Wireless technology is a revolutionary paradigm shift, enabling Multimedia communications between people from any location. The evolution of wireless communication systems and networks in recent years has been explosive. Wireless communication brings fundamental changes to data networking and telecommunications, and makes integrated networks a reality. Wireless Networks focuses on networking and user aspects. Network architecture for personal communications systems, wireless LANs, radio, tactical and other wireless networks, and design and analysis of protocols are addressed on a regular basis. The continuing trend of convergence of wireless services and networks mean that a lot of new industries and research institutions are looking into integrating satellite, mobile and GPS networks. This blog provides a comprehensive introduction to the underlying theory, design techniques of wireless communications, overview of wireless systems and wireless network standards.
2G – GSM an Overview
During the early 80s, analog cellular telephone systems were experiencing rapid growth. Each country developed its own system, which was incompatible with everyone else's in equipment and operation.
In 1982 the Conference of European Posts and Telegraphs (CEPT) formed a study group called the Groupe Spécial Mobile (GSM) to study and develop a pan-European public land mobile system. In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute (ETSI), and phase I of the GSM specifications were published in 1990. Commercial service was started in mid-1991, and GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for
The GSM core network consists of several kinds of nodes. The important nodes are the
Base Transceiver Station (BTS),
Base Station Controller (BSC),
Mobile Switching Center (MSC)
Visitor Location Register (VLR)
Home Location Register (HLR)
2.5G – GPRS an Overview
The importance in support of data communication for mobile communication networks is increasing. New requirements for mobile networks are raised for new data services, like sending and receiving E-mails, browsing to IP-based networks. The increasing need for bandwidth cannot be adequately fulfilled by the GSM standard.
The General Packet Radio Service as an extension to Second generation GSM provides virtual connections, short connection setup times and data rates up to 115 kbit/s for each user, whereas the available bandwidth can be shared among different users. The high bandwidth will be achieved.
In a GSM Network Base Station Controller (BSC) splits or combines the voice and data traffic dependent on the direction. Voice traffic is sent to a GSM network while data traffic is transported via a separated IP-based backbone network. Two new types of nodes are introduced in GPRS, the Serving GPRS Support Node (SGSN) and the Gateway GPRS Support Node (GGSN). The GGSN is responsible for the connection to other packet oriented networks and stores the information about the location of the GPRS users. The SGSN, like the MSC in the GSM-network, is responsible for the support of user mobility and the access control of users to the radio resources. The GPRS network is only connected with the GSM Network at the BSC
3G - W–CDMA An Overview
In January 1998, ETSI decided to choose the W–CDMA (Wideband Code Division Multiple Access) technology to be the access techniques for the3G mobile telephone system. In WCDMA systems the CDMA air interface is combined with GSM based networks. WCDMA is a CDMA channel that is four times wider than the current channels that are typically used in 2G networks. The WCDMA supports High data rate transmission up to 384 Kbps with wide area coverage, 2 Mbps with local coverage. The WCDMA system is High service flexibility support of multiple parallel variable rate services on each connection. WCDMA supports inter frequency hand over and hand over to other systems, including hand over to GSM.
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