ETSI TBR 028 ed.1 (1997-12)

SLOVENSKI STANDARD
01-oktober-1999
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96$7=HPHOMVNHVDWHOLWVNHSRVWDMHVDPR]DRGGDMDQMH]DRGGDMDQMHLQ
VSUHMHPDQMHDOLVDPR]DVSUHMHPDQMHNLGHOXMHMRYIUHNYHQþQLKSDVRYLK
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Satellite Earth Stations and Systems (SES); Very Small Aperture Terminal (VSAT);
Transmit-only, transmit/receive or receive-only satellite earth stations operating in the
11/12/14 GHz frequency bands
Ta slovenski standard je istoveten z: TBR 028 Edition 1
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL TBR 28
BASIS for December 1997
REGULATION
Source: ETSI TC-SES Reference: DTBR/SES-00006
ICS: 33.020
Key words: Satellite, earth station, VSAT, FSS, type approval
Satellite Earth Stations and Systems (SES);
Very Small Aperture Terminal (VSAT);
Transmit-only, transmit/receive or receive-only
satellite earth stations
operating in the 11/12/14 GHz frequency bands
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 4 92 94 42 00 - Fax: +33 4 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 1997. All rights reserved.

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TBR 28: December 1997
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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TBR 28: December 1997
Contents
Foreword .7
Introduction.7
1 Scope .9
2 Normative references.10
3 Definitions and abbreviations .10
3.1 Definitions .10
3.2 Abbreviations .12
4 Requirements.13
4.1 Off-axis spurious radiation.13
4.1.1 Justification.13
4.1.2 Specification .13
4.1.2.1 Transmit VSAT .13
4.1.2.2 Receive-only VSAT.14
4.1.3 Conformance tests .14
4.2 On-axis spurious radiation for transmit VSAT .14
4.2.1 Justification.14
4.2.2 Specification .14
4.2.2.1 Carrier-on state.14
4.2.2.2 Carrier-off state and transmission disabled state .15
4.2.3 Conformance tests .15
4.3 Off-axis EIRP emission density within the band .15
4.3.1 Justification.15
4.3.2 Specification .15
4.3.3 Conformance tests .16
4.4 Transmit polarization discrimination .16
4.4.1 Justification.16
4.4.2 Specification .16
4.4.3 Conformance tests .16
4.5 Carrier suppression .16
4.5.1 Justification.16
4.5.2 Specification .16
4.5.3 Conformance tests .16
4.6 ElectroMagnetic Compatibility (EMC) .16
4.7 Mechanical (antenna pointing) for transmit VSAT .17
4.7.1 Justification.17
4.7.2 Specification .17
4.7.3 Conformance tests .17
4.8 Control and monitoring for transmit VSAT.17
4.8.1 General.17
4.8.1.1 Control and Monitoring Functions (CMF) .17
4.8.1.2 Specification of states.19
4.8.2 Control Channels (CC).19
4.8.2.1 Justification.19
4.8.2.2 Specification .20
4.8.2.3 Conformance tests .20
4.8.3 Self monitoring functions.20
4.8.3.1 Processor monitoring.21
4.8.3.1.1 Justification .21
4.8.3.1.2 Specification.21
4.8.3.1.3 Conformance tests.21
4.8.3.2 Transmit subsystem monitoring .21
4.8.3.2.1 Justification .21

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TBR 28: December 1997
4.8.3.2.2 Specification. 21
4.8.3.2.3 Conformance tests. 21
4.8.3.3 VSAT transmission validation . 21
4.8.3.3.1 VSAT transmission validation by the
CCMF. 21
4.8.3.3.1.1 Justification . 21
4.8.3.3.1.2 Specification. 22
4.8.3.3.1.3 Conformance tests. 22
4.8.3.3.2 VSAT transmission validation by
receiving station(s) . 22
4.8.3.3.2.1 Justification . 22
4.8.3.3.2.2 Specification. 22
4.8.3.3.2.3 Conformance tests. 22
4.8.3.3.3 Transmission validation for VSAT
using external CC. 22
4.8.3.3.3.1 Purpose. 22
4.8.3.3.3.2 Specification. 22
