by erasure nodes was studied to overcome the performance limitation due to the nature of the uni-directional bus architecture of DQDB with slot reuse. The LDQDB-SR adopts the destination slot release and an inter-segment bandwidth regulation based on the distributed queuing system of(More)
SUMMARY In this paper, efficient data transmission methods in wire and wireless interworking environments are studied in the case of handover occurring. To provide efficient mobile data service based on TCP, the wire and wireless interworking module with analysis function of TCP frame header protects the duplicated transmission of TCP frames. Also, by using(More)
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