IEC TS 62657-2:2011

IEC/TS 62657-2 ®
Edition 1.0 2011-11
TECHNICAL
SPECIFICATION
colour
inside
Industrial communication networks – Wireless communication network –
Part 2: Coexistence management

IEC/TS 62657-2:2011(E)
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IEC/TS 62657-2 ®
Edition 1.0 2011-11
TECHNICAL
SPECIFICATION
colour
inside
Industrial communication networks – Wireless communication network –
Part 2: Coexistence management

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XB
ICS 25.040; 35.100 ISBN 978-2-88912-782-5

– 2 – TS 62657-2  IEC:2011(E)
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms, definitions, abbreviated terms and conventions . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 15
3.3 Conventions . 16
4 Coexistence concept in industrial automation . 16
4.1 Overview . 16
4.2 Objective . 17
4.3 Necessity to implement a coexistence management . 19
4.4 Interference potential . 21
4.5 Ancillary conditions . 23
4.6 Best practices to achieve coexistence . 23
4.7 Coexistence conceptual model . 25
4.8 Coexistence management and selection of a wireless communication
solution . 26
4.9 Coexistence management system . 27
5 Coexistence management parameters . 28
5.1 General . 28
5.2 Explanation of coexistence parameters . 28
5.2.1 Adjacent channel selectivity . 28
5.2.2 Antenna gain . 28
5.2.3 Antenna radiation pattern . 28
5.2.4 Bandwidth . 28
5.2.5 Bit rate of physical link . 29
5.2.6 Centre frequency . 29
5.2.7 Characteristic of the area of operation . 29
5.2.8 Communication load . 29
5.2.9 Cut-off frequency . 30
5.2.10 Data throughput . 31
5.2.11 Duty cycle . 31
5.2.12 Effective radiated power (EIRP, ERP) . 32
5.2.13 Frequency hopping procedure . 33
5.2.14 Future expansion plan . 33
5.2.15 Geographical dimension of the plant . 33
5.2.16 Infrastructure components . 33
5.2.17 Initiation of data transmission . 33
5.2.18 Length of user data per transmission interval . 33
5.2.19 Limitation from neighbors of the plant . 33
5.2.20 Maximum dwell time . 33
5.2.21 Maximum number of retransmissions . 34
5.2.22 Maximum transmitter sequence . 34
5.2.23 Mechanisms for adaptivity . 35
5.2.24 Medium access control mechanism. 35

TS 62657-2  IEC:2011(E) – 3 –
5.2.25 Modulation . 36
5.2.26 Natural environmental conditions . 36
5.2.27 Organisational parameters . 36
5.2.28 Other frequency users . 36
5.2.29 Packet loss rate (PLR) . 36
5.2.30 Physical links . 36
5.2.31 Positions of wireless devices and distances between them . 37
5.2.32 Power spectral density (PSD) . 37
5.2.33 Purpose of the automation application . 38
5.2.34 Radio channel . 38
5.2.35 Radio propagation conditions . 38
5.2.36 Receiver blocking . 38
5.2.37 Receiver maximum input level . 39
5.2.38 Receiver sensitivity. 39
5.2.39 Regional radio regulations . 39
5.2.40 Relative movement . 39
5.2.41 Reliability required . 39
5.2.42 Response time . 39
5.2.43 Security level required . 40
5.2.44 Spatial coverage of the wireless communication network . 40
5.2.45 Spurious response . 40
5.2.46 Topology . 40
5.2.47 Total radiated power (TRP). 40
5.2.48 Transmission gap . 40
5.2.49 Transmission interval . 41
5.2.50 Transmission time . 42
5.2.51 Transmitter spectral mask . 44
5.2.52 Type of antenna . 45
5.2.53 Update time . 45
5.2.54 Used frequency bands . 46
5.2.55 Wireless devices . 46
5.2.56 Wireless networks . 46
5.2.57 Wireless technology or standard . 46
6 Coexistence management information structures . 47
6.1 General . 47
6.2 General plant characteristic . 47
6.3 Application communication requirements . 48
6.3.1 Overview . 48
6.3.2 Requirements influencing the characteristic of wireless solutions . 49
6.3.3 Performance requirements . 49
6.4 Characteristic of wireless communication system and device type . 50
6.4.1 Overview . 50
6.4.2 Characteristic of wireless communication system type . 50
6.4.3 Characteristic of wireless devices type . 51
6.5 Characteristic of wireless communication solution . 53
6.5.1 Overview . 53
6.5.2 Wireless network solution . 54
6.5.3 Wireless devices solution . 54
7 Coexistence management process . 55

