ETSI ETR 015 ed.1 (1991-03)

SLOVENSKI STANDARD
01-november-1998
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Digital Enhanced Cordless Telecommunications (DECT); Reference document
Ta slovenski standard je istoveten z: ETR 015 Edition 1
ICS:
33.070.30 'LJLWDOQHL]EROMãDQH Digital Enhanced Cordless
EUH]YUYLþQHWHOHNRPXQLNDFLMH Telecommunications (DECT)
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETSI ETR 015
TECHNICAL March 1991
REPORT
Source: ETSI TC-RES 3 Reference: DTR/RES-03001
ICS: 33.080, 33.060.20
Telephones, cordless telephony, digital radio systems
Key words:
Radio Equipment and Systems
Digital European Cordless Telecommunications (DECT)
Reference document
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: secretariat@etsi.fr
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1991. All rights reserved.
New presentation - see History box

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ETR 015: March 1991
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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Contents
Foreword.5
1 Introduction.7
1.1 The current situation.7
1.2 What is DECT ?.7
1.2.1 Basic characteristics.7
1.2.2 DECT Systems .7
1.2.3 Benefits of DECT .8
2 Services definition .8
2.1 Introduction.8
2.2 Areas of application: user group.8
2.3 Service principles .9
2.4 Capability and features.9
2.4.1 Residential use.10
2.4.1.1 Basic capability .10
2.4.1.2 Enhancement features .10
2.4.2 Public use.10
2.4.2.1 Basic capability .10
2.4.2.2 Features depending on infrastructure enhancements .10
2.4.3 Small (business) system use .10
2.4.3.1 Basic capability .10
2.4.3.2 Features depending on infrastructure enhancements .10
2.4.4 Large (business) system use.11
2.4.4.1 Capability.11
2.4.5 Non-voice services for DECT.11
2.4.5.1 Applications.11
2.4.5.2 Teleservices.12
2.4.5.3 Bearer services. 12
2.4.5.4 Spectrum efficiency .12
2.4.5.5 Error ratios .12
2.4.5.6 Asymmetry.12
2.4.5.7 System requirements.13
2.4.6 Evolutionary applications.13
2.4.6.1 DECT extension to cellular radio .13
2.4.6.2 Radio extension of the local public network.13
2.4.6.3 Distributed DECT head-ends .13
2.5 Grade of service.13
2.5.1 Large (business) system use.14
2.5.2 Residential and small (business) system use .14
2.5.3 Public use (telepoint) .14
2.5.4 Non-voice services .14
2.6 Performance requirements.14
2.6.1 Residential busy-hour traffic density.14
2.6.2 Business cordless telecommunication systems busy-hour traffic density .15
2.6.3 Telepoint .15
2.7 Authentication and security.15
3 Radio aspects.16
3.1 Principles of DECT radio usage.16
3.1.1 Introduction.16
3.1.2 Differences to standard ISDN.17
3.1.3 Scope .17
3.2 The layered structure on the radio link .18

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3.2.1 Overview .18
3.2.2 Physical Layer (PHL) .19
3.2.3 Medium Access Control layer (MAC) .20
3.2.6 Management Entity (MGE).21
3.3 Capacity management in DECT.22
3.3.1 Introduction.22
3.3.2 The concept of the basic DECT base station .22
3.3.3 The Dynamic Channel Selection (DCS).22
3.3.4 Call set-up using base station beacon channels.23
3.3.5 Handover.23
3.4 Radio resource .23
3.4.1 Spectrum requirements.23
3.4.2 The allocated frequency band.24
3.4.3 Evolution of spectrum usage.24
4 Networks structure - network aspects of DECT .25
4.1 Introduction.25
4.2 Architectural aspects.25
4.3 Control and user elements .27
4.4 Protocol features.28
4.4.1 The data link protocol .30
4.4.2 Network layer protocol.30
4.5 Speech compatibility.32
5 Time scale.32
5.1 Achievements.32
5.2 Timescale.33
5.3 List of deliverable documents .33
6 DECT terminology .34
6.1 Scope .34
6.2 Definitions.34
6.3 Glossary.43
6.4 Acknowledgement.46
History .47

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Foreword
ETSI Technical Reports (ETRs) are informative documents resulting from ETSI studies which are not
appropriate for European Telecommunication Standard (ETS) or Interim - European Telecommunication
Standard (I-ETS) status.
