Indoor Radio Planning (eBook)

A Practical Guide for 2G, 3G and 4G

Morten Tolstrup (Autor)

eBook Download: EPUB

2015 | 3. Auflage
John Wiley & Sons (Verlag)
978-1-118-91359-8 (ISBN)

Infos

Why is high performance indoor wireless service needed, and how is it best implemented? As the challenge of providing better service and higher data speeds and quality for mobile applications intensifies, ensuring adequate in-building and tunnel coverage and capacity is increasingly important. A unique, single-source reference on the theoretical and practical knowledge behind indoor and tunnel radio planning, this book provides a detailed overview of mobile networks systems, coverage and capacity solutions with 2G, 3G and 4G cellular system technologies as a backdrop.

Morten Tolstrup has held a number of jobs for major DAS suppliers over the past decade, in multiple flagship DAS projects and deployments on a global scale. In addition to this, he spent 13 years in a number of different engineering positions with a mobile operator in Denmark, mainly focusing on indoor RF planning, tunnels, airports andSmall Cells. Morten has presented more than 100 papers, conference workshops and DAS training events around the world. This book is now the official textbook for a DAS planning Certification training program from a leading DAS supplier.

Textauszug

2
Overview of Cellular Systems

This book is concentrated around the topic of indoor radio planning from a practical perspective, and it is not the within the scope of this book to cover the full and deep details of the 2G (GSM), 3G (UMTS) and 4G (LTE) systems and structures. This book will only present the most important aspects of the network structure, architecture and system components, in order to provide basic knowledge and information that is needed as a basis for design and implementation of indoor coverage and capacity solutions. For more details on cellular systems in general refer to [2].

2.1 Mobile Telephony

2.1.1 Cellular Systems

The concept of cellular coverage was initially developed by AT&T/Bell Laboratories. Prior to that, the mobile telephony systems were manual systems used only for mobile voice telephony. Typically implemented with high masts that covered large areas, and with limited capacity per mast, they were only able to service few users at the same time – in some cases even only one call per mast! These systems also lacked the ability to hand over calls between masts, so mobility was limited to the specific coverage area from the servicing antenna, although in reality the coverage area was so large that only rarely would you move between coverage areas. Remember that, at that point, there were no portable mobile telephones, only vehicle-installed terminals with roof-top antennas. Over time the use of mobile telephony became increasingly popular and the idea was born that the network needed to be divided into more and smaller cells, accommodating more capacity for more users, implementing full mobility for the traffic and enabling the system to hand over traffic between these small cells.

From this initial concept several cellular systems were developed over time and in different regions of the world. The first of these cellular systems was analog voice transmission, and some ‘data transmission' modulated into the voice channel for signaling the occasionally handover or power control command.

Some of the most used standards were/are AMPS, D-AMPS, TACS, PCS, CDMA, NMT, GSM (2G), DCS (2G), UMTS (3G, WCDMA) and LTE (4G).

AMPS

AMPS (Advanced Mobile Phone System) is the North American standard and operates in the 800 MHz band. The AMPS system was also implemented outside North America in Asia, Russia and South America. This is an analog system using FM transmission in the 824–849 and 869–894 MHz bands. It has 30 kHz radio channel spacing and a total of 832 radio channels with one user per radio channel.

D-AMPS

D-AMPS (Digital Advanced Mobile Phone System) evolved from AMPS in order to accommodate the increasingly popular AMPS network with fast-growing traffic and capacity constraints. The D-AMPS system used TDMA and thus spectrum efficiency could be improved, and more calls could be serviced in the same spectrum with the same number of base stations.

TACS

TACS (Total Access Cellular System) was also derived from the AMPS technology. The TACS system was implemented in the 800–900 MHz band. First implemented in the UK, the system spread to other countries in Europe, China, Singapore, Hong Kong and the Middle East and Japan.

PCS

PCS (Personal Communications System) is a general term for several types of systems developed from the first cellular systems.

CDMA

CDMA (Code Division Multiple Access) was the first digital standard implemented in the USA. CDMA uses a spread spectrum in the 824–849 and 869–894 MHz bands. There is a channel spacing of 1.23 MHz, and a total of 10 radio channels with 118 users per channel.

NMT

NMT (Nordic Mobile Telephony) was the standard developed by the Scandinavian countries, Denmark, Norway and Sweden, in 1981. Initially NMT was launched on 450 MHz, giving good penetration into the large forests of Sweden and Norway, and later also deployed in the 900 MHz band (the band that today is used for GSM). Being one of the first fully automatic cellular systems in the world (it also had international roaming), the NMT standard spread to other countries in Europe, Asia and Australia.