4.8.3.3.3.3 Conformance tests. 22
4.8.4 Reception of commands from the CCMF. 22
4.8.4.1 Disable message . 23
4.8.4.1.1 Justification . 23
4.8.4.1.2 Specification. 23
4.8.4.1.3 Conformance tests. 23
4.8.4.2 Enable message . 23
4.8.4.2.1 Justification . 23
4.8.4.2.2 Specification. 23
4.8.4.2.3 Conformance tests. 23
4.8.5 Power-on/Reset . 23
4.8.5.1 Justification . 23
4.8.5.2 Specification. 23
4.8.5.3 Conformance tests. 23
5 Test methods for the complete VSAT . 24
5.1 Off-axis spurious radiation . 24
5.1.1 Test method. 25
5.1.1.1 Up to 1 000 MHz . 25
5.1.1.1.1 Test site. 25
5.1.1.1.2 Measuring receivers. 25
5.1.1.1.3 Procedure. 26
5.1.1.2 Above 1 000 MHz. 26
5.1.1.2.1 Identification of the significant
frequencies of spurious radiation . 26
5.1.1.2.1.1 Test site. 26
5.1.1.2.1.2 Procedure. 26
5.1.1.2.2 Measurement of radiated power levels
of identified spurious radiation . 27
5.1.1.2.2.1 Test site. 27
5.1.1.2.2.2 Procedure. 27
5.1.1.2.3 Measurement of conducted spurious
radiation at the antenna flange. 28
5.1.1.2.3.1 Test site. 28
5.1.1.2.3.2 Procedure. 28
5.2 On-axis spurious radiation . 29
5.2.1 Test method. 29
5.2.1.1 Test site . 29
5.2.1.2 Method of measurement. 29
5.2.1.2.1 General. 29
5.2.1.2.2 Method of measurement at the
antenna flange. 29
5.2.1.2.3 Method of measurement with a test
antenna . 30
5.3 Off-axis EIRP emission density within the band. 31
5.3.1 Test method. 31

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TBR 28: December 1997
5.3.1.1 Transmit output power density.31
5.3.1.1.1 Test site .31
5.3.1.1.2 Method of measurement.31
5.3.1.2 Antenna transmit gain.32
5.3.1.2.1 General .32
5.3.1.2.2 Test site .32
5.3.1.2.3 Method of measurement.32
5.3.1.3 Antenna transmit radiation patterns.33
5.3.1.3.1 General .33
5.3.1.3.2 Test site .33
5.3.1.3.3 Test arrangement .33
5.3.1.3.4 Co-polar radiation pattern - azimuth .34
5.3.1.3.5 Co-polar radiation pattern - elevation.34
5.3.1.3.6 Cross-polar radiation pattern - azimuth 35
5.3.1.3.7 Cross-polar radiation pattern -
elevation.35
5.3.2 Computation of results .36
5.4 Transmit polarization discrimination .36
5.4.1 General.36
5.4.2 Test site.36
5.4.2.1 Method of measurement.36
5.5 Carrier suppression .38
5.5.1 Test method .38
5.6 Antenna pointing for transmit VSAT .38
5.6.1 Test method .38
5.7 Control and monitoring for transmit VSAT.38
5.7.1 Test arrangement.39
5.7.2 Control Channels (CC).39
5.7.2.1 Test method.39
5.7.2.1.1 Test method for internal CC.40
5.7.2.1.2 Test method for external CC .40
5.7.3 Processor monitoring .40
5.7.3.1 Test method.40
5.7.4 Transmit subsystem monitoring .41
5.7.4.1 Test method.41
5.7.5 VSAT transmission validation.41
5.7.5.1 Test method for VSAT validation by the CCMF for VSAT
using internal CC .41
5.7.5.2 Test method for VSAT validation by receiving station(s)
for VSAT using internal CC .41
5.7.5.3 Test method for transmission validation for VSAT using
external CC.41
5.7.6 Reception of commands from the CCMF.41
5.7.6.1 Test method.41
5.7.7 Power-on/Reset.42
5.7.7.1 Test method.42
6 Test methods for modified VSAT .43
6.1 Antenna subsystem replacement .43
Annex A (normative): The TBR Requirements Table (TBR-RT).44
Annex B (informative): Pointing stability methodology .45
Annex C (informative): Bibliography.46
History.47

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Foreword
This Technical Basis for Regulation (TBR) has been produced by the Satellite Earth Stations and Systems
(SES) Technical Committee of the European Telecommunications Standards Institute (ETSI).