An ETR may be used to publish material which is either of an informative nature, relating to the use or
application of ETSs or I-ETSs, or which is immature and not yet suitable for formal adoption as an ETS or
I-ETS.
This ETR has been produced by the Technical Committee RES, Radio Equipment and Systems, Sub-
Technical Committee 3 (in charge of DECT) of the European Telecommunications Standards Institute
(ETSI).
The present document aims to provide an overall description of the DECT system and concept, DECT
standing for Digital European Cordless Telecommunications.
DECT : Digital European Cordless Telecommunications;
ETSI : European Telecommunications Standards Institute;
RES3 : ETSI Radio Equipment and Systems, Sub-Technical Committee 3, (in charge of DECT);
CEPT : Conférence Européenne des Postes et Télécommunications.

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Blank page
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1 Introduction
At the present time there are a number of incompatible cordless telephone systems within Europe. These
systems fulfil only a proportion of the requirements and opportunities for personal communication
expectations.
The presence of the current systems has itself encouraged an extension of the concept and expectations
for cordless communication. Market research has established a clear demand for cordless capabilities
beyond those currently offered.
The greatest opportunity for European telecommunications organisations lies in offering a single standard
enhanced cordless system for Europe. The size of the European market and the capacity of the European
manufacturing base indicates that the fulfillment of the European need will create a spring-board for
opportunities outside Europe.
Only a common standard defined by industry, PTTs, and Administrations under the auspices of the
European Telecommunications Standards Institute (ETSI) can open up the European market to its full
potential.
1.1 The current situation
The extent to which the market is divided can be seen from a review of current products :
- Illegally imported Cordless Telephones;
- National specifications, working generally in one country (UK, France), using low frequencies under
50 MHz;
- CEPT analogue products (CT 1) working around 900 MHz, adopted only by some countries;
- A digital (FDMA) system, developed in the UK, offering the telepoint function as a feature. CT2/CAI;
- A digital (TDMA) system, developed in Sweden and emphasizing business cordless telephony. CT3.
A common European standard will remove the restriction and enhance market opportunities.
This common European standard will be DECT.
1.2 What is DECT ?
1.2.1 Basic characteristics
The DECT concept is one of versatility of application at a cost that encourages wide availability and market
adoption.
The concept includes a definition of personal portable communications that requires small, easy to use
terminals.
DECT will provide personal communication services at home, in the office and in the street.
The quality of communications is similar to that of a standard telephone.
DECT offers low-power cordless access between portables and infrastructure, at ranges up to several
hundred meters. It is utilising dynamic channel selection from approximately 120 available channels.
1.2.2 DECT Systems
- A DECT residential system that interconnects to a PSTN with the features and responses of a
standard wired telephone;
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- A DECT Business Cordless Telecommunications systems (BCT) that combines the features of a
PBX with the mobility of cordless telecommunications for both voice and non-voice applications;
- A DECT telepoint facility that offers public network access to a handset through a public, or privately
owned, base station;
- A DECT access system that provides a radio means of extending public and private networks into
customer/user premises.
1.2.3 Benefits of DECT
- Versatile application based on a common technology provides an economy of scale that will yield
low cost and encourage a wide take-up.
- DECT will allow full cordless application in an average office environment (typically in one hundred
times the density of a mobile radio system);
- The user has the opportunity to select from a number of communication options, to suit his particular
requirements;
- The manufacturer has the option to provide competitively targeted product according to his own
market perceptions;
- The network provider (public and private) has the opportunity to introduce new services and provide
alternative means of network access;
- National communication authorities have the opportunity to encourage competitive service provision
in new areas;
- DECT allows the use of private "on site" user applications.
2 Services definition
2.1 Introduction
In this section the service and facility requirements of envisaged cordless-telecommunication applications
are considered. The approach adopted is to identify application areas, define basic service principles,
determine functional capability requirements, and quantify performance parameters. Approaching the
problem of definition from a user-group point of view avoids the difficult task of identifying and defining
particular applications, especially applications associated with so called large business systems.
2.2 Areas of application: user group
- Residential - private use in houses and apartment blocks;
- Public Access - telepoint, phonepoint access to a PSTN;
- Small (business) CT systems - typically key systems;
- Large (business) CT systems - multi-cell PBX-based building mobile system with roaming and
handover;
- Integrated services premises networks, small and large (business) applications - voice and data
telephony and LAN access;
- Evolutionary applications - radio access to local public and other networks.

