William Chan is a senior product manager for Spirent Communications focused on cellular-assisted positioning solutions for automated device testing, O-RAN O-RU testing solution and RF channel emulation. William has an extensive background in wireless communications and is actively involved in the 3GPP, CTIA, O-RAN Alliance, PTCRB, and GCF organizations where he is a key contributor to test specifications, test plans and validation processes, esp for location testing covering both GNSS and cellular location technologies such as OTDOA, E-CID, RTT, Wi-Fi location, Sensor etc. He has concentrated on location technologies for over 18 years, from E-OTD in the GSM era to recent 5G NSA/SA location testing. He frequently works alongside subject matter experts at major US carriers to help define test specifications and plans to satisfy evolving FCC E911 requirements. Besides, other areas of expertise include test and measurement, O-RAN RU testing, MIMO propagation measurement, modeling, simulation, and emulation, and the impact of MIMO propagation in wireless networks (3G, LTE, 5G, Open RAN, VoLTE, VoWi-Fi).