Introduction
The SES Directive [1] which supplements the TTE Directive [2] concerns the harmonization of conditions
for the placing on the market of such equipment.
Two classes of standards are applicable to satellite earth station equipment. European
Telecommunication Standards (ETSs) give the full technical specifications for this equipment, whereas
Technical Bases for Regulation (TBRs) give the essential requirements under the SES Directive [1] and
the TTE Directive [2] for placing such equipment on the market. Receive-only equipment, not intended for
terrestrial connection to the public telecommunications network, may be put into use. Nothing in this TBR
is construed to prevent the use of Community internal production control procedures as set out in the
annexes to the two Directives for such receive-only equipment. This TBR is based on ETS 300 157,
ETS 300 159, ETS 300 160 and ETS 300 456 (see annex C, Bibliography).

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TBR 28: December 1997
1 Scope
This Technical Basis for Regulation (TBR) specifies the technical requirements that apply to Very Small
Aperture Terminals (VSAT) for compliance with Articles 4.1 and 4.3 of the SES Directive [1].
These VSAT have the following characteristics:
- The VSAT are operating in one or more frequency ranges in the exclusive part of the following
bands allocated to the Fixed Satellite Services (FSS):
- 14,00 GHz to 14,25 GHz (earth-to-space);
- 12,50 GHz to 12,75 GHz (space-to-earth);
or in the shared parts of the following bands, allocated to the FSS and Fixed Services (FS):
- 14,25 GHz to 14,50 GHz (earth-to-space);
- 10,70 GHz to 11,70 GHz (space-to-earth).
- The VSAT use linear polarization.
- The VSAT operate through a geostationary satellite at least 3° away from any other geostationary
satellite operating in the same frequency band and covering the same area.
- The VSAT antenna diameter does not exceed 3,8 m, or equivalent corresponding aperture.
- The VSAT are either:
- transmit only VSAT: designed for transmission only of radio-communications signals in any of
the frequency bands (earth-space) specified above; or
- transmit and receive VSAT: designed for transmission and reception of radio-
communications signals in any of the frequency bands specified above; or
- receive only VSAT: designed for reception only of radio-communications signals in any of the
frequency bands (space-earth) specified above.
- The VSAT are designed usually for unattended operation.
- The VSAT are operating as part of a satellite network (e.g. star, mesh or point-to-point) used for the
distribution and/or exchange of information between users.
- The VSAT are controlled and monitored by a Centralized Control and Monitoring Function (CCMF).
The CCMF is outside the scope of this TBR.
This TBR applies to the VSAT with its ancillary equipment and its various terrestrial ports, and operated
under the conditions which are within the ranges of humidity, temperature and supply voltage declared by
the manufacturer.
The requirements have been selected to ensure an adequate level of compatibility with other radio
services. The levels, however, do not cover extreme cases which may occur in any location but with a low
probability of occurrence.
This TBR may not cover those cases where a potential source of interference which is producing
individually repeated transient phenomena or a continuous phenomenon is present, e.g. a radar or
broadcast site in the near vicinity. In such a case it may be necessary to use special protection applied to
either the source of interference, or the interfered part or both.
This TBR does not contain any requirement, recommendation or information about the installation of the
VSAT.