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2.3 Service principles
- The technical system specification makes provision for both voice and non-voice transmission;
- The DECT timescale coincides with the introduction of ISDN services. The implementation of all
ISDN basic rate services will be possible within the DECT specification;
- To provide the facilities and quality of service to key markets DECT minimises its use of bandwidth
to that required by the service carried at any time;
- The DECT specification does not inherently pre-allocate spectrum by application and should seek to
offer an integrated communication structure embracing all applications;
- The cost of implementing basic voice only operation must not be significantly penalised by the
non-voice provisions in the specification;
- The potential total market for DECT is large with the consequent requirement for low-cost,
small-size, high volume products, used in high-capacity applications;
- The technical system specification makes provision for interoperability of a handset unit between
user groups. Interoperability is not mandatory;
NOTE: The intention is not to preclude interoperability or hamper single user group
applications.
- The user perception of the combination of quality and value of communication of DECT apparatus
must be at least equal to that offered by existing wired telephone services noting there are two
parties to communication.
2.4 Capability and features
Capability and features are aligned according to area of application (market segment) rather than product
type. It is recognised that widely differing products could serve the same market segment, or a
combination of market segments.
The technical system specification makes provision for both basic capabilities and enhancement features.
Some capabilities and features are common to the four prime areas of application (residential, public, small
system and large system) and for convenience are listed as follows.
Basic capability
- Function as an equivalent replacement for a wired telephone connected directly to indirectly (e.g. via
PABX) to a PSTN;
- Signalling capacity to support standard telephony features;
- Dialling and calling security;
- Emergency services.
Enhancement features
- Interface with ISDN;
- Non-voice transmission, with ability to communicate up to maximum available transmission capacity;
- Air-interface voice, and non-voice, privacy;
- Hands-free operation;
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- Handsets serving a combination of market segments or services.
2.4.1 Residential use
2.4.1.1 Basic capability
- Base-station ringer.
2.4.1.2 Enhancement features
- 2 PSTN lines;
- 2 to 4 handsets;
- Intercom via the base station;
- Call transfer between handsets.
2.4.2 Public use
2.4.2.1 Basic capability
- Out-going calls only;
- Secure authentication of handset and user for billing;
- User indication of service availability on handset;
- Multiple independent network operation;
- Tandem use with other mobile systems, appropriate to car, train, plane and ship.
2.4.2.2 Features depending on infrastructure enhancements
- In-coming call (local log-on);
- In-call hand-over to adjacent telepoint base-station;
- Outgoing calls queuing capability for access to radio interface.
2.4.3 Small (business) system use
2.4.3.1 Basic capability
- Single cell;
- 20 extensions or less;
- Handset inaccessible indication at base unit;
- Secure authentication of handset.
2.4.3.2 Features depending on infrastructure enhancements
- Secure validation of handset user;
- Independent small (business) systems can be interconnected (by wire) to achieve coverage
expansion without handover;
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- Handsets can enrol on other units;
- Message (acknowledged paging) service.
2.4.4 Large (business) system use
No realistic judgement could be made between basic and enhancement features. It is considered essential
the specified system should support the following.
2.4.4.1 Capability
- Multi-cell operation;
- Roaming (to find a person for incoming and outgoing calls within the nominated communication
area);
- Handover during call;
- Normal (wired) PBX functions must be supported;
- Bearer services (to be expanded);
- Teleservices (e.g. teletext and fax);
- Handset or terminal enrolment;
- Support for systems of highly variable user densities;
- Terminals mounted in a vehicle (e.g. warehouse vehicles).
2.4.5 Non-voice services for DECT
The development of DECT will coincide with the establishment of ISDN networks and the widespread use
of integrated services voice/data networks in the office. It is therefore essential that DECT can support an
adequate range of non-voice services, to prevent it becoming obsolete before its introduction.
2.4.5.1 Applications
The applications of DECT data terminals fall into two categories:
- Primarily static, using DECT as a cordless drop-line bearer to a high-speed back-bone. Application
areas and requirements are related to those anticipated for general network terminal usage;
- Primarily portable, for entirely new applications made possible by the DECT network link such as:
- portable multi-media (e.g. voice and fax) mail terminal;
- note-pad with large network-based memory;
- portable access to personal and corporate data bases;
- ultra-light, small network-slaved PC emulator;
- cordless ISD videophone.
