Cellular Networks E-Book

Dr.Prakash Kumar

• Herausgeber: BookRix
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Veröffentlichungsjahr: 2021

Beschreibung

The text book is written in simple and easily understandable language.This book can be used as a self-study guide for compter science students.I made (Dr.Prakash Kumar)sincere attempts to analyse every important topic completely and put before the reader of this book in the best presentable form.

With its simple style and broad coverage, this book is an essential text for undergraduate,postgraduate science and engineering students. AMIE candidates as well as BCA,MCA and PGDCA students would also find it very useful.

This book is uniquely different from many other books in a number of ways. Some of the unique features of the book are as under:

• Beginner to advanced apporoach to the subject.
• Simple and easy understandable language.
• Include examples to illustrate concept.
• Systematic and sequential arrangement of different topics.
• It can be used for one semester or one quarter course.
• Eminently suitable for self study.

Leseprobe

Dr.Prakash Kumar

Cellular Networks

Networks

BookRix GmbH & Co. KG81371 Munich

Chapter 1 : Introduction

1.

A Cellular Network : Introduction

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1.1 Introduction

A cellular network is a radio network distributed over land through cells where each cell includes a fixed location transceiver known as base station. These cells together provide radio coverage over larger geographical areas. User equipment (UE), such as mobile phones, is therefore able to communicate even if the equipment is moving through cells during transmission.

Cellular networks give subscribers advanced features over alternative solutions, including increased capacity, small battery power usage, a larger geographical coverage area and reduced interference from other signals. Popular cellular technologies include the Global System for Mobile Communication, general packet radio service, 3GSM and code division multiple access.

Cellular network technology supports a hierarchical structure formed by the base transceiver station (BTS), mobile switching center (MSC), location registers and public switched telephone network (PSTN). The BTS enables cellular devices to make direct communication with mobile phones. The unit acts as a base station to route calls to the destination base center controller. The base station controller (BSC) coordinates with the MSC to interface with the landline-based PSTN, visitor location register (VLR), and home location register (HLR) to route the calls toward different base center controllers.

Cellular networks maintain information for tracking the location of their subscribers' mobile devices. In response, cellular devices are also equipped with the details of appropriate channels for signals from the cellular network systems. These channels are categorized into two fields:

Strong Dedicated Control Channel: Used to transmit digital information to a cellular mobile phone from the base station and vice versa.Strong Paging Channel: Used for tracking the mobile phone by MSC when a call is routed to it.

1.2  Cellulat Network : Architecture 

A typical cell site offers geographical coverage of between nine and 21 miles. The base station is responsible for monitoring the level of the signals when a call is made from a mobile phone. When the user moves away from the geographical coverage area of the base station, the signal level may fall. This can cause a base station to make a request to the MSC to transfer the control to another base station that is receiving the strongest signals without notifying the subscriber; this phenomenon is called handover. Cellular networks often encounter environmental interruptions like a moving tower crane, overhead

Figure 1 :Cellular Network

power cables, or the frequencies of other devices.

To the mobile user, the main part of equipment is the handset and the radio unit; these could be separate units or an integral unit allowing portability. Additional units could be added to the basic unit - answering equipment, and data terminals.

A cellular radio telephone service differs from previous modes of mobile communications in a number of ways. One significant aspect is the improvement of the utilization of the radio spectrum, made possible by the management techniques of the spectrum (e.g. frequency re-use).

Chapter 2: Elements of a Cellular Network

 2

ELEMENTS OF A CELLULAR NETWORK

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 2.1 Overview 

In this section, the general system architecture of a cellular network is introduced:

Mobile Station (MS) : This is basically the mobile phone.Base Station (BS): The covered area of a cellular network is 

Figure 2 : Elements of Cellular Network

divided into smaller areas called cells. Each cell has a base station which communicates simultaneously with all mobiles within the cell, and passes traffic to the Mobile Switching Centre. The base station is connected to the mobile phone via a radio interface.

Mobile Switching Centre (MSC): This controls a number of cells (or cluster), arranges base stations and channels for the mobiles and handles connections.National Carrier Exchange: This is the gateway to the national fixed public switched telephone network (PSTN). It handles connections on behalf of the national communication systems, and is usually integrated with the MSC.