Download Cordless Telecommunications in Europe: The Evolution of Personal Communications PDF

TitleCordless Telecommunications in Europe: The Evolution of Personal Communications
Author
LanguageEnglish
File Size7.5 MB
Total Pages310
Document Text Contents
Page 1

Cordless Telecommunications in Europe

Page 2

Wally H. W. Tuttlebee (Ed.)

Cordless
Telecommunications
in Europe

The Evolution of Personal
Communications

With 82 Figures

Springer-Verlag
London Berlin Heidelberg New York
Paris Tokyo Hong Kong

Page 155

The Radio Channel

(CR), seeks to coordinate European-wide policy towards the identification,
allocation and timely provision of spectrum for apparatus expected to be
standardised by ETSI for wide use and sale throughout western Europe
(generally the EEC and EFfA countries). The CEPT also coordinates the
European response to World Administrative Radio Conferences, for example
the coming WARC in 1992.

The range of services recognised by this regulatory process encompasses
terrestrial and satellite point-to-point and point-to-multipoint (broadcast)
systems, radar, navigation, astronomy, emergency services, radio and TV
broadcasting and of course mobile services. The mobile services include
communications for vehicle fleet operators, paging and cellular radiophone
as well as cordless communications. The distribution of these services with
respect to frequency does vary and furthermore in most nominated bands
of frequencies more than one service is identified.

Unacceptable mutual interference between sharing services is often
possible, with the result that one of the services is given primary status.
This in practice means the secondary services cannot expect protection from
interference from the primary service, nor must they cause unacceptable
interference to the primary service. It can be readily appreciated, therefore,
that if the mobile service is accorded secondary status in a particular
frequency band already used by the primary service in a particular area,
then the use of the band for mobile services is virtually excluded if the
above interference criteria are to be met. Such conflicts occur, for example,
in those bands allocated on a primary basis to TV broadcasting (470 MHz
to 862 MHz) or to terrestrial point-to-point and point-to-multipoint micro-
wave links (e.g. 1.7 GHz to 2.3 GHz). In the face of the current burgeoning
demand for radio spectrum for mobile services the radio frequency regulatory
authorities, at national and international level, have the very difficult task
of judging the relative merits of one service with respect to another within
the constraints of political and socio-economic policies and the perceived
needs and preferences of the public at large.

To exemplify the problem, we consider the question "Should 50 MHz of
prime broadcast TV spectrum be vacated and transferred to serve the needs
of mobile services?" These services are, after all, serving business both large
and small and making significant inroads into the consumer market. Indeed
projections for the year 2005 suggest that 50% of all telephone calls will
involve a mobile link. Thus mobility will provide employment as well as
facilities important to a country's well-being. However, broadcast TV offers
hours of entertainment and edification per person per day at a minimal
price to the viewer. A government that proposed such a swap policy would
scarcely be popular. The now classical response to this problem is to
recommend the transfer of broadcast services onto multi-channel. multi-
choice, coaxial or optical-fibre networks feeding each home. Yet doing so
in a densely populated country can cost billions and far outweigh the
economic benefits of an increase in mobile services and opportunities. The
question of who pays also arises. Should the money come from the tax

145

Page 156

146 Cordless Telecommunications in Europe

payer or a levy on the mobile service users? In resolving such issues of
choice the frequency regulator should not be envied, nor castigated.

The mobile service provider could avoid these problems by identifying
and requesting to occupy unused spectrum but, in the interests of European
standardisation, such spectrum should be available throughout western
Europe. This is a difficult task to achieve below about 30 GHz and almost
certainly impossible below 10 GHz without major changes in present
spectrum allocations. So, what is the optimum frequency band for present
cordless technology?

Cordless apparatus is very sensitive to component costs. The relative lack
of success of the analogue CEPT CTI cordless telephone can be attributed
to its near to 5 : 1 mature cost differential compared with the more freely
available and lesser technology solutions, of which UK cn and the illegal
imports in other countries are prime examples. For cordless products to
succeed in the mass consumer and small business markets fundamental
component technology must be mature and basic component production
costs must have the potential to be reduced to levels competitive with
existing products. The ability to exploit existing high-volume component
technology developed for other mobile services in the region of 1 GHz
would assist cordless products in this regard. Other factors point to about
1 GHz being a favourable choice of frequency.

Man-made noise is one such factor. The unintentionally-radiated radio
frequency noise produced by electrical equipment raises the effective receiver
noise level well above that expected from consideration of thermal noise
alone. Sources of this noise are electric motors, car ignition, radio frequency
heaters and domestic appliances. From this abbreviated list it would be
expected that the level of noise will be a function of urban population
density and many researchers have confirmed this (see [1] for a comprehensive
list). Thus no precise statistical definition can be given to the quantity but,
as Fig. 7.1 indicates, the importance of man-made noise significantly
diminishes for radio equipment operating in the 1 GHz to 2 GHz range.
This tendency for man-made noise to push the desirable choice of frequency
upwards is offset by the fact that free-space transmission loss increases in
proportion to the square of the frequency. Thus, a frequency increase from
200 MHz to 2 GHz produces a hundredfold increase (20 dB) in transmission
path loss for a given range. In the range 1 GHz to 2 GHz these two factors
tend to balance each other.