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2.4.5.2 Teleservices
From a service and facilities perspective, applications such as these examples require the support of a
group of general teleservices. These are:
- remote terminal service;
- batch file transfer;
- real-time file access;
- generic ISDN connection-based services.
Applications such as videophone can be successfully mapped on to the last category. To support the other
teleservices, DECT must have, as a minimum requirement, appropriate bearer capabilities over which
external processes can offer the teleservices. The integration of the teleservice processes in DECT
depends upon the implementer. Remote terminal protocols such as X and OSI VT, batch file services such
as FT AM and real-time access for X.400 protocols P3 and P7 will be examples to be supported.
2.4.5.3 Bearer services
In order to use the spectrum efficiently, DECT must offer bearers which are well matched to the needs of
the teleservices. A (2B + D) so bearer (net 144 kb/s connection-based full duplex) are necessary to meet
the needs of the generic ISDN connection-based services, but it is neither efficient nor adequate for the
other teleservices. The requirements of the other teleservices are summarised in the table below:
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡ Application ‡ Link Establishment ‡ Transaction Duration ‡ Full Rate   ‡
‡       ‡    Time     ‡   at Full Rate   ‡        ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ Remote Term ‡          ‡           ‡        ‡
‡ - text   ‡ 50 ms       ‡ 100 ms - 5 secs   ‡ 10 - 20 kb/s ‡
‡ - graphics ‡ 50 ms       ‡ 500 ms - 10 secs  ‡ 24 - 128 kb/s ‡
‡       ‡          ‡           ‡        ‡
‡ Batch File  ‡          ‡           ‡        ‡
‡ Transfer   ‡          ‡           ‡        ‡
‡ - light  ‡ 1 - 5 secs    ‡ 1 - 30 secs     ‡ 32 kb/s    ‡
‡ - heavy  ‡ 1 - 30 secs    ‡ 5 - 1000 secs    ‡ 64 kb/s    ‡
‡       ‡          ‡           ‡        ‡
‡ Real-time  ‡          ‡           ‡        ‡
‡ file access ‡          ‡           ‡        ‡
‡ - slices  ‡ 50 ms       ‡ 200 ms - 2 secs   ‡ 64 - 256 kb/s ‡
‡ - chunks  ‡ 500 ms      ‡ 1 - 10 secs     ‡ 64 - 256 kb/s ‡
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
2.4.5.4 Spectrum efficiency
Provided the link establishment time requirements are met, the long-term channel usages of these are
typically of the order of 0.01 - 0.1 erlangs. These will be translated into spectrum occupancy of 1 erlang,
however, if the radio channel access technique cannot meet the link establishment time requirements and
thus continuously open channels are required.
2.4.5.5 Error ratios
A characteristic of non-voice services is the high-quality logical channel they require. Net bit-error ratios of
10 are the minimum acceptable. These may of course be accomplished by use of FEC and ARQ at
-8
layers 1-4, but carry an overhead in the physical layer.
2.4.5.6 Asymmetry
Since non-voice services often involve a flow of information which is predominantly in one direction,
unidirectional or asymmetric bearers can offer more efficient performance. Greatest efficiency can be
achieved if the bearer dynamically adjusts its forward/return ratio to the data requirements. Should this be
impractical, a mode with 10 : 1 forward/return ratio is required.

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2.4.5.7 System requirements
The need to use spectrum efficiently and at the same time offer an acceptable standard of non-voice
performance, therefore impose certain fundamental requirements on the system. These are listed in order
of importance:
- a radio resource assignment system capable of allocating different amounts of bandwidth to a
channel of the time the channel is established;
- a radio resource assignment system capable of allocating bandwidth between up and down link
independently.
Other issues, such as error correction, can be dealt with either at layers 1, 2, or 3 within DECT, or layer 4
of the teleservices function, and thus need further detailed consideration.
2.4.6 Evolutionary applications
2.4.6.1 DECT extension to cellular radio
Clear need is seen for DECT extensions to cellular radio systems to meet the requirements of:
- telepoint in a mobile environment, for example trains;
- to provide portable cordless access to mobile communications (including the GSM) particular in
areas where hand portable cellular transceivers are inadequately served.
