Broadband Access Technology PDF

Broadband Access Technology Broadband? Components of Broadband Communication Systems Components of Broadband Communication Systems Broadband telecommunication network architectures Broadband telecommunication network architectures Broadband telecommunication network architectures...

Broadband Access Technology Broadband? Components of Broadband Communication Systems Components of Broadband Communication Systems Broadband telecommunication network architectures Broadband telecommunication network architectures Broadband telecommunication network architectures  Broadband telecommunication network architectures The previous figure shows a typical broadband communication network architecture. It consists of the central office (CO) and the residential and business sections. The digital subscriber line access multiplexer (DSLAM) that handles all the traffic generated from the user (residential or business) and the data center make up part of the CO. The DSLAM takes many customer connections and puts them on a single high speed connection to the Internet  Broadband telecommunication network architectures The asynchronous transfer mode (ATM) switch in the Figure is a local exchange switch that allows a connection to the PSTN for telephone access. The Internet service provider (ISP) is the company that provides the Internet services that the customer pays for. The CO is connected to two types of customers— residential and business. Each of these customers will normally have different equipment that allows access to the network provided to them. Broadband telecommunication network architectures  Broadband telecommunication network architectures The above Figure displays a diagram of the typical setup of an office network used by a business customer. The proxy server is a server that acts as an intelligent access point between the business user and the Internet in order to provide security, administrative control, and caching service for the LAN in the business. The proxy server as a whole separates the internal network of the business from the outside network. The ADSL bridge is a connection device that connects the LAN of the reference business user to another LAN that encompasses the same type of network protocol. The ADSL bridge also separates telephone usage from Internet usage by the user.  Cable Broadband Data Network Architecture The basic broadband cable network architecture as shown in the following figure:  Cable Broadband Data Network Architecture It consists of three distinct blocks: regional cable headend, distribution hub, and fiber node (or local distributor). From the distribution hub, coaxial cable is usually used to connect customer premises.  The importance of Broadband Communication One important application is videoconferencing in the health care industry, which will allow specialists to pay more attention to critical patients and use videoconferencing in less serious cases, in order to save valuable time. Since the need for integrating data, voice, and video is needed for new applications that have been proposed, broadband networks are the only means of achieving these innovative ideas.  Internetworking Internetworking means connecting two or more computer networks using certain devices. The types of devices that can be used in the interconnection of broadband networks are as follows: bridges WAN switches routers gateways Most of the internetworks use telecommunication facilities with data transferring speeds of 19.2 kbps and 56 kbps. Others include digital Tl (1.544 Mbps) and T3 (44.736 Mbps) transfer speeds.  Internetworking A signaling mechanism is also used in internetworking broadband system networks. Internetworking or intersystem signaling of a network uses signaling to communicate between networks not users. DTMF (Dual tone multi-frequency) is an example of an internetworking protocol that connects networks and switches. Multi-frequency (MF) signaling is one of the common modes used in internetworking. MF is the process of using tone pulses in the frequency range to transmit digits by combining two of six frequencies.  Standards Standards play an important role in broadband communication systems. There are different standards organizations that help in the development of the different standards that govern the various products available in the world. These highly complex technical standards are usually set by committees formed by industry consortia and/or government organizations. The International Standards Organization (ISO) and the Institute of Electrical and Electronics Engineers (IEEE) set the standards for various network systems. Some of the principal communication standards bodies are the United States ANSI Committee on Telecommunications and the Telecommunications Industry Association (TIA); the Japanese Telecommunications Technology Committee (TTC); the European Telecommunications Standards Institute (ETSI); and the International Telecommunications Union (ITU).