Research Highlights Seminar with John Liu: Challenges and Opportunities in The Next Generation Emergency Call Systems


April 5, 2024    
1:10 pm - 2:00 pm


2222 Coover Hall
2520 Osborn Dr., Ames, Iowa, 50011

Event Type

Title: Challenges and Opportunities in The Next Generation Emergency Call Systems

Abstract: Mobile emergency call systems were launched in 1996 in the USA and Europe. The current 911 call system in the U.S. is obsolete. It failed to locate callers during natural disasters or vehicle pileups caused by bad weather. It does not support reception of caller GPS location data. When a person calls 911 for help in emergency, the dispatcher has to ask the caller to tell the location. The next generation emergency call system needs to transmit GPS location data automatically in real time along with necessary information and support voice communications.

The EU emergency call system launched in 2017 is the most advanced emergency call infrastructure in the world. It follows 3GPP TS 26.267/268/269 standards as the core technologies for real-time emergency data transmission. Road tests in EU countries have shown that the failure rate of emergency data packet delivery was 30% with average delay 13 seconds and variance 52 seconds much larger than 4 seconds demanded by the EU government.

In this talk scientific challenges and engineering bottlenecks in mobile emergency call systems will be discussed. Speech codec distortion to data signal will be presented. Radio channel fading statistics after power control in cellular systems will be shown as measured from field experiments. The nonlinear distortion of speech codec and the channel fading together make the mobile emergency call system yet to be understood and conquered.

Bio: John Q. Liu received the B.S. degree in quantum electronics and the M.S. degree in computer science from Peking University, Beijing, China, in 1990 and 1992, respectively, the M.S. degree in electrical engineering from New Mexico State University, Las Cruces, in 1993, and the Ph.D. degree in electrical engineering from the University of Southern California, Los Angeles, in 1996. From 1996 to 2000 he was a senior member of technical staff with Hughes Electronics Corporation. He invented and designed the DirecTV modem series. He is now associate professor at Wayne State University, Detroit, MI. His current research interests include detection of fatal heart disease, emergency call systems, advanced embedded systems, radio network security, ultra-wideband communications, free-space optical communications, modulation and coding, synchronization, signal design and detection.


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