2.4.6.2 Radio extension of the local public network
This application envisages the use of DECT as the access medium from the distribution point to the
customer premises, within the normal DECT coverage capabilities.
2.4.6.3 Distributed DECT head-ends
The DECT system is the basis for a range of business and telepoint-like services. It is expected that the
combination of cheaper digital transmission (fibre) and a larger private switches will lead to situations
where the radio part of the DECT will be distributed but the base-band processes, channel control and
signalling will be centralised. DECT with a 7 to 10 year life-span must accommodate such developments.
Investigation of the necessary range has indicated the following:
- In the USA the distance between a private central switch (centrex) and customer building is
generally cable-quality limited (copper cables) to typically 12,000 feet (3,8 km);
- Currently equivalent UK plans envisage using local exchanges as the central location, which indicates
a services range up to 5 km.
- A telepoint system with the remote transmitters and receivers would require also a 5 km range;
- For application of DECT in a suburban local-network cordless-access mode, range from a residence
to an appropriate network concentration point would be 5 - 7 km.
It would seem therefore that DECT should accommodate a transmission range between the DECT control
centre and radio head-end of 5 km.
2.5 Grade of service
In terms of user acceptability of such proposals it is essential that cordless connections should closely
match wire-connected terminals from a grade-of-service (GOS) point of view. In this report GOS is
equated to the overall probability of a call not being set-up or, worse still, being curtailed during a call, in
the busy hour.
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ETR 015: March 1991
Assuming that all parts that contribute to a call set-up GOS are small, then the overall value is the sum of
its parts. These parts for a cordless system are considered to be.
- That for a PABX alone, typically in the range 0.1% to 0.01%;
NOTE: in the absence of cordlessness this, plus the element for the PSTN, is what the terminal
user perceives.
- That due to congestion in the radio beared channels;
- That due to loss of radio communication caused by poor radio signal coverage of the nominated
communication area or cell.
2.5.1 Large (business) system use
It is proposed that the sum of the above parts for call set-up (for on-site part) anywhere in the defined
communication area in a cordless business communication system shall not exceed 1%. This value is
believed to be acceptable to a business environment in exchange for mobility or freedom from
telecommunication wiring restraint.
To a user call curtailment is far more unacceptable than failure to establish a call. It is recommended that
the probability of curtailment shall not exceed 0.1% but 0.01% is preferable.
2.5.2 Residential and small (business) system use
It is recommended that the above objectives should apply for residential and small system use. However,
in practice such factors as base station siting, density of uncoordinated users, propagation conditions will
have a critical effect and are difficult to control. Nevertheless, it is recommended these objectives be used
when designing equipment and characterizing performance for residential and single-line business use. This
is particularly important when the cordless equipment is designed to be used as the primary means of
communication.
2.5.3 Public use (telepoint)
Expectation of the telepoint service is that GOS criteria should be the same as that for large system use
within the nominated coverage area. However, commercial factors, independent of the DECT specification,
may well limit performance during peak traffic periods.
2.5.4 Non-voice services
Informatic services will be characterized by both the capacity to access suitable channels and access them
within an acceptable time. GOS in this context implies the probability of failure; at the present time it is
recommended that this value should be 1% in common with voice bearer services.
2.6 Performance requirements
In practice telecommunication traffic density in an interference limited radio system should be considered in
a three-dimensional way. The dimensional assumptions made in this report are, however subject to
change.
2.6.1 Residential busy-hour traffic density
i) Suburban (detached houses): wide area traffic density = 150E/km
ii) Urban (department block): wide area traffic density = 200E/km
Busy-hour traffic density within interference range of any handset is equivalent to 1000 E/km ground
projection.
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ETR 015: March 1991
iii) Urban (apartment block)
NOTE: Cordless terminal penetration assumed 30%
Busy-hour traffic per terminal assumed 0.05 erlangs.
Growth and convenience of cordless telephony is expected to raise terminal activity
from present levels.
