- in charge of pre-sales department and technical support department at Secuve Co., Ltd.

- pre-sales and technical support for MIDI sound chip, JEPG CODEC, MPEG CODEC, 3D acceleration chip to the customers (cellular phone vendor, cellular phone design house, auto-navigation vendor, car blackbox vendors)

- be in charge of SMS (Short Messaging Service) function on 2G CDMA cellular phones for US and South American market- developed S/W download utility for Lab-testing environment- be in charge of CDG testing at Lucent, Motorola, and Nortel testing Labs

- designed and developed ADSL/VDSL subscriber modems- developed Korean B-WLL(Broadband Wireless Local Loop) standard specification by participating in TTA STG 10 working group- build a strategic alliance with Motorola LMDS division- performed B-WLL BMT(BenchMark Test) on Walla Walla, Washington

- participated in DAMA-SCPC (Demand Assignment Multiple Access - Single Carrier Per Channel) satellite communication system development project (International Joint Project with Alenia Spazio, Italy)- participated in DTV RSMS (Resource and Subscriber Management System) project (International Joint Project with MPR Teltech, Canada)- participated in KOMPSAT (KOrean Multi-Purpose SATellite) project and developed remote M&C (Monitoring and Control) function for the active tracking antenna system.

- to develop function specification document for the large scale electronic exchange system, TDX-10- to develop an automatic dimensioning system for TDX-10 based on AI(Artificial Intelligence) technology- to develop and test SCCP (Signalling Connection Control Part) of No. 7 protocol for AIN(Advanced Intelligent Network) services