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Joined: Dec 2008
21-09-2008, 11:08 AM
Roke Manor Research is a leading provider of mobile telecommunications technology for both terminals and base stations. We add value to our clients' project and implimentations by reducing time-to-market and lowering production costs, and provide lasting benefits through building long-term relationships and working in partnership with our customers.
We have played an active role in cellular communications technology since the 1980's, working initially in GSM and more recently in the definition and development of 3G (UMTS). Roke Manor Research has over 200 engineers with experience in designing hardware and software for 3G terminals and base stations and is currently developing technology for 4G and beyond.
We are uniquely positioned to provide 2G, 3G and 4G expertise to our customers.
The role of Roke Manor Research engineers in standardisation bodies (e.g. ETSI and 3GPP) provides us with intimate knowledge of all the 2G and 3G standards (GSM, GPRS, EDGE, UMTS FDD (WCDMA) and TD-SCDMA standards). Our engineers are currently contributing to the evolution of 3G standards and can provide up-to-the-minute implementation advice to customers.
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Joined: Apr 2012
13-04-2012, 04:18 PM
CHAPTER 1.docx (Size: 37.56 KB / Downloads: 60)
The goal for the next generation of mobile communications system is to seamlessly provide a wide variety of communication services to anybody, anywhere, anytime. The intended service for next generation mobile phone users includes services like transmitting high speed data, video and multimedia traffic as well as voice signals. The technology needed to tackle the challenges to make these services available is popularly known as the Third Generation (3G) Cellular Systems. The first generation systems are represented by the analog mobile systems designed to carry the voice application traffic.
Commercial mobile cellular system first became available in early 1980’s. These first systems were deployed, utilizing analog technology over circuit switched networks. They had very limited features, poor voice quality, and limited radio coverage, although they have vastly improved over last two decades and are still widely deployed around the world. In addition, data transfer was limited to 9600 baud.
First Generation Cellular Systems
The first generation cellular systems generally employ analog Frequency Modulation (F M) techniques. The Advanced Mobile Phone System (AMPS) is the most notable of the first generation systems. AMPS was developed by the Bell Telephone System. It uses FM technology for voice transmission and digital signaling for control information. Other first generation systems include:
• Narrowband AMPS (NAMPS)
• Total Access Cellular System (TACS)
Second Generation Cellular Systems
Second generation 2G cellular telecom networks were commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991. Three primary benefits of 2G networks over their predecessors were that phone conversations were digitally encrypted; 2G systems were significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels; and 2G introduced data services for mobile, starting with SMS text messages.
Third Generation Cellular Systems
3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. Application services include wide-area wireless voice telephone, mobile Internet access, video calls and mobile TV, all in a mobile environment.
Joined: Apr 2012
15-06-2012, 05:21 PM
Cellular Communication Technologies
Cellular Communication.doc (Size: 1.97 MB / Downloads: 34)
Today’s work force is demanding mobility, flexibility and real-time access to critical data. Over recent years, the trend towards the smaller and faster device, coupled with the need for information access on the move, has paved the way for a new technology of the Mobile Communications. Mobility is the ability to access information and services anywhere anytime anyhow. On the telecom front, numerous wireless technologies have been introduced in the country. It started with Global System Mobile telecommunications (GSM) based mobile phones, and today we can see General Packet Radio Service (GPRS) technologies being implemented as well.
The success of any technology largely depends upon its widespread usage, which in turn depends upon the number of applications that can be made from it. A cellular mobile communication system uses a large number of low-power wireless transmitters to create cells – the basic geographic service area of a wireless communication system. Variable power levels allow cells to be sized according to the subscriber density and demand within a particular region. As mobile users travel from cell to cell, their conversations are “handed off” between cells in order to maintain seamless service.
Mobile Communication Principles
Each mobile uses a separate, temporary radio channel to talk to the cell site. The cell site talks to many mobiles at once, using one channel per mobile. Channels use a pair off frequencies for communication –one frequency, the forward link, for transmitting from the cell site and one frequency, the reverse link, for the cell site to receive calls from the users. Radio energy dissipates over distance, so mobiles must stay near the base station to maintain communications. The basic structure of mobile networks includes telephone systems and radio services.
Mobile Telephone System Using The Cellular Concept
Inference problems caused by mobile units using the same channel in adjacent areas proved that all channels could not be reused in every cell. Areas had to be skipped before the same channel could be reused. Even though this affected the efficiency to the original concept, frequency reuse was still a viable solution to the problems of mobile telephony systems.
Cellular System Architecture
Increases in demand and the poor quality of existing service led mobile service providers to research ways to improve the quality of service and to support more users in their systems. Because the amount of frequency spectrum available for mobile cellular use was limited, efficient use of the required frequencies was needed for mobile cellular coverage. In modern cellular telephony, rural and urban regions are divided into areas according to specific provisioning guidelines. Provisioning for each region is planned according to an engineering plan which mainly includes cells, clusters.
On the telecom front, numerous wireless technologies have been introduced in the country. It started with GSM based mobile phones The developers of GSM choose an unproven digital system and provided 8000 pages of recommendations that had enough flexibility to allow competitive innovation but at the same time ensured proper internetworking between the components of the system. At present there are hundreds of functional GSM networks in an equally large number of countries and the abbreviation now aptly stands for global system for mobile telecommunications.