2.6.2 Business cordless telecommunication systems busy-hour traffic density
(i) Ground Projected Area mean
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡ Building Density      ‡ low (suburban) ‡ design ‡ High (city centre) ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ Number of floors      ‡    3    ‡  6  ‡    20     ‡
‡ Ground area occupied    ‡    0.2   ‡  0.5 ‡    0.6     ‡
2 2 2
‡ Area per cordless terminal ‡   40 m   ‡ 20 m ‡    20m     ‡
‡ Erlang/km         ‡   3000   ‡ 30000 ‡   120000    ‡
‡              ‡        ‡    ‡          ‡
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
This table serves to indicate net spectrum activity for inter-building interference purposes. Range of any
handset is equivalent to 40.000 E/km ground projection.
(ii) Localized peak
Busy-hour traffic density within interference range of any handset is equivalent to 40,000 E/Km ground
projection.
NOTE: Cordless terminal penetration assumed 100%, the total office concept.
Busy-hour traffic per terminal assumed 0.2 erlangs.
2.6.3 Telepoint
According to present estimates the following statistics have been proposed. These may be revised in the
light of growth in public mobile radio usage.
Rush-hour traffic density in a London railway station has been calculated to be 900 erlangs/km . Similar
calculations for airport terminals indicated 5500 erlangs/km (London Heathrow, a single terminal)
2 2
1800 erlangs/km (Madrid, Barajas) and 322 erlangs/km (Frankfurt/Main).
It is envisaged that there will be many licensed public telepoint service providers within Europe (we assume
more than one per country). Consequently to offer an effective service DECT telepoint will have the
capability to support a roaming service between independent service providers. This will require the
capability for multiple, concurrent, handset registration.
2.7 Authentication and security
Any public service, e.g. telepoint which requires a charge to be made is vulnerable to attack for the
purpose of fraudulent use. DECT will, therefore, have a secure authentication and validation process
appropriate to a pocketable handset or other terminal equipment, and forming part of DECT common air
interface specification. The process adopted supports:
- removable identification modules and built-in authentication algorithms;
- roaming between telepoint service providers and therefore has the capability to support multiple
registrations.
General consideration of the need for authentication has led to the conclusion that these facilities are also
important for cordless business communications systems to guard against call interception and

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ETR 015: March 1991
eavesdropping. As a result the provision of a secure authentication process between cordless part and
cordless fixed part is MANDATORY, whether the process is built-in at manufacture or a detachable
authentication module (semi-removable module, or a form of "smart" card). This is achieved by the
provision of a standard (common) authentication algorithm and provision for a private authentication
algorithm as indicated in the following table.
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡                    ‡  STANDARD   ‡   PRIVATE  ‡
‡                    ‡  ALGORITHM   ‡   ALGORITHM ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ AUTHENTICATION             ‡         ‡        ‡
‡ PROCESS                ‡  MANDATORY   ‡   OPTIONAL  ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ PROVISION               ‡         ‡        ‡
‡                    ‡         ‡        ‡
‡ (i) Built-in to the cordless     ‡  MANDATORY   ‡   OPTIONAL  ‡
‡   portable part           ‡         ‡        ‡
‡                    ‡         ‡        ‡
‡ (ii) Detachable authentication     ‡  OPTIONAL   ‡   OPTIONAL  ‡
‡   module              ‡         ‡        ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ USAGE                 ‡         ‡        ‡
‡                    ‡         ‡        ‡
‡ (i) By Telepoint service providers  ‡  OPTIONAL   ‡   OPTIONAL  ‡
‡   own customers           ‡         ‡        ‡
‡                    ‡         ‡        ‡

1)
‡ (ii) For authentication of roaming ‡  ACCEPTANCE  ‡   OPTIONAL  ‡
‡   Telepoint portable part      ‡         ‡        ‡
‡                    ‡         ‡        ‡
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
Table 1
A mechanism for by-passing the authentication procedure for the purpose of accessing the emergency
services must be provided.
DECT will also have the capability to cipher the traffic signal thereby providing a degree of "privacy" to
communication.
3 Radio aspects
3.1 Principles of DECT radio usage
3.1.1 Introduction
This part presents the basic concepts of the Digital European Cordless Telecommunication systems
(DECT) radio usage. The concepts presented here are applicable for cordless extensions to all
circuit-switched networks, such as ISDN, analogue PSTN, or PABX. However main attention is given to
ISDN-applications and public cordless services, e.g. telepoints.
In defining DECT, the following key objectives were considered:
- the structure should allow any reasonable application;
- the structure should allow any reasonable implementation; and
- the structure should allow the cordless extension to be an ISDN-terminal.