Compliance of a VSAT to the requirements of this TBR does not imply compliance to any requirement
related to the use of the VSAT (e.g. licensing requirements).

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TBR 28: December 1997
2 Normative references
This TBR incorporates by dated or undated reference, provisions from other publications. These
references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references, subsequent amendments to, or revisions of any of these publications apply to this TBR
only when incorporated into it by amendment or revision. For undated references the latest edition of the
publication referred to applies.
[1] Council Directive 93/97/EEC of 29 October 1993 supplementing Directive
91/263/EEC in respect of satellite earth station equipment. Called the
"SES Directive" in the present document the.
[2] Council Directive 91/263/EEC of 29 April 1991 on the approximation of the laws
of Member States concerning telecommunications terminal equipment, including
the mutual recognition of their conformity. Called the "TTE Directive" in the
present document the.
[3] ETS 300 673 (1996): "Radio Equipment and Systems (RES); ElectroMagnetic
Compatibility (EMC) standard for 4/6 GHz and 11/12/14 GHz Very Small
Aperture Terminal (VSAT) equipment and 11/12/13/14 GHz Satellite News
Gathering (SNG) Transportable Earth Station (TES) equipment".
[4] CISPR 16-1 (1993): "Specification for radio interference measuring apparatus
and measurement methods; Part 1: Radio disturbance and immunity measuring
apparatus" (annex G: Validation of the open area test site for the frequency
range of 30 MHz to 1 000 MHz).
NOTE: This TBR also contains a number of informative references which have been included
to indicate the sources from which various material has been derived, hence they do
not have an associated normative reference number. Details of these publications are
given in annex C, bibliography.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of this TBR, the following definitions apply:
ancillary equipment: Equipment used in connection with a VSAT is considered as ancillary if the three
following conditions are met:
a) the equipment is intended for use in conjunction with the VSAT to provide additional operational
and/or control features (e.g. to extend control to another position or location); and
b) the equipment cannot be used on a stand alone basis, to provide user functions independently of
the VSAT; and
c) the absence of the equipment does not inhibit the operation of the VSAT.
carrier-off state: A VSAT is in this state when it is authorized by the Centralized Control and Monitoring
Functions (CCMF) to transmit, but when it does not transmit any signal.
NOTE 1: The existence of a carrier-off state depends on the system of transmission used. For
VSAT designed for continuous transmission mode there may be no carrier-off state.
carrier-on state: A VSAT is in this state when it is authorized by the CCMF to transmit and when it
transmits a signal.
Centralized Control and Monitoring Functions (CCMF): A set of functional entities that, at system
level, monitor and control the correct operation of all transmit VSAT in a network.

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TBR 28: December 1997
Control Channel (CC): A channel or channels by which VSAT receive control information from the
CCMF.
cross-polarization discrimination: The ratio of the on-axis co-polar gain to the cross-polar gain in a
given direction, at a transmit or receive frequency.
external control channel: A control channel which is either (i) carried by the VSAT network via the same
or another satellite, but not within the internal protocol of the VSAT system, or (ii) carried by the PSTN or
some other means.
external response channel: A response channel which is either (i) carried by the VSAT network via the
same or another satellite, but not within the internal protocol of the VSAT system, or (ii) carried by the
PSTN or some other means.
indoor unit: Is composed of that part of the VSAT which is not part of the outdoor unit. It is generally
installed inside a building and is connected to the outdoor unit. The connection cable between the outdoor
and indoor unit is considered part of the indoor unit.
integral antenna: An antenna which may not be removed during the tests according to the
manufacturer's statement.
internal control channel: A control channel which is carried by the VSAT network via the same satellite
as used for transmission of user data and within the internal protocol structure of the VSAT system.
internal response channel: A response channel which is carried by the VSAT network via the same
satellite as used for transmission of user data and within the internal protocol structure of the VSAT
system.
manufacturer: The legal entity responsible under the terms of the Council Directive 93/97/EEC
(SES Directive) [1] for placing the product on the market in a member state.
network: In this TBR a network is any network configuration including star, mesh and point-to-point
configurations.
nominated bandwidth: The bandwidth of the VSAT radio frequency transmission is nominated by the
manufacturer. The nominated bandwidth is centred on the transmit frequency and does not exceed
5 times the occupied bandwidth.
