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Bernhard H. Walke | |
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Born | 28 July 1940 |
Bernhard H. Walke (born 28 July 1940 in Neisse, Upper Silesia) is a pioneer of mobile Internet access [1] and professor emeritus at RWTH Aachen University in Germany. He is a driver of wireless and mobile 2G to 5G cellular radio networks technologies. In 1985, he proposed a local cellular radio network [2] comprising technologies in use today in 2G, 4G and discussed for 5G systems. For example, self-organization of a radio mesh network, integration of circuit- and packet switching, de-centralized radio resource control, TDMA/spread spectrum data transmission, antenna beam steering, spatial beam multiplexing, interference coordination, S-Aloha based multiple access and demand assigned traffic channels, mobile broadband transmission using mm-waves, and multi-hop communication. [3]
In 1991, he proposed CELLPAC [4] for packet switching in GSM which triggered development of ETSI standard GPRS. GPRS air-interface protocols follow a 1993 version [5] of CELLPAC. In 1999, he proposed fixed two-hop decode-and-forward relays [6] for cellular radio, now mandatory in standards 3GPP LTE Rel.10 and IEEE 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 ETSI/BRAN HiperLAN2 medium access control protocol [7] adopted by standard IEEE 802.16 (WiMax) and used as a baseline in 3GPP LTE-Advanced. Radio spectrum requirements for packet-switching mobile radio systems were calculated by World Radio Conference 2007 using a queuing model [8] developed by Walke and his team. [9] Work by Walke and his team on wireless quality of service supporting multi-hop [10] radio networks [11] [12] materialized in standard IEEE 802.11s.
Walke earned his Dipl. Ing. (M.Sc.) 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 in 1983 at AEG Telefunken (later taken-over in part by Airbus), he moved to FernUniversität Hagen, Germany, as a professor for data processing techniques. During 1990–2007, he was professor and director of the School of Communications Networks (ComNets) at RWTH Aachen's Faculty of Electrical Engineering and Information Technology until 2017 where he was head of the ComNets Research Group. [13]
In 2001, Walke, together with his ComNets colleagues Marc Peter Althoff and Peter Seidenberg and the Aachen-based P3 - Ingenieurgesellschaft für Management und Organisation mbH as investor and manager represented through Michael Tobias, was one of the founders of the P3 Solutions GmbH to offer consulting services to mobile network providers and vendors and the public sector, [14] although he didn't play an active role in the day-to-day business of the company. On 31 July 2009, the company absorbed its sister P3 networks GmbH to become P3 communications GmbH. In the 2010s, Walke sold his shares in the company. On 10 January 2019, when the holding company P3 group GmbH (the successor of the P3 Ingenieurgesellschaft mbH) split into the Aachen-headquartered P3 group AG (which was renamed into umlaut AG on 25 October 2019 and firms as umlaut SE since 22 October 2020) and the newly founded P3 global GmbH based in Stuttgart (which was renamed (back) into P3 group GmbH on 20 January 2020), [15] the core of the company stayed with umlaut and was renamed into umlaut communications GmbH. On 14 June 2021, it was announced that umlaut SE would become part of Accenture's Industry X endeavour. [16]
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as mobile phones and tablets. GSM is also a trade mark owned by the GSM Association. GSM may also refer to the Full Rate voice codec.
General Packet Radio Service (GPRS), also called 2.5G, is a packet oriented mobile data standard on the 2G cellular communication network's global system for mobile communications (GSM). GPRS was established by European Telecommunications Standards Institute (ETSI) in response to the earlier CDPD and i-mode packet-switched cellular technologies. It is now maintained by the 3rd Generation Partnership Project (3GPP).
A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking allows homes, telecommunications networks and business installations to avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Admin telecommunications networks are generally implemented and administered using radio communication. This implementation takes place at the physical level (layer) of the OSI model network structure.
In IEEE 802 LAN/MAN standards, the medium access control (MAC), also called media access control, is the layer that controls the hardware responsible for interaction with the wired or wireless transmission medium. The MAC sublayer and the logical link control (LLC) sublayer together make up the data link layer. The LLC provides flow control and multiplexing for the logical link, while the MAC provides flow control and multiplexing for the transmission medium.
Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options.
4G is the fourth generation of broadband cellular network technology, succeeding 3G and preceding 5G. A 4G system must provide capabilities defined by ITU in IMT Advanced. Potential and current applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television.