Component cost, man-made noise and the fundamental law of transmission
loss all point to an optimum choice of cordless telecommunications band
between 1 GHz and 2 GHz, with 1 GHz being preferred for cost reasons.
After extensive deliberations involving all the above factors and a consider-
ation of the ease with which existing users of the band can be re-
accommodated, the CEPT recommended an allocation for the Digital
European Cordless Telecommunications standard (DECT) in the region of
1.9 GHz. In making this decision the CEPT recognised that by the turn of
the century Europe will probably have standardised a further generation of
mobile equipment and it would seem pragmatic to focus these potential

Page 309

Subject Index

Phase Lock Loop (PLL) 215
Phase Shift Keying (PSK) 177-8
Phonepoint 41. 71
Pointe1 75-8. 96

infrastructure requirments 77-8
present and future market prospects 78

Power source 210
Private networks 105-6
Project Teams (PT) 56-7
Protocol conversion 90--1
Protocols 181-3
Public switched telephone network

(PSTN) 10. 19. 33. 43. 73. 90. 109
Pulse Code Modulation (PCM) 35. 111-13

Q.931 standard 105. 106
Ouantising Distortion Unit (qdu) 120

RACE 55. 228. 234-7. 248
Radio Administration. Regulation and

Frequency Management Committee
(RARF) 55

Radio channel 143--85
aims for 143--4
coverage in buildings 153--62
dispersive 162-5
system modelling techniques 165-8
usage of 169-75

Radio frequency 211-15
Rayleigh fading 148-9
Received Signal Strength Indication

(RSSI) 36. 214
Receiving Loudness Rating (RLR) 123
Recommendations 57-8
Registration 91
Regulations 58
Reports 57-8
Reservation Request CSMA (RRCSMA)

198
Residential systems 273--4
Roaming 100
Root-mean-square (RMS) delay spread 165

Sending Loudness Rating (SLR) 123
Service and Facilities (SF) Committee 55
Side Tone Masking Rating (STMR) 124-5.

127
Signal-to-Noise Ratio (SNR) 112
Signal-to-Ouantising-Error Ratio (SOER)

112
Signalling System No.7 (SS7) 105
Silicon technology 227
Smart cards 103
Specifications 57-8
Spectrum choice 144-7

Spectrum requirements 147-53
Speech coding 270-1. 284
Speech conversion 91
Speech encoding 224
Speech encryption 140-1
Speech quality 109. 120-1
Standards 57-8

for analogue systems 61-3
for digital systems 63-5
need for 59--61

Strategic Review Committee (SRC) 56
Superheterodyne receiver architecture 211
Surface Acoustic Wave (SAW) 212. 228
Surface Mount Technology (SMT) 220
Synchronous Data Link Control (SDLC)

196
System modelling techniques 165--8

Talker Echo Loudness Rating (TELR)
125. 129

Technical Recommendations Applications
Committee (TRAC) 55

Telephone Acoustic Loss (TAL) 125
Telephone Identity module (TIM) 103
Telepoint 1. 15. 19. 32. 33. 39. 67-75.

93--6. 237. 275
comparison with cellular radio 73
development of 96
European service 84-5
implementation of 72
in Finland 83
in France 75
in Germany 79-82
in Italy 82
market 19-20
Memorandum of Understanding (MoU)

114-5
network licences 68-9
operators 12-13
service evolution 74-5
service implementation 69-74
UK networks 68-75
UK services 94-6

Terrestrial Flight Telephone Service
(TFTS) 240

Time dispersion 162
Time Division Duplex (TDD)

transmission 36-8. 45. 64. 139.
169-70. 221. 279

Time Division Multiple Access (TDMA)
28.44.76. 139. 171-3.221. 222. 225

Time Division Multiple Accessrrime
Division Duplex (TDMA/TDD) 28.
29.44

TMS320 228
T/R 24-03 61

303

Page 310

304

Transceiver architecture and design 211-17
Transmission Plan. see Voice Transmission

Plan

Universal Cordless Telephone System 32
Universal Mobile Communications (UMC)

15
Universal Mobile Telecommunication

System (UMTS) 234--5
Universal Personal Communicator 40

Video telephony 189
Voice coding 111-22
Voice security 140-1
Voice transmission plan 110. 122-8. IR8.

270--1
CT2 CAl 27U-1
definitions 122-6
digital cordless telephone system 126--R
specific systems 12R

Voltage controlled oscillator (VCO) 215-16

Waveform coding III
Wideband services IR9
Wireless PABX. see PABX

Subject Index

World Administrative Radio Conference
(WARC) 53. 144

World standard 249-50
Worldwide telecommunications standards

52--4

Zonephone 3U-9. 69. 70
access security 39
description of 33-9
frame structure and signalling 37
origins and evolution 31-3
physical format 34--5
power source 35
spatial diversity 36
speech processing system 35
user controls 34--5
voice privacy 39

Similer Documents