NOTE 2: The nominated bandwidth is wide enough to encompass all spectral elements of the
transmission which have a level greater than the specified spurious radiation limits.
The nominated bandwidth is wide enough to take account of the transmit carrier
frequency stability. This definition is chosen to allow flexibility regarding adjacent
channel interference levels which will be taken into account by operational procedures
depending on the exact transponder carrier assignment situation.
occupied Bandwidth (Bo): For a digital modulation scheme - the width of the signal spectrum 10 dB
below the maximum inband density. For an analogue modulation scheme - the width of a frequency band
such that, below the lower and above the upper frequency limits, the mean power emitted is equal to
0,5 % of the total mean power of the emission.
outdoor unit: The part of the VSAT intended to be installed outdoor, as declared by the manufacturer, or
as indicated in the user documentation.
The outdoor unit usually comprises three main parts:
a) the antenna sub-system which converts the incident radiation field into a guided wave and
vice versa;
b) the Low Noise Block (LNB) down converter, which is a device that amplifies, with very low internal
noise, the received signals in the Radio Frequency (RF) band and converts them to intermediate
frequencies;
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TBR 28: December 1997
c) the upconverter and the power amplifier which convert from the intermediate frequency to RF and
amplify the low level RF signals for transmission through the antenna subsystem.
NOTE 3: The installation equipment (means of attachment) is outside the scope of this TBR.
However, the antenna structures and other components directly mounted on the
antenna and forming an integral part of it, are subject to the specifications of this TBR.
removable antenna: An antenna which may be removed during the tests according to the manufacturer's
statement.
Response Channel (RC): A channel by which VSAT transmit monitoring information to the CCMF.
spurious radiation: Any radiation outside the nominated bandwidth.
NOTE 4: For a receive-only VSAT there is no nominated bandwidth therefore any radiation is a
spurious radiation.
transmit VSAT: A VSAT capable of being used either for transmission only, or for transmission and
reception.
transmission disabled state: A VSAT is in this state when it is not authorized by the CCMF to transmit.
3.2 Abbreviations
For the purposes of this TBR, the following abbreviations apply:
CC Control Channel
CCD Central Control Disable
CCE Central Control Enable
CCMF Centralized Control and Monitoring Functions
CMF Control and Monitoring Functions
CV Control Variable
EIRP Equivalent Isotropically Radiated Power
EMC ElectroMagnetic Compatibility
ETS European Telecommunication Standard
EUT Equipment Under Test
FSS Fixed Satellite Service
HPA High Power Amplifier
ITU International Telecommunications Union
LNA Low Noise Amplifier
LNB Low Noise Block
modem MOdulator/DEModulator
PSTN Public Switched Telephone Network
RC Response Channel
RE Reset Event
RF Radio Frequency
RR ITU Radio Regulations
SMF Status Monitoring Fail
SMP Status Monitoring Pass
SMV Self Monitoring Variable
STE Special Test Equipment
VSAT Very Small Aperture Terminal
XPD Cross Polar Discrimination

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TBR 28: December 1997
4 Requirements
4.1 Off-axis spurious radiation
4.1.1 Justification
To limit the level of interference to terrestrial and satellite radio services.
4.1.2 Specification
4.1.2.1 Transmit VSAT
1) The VSAT shall not exceed the limits for radiated interference field strength over the frequency
range from 30 MHz to 1 000 MHz specified in table 1.
Table 1: Limits of radiated field strength at a test distance of 10 m
Frequency range Quasi-peak limits
(MHz) (dBμV/m)
30 to 230 30
230 to 1 000 37
The lower limits shall apply at the transition frequency.