– 4 – TS 62657-2  IEC:2011(E)
7.1 General . 55
7.1.1 Overview . 55
7.1.2 Suitable documentation method . 56
7.1.3 Documentation . 56
7.1.4 Application of tools . 56
7.2 Establishment of a coexistence management system . 56
7.2.1 Nomination of a coexistence manager . 56
7.2.2 Responsibility of a coexistence manager . 57
7.2.3 Support by radio experts. 57
7.2.4 Training . 57
7.3 Maintaining coexistence management system . 58
7.4 Phases . 58
7.4.1 Investigation phase . 58
7.4.2 Practical tips to accomplish an investigation . 58
7.4.3 Planning phase . 61
7.4.4 Implementation phase . 63
7.4.5 Operation phase . 64
8 Coexistence parameter templates. 65
Bibliography . 69

Figure 1 – Area of consideration . 19
Figure 2 – Examples of wireless equipment in industrial environments . 20
Figure 3 – Progression of expense to achieve coexistence corresponding to the
application classes . 23
Figure 4 – Separation of wireless communication systems according to frequency and
time . 24
Figure 5 – Coexistence conceptual model . 26
Figure 6 – Selection of a wireless communication system and coexistence
management process . 27
Figure 7 – Communication load in case of two wireless devices . 29
Figure 8 – Communication load in the case of several wireless devices . 30
Figure 9 – Cut-off frequencies derived from maximum power level . 31
Figure 10 – Duty cycle . 32
Figure 11 – Maximum dwell time . 34
Figure 12 – Maximum transmitter sequence . 35
Figure 13 – Distance of the radio components . 37
Figure 14 – Power spectral density of an IEEE 802.15.4 system . 38
Figure 15 – Minimum transmitter gap . 41
Figure 16 – Communication cycle, transmission interval and production cycle . 42
Figure 17 – Example of the density functions of transmission delay . 43
Figure 18 – Example of the distribution functions of transmission time . 44
Figure 19 – Transmitter spectral mask of an IEEE 802.15.4 system . 45
Figure 20 – Example of distribution functions of the update time . 46
Figure 21 – Principle for use of coexistence parameters . 47
Figure 22 – Parameters to describe the general plant characteristic . 48
Figure 23 – Parameters to describe automation communication requirements. 49

TS 62657-2  IEC:2011(E) – 5 –
Figure 24 – Parameters to describe network and device type . 50
Figure 25 – Power spectral density and transmitter spectral mask of a DECT system . 52
Figure 26 – Medium utilization in time of a DECT system . 52
Figure 27 – Parameters to describe network and device type . 54
Figure 28 – Planning of a wireless communication system in the coexistence
management process . 62
Figure 29 – Planning of a wireless communication system in the coexistence
management process . 65

Table 1 – Application communication requirements and profiles. 18
Table 2 – Application profile dependent observation time values . 32
Table 3 – List of parameters used to describe the general plant characteristic . 48
Table 4 – List of parameters used to describe the requirements influencing the
characteristic of wireless solutions . 49
Table 5 – List of parameters used to describe the performance requirements . 50
Table 6 – List of parameters used to describe the wireless communication system type . 51
Table 7 – List of parameters used to describe the transmitter of a wireless device type . 53
Table 8 – List of parameters used to describe the receiver of a wireless device type . 53
Table 9 – List of parameters used to describe the wireless network solution . 54
Table 10 – List of parameters used to describe the transmitter of a wireless device
solution . 55
Table 11 – List of parameters used to describe the receiver of a wireless device
solution . 55
Table 12 – Template to describe the general plant characteristic . 66
Table 13 – Template to describe the automation communication requirements . 66
Table 14 – Template used to describe the wireless communication system type . 67
Table 15 – Template used to describe a wireless device type . 67
Table 16 – Template used to describe the wireless network solution . 68
Table 17 – Template used to describe a wireless device solution . 68

– 6 – TS 62657-2  IEC:2011(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
WIRELESS COMMUNICATION NETWORK –