Unstructured Supplementary Service Data (USSD), sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator's computers. USSD can be used for WAP browsing, prepaid callback service, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network. The service does not require a messaging app, and does not incur charges.
The IEEE 802.21 refers to Media Independent Handoff (MIH) and is an IEEE standard published in 2008. The standard supports algorithms enabling seamless handover between wired and wireless networks of the same type as well as handover between different wired and wireless network types also called Media independent handover (MIH) or vertical handover. The vertical handover was first introduced by Mark Stemn and Randy Katz at U C Berkeley. The standard provides information to allow handing over to and from wired 802.3 networks to wireless 802.11, 802.15, 802.16, 3GPP and 3GPP2 networks through different handover mechanisms.
ComNets, a chair of RWTH Aachen University, is a former university department in Germany working on Mobile Communications. Head of ComNets was Bernhard Walke. Research projects are mainly funded by third parties like national and European boards and communication industries. The research activities of about 40 fully employed research assistants are focused on design and further development as well as quantitative performance analysis of mobile communication systems like GPRS, TETRA, EDGE, UMTS, Next Generation, Dedicated Short Range Communication Systems, Hybrid Systems, Ad hoc and Multi-hop WLAN, HiperLAN/2, HiperMAN, mobile Satellite and High-Altitude Platforms. Stochastic simulation based on emulated protocol stacks and traffic theory are the main analysis methods. Essential results of ComNets' work have been incorporated into the standards ETSI-GPRS, CEN-DSRC, ETSI/HiperLAN/2, IEEE 802.11 e/h/s.
Wi-Fi calling refers to mobile phone voice calls and data that are made over IP networks using Wi-Fi, instead of the cell towers provided by cellular networks. Using this feature, compatible handsets are able to route regular cellular calls through a wireless LAN (Wi-Fi) network with broadband Internet, while seamlessly change connections between the two where necessary. This feature makes use of the Generic Access Network (GAN) protocol, also known as Unlicensed Mobile Access (UMA).
This article is intended to give an overview of the history of telecommunications in Malaysia.
Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, wireless sensor systems, and radio broadcasting networks. RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible.
A wide variety of different wireless data technologies exist, some in direct competition with one another, others designed for specific applications. Wireless technologies can be evaluated by a variety of different metrics of which some are described in this entry.
Mobile broadband is the marketing term for wireless Internet access via mobile networks. Access to the network can be made through a portable modem, wireless modem, or a tablet/smartphone or other mobile device. The first wireless Internet access became available in 1991 as part of the second generation (2G) of mobile phone technology. Higher speeds became available in 2001 and 2006 as part of the third (3G) and fourth (4G) generations. In 2011, 90% of the world's population lived in areas with 2G coverage, while 45% lived in areas with 2G and 3G coverage. Mobile broadband uses the spectrum of 225 MHz to 3700 MHz.
Opportunity-Driven Multiple Access (ODMA) is a UMTS communications relaying protocol standard first introduced by the European Telecommunication Standards Institute (ETSI) in 1996. ODMA has been adopted by the 3rd-Generation Partnership Project, 3GPP to improve the efficiency of UMTS networks using the TDD mode. One of the objectives of ODMA is to enhance the capacity and the coverage of radio transmissions towards the boundaries of the cell. While mobile stations under the cell coverage area can communicate directly with the base station, mobile stations outside the cell boundary can still access the network and communicating with the base station via multihop transmission. Mobile stations with high data rate inside the cell are used as multihop relays.
The 3GPP has defined the Voice Call Continuity (VCC) specifications in order to describe how a voice call can be persisted, as a mobile phone moves between circuit switched and packet switched radio domains.
GEO-Mobile Radio Interface, better known as GMR, is an ETSI standard for satellite phones. The GMR standard is derived from the 3GPP-family terrestrial digital cellular standards and supports access to GSM/UMTS core networks. It is used by ACeS, ICO, Inmarsat, SkyTerra, TerreStar and Thuraya.
International Mobile Telecommunications-Advanced are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G mobile phone and Internet access service.
Vehicle-to-everything (V2X) is communication between a vehicle and any entity that may affect, or may be affected by, the vehicle. It is a vehicular communication system that incorporates other more specific types of communication as V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), V2V (vehicle-to-vehicle), V2P (vehicle-to-pedestrian), V2D (vehicle-to-device).