Career
He is an outstanding driver of wireless and mobile 2G to 5G cellular radio networks technologies. In 1985 he proposed a local cellular radio network comprising technologies present in 2G to 4G or discussed for 5G systems like self-organization of a radio mesh network, integration of circuitand packet switching, de-centralized radio resource control, Time Division Multiple Access/spread spectrum information transmission, antenna beam-steering, spatial beam multiplexing, interference coordination, South-Aloha based multiple access and demand assigned traffic channels, mobile broadband transmission using mm-waves, and multi-hop communication. In 1991 he proposed CELLPAC for packet switching in Group Special Mobile which triggered development of standard GPRS. In 1999 he proposed fixed two-hop decode-and-forward relays for cellular radio, now mandatory in standards 3GPP LTE Relations.10 and Institute of Electrical and Electronics Engineers 802.16.1 (mobile broadband WiMAX).
The relay concept triggered evolution of cellular radio architecture towards 3GPP LTE Small Cell networks, e.g. femto and pico cells operating like relays on radio resources provided by a donor base station.
The Communications Networks (ComNets) research team in large parts designed the European Telecommunications Standards Institute/BRAN HiperLAN2 medium access control protocol adopted by standard Institute of Electrical and Electronics Engineers 802.16 (WiMax) and used as a baseline in 3GPP LTE. Radio spectrum requirements for packet-switching mobile radio systems were calculated by World Radio Conference 2007 using a queuing model developed by Bernhard and his team Work by Bernhard and his team on wireless quality of service supporting multi-hop radio networks materialized in standard Institute of Electrical and Electronics Engineers 802.11s.
Walke earned his Diploma Ing. (Master of Science ) degree in Electrical Engineering and Data Processing (1965) from University of Stuttgart, Germany.
He worked two years as a Trainee with Telefunken and joined Telefunken Research (1967) where he received his doctorate (1975) from University of Stuttgart.
As a department head at General Electric Company Telefunken (now Airbus AG) he switched to FernUniversität Hagen, Germany (1983) as a professor for Data Processing Techniques. During 1990-2007 he was professor and director of the School of Communications Networks (ComNets) at Rheinisch-Westfälische Technische Hochschule Aachen" Faculty of Electrical Engineering and Information Technology and thereafter (until 2012) head of the ComNets Research Group.