Part 2: Coexistence management

FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62657-2, which is a technical specification, has been prepared by subcommittee 65C:
Industrial networks, of IEC technical committee 65: Industrial-process measurement, control
and automation.
TS 62657-2  IEC:2011(E) – 7 –
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
65C/645/DTS 65C/661A/RVC
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 62657 series, under the general title Industrial networks –
Wireless communication network, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 8 – TS 62657-2  IEC:2011(E)
INTRODUCTION
The market is in need of several network solutions, each with different performance
characteristics and functional capabilities, matching diverse application requirements.
Industrial automation applications covering different industrial applications such as process
automation, factory automation, water/waste water treatments and other industrial
applications up to power generation and power distributions applications, require different
behaviours of wireless networks as, for example, in telecommunications, or for commercial
items such as remote controls or toys. These requirements will be specified in the future
IEC 62657-1.
In industrial premises, a lot of different wireless communication networks have to operate ®
1 2 3
together such as IEC 62591 [9] (WirelessHART ) and future IEC 62601[10] (WIA-PA), both
using IEEE 802.15.4 for the process applications and such as IEC 61784-1 [5] and
IEC 61784-2 [6] CPs using IEEE 802.11 [12] and IEEE 802.15.1 [13] for factory automation
applications with different wireless communication systems. Different to wired fieldbuses,
wireless communication interfaces can interfere with others on the same premises or in the
same environment, disturbing each other. Therefore, it is not tolerable to have multiple
wireless communication networks in the same facility or environment without a predictable
assuredness of coexistence.
The IEC 62657 series has two parts:
− Part 1: Wireless communication requirements and spectrum considerations
− Part 2: Coexistence management
Future IEC 62657-1 [11] provides requirements for regulators in order to obtain additional
dedicated and worldwide unique spectrum and its standardized usage. It is intended to
facilitate harmonization of future adjustments to the international, national and local
regulations.
This part of IEC 62657, which is a technical specification, provides guidance to the users of
wireless communication networks on selection and proper use of wireless communication
networks. To provide suitable wireless devices to the market, it also serves vendors in
describing the behaviours of wireless devices to build wireless networks matching the
application requirements.
This specification is based on analyses of a number of international standards, which focus on
specific technologies. The intention of this standard is not to invent new parameters but to
use already defined ones and to be technology independent.
___________
WirelessHART is the registered trade name of the HART Communication Foundation. This information is given
for the convenience of users of this document and does not constitute an endorsement by IEC of the product
named. Equivalent products may be used if they can be shown to lead to the same results.
Figures in square brackets refer to the bibliography.
To be published.
TS 62657-2  IEC:2011(E) – 9 –
INDUSTRIAL COMMUNICATION NETWORKS –
WIRELESS COMMUNICATION NETWORK –

Part 2: Coexistence management

1 Scope
This part of IEC 62657, which is a technical specification, specifies the fundamental
assumptions, concepts, parameters, and procedure for wireless communication coexistence.
This specification provides guidelines, requirements, and best practices for wireless
communications’ availability and performance, covering the life cycle of wireless
communication coexistence to help the work of all persons involved with the relevant
responsibilities to cope with the critical aspects in each phase of wireless communication
coexistence management in an automation plant.
Additionally this specification provides a common point of reference for wireless
communication coexistence for industrial automation sites as a homogeneous guideline to
help the users assess and gauge their plant efforts. Life cycle aspects include: planning,
designing, installation, implementation, operation, maintenance, administration and training.
This specification deals with the operational aspects of wireless communication coexistence
regarding both the static human/tool-organization and the dynamic network self-organization.
This technical specification specifies coexistence parameters and how they are used in an
application requiring wireless coexistence.
NOTE Measurement methods of parameters could be the subject of a later edition.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
IEC 61804-3, Function blocks (FB) for process control – Part 3: Electronic Device Description
Language (EDDL)
IEEE 802.15.4, IEEE Standard for Local and metropolitan area networks – Part 15.4: Low-
Rate Wireless Personal Area Networks (LR-WPANs)
3 Terms, definitions, abbreviated terms and conventions
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
adjacent channel interference
interference that occurs when two or more wireless applications use adjacent frequency
channels
– 10 – TS 62657-2  IEC:2011(E)
3.1.2
adjacent channel selectivity
ability of a radio receiver to respond to the desired signal and to reject signals in adjacent
frequency channels
3.1.3
antenna
structure or device used to collect or radiate electromagnetic waves
3.1.4
antenna gain
ratio of the power required at the input of a reference antenna to the power supplied to the
input of the given antenna to produce, in a given direction, the same field strength at the
same distance
[SOURCE: Federal Standard 1037C, modified] [16]
3.1.5
antenna radiation pattern
variation of the field intensity of an antenna as an angular function with respect to the axis
3.1.6
automation application data length
number of octets that are exchanged at the communication interface
3.1.7
automation application
application of measurement and automatic control in the industrial automation branches
3.1.8
bandwidth
difference between upper cut-off frequency and lower cut-off frequency
3.1.9
centre frequency
geometric mean of lower cut-off frequency and upper cut-off frequency of a radio channel
3.1.10
channel occupation
time in which the medium is busy
NOTE 1 to entry: Beyond the pure transfer of user data, this time includes all time slices necessary to process the
transmission protocol, e.g. to transfer an acknowledgement.
3.1.11
co-channel
refers to emissions or transmissions in the same frequency channel
[SOURCE: IEC 60050-713:1998, 713-06-23, modified] [2]
3.1.12
coexistence
wireless communication coexistence
state in which all wireless communication solutions of a plant using shared medium fulfill all
their application communication requirements
NOTE 1 to entry: The status of coexistence is characterized by meeting the limit values of relevant parameters for
all wireless applications in the considered area. This status has to be ensured with appropriate measures in
planning and in operation. This clarifies that coexistence is not a static attribute of a wireless communication
solution, but rather a status within the life cycle of a plant. It is possible to leave this status temporarily or

