ETSI TS 102 576 V1.1.1 (2012-03)

Electromagnetic compatibility and Radio spectrum Matters (ERM); Digital cellular telecommunications system (Phase 2+); Radio access network equipment specification; GSM onboard aircraft; Methodology for showing conformance with operational requirements

DTS/ERM-GSMOBA-002-2

General Information

• Status: Published
• Publication Date: 29-Feb-2012
• Technical Committee: ERM GSMOBA - ERM/MSG Joint group on GSM onboard aircraft
• Current Stage: 12 - Completion
• Due Date: 14-Mar-2012
• Completion Date: 01-Mar-2012

Standards Content (Sample)

Technical Specification
Electromagnetic compatibility
and Radio spectrum Matters (ERM);
Digital cellular telecommunications system (Phase 2+);
Radio access network equipment specification;
GSM onboard aircraft;
Methodology for showing conformance with
operational requirements
2 ETSI TS 102 576 V1.1.1 (2012-03)

Reference
DTS/ERM-GSMOBA-002-2
Keywords
GSM, radio
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© European Telecommunications Standards Institute 2012.
All rights reserved.
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ETSI
3 ETSI TS 102 576 V1.1.1 (2012-03)
Contents
Intellectual Property Rights . 4
Foreword . 4
Introduction . 4
1 Scope . 5
2 References . 5
2.1 Normative references . 5
2.2 Informative references . 5
3 Definitions, symbols and abbreviations . 6
3.1 Definitions . 6
3.2 Symbols . 6
3.3 Abbreviations . 6
4 Operational requirements . 7
4.1 Considerations for installation of GSM onboard aircraft system . 7
4.2 Maximum E.I.R.P. of the aircraft due to the GSM onboard aircraft system . 7
4.3 Derivation of the minimum power level of the NCU at the antenna input (criterion A) . 8
4.4 Derivation of the permitted maximum power level of the GSMOBA system at the antenna input
(Criterion B) . 9
4.5 Derivation of the effective power level due to the MS onboard aircraft (Criterion C) . 10
4.6 Description of test methodology to derive key parameters . 10
4.6.1 Cabin coupling loss . 10
4.6.1.1 General description of test set up . 10
4.6.1.2 Definition . 11
4.6.1.3 Test purpose . 11
4.6.1.4 Test procedure . 11
4.6.2 Consideration for RF attenuation measurement on aircraft . 13
4.6.3 Aircraft attenuation in combination with the aircraft antenna system . 14
4.6.3.1 Test purpose . 14
4.6.3.2 Methods of measurement . 14
4.6.3.3 Calculation of combined effective aircraft attenuation and antenna system . 15
4.6.4 Attenuation of aircraft at window . 16
4.6.4.1 Test purpose . 16
4.6.4.2 Methods of measurement . 16
4.6.4.3 Calculation of aircraft attenuation at the window . 17
Annex A (informative): System Description . 19
A.1 High level System Description . 19
A.2 OBTS . 20
A.3 RF Screening . 20
A.4 Antenna system . 20
A.5 Antenna system installation . 20
History . 21