2) When the VSAT is in the transmission disabled state, the off-axis spurious Equivalent Isotropically
Radiated Power (EIRP) from the VSAT, in any 100 kHz band, shall not exceed the limits in table 2,
for all off-axis angles greater than 7°:
Table 2: Limits of spurious EIRP - transmission disabled state
Frequency band EIRP limit
(dBpW)
1 000,0 MHz to 10,7 GHz 48
10,7 GHz to 21,2 GHz 54
21,2 GHz to 40,0 GHz 60
The lower limits shall apply at the transition frequency.
3) This specification applies outside the nominated bandwidth. For both the carrier-on and carrier-off
states, the off-axis spurious EIRP in any 100 kHz band from the VSAT, shall not exceed the limits in
table 3, for all off-axis angles greater than 7°:
Table 3: Limits of spurious EIRP
Frequency band EIRP limit
(dBpW)
1 000,0 MHz to 3,4 GHz 49
3,4 GHz to 10,7 GHz 55
10,7 GHz to 13,85 GHz 61
13,85 GHz to 14,0 GHz 75 (see note)
14,25 GHz to 14,65 GHz 75 (see note)
14,65 GHz to 21,2 GHz 61
21,2 GHz to 40,0 GHz 67
NOTE: This limit may be exceeded in a frequency band which shall not exceed 50 MHz, centred
on the carrier frequency, provided that the on-axis EIRP density at the considered
frequency is 50 dB below the maximum on-axis EIRP density of the signal (within the
nominated bandwidth) expressed in dBW/100 kHz.
The lower limits shall apply at the transition frequency.

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TBR 28: December 1997
In the frequency band 28,0 to 29,0 GHz, for any 20 MHz band within which one or more spurious
signals exceeding the above limit of 67 dBpW are present, then the power of each of those
spurious signals exceeding the limit shall be added in watts, and the sum shall not exceed
78 dBpW.
For VSAT designed to transmit simultaneously several different carriers (multicarrier operation), the
above limits apply to each individual carrier when transmitted alone.
4) These limits are applicable to the complete VSAT equipment, comprising of the indoor and outdoor
units with at least 10 m of cable connecting them.
4.1.2.2 Receive-only VSAT
1) The VSAT shall not exceed the limits for radiated interference field strength specified in table 4 over
the frequency range from 30 MHz to 1 000 MHz.
Table 4: Limits of radiated field strength at a test distance of 10 m
Frequency range Quasi-peak limits
(MHz) (dBμV/m)
30 to 230 30
230 to 1 000 37
The lower limits shall apply at the transition frequency.
2) The off-axis spurious EIRP from the VSAT, in any 100 kHz band, shall not exceed the limits in
table 5, for all off-axis angles greater than 7°:
Table 5: Limits of spurious EIRP
Frequency band EIRP limit
(dBpW)
1 000,0 MHz to 10,7 GHz 48
10,7 GHz to 21,2 GHz 54
21,2 GHz to 40,0 GHz 60
The lower limits shall apply at the transition frequency.
3) These limits are applicable to the complete VSAT equipment, comprising of the indoor and outdoor
units with at least 10 m of cable connecting them.
4.1.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.1.
4.2 On-axis spurious radiation for transmit VSAT
4.2.1 Justification
To limit the level of interference to satellite radio services.
4.2.2 Specification
4.2.2.1 Carrier-on state
In the 14,0 GHz to 14,5 GHz band the EIRP spectral density of the spurious radiation and outside the
nominated bandwidth shall not exceed 4 - 10 log N dBW in any 100 kHz band.
In a bandwidth of 5 times the occupied bandwidth centred on the carrier centre frequency, the EIRP
spectral density of the spurious radiation outside the nominated bandwidth, shall not exceed
18 - 10 log N dBW in any 100 kHz band.

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TBR 28: December 1997
N is the maximum number of VSAT which are expected to transmit simultaneously in the same carrier
frequency band. This number shall not be exceeded for more than 0,01 % of the time. The value of N and
the operational conditions of the system shall be declared by the manufacturer.