TS 62657-2  IEC:2011(E) – 11 –
permanently due to certain events. The parameter limit values are determined by the automation application in
which the wireless communication takes place. This also implies that it is not reasonable to try to evaluate or
ensure the coexistence separate from an automation application.
3.1.13
coexistence assessment
undertaking of an investigation in order to arrive at a judgment, based on evidence of the
suitability of a set of products and their installation to achieve coexistence
[SOURCE: derived from IEC 62278] [8]
3.1.14
coexistence planning
process that describes the allocation of radio resources (such as time, frequencies, transmit
power, space, etc.) to each wireless system in order to achieve coexistence
3.1.15
coexistence management
process to establish and to maintain coexistence that includes technical and organizational
measures
3.1.16
communication interface
exposed interface between an automation application and the wireless component
NOTE 1 to entry: There is no consistently defined interface for measurement and automation. The interface of the
device might be a serial or a parallel hardware interface, a fieldbus interface, a software interface, or serial,
parallel, discrete, and analog interface.
3.1.17
communication load
requirement of the automation application to transfer a certain amount of user data within a
certain period of time
3.1.18
duty cycle
ratio of the transmitter sequence referenced to a given observation time for the used radio
channel
3.1.19
dwell time
period spent at a particular frequency during any single hop of a frequency hopping system
3.1.20
effective radiated power
power supplied to the antenna multiplied by antenna gain
3.1.21
external wireless systems
wireless applications beyond the scope of the coexistence management process, but
potentially affecting the wireless communication systems administrated by the coexistence
management
NOTE 1 to entry: External systems can be operated on adjacent sites and irradiate into the considered location.
3.1.22
frequency band
range in the frequency spectrum that is assigned for use to specific applications by regulatory
organizations
– 12 – TS 62657-2  IEC:2011(E)
3.1.23
frequency channel
part of a frequency band that is used under a specification (standard or device specification)
by a wireless communication system
NOTE 1 to entry: The coordinated use of different frequency channels is one of the measures to achieve
coexistence.
3.1.24
immunity
ability of an item to continue operating properly in the event of an interference, up to a certain
level of interference, and to be resilient above this level
NOTE 1 to entry: Immunity changes if the environmental conditions change.
NOTE 2 to entry: Immunity of an item is achieved by adding to the robustness of the item the ability to be resilient
to interference.
3.1.25
intermodulation sensitivity
levels of out-of-band interfering signals that, when mixed in the receiver front-end, produce an
in-band third order non-linearity product
3.1.26
jitter
time variation of an expected occurrence
NOTE 1 to entry: Examples are variation of transmission time and update time.
3.1.27
lower cut-off frequency
frequency furthest below the frequency of maximum power where the power spectral density
drops below a certain level
3.1.28
mechanisms for adaptivity
measures to modify one or more of the systems operational parameters in order to improve
the systems robustness against interferences and to minimize the medium utilization
3.1.29
metrics
set of quantitative indicators corresponding to selected properties of a communication device,
equipment, or wireless communication system
3.1.30
plant
complete set of technical equipment and facilities for solving a defined technical task
NOTE 1 to entry: A plant includes apparatus, machines, instruments, devices, means of transportation, control
equipment and other operating equipment.
[SOURCE: IEC 60050-351:2006, 351-21-45] [1]
3.1.31
power spectral density
signal power per defined bandwidth
3.1.32
radio channel
span of the frequency spectrum which is characterized by lower cut-off frequency and upper
cut-off frequency or by centre frequency and bandwidth