Many of the concepts presented in this Document are similar to those applied in the Pan-European digital
mobile radio system (GSM). On the other hand, the unpredictable traffic and propagation conditions in a
mostly private environment require sometimes different approaches to be taken.

1)
Roaming is defined (in this context) as the ability of a cordless terminal equipment to receive or initiate calls on independent
telepoint networks
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ETR 015: March 1991
3.1.2 Differences to standard ISDN
There are three aspects of radio communication which result in major differences to wired ISDN: resource
management, mobility management, and error management.
Resource management
In radio communications the transmission medium is shared among the users and needs careful
management. Conversely, a wired ISDN subscriber has assigned the physical transmission medium
(his/her subscriber loop) all the time. The radio resource management needs result in specific layer 1 and
2 procedures not known in wired ISDN.
Mobility management
The fact that a cordless user is mobile and roaming is very similar to the case where a wired ISDN user
would be allowed to unplug his unit and to reconnect it at an arbitrary place in the network, this even
during a call. To cover these cases, reliable link management procedures are needed in the lower layer
protocols of systems offering handover. In addition, public systems need an authentication procedure in the
network layer protocols.
Error management
The unreliable radio channel requires error control mechanisms which are not present in the wired ISDN
layer 2 protocol.
3.1.3 Scope
The system design remains still in an evolutionary stage. Below is presented a consistent layered structure
capable of supporting 32 kbit/s circuit-mode services. DECT will consist of several compatible structures
which remain to be developed to provide different service modes.

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ETR 015: March 1991
3.2 The layered structure on the radio link
3.2.1 Overview
A structure of four layers is used for the signalling protocols as shown in figure 1.
C-Plane U-Plane
Signalling Interworking Application Processes
Application Process
Management
Network
Layer
Entity
Layer
Data-Link Data-Link
Control Control
Layer Layer
Medium-Access Control Layer
Physical Layer
Figure 1: DECT Layer Structure
OSI Layer 1 OSI Layer 2 OSI Layer 3

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ETR 015: March 1991
The traditional OSI layer 1 comprises DECT's physical and parts of the Medium Access Control (MAC) layer.
The other part of MAC and the complete Data Link Control (DLC) layer are comparable to the OSI layer 2.
DECT's network and OSI layer 3 are identical. The physical layer (PHL) creates a set of bit pipes through the
radio medium. As such it is comparable to the road network. In the DECT Cordless Fixed Part (CFP) the
1)
physical layer's logical end is usually at the Radio Fixed Part (RFP).
The MAC layer's task is to choose a suitable physical channel and to pass information reliably through this
channel. If the service to be offered to the higher layers requires it, MAC has the possibility to activate
multiple physical channels and to offer asymmetric throughput. The logical end of the MAC is again the RFP.
The DLC layer provides reliable transport of the data through the radio medium even when cells (or RFPs)
are switched during communication (handover). The DLC layer's logical end point is in the Common Control
Fixed Part (CCFP).
The NetWork Layer (NWL) is responsible for the transport of data between network nodes. As such it
provides the data routes within the DECT network as well as to the outside world. The logical end here again
is in the CCFP. Transport of the information to the end user would be the task of the Transport Layer.
The DLC and Network Layers are described in Clause 4, Networks structure.
The functions of the layers and the according primitives between them by definition involve always peer-to-
peer communication. There are, however, a wide variety of functions which involve only one peer and
typically require decisions to be made (e.g. the decision to initiate a hand-over). Furthermore, some of these
management functions require information from more than one layer. Therefore the management functions
are contained in a management entity (MGE) which interfaces to all layers.
3.2.2 Physical Layer (PHL)
The physical layer's tasks are as follows:
[1] Modulate and demodulate radio carriers with a bit stream of a defined rate to
create a RF channel;
[2] Create physical channels with fixed throughput;
[3] Observe the radio environment to (i) activate physical channels on request of
MAC, to (ii) recognise calling physical channels (i.e. attempts from one end point
to establish a physical channel), to (iii) acquire and maintain synchronisation
between transmitters and receivers, and to (iv) notify the management entity
about the status (field strength, quality, etc.) of physical channels.
Some details concerning the physical layers are given in figure 2
RF channels
RF channels are radio carriers allocated to the DECT service modulated with a bit stream of 1152 kbit/s. T
...