NOTE 1: The on-axis spurious radiations, outside the 14,0 GHz to 14,5 GHz band, are indirectly
limited by subclause 4.1.2.1. Consequently no specification is needed.
NOTE 2: Intermodulation limits inside the band 14,0 GHz to 14,5 GHz are to be determined by
system design and are subject to satellite operator specifications.
For VSAT designed to transmit simultaneously several different carriers (multicarrier operation), the above
limits only apply to each individual carrier when transmitted alone.
4.2.2.2 Carrier-off state and transmission disabled state
In the 14,0 GHz to 14,5 GHz band the EIRP spectral density of the spurious radiation outside the
nominated bandwidth shall not exceed -21 dBW in any 100 kHz band.
4.2.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.2.
4.3 Off-axis EIRP emission density within the band
Off-axis EIRP emission density (co-polar and cross-polar) within the band 14,0 GHz to 14,5 GHz.
4.3.1 Justification
Protection of other satellite (uplink) systems.
4.3.2 Specification
The maximum EIRP in any 40 kHz band within the nominated bandwidth of the co-polarized component in
any direction φ degrees from the antenna main beam axis shall not exceed the following limits:
33 - 25 log φ - 10 log N dBW for 2,5°≤φ ≤ 7,0°;
+12 - 10 log N dBW for 7,0° < φ≤ 9,2°;
36 - 25 log φ - 10 log N dBW for 9,2° < φ≤ 48°;
- 6 - 10 log N dBW for φ > 48°.
Where φ is the angle, in degrees, between the main beam axis and the direction considered, and N is the
maximum number of VSAT which may transmit simultaneously in the same carrier frequency band.
This number shall be declared by the manufacturer.
For φ > 70° the values given above may be increased to 4 - 10 log N dBW over the range of angles for
which the particular feed system may give rise to relatively high levels of spillover.
For antennas designed for minimum off-axis gain in the direction of the geostationary orbit, the
specification for φ between 2,5° and 20° need only be met within ±3° of a plane bisected by the main beam
axis. This plane shall be marked and identified on the antenna in order to be able to align it tangentially to
the geostationary orbit. There shall be an axis of rotation along or parallel to the main beam axis, with
adjustment capability to an accuracy of 0,5°. The antenna shall be capable of having the above plane
aligned with the geostationary orbit plane.
In addition the maximum EIRP in any 40 kHz band within the nominated bandwidth of the cross-polarized
component in any direction φ degrees from the antenna main beam axis shall not exceed the following
limits:
23 - 25 log φ - 10 log N dBW for 2,5°≤φ ≤ 7,0°;
+2 - 10 log N dBW for 7,0° < φ≤ 9,2°.

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TBR 28: December 1997
Where φ is the angle, in degrees, between the main beam axis and the direction considered, and N is the
maximum number of VSAT which may transmit simultaneously in the same carrier frequency band.
This number shall be declared by the manufacturer.
4.3.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.3.1 with the results being
computed in accordance with subclause 5.3.2.
4.4 Transmit polarization discrimination
4.4.1 Justification
Protection of signals on the orthogonal polarization.
4.4.2 Specification
The polarization discrimination of the antenna system in the transmit frequency band shall exceed the
values shown in table 6 within the -1 dB contour of the main beam.
Table 6: Cross Polar Discrimination (XPD) limits according to the maximum EIRP density
capability
XPD Max EIRP density
(dB) (dBW/4 kHz)
≥ 35
25 33
Linear interpolation shall apply between the above values.
The method of calculation of maximum EIRP density is given in subclause 5.4.
NOTE: Some satellite operators may require improved values of cross polar discrimination.
4.4.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.4.
4.5 Carrier suppression
4.5.1 Justification
To allow for the satisfactory suppression of transmissions of a VSAT by the CCMF.
4.5.2 Specification
When the VSAT carrier is suppressed the VSAT shall be in the transmission disabled state and the EIRP
density shall not exceed 4 dBW in any 4 kHz band within the nominated bandwidth.