TS 62657-2  IEC:2011(E) – 13 –
3.1.33
(radio) resource
means used by multiple wireless communication solutions for the purpose of radio signal
transmission
3.1.34
receiver blocking
effect of a strong out-of-band interfering signal on the receiver’s ability to detect a low-level
wanted signal
3.1.35
receiver maximum input level
maximum signal power that the system can tolerate without distortion of the signal
3.1.36
receiver sensitivity
minimal signal power to receive data with a defined bit error rate
3.1.37
robustness
ability of an item to continue operating properly in the event of an interference, up to a certain
level of the interference
NOTE 1 to entry: The robustness of an item may be increased with measures that modify one or more of its
operational parameters
3.1.38
spurious response
receiver output due to unwanted signals (i.e. having frequencies other than those of the tuned
frequency channel)
3.1.39
radio robustness
attribute of wireless communication to fulfill the designated function despite the presence of
other active wireless communication applications interfering in the sphere of influence
NOTE 1 to entry: This is consistent with the definition of coexistence in IEEE 802.15.2 [14].
3.1.40
shared medium
frequency band shared by several wireless applications as assigned by regulatory
organizations
NOTE 1 to entry: Especially in the industrial, scientific and medical (ISM)-bands, many wireless applications can
be used. Due to this joint use, the term 'shared medium' is used in this technical specification. The frequency
ranges are used by diverse ISM and wireless applications.
3.1.41
transfer interval
time difference between two consecutive transfers of user data from the automation
application via the communication interface to the communication module
3.1.42
wireless application
any use of electromagnetic waves with devices or equipment for the generation and use of
radio frequency energy
NOTE 1 to entry: This term is more comprehensive than the term wireless communication system, because in
wireless applications the frequency energy is not only used for information transfer.

– 14 – TS 62657-2  IEC:2011(E)
NOTE 2 to entry: The use of the electromagnetic energy may be either intentional (as needed to serve the
specific application) or unintentional/incidental.
3.1.43
wireless communication
communication in which electromagnetic radiations are used to transfer information without
the use of wires or optical fibers
[SOURCE: IEC 60050-732: 2010, 732-01-05, modified] [3]
3.1.44
wireless communication solution
specific implementation or instance of a wireless communication system
NOTE 1 to entry: A wireless communication solution may be composed of products of one or more producers.
3.1.45
wireless network
wireless communication solution consisting of at least two wireless devices
3.1.46
wireless communication system
set of interrelated elements providing a wireless communication
NOTE 1 to entry: A wireless communication system is a high level representation of a system, while a wireless
communication solution is a practical instance of a system.
3.1.47
total radiated power
spatial power density integrated across the surface of the sphere
3.1.48
transmission gap
gap between two successive channel usages by a transmitter
3.1.49
transmission sequence duration
time that a transmitter uses the spectrum for the specific sequence in order to transfer data
3.1.50
transmitter spectral mask
maximum limit of power spectral density over a frequency range
3.1.51
upper cut-off frequency
frequency furthest above the frequency of maximum power where the power spectral density
drops below a certain level
TS 62657-2  IEC:2011(E) – 15 –
3.2 Abbreviated terms
AFH Adaptive Frequency Hopping spread spectrum
BOS Wireless communication systems for public authorities and organizations with
safety functions
CEPT European Conference of Postal and Telecommunications Administrations
CP Communication Profile according to IEC 61784-2 [6]
CSMA Carrier Sense Multiple Access
DAA Detect and Avoid
DAR Detect and Reduce
DAS Detect and Suppress
DECT Digital Enhanced Cordless Telecommunications
EDDL Electronic Device Description Language
EIRP Equivalent Isotropic Radiated Power
EMC Electro-Magnetic Compatibility
ERO Electronic Communications Committee of the CEPT
ERP Effective Radiated Power
FB Function blocks
GSM Global System for Mobile Communicat
...