About the Authors

Rainer Liebhart has over 20 years of experience in the telecommunication industry. He held several positions within the former Siemens Fixed and Mobile Networks divisions and now in Nokia Networks division. He started his career as SW Engineer, worked later as standardization expert in 3rd Generation Partnership Project (3GPP) and European Telecommunications Standards Institute (ETSI) in the area of Internet Protocol Multimedia Subsystem (IMS), took over responsibilities as Worldwide Interoperability for Microwave Access (WiMAX) and Mobile Packet Core System Architect and is currently heading the Mobile Broadband Core Network standardization team in Nokia Networks. He is the Nokia Networks main delegate in 3GPP SA2 with the focus on Long-Term Evolution/System Architecture Evolution (LTE/SAE). He is (co-)author of over 50 patents in the telecommunication area. Rainer Liebhart holds an MS in Mathematics from the Ludwig-Maximilians University in Munich, Germany.

Devaki Chandramouli has over 14 years of experience in the telecommunication industry. She spent the early part of her career with Nortel Networks and is currently with Nokia, Networks division. At Nortel, her focus was on design and development of embedded software solutions for Code Division Multiple Access (CDMA) networks. Later, she represented Nortel in the WiMAX Forum and worked on WiMAX architecture and protocol development. At Nokia, her focus areas include architecture development within 5G research and standards development for 3GPP access, LTE/SAE-related topics. She is also an active participant and contributor to 3GPP standards. She has (co-)authored over 40 patents in wireless communications. She received her BE in Computer Science from Madras University (India) and MS in Computer Science from University of Texas at Arlington (United States).

Curt Wong has over 18 years of experience in the telecommunication industry. He started his career with Nokia Networks since 1995 and held several positions, including the area of research and development, interoperability testing, product management, and new technologies standardization. In recent years, his primary focus has been in the areas of wireless system-level developments, with emphasis on the infrastructure side of cellular networks. His current activities and involvement are on voice services over LTE, including IMS, emergency aspects, group communication over LTE, and interworking with legacy 2G and 3G networks. He is an active participant and contributor to 3GPP standards. He has a BS in electrical engineering from the University of Texas at Austin and an MS in telecommunications from Southern Methodist University, Dallas,TX.

Jürgen Merkel has over 20 years of experience in the telecommunication industry. He started his career in Alcatel where he held several positions in system design, product management, and business development and strategy – always with a tight linkage to standardization in ETSI Special Mobile Group (SMG) and 3GPP. In Nokia, he is a member of the Mobile Broadband standardization team, focusing on services and service requirements. He heads the Nokia Networks delegation in 3GPP SA1, and is an active contributor and driver for group communication aspects in 3GPP. Jürgen Merkel holds a MS in electronic engineering from the University of Stuttgart, Germany.