4.5.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.5.
4.6 ElectroMagnetic Compatibility (EMC)
There are no specific EMC requirements under this TBR, however, ETS 300 673 [3] contains the EMC
requirements for VSAT.
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4.7 Mechanical (antenna pointing) for transmit VSAT
4.7.1 Justification
Protection of signals to and from both the same and adjacent satellites.
4.7.2 Specification
a) Pointing stability:
Under the condition of 100 km/h maximum wind speed, with gusts of 130 km/h lasting 3 seconds,
the installation shall not show any sign of permanent distortion and shall not need repointing after
the application of the wind load.
b) Pointing accuracy capability:
Specification 1: Main beam pointing accuracy
The antenna mount shall allow the position of the antenna transmit main beam axis to be
maintained with an accuracy better than the off-axis angle measured when the main beam gain has
decreased by 1 dB at any frequency in the equipment operating band, over the full range of azimuth
and elevation movement available to the antenna.
Specification 2: Non-symmetrical main beam orientation
This specification applies to antennas designed for minimum off-axis gain in the direction of the
geostationary orbit (e.g. elliptical antennas). The plane bisected by the main beam axis and where
the off-axis is minimum shall be marked on the antenna. There shall be an axis of rotation along or
parallel to the main beam axis, with adjustment capability to an accuracy of 0,5°. The antenna shall
be capable of having the above plane aligned with the geostationary orbit plane.
c) Polarization angle alignment capability:
The polarization angle shall be continuously adjustable in a range of at least 180°;
it shall be possible to fix the transmit antenna polarization angle with an accuracy of at least 1°.
4.7.3 Conformance tests
Conformance tests shall be carried out in accordance with subclause 5.6.
4.8 Control and monitoring for transmit VSAT
4.8.1 General
The following minimum set of control and monitoring functions shall be implemented in VSAT in order to
minimize the probability that they may originate transmissions that may interfere with other systems.
Under any fault condition when the VSAT transmissions are being suppressed the EIRP density shall not
exceed the limits for the transmission disabled state specified in subclauses 4.1, 4.2 and 4.5.
4.8.1.1 Control and Monitoring Functions (CMF)
A VSAT shall implement two sets of control and monitoring functions:
a) Monitoring functions: these functions encompass all the checks and verifications that the VSAT
shall perform in order to identify any anomalous situation which may cause impairments to other
systems.
The overall result of these checks and verifications are contained in a functional variable named
Self Monitoring Variable (SMV). The states of this variable are "Pass" and "Fail".
The state of the SMV may change as a result of events. These are:
- Status Monitoring Pass event (SMP);
- Status Monitoring Fail event (SMF).

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TBR 28: December 1997
The circumstances under which these events may take place are specified in subclause 4.8.3 of
this TBR.
b) Control functions: these functions are associated with the ability of the CCMF to inhibit and to permit
transmissions from an individual VSAT.
These functions are reflected in the state of a functional variable, resident at each VSAT, named
Control Variable (CV). The states of this variable are "enable" and "disable".
The CV may change as a result of events. These are:
- Central Control Disable (CCD);
- Central Control Enable (CCE).
The circumstances associated to the reception of the messages resulting in these events are
specified in subclause 4.8.4 of this TBR.
Besides these two sets of control and monitoring functions, the VSAT shall achieve a controlled
non-transmitting state following actuation of the terminal (power-on).
VSAT that allow local operator intervention may include a terminal reset function which when actuated
results in a Reset Event (RE).
Subclause 4.8.5 specifies the functions associated with the occurrence of the "power-on" and REs.
The combination of the SMV and CV results in the definition of 4 possible states in which a VSAT may be
from the control and monitoring point-of-view.
The states of the VSAT are:
- out-of-service;
- checking;
- stand-by;
- in-service.
Figure 1 shows the state transition diagram associated with these 4 states. The operational behaviour of
the VSAT (with respect to control and monitoring), in each of these s
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