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Bernhard H. Walke
Bernhard H. Walke (born 28 July 1940 in Neisse, Upper Silesia) is a pioneer of mobile Internet access 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 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. In 1991, he proposed CELLPAC for packet switching in GSM which triggered development of ETSI standard GPRS. GPRS air-interface protocols follow a 1993 version of CELLPAC. In 1999, he proposed fixed tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neisse
The Lusatian Neisse (german: Lausitzer Neiße; pl, Nysa Łużycka; cs, Lužická Nisa; Upper Sorbian: ''Łužiska Nysa''; Lower Sorbian: ''Łužyska Nysa''), or Western Neisse, is a river in northern Central Europe.''Neisse River'' at www.britannica.com. Retrieved 4 Feb 2011. at http://eagri.cz/public. Retrieved 4 Feb 2011. It rises in the , near |
LTE Advanced
LTE Advanced (LTE+) is a mobile communication standard and a major enhancement of the LTE (telecommunication), Long Term Evolution (LTE) standard. It was formally submitted as a candidate 4G to ITU-T in late 2009 as meeting the requirements of the IMT-Advanced standard, and was standardized by the 3rd Generation Partnership Project (3GPP) in March 2011 as 3GPP Release 10. The LTE+ format was first proposed by NTT DoCoMo of Japan and has been adopted as the international standard. LTE standardization has matured to a state where changes in the specification are limited to corrections and bug fixes. The first commercial services were launched in Sweden and Norway in December 2009 followed by the United States and Japan in 2010. More LTE networks were deployed globally during 2010 as a natural evolution of several 2G and 3G systems, including Global system for mobile communications (GSM) and Universal Mobile Telecommunications System (UMTS) in the 3GPP family as well as CDMA2000 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WiMax
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. The WiMAX Forum was formed in June 2001 to promote conformity and interoperability, including the definition of system profiles for commercial vendors. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL". IEEE 802.16m or WirelessMAN-Advanced was a candidate for 4G, in competition with the LTE Advanced standard. WiMAX was initially designed to provide 30 to 40 megabit-per-second data rates, with the 2011 update providing up to 1 Gbit/s for fixed stations. WiMAX release 2.1, popularly branded as WiMAX 2+, is a backwards-compatible transition from previous WiMAX generations. It is compatible and interoperable with TD-LTE. Terminology WiM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operations center in Piscataway, New Jersey. The mission of the IEEE is ''advancing technology for the benefit of humanity''. The IEEE was formed from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers in 1963. Due to its expansion of scope into so many related fields, it is simply referred to by the letters I-E-E-E (pronounced I-triple-E), except on legal business documents. , it is the world's largest association of technical professionals with more than 423,000 members in over 160 countries around the world. Its objectives are the educational and technical advancement of electrical and electronic engineering, telecommunications, computer engineering and similar disciplines. History Origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Access Control
In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical 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 (i.e. EtherType, 802.1Q VLAN tag etc), while the MAC provides flow control and multiplexing for the transmission medium. These two sublayers together correspond to layer 2 of the OSI model. For compatibility reasons, LLC is optional for implementations of IEEE 802.3 (the frames are then "raw"), but compulsory for implementations of other IEEE 802 physical layer standards. Within the hierarchy of the OSI model and IEEE 802 standards, the MAC sublayer provides a control abstraction of the physical layer such that the complexities of physical link control are invisible to the LLC and upper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HiperLAN
HiperLAN (High Performance Radio LAN) is a wireless LAN standard. It is a European alternative for the IEEE 802.11 standards (the IEEE is an international organization). It is defined by the European Telecommunications Standards Institute (ETSI). In ETSI the standards are defined by the BRAN project (Broadband Radio Access Networks). The HiperLAN standard family has four different versions. HiperLAN/1 Planning for the first version of the standard, called HiperLAN/1, started 1992, when planning of 802.11 was already going on. The goal of the HiperLAN was the high data rate, higher than 802.11. The standard was approved in 1997. The functional specification is EN300652, the rest is in ETS300836. The standard covers the Physical layer and the Media Access Control part of the Data link layer like 802.11. There is a new sublayer called Channel Access and Control sublayer (CAC). This sublayer deals with the access requests to the channels. The accomplishing of the request is depend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ComNets
ComNets (''Communication Networks''), 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, Enhanced Data Rates for GSM Evolution, EDGE, UMTS, Next Generation, DSRC, Dedicated Short Range Communication Systems, Hybrid Systems, Ad hoc and Multi-hop Wireless LAN, WLAN, HIPERLAN#HIPERLAN.2F2, 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, European Committ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Station
Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service." The term is used in the context of mobile telephony, wireless computer networking and other wireless communications and in land surveying. In surveying, it is a GPS receiver at a known position, while in wireless communications it is a transceiver connecting a number of other devices to one another and/or to a wider area. In mobile telephony, it provides the connection between mobile phones and the wider telephone network. In a computer network, it is a transceiver acting as a switch for computers in the network, possibly connecting them to a/another local area network and/or the Internet. In traditional wireless communications, it can refer to the hub of a dispatch fleet such as a taxi or delivery fleet, the base of a TETRA network as used by government and emergency services or a CB shack. Land s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Resource Management
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. RRM concerns multi-user and multi-cell network capacity issues, rather than the point-to-point channel capacity. Traditional telecommunications research and education often dwell on channel coding and source coding with a single user in mind, but when several users and adjacent base stations share the same frequency channel it may not be possible to achie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate. There are several different types of repeaters; a telephone repeater is an amplifier in a telephone line, an optical repeater is an optoelectronic circuit that amplifies the light beam in an optical fiber cable; and a radio repeater is a radio receiver and transmitter that retransmits a radio signal. A broadcast relay station is a repeater used in broadcast radio and television. Overview When an information-bearing signal passes through a communication channel, it is progressively degraded due to loss of power. For example, when a telephone call passes through a wire telephone line, some of the powe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picocell
A picocell is a small cellular base station typically covering a small area, such as in-building (offices, shopping malls, train stations, stock exchanges, etc.), or more recently in-aircraft. In cellular networks, picocells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage, such as train stations or stadiums. Picocells provide coverage and capacity in areas difficult or expensive to reach using the more traditional macrocell approach. Overview In cellular wireless networks, such as GSM, the picocell base station is typically a low-cost, small (typically the size of a ream of A4 paper), reasonably simple unit that connects to a base station controller (BSC). Multiple picocell 'heads' connect to each BSC: the BSC performs radio resource management and hand-over functions, and aggregates data to be passed to the mobile switching centre (MSC) or the gateway GPRS support node (GG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femtocell
In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. A broader term which is more widespread in the industry is ''small cell'', with ''femtocell'' as a subset. It connects to the service provider's network via broadband (such as DSL or cable); current designs typically support four to eight simultaneously active mobile phones in a residential setting depending on version number and femtocell hardware, and eight to sixteen mobile phones in enterprise settings. A femtocell allows service providers to extend service coverage indoors or at the cell edge, especially where access would otherwise be limited or unavailable. Although much attention is focused on WCDMA, the concept is applicable to all standards, including GSM, CDMA2000, TD-SCDMA, WiMAX and LTE solutions. The use of femtocells allows network coverage in places where the signal to the main network cells might be too weak. Furthermore, femtoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