ETSI
4 ETSI TS 102 576 V1.1.1 (2012-03)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Electromagnetic compatibility and
Radio spectrum Matters (ERM).
Introduction
The present document defines methodology for showing conformance to the operational requirements for a GSM
onboard aircraft system (GSMOBA) whose essential requirements to demonstrate conformity to Article 3.2 of the
R&TTE Directive [i.1] are defined in the EN 302 480 [3].
The present document provides a methodology in order to derive power values at the antenna output port of the system
which can be used to demonstrate conformance to any E.I.R.P. limits defined outside the aircraft. Given the dependence
of the E.I.R.P. levels outside the aircraft on the specific system implementation, the present document also identifies
testing procedures to determine the value of the key relevant RF parameters of the aircraft.
ETSI
5 ETSI TS 102 576 V1.1.1 (2012-03)
1 Scope
The present document specifies the methodology for showing conformance to the operational requirements for a GSM
onboard aircraft system, which allows communication in the GSM 1800 frequency band and which ensures that mobile
terminals will not connect to ground based mobile networks.
The present document further specifies measurement methodologies allowing to define the key RF parameters of the
aircraft, which are:
• the aircraft attenuation as observed at the windows;
• the aircraft attenuation in combination of the antenna system as observed at the antenna system feeding point;
• the effective cabin coupling loss within the aircraft cabin.
The present document also provides a way to translate the power level generated by the GSM onboard aircraft system at
the antenna system output port to an E.I.R.P. defined outside the aircraft.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
[1] ECC/DEC/(06)07: "ECC Decision of 1 December 2006 on the harmonised use of airborne GSM
systems in the frequency bands 1710 -1785 and 1805 - 1880 MHz".
[2] ECC REPORT 93: "Compatibility between GSM equipment on board aircraft and terrestrial
networks".
[3] ETSI EN 302 480: "Electromagnetic compatibility and Radio spectrum Matters (ERM);
Harmonized EN for the GSM onboard aircraft system covering the essential requirements of
Article 3.2 of the R&TTE Directive".
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio
equipment and telecommunications terminal equipment and the mutual recognition of their
conformity.
ETSI
6 ETSI TS 102 576 V1.1.1 (2012-03)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
aircraft type: term given to a common platform of aircraft which possess the same RF characteristics
antenna system type: specific antenna characteristics which are uniquely defined by a set of RF parameters
GSM onboard aircraft system: system comprising the functions provided by the NCU and the OBTS
installation type: term given to the precise manner of installation of the dedicated antenna system
Network control Unit (NCU): component of the GSM onboard aircraft system preventing direct connection of the
onboard mobile terminals with mobile networks on the ground by raising the noise floor in the cabin
Onboard Base Transceiver Station (OBTS): component of the GSM onboard aircraft system responsible for radio
transmission and reception to or from the onboard mobile terminals
3.2 Symbols
For the purposes of the present document, the following symbols apply:
λ wavelength
dB decibel
dBm power in decibel relative to 1 mW
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ACU Antenna Coupling Units
ASP Additional Screening Power
BTS Base Transceiver station
CCL Cabin Coupling Loss
CDF Cumulative Distribution Function
CDMA Code Division Multiple Access
CW Continuous Wave
E.I.R.P. Effective Isotropic Radiated Power
ECC Electronic Communications Committee
FSL Free Space Loss
GSM Global System for Mobile communications
GSMOBA GSM OnBoard Aircraft
MS Mobile Station
NCU Network Control Unit
OBTS OBA Base Transceiver System
PG Processing Gain
R&TTE Radio and Telecommunications Terminal Equipment
RF Radio Frequency
UMTS Universal Mobile Telecommunications System
WCDMA Wide Code Division Multiple Access
ETSI
7 ETSI TS 102 576 V1.1.1 (2012-03)
4 Operational requirements
4.1 Considerations for installation of GSM onboard aircraft
system
The requirements for operation of a GSMOBA system in order to comply with defined limits, are highly dependent on
many factors, including the aircraft size and type, its RF isolation characteristics, propagation characteristics within the
cabin and the installation of the GSMOBA system.
Considerations to show compliancy will depend on different elements of technical system design and choice of
installation for achieving compliance with the limits, such as:
- Variation of the output power of NCU/ OBTS outside the aircraft depending on the fuselage attenuation.
- Choosing for the NCU/ OBTS an appropriate antenna type, number and their placement so as to achieve the
most efficient coverage along the cabin while limiting radiation outside the aircraft.
- Valuating the propagation characteristics inside the cabin, e.g. variation of signal strength due to the layout of
the cabin, and factoring this into the evaluation of emissions radiated outside the aircraft.
Results of measurement campaigns have indicated that the effective attenuation of signals by an aircraft is dependent on
the aircraft type. Furthermore the signal leakage of the OBTS will be subject to the RF variations of different antenna
systems and their various installations. Hence system compliancy tests carried out on aircraft can only be used as
validation for the same combination of the system type and the aircraft type, i.e. validation of antenna system "A" with
aircraft type "X" cannot be used on an aircraft type "Z" or using antenna system "B".
To show conformance with the requirements the methodology described in the following clauses is defined.
Conformance shall be shown with respect to the following three criteria:
a) Minimum power at NCU antenna connector must be sufficient to inhibit connection to all relevant terrestrial
networks at the height above ground the system is to be operated. The methodology is described in clause 4.3.
b) The far field E.I.R.P. outside the aircraft from the OBTS/NCU must be low enough to ensure non-interference
with terrestrial MSs. The methodology is described in clause 4.4.
c) The E.I.R.P. outside the aircraft from the MSs must be low enough to ensure non-interference with terrestrial
base stations. The methodology is described in clause 4.5.
The criteria will be referred to as A, B and C in the remainder of the present document. The system can only be
operated at height above ground for which compliance with all the criteria A, B and C can be shown.
The calculations shown in clauses 4.4, 4.5 and 4.6 contain a number of input parameters which must be measured or
estimated. The test methodologies to derive these parameters are described in clause 4.7.
4.2 Maximum E.I.R.P. of the aircraft due to the GSM onboard
aircraft system
It is expected that spectrum regulatory limits imposed on the GSM onboard aircraft system when installed in the aircraft
will be specified as an E.I.R.P. value defined outside the aircraft. The benefits for a regulatory body using this approach
are that the limits are independent of the aircraft type and technical characteristics, such as size, fuselage construction
and its RF shielding features and they are technology neutral.
Such limits can be found in the Annex of ECC Decision ECC\DEC\(06)07 [1] which provides the maximum permitted
E.I.R.P. emitted by the NCU/ OBTS and MS. These levels are defined outside the aircraft, and are listed in table 1 and 2
respectively.
ETSI
8 ETSI TS 102 576 V1.1.1 (2012-03)
Table 1: Maximum permitted E.I.R.P. produced by NCU/ OBTS outside the aircraft
Starting E.I.R.P. produced by NCU/ OBTS, outside the aircraft in dBm/channel
Height 460 MHz to 470 MHz 921 MHz to 960 MHz 1 805 MHz to 1 880 MHz 2 110 MHz to 2 170 MHz
above
Channel Channel Channel Channel
ground
Bandwidth = 1,25 MHz Bandwidth = 200 kHz Bandwidth = 200 kHz Bandwidth = 3,84 MHz
In metres
3 000 -17,0 -19,0 -13,0 1,0
4 000 -14,5 -16,5 -10,5 3,5
5 000 -12,6 -14,5 -8,5 5,4
6 000 -11,0 -12,9 -6,9 7,0
7 000 -9,6 -11,6 -5,6 8,3
8 000 -8,5 -10,5 -4,4 9,5
Table 2: Maximum permitted E.I.R.P. produced by the GSM terminal outside the aircraft
Maximum E.I.R.P., defined outside the
Height above
aircraft, resulting from the GSM mobile
ground
terminal in dBm/channel
(m)
1 800 MHz
3 000 -3,3
4 000 -1,1
5 000 0,5
6 000 1,8
7 000 2,9
8 000 3,8
4.3 Derivation of the minimum power level of the NCU at the
antenna input (criterion A)
The minimum power level required will depend on the following parameters:
1) Maximum power level of mobile network from the ground received inside the aircraft cabin P is
max-inside_aircraft
defined as follow:
P = P − A
max_ inside _ aircraft max_ outside _ aircraft aircrafWindowfMHz
Where:
� P being the theoretical highest signal strength power values outside the aircraft (and
max-outside_aircraft
defined in Table 3).
Table 3: Theoretical maximum power received outside aircraft from mobile networks on the ground
Received power per system bandwidth (dBm/bandwidth)
Band 450 MHz 900 MHz 1 800 MHz 2GHz
Height CDMA GSM UMTS GSM UMTS UMTS
3 Km -70,7 -68,5 -78,5 -76,7 -86,7 -87,6
4 Km -73,0 -70,9 -80,9 -77,6 -89,2 -89,8
5 Km
-74,9 -72,7 -82,7 -78,5 -91,1 -91,4
6 Km -76,4 -74,2 -84,3 -79,3 -92,7 -92,7
7 Km -77,7 -75,5 -85,5 -80 -94 -93,8
8 Km -78,8 -76,6 -86,6 -80,6 -95,2 -94,7
9 Km -79,7 -77,6 -87,5 -81,1 -96,2 -95,5
10 Km -80,6 -78,5 -88,4 -81,5 -97,1 -96,2
NOTE: The values contained in table 2 have been derived from tables contained
in section 8.1.1 from the ECC Compatibility Report 93 [2].