GSM/2G

GSM (Global System for Mobile communication), or 2G, was launched in the early 1990s, and was one of the first truly digital systems for mobile telephony. It was specified by ETSI and originally intended to be used only in the European countries. However GSM proved to be a very attractive technology for mobile communications and, since the launce in Europe, GSM has evolved to more or less a global standard.

DCS/2G

Originally GSM was specified as a 900 MHz system, and since then the same radio structure and signaling system have been used for DCS1800/2G-1800 (Digital Cellular Telecommunication System). The GSM basic has also been applied to various spectra around 800–900 and 1800–1900 MHz across the world, the only difference being the frequencies.

UMTS/3G (WCDMA)

After the big global success with the second generation (2G) GSM and the increased need for spectrum efficiency and data transmission, it was evident that there was a need for a third-generation mobile system. UMTS was selected as the first 3G system for many reasons, mainly because it is a very efficient way to utilize the radio resources – the RF spectrum. WCDMA has a very good rejection of narrowband interference, is robust against frequency selective fading and offers good multipath resistance due to the use of rake receivers. The handovers in WCDMA are imperceptible due to the use of soft handover, where the mobile is serviced by more cells at the same time, offering macro-diversity.

However there are challenges when all cells in the network are using the same frequency. UMTS is all about noise and power control. Strict power control is a necessity to make sure that transmitted signals are kept to a level that insures they all reach the base station at the same power level. You need to minimize the inter-cell interference since all cells are operating on the same frequency; this is a challenge.

Even though soft handovers insure that the mobile can communicate with two or more cells operating on the same frequency, one must remember that the same call will take up resources on all the cells the mobile is in soft handover with. The handover zones need to be minimized to well-defined small areas, or the soft HO can cannibalize the capacity in the network.

UMTS has now become the global standard and has been accepted throughout the world. Several upgrades that can accommodate higher data speed HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Data Access) can service the users with data speeds in excess of 10 Mbps.

There are several current considerations about converting the current GSM900 spectrum into UMTS900, giving a much higher spectrum efficiency, and better indoor RF penetration.

2.1.2 Radio Transmission in General

Several challenges need to be addressed when using radio transmission to provide a stable link between the network and the mobile station. These radio challenges are focused around the nature of the propagation of radio waves and especially challenges of penetrating the radio service into buildings where most users are located these days.

The challenges are mainly radio fading, noise control, interference and signal quality. These challenges will be addressed throughout this book, with guidelines on how to design a high-performing indoor radio service.

2.1.3 The Cellular Concept

After the initial success with the first mobile system, it was evident that more capacity needed to be added to future mobile telephony systems. In order to implement more capacity to accommodate more users in the increasingly more popular mobile telephony systems, new principles needed to be applied. The new concept was to divide the radio access network into overlapping ‘cells', and to introduce a handover functionality that could insure full mobility throughout the network, turning several masts into one coherent service for the users.

Dividing the network into cells has several advantages and challenges. The advantages are:

• Frequency reuse – by planning the radio network with relative low masts with limited coverage area, compared with the first mobile systems, you could design a radio network where the cells will not interfere with each other. Then it is possible to deploy the same radio channel in several cells throughout the network, and at the same time increase the spectrum and radio network efficiency thanks to frequency reuse.
• Capacity growth – the cellular network could start with only a few cells, and as the need for better coverage and more capacity grew, these large cells could be split into smaller cells, increasing the radio network capacity even more with tighter reuse of the frequencies (as shown in Figure 2.1).
• Mobility – it is paramount for cellular networks that handovers are possible between the cells, so the users can roam through the network with ongoing connections and no dropped calls. With the advent of the first cellular systems, mobile users could now move around the network, utilizing all the cells as one big service area.

Figure 2.1 The cell structure of a cellular radio network. Cells will be split into smaller cells as the network evolves, and the capacity need grows

The challenges are:

• Network...

Produkt-Details

• Erscheint lt. Verlag: 10.4.2015
• Sprache: englisch
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• Schlagworte: 3G • 4G • Communication Technology - Networks • Drahtlose Kommunikation • Electrical & Electronics Engineering • Elektrotechnik u. Elektronik • Indoor radio planning • Kommunikationsnetz • Kommunikationsnetze • Mobile & Wireless Communications
• ISBN-10: 1-118-91359-0 / 1118913590
• ISBN-13: 978-1-118-91359-8 / 9781118913598