ETSI
9 ETSI TS 102 576 V1.1.1 (2012-03)
� A being the effective attenuation to the ground based signals due to the aircraft at the
aircraft windowf MHz
window. The measurement of this parameter is defined in clause 4.6.4.
2) The consideration of additional screening power (ASP ) which is the combination of the screening
technology
margin necessary for controlling additional processing gain (PG) inherent to some cellular technologies and
the C/I or Eb/N0 (signal to noise ratio or energy per bit to power spectral density ratio) value according to the
cellular technology in to provide effective screening of the pilot broadcast signals:
For GSM:
C
⎛ ⎞
ASP = −
⎜ ⎟
technolog y
I
⎝ ⎠
For WCDMA/CDMA2000:
Eb
ASP = PG −
technolog y
N0
Note that the pilot channel for CDMA systems is a fraction of the total channel power.
Table 4: Processing gain, C/I and Eb/N0
Mobile Processing Delta between Pilot Channel C/I or Eb/N0
Technology gain (dB) and total power (dB)
(see note) (see note)
GSM N/A N/A 4
WCDMA 21 -10 4,3
CDMA2000 20 -8 2,3
NOTE: Parameters taken from the ECC Compatibility Report 93 [2].

3) The required NCU input power at the antenna port in order to provide the necessary power level at the aircraft
window: i.e. the effective coupling loss within the cabin:
- The measurement of the Cabin coupling loss (CCL) is defined in clause 4.6.1.
Translation equation for minimum power required equates to:
P f P + ASP + CCL
req max_ inside _ aircraft techno log y

Where:
• P : power required to screen (dBm/ bandwidth).
req
• P : Maximum power received from the ground based network inside the aircraft (dBm/bandwidth)
max_inside_aircraft
the value may be calculated from theoretical principles or directly measured.
• ASP : additional screening power (dB).
technology
• CCL: cabin coupling loss (dB).
4.4 Derivation of the permitted maximum power level of the
GSMOBA system at the antenna input (Criterion B)
The maximum permitted power level will depend on the attenuation due to the aircraft fuselage in combination of the
dedicated antenna.
Translation equat
...