1、TIAlEIA TELECOMMUNICATIONS SYSTEMS BULLETIN Interference Criteria for Microwave Systems TSB10-F (Revision of TSB10-E) JUNE 1994 TELECOMMUNICATIONS INDUSTRY ASSOCIATION -EEiEn TELECO“UNICATIONS a-l.p (br -, IndbnwMhIbeEbdnmklahetrksbsacULoa INDllSlRY ASSOCIATION Telecommunications Systems Bulletin TS
2、B-10-F (Sperede TSB-IO-E) Interference Criteria for Microwave Systems Telecommunications Industry Association 200 1 Pennsylvania Avenue, NW USA Wahinston, DC 20006-1813 EIA TSBLO-F 94 m 3234600 0555384 7T7 m This Bulletin was adopted on: 1994.05.3 1 First Printing: 1994.07.15 Copyright O I994 by Tel
3、mmmmications Industry Association AU rights med. No part of this publication may be reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechmical, photocopying, recording or otherwise) without written permission of the publisher. Organizations may obtain permission to
4、reprduce a limited number of copies through entering into a license agreement with TIA/EIA. Interested organbations should contact: MIA Publications Office, 2001 Pennsylvania, Ave., NW, Washington, DC, T +1 (202) 457-4963. printed in the United States of America TIA TSB 10-F Table of Contents Table
5、of Contents Notice Preface Terms and Definitions Sections: 1 Interference Criteria for Microwave System in the Merged Domestic Public Fixed Radio Services and Private Operational-Fixed Microwave Service Bands 1 .O Introduction 2 - Technical Considerations for Interference Analysis 2.0 Introduction 2
6、.1 Spurious Response Interference Windows 2.2 FM-FDM Interfering Signals 2.3 Video Interfig Signals 2.4 Digital Interfering Signals 2.5 Interference Criteria 3 Applications (Interference Calculations and Measurements) 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 Introduction General How to Calculate Inte
7、rference Levels and CA Ratios Existing Systems New System (and Modifications or Extensions of Existing Systems) Examples Passive Repeaters Methods Suggested for Obstructed Interfering Paths Measurement Considerations for FM-FDM Analog Microwave Systems Measurement Considerations for Digital Microwav
8、e Systems 4 Technical Considerations for Path Design 4.0 Introduction 4.1 CA Objective Curves 4.2 Perfomance as a Coordination Criterion in Victim Microwave Links 4.3 Automatic Transmit Power Control in Digital Links 111 . TIA TSB 10-F 5 Annexes: A B 4.4 Rain Fade Outage Calculations for Links Above
9、 10 GHz 4.5 Bibliography Channeling and Frequency Pairing Plans 5.0 Intraduction 5.1 Frequency Plan Tables 5.2 Channeling Plans Methods for Computing the Interference Objectives of FM-FDM Receivers A- 1 A-2 A-3 A4 A-5 A-6 A-7 A-8 A-9 A-IO A-1 1 A-12 A-13 A- 14 Introduction FM-FDM Interfering Signals
10、 Digital Interfering Signals Interference Reduction Factor and Carrier-teInterference Ratios Carrier-teInterference Objective Filter Selectivity Instability of the RF Carrier Frequency Minimum CA Objective Characteristics of FM-FDM Signals CD Objective Curves Adjacent Channel Noise FM Receiver Thres
11、hold Co-channel Intercarrier Beat Interference Emphasis Methods for Computing the Interference Objectives of Digital Receivers B- 1 Introduction B-2 Threshold-to-Interference (TA) Ratio B-3 Default Calculations for Coordinating Interference into Digital Receivers C Methods for Computing the Interfer
12、ence Objectives of J?“Video Receivers C- 1 Introduction C-2 Co-channel hterf-ce D Methods for Computing the Interference Objectives of A“VSB Video Receivers D- 1 Introduction to AM-VSB Video D-2 Performance of AM System in Noisy Environments G-3 Derivation of AM-VSB Signal-to-Noise Versus Carrier-to
13、-Noise Ratios 0-4 General Considerations for CA Calculations in the 12.7-13.25 GHz Band iv TIA “SB 10-F D-5 General Considerations for CA Calculations in the 18.14-18.58 GHz band E F G - Index Industry Contributions to TIA Bulletin 10-F E-1 TR-14. 1 1 / NSMA Joint Committee Contributions E-2 Telmato
14、r (now PCIA) Spectrum Sharing Report PCSPOFMS Spectrum Sharing Considerations F- 1 Introduction F-3 Interference Potential Determination Factors F4 Propagation Loss Models F-5 Active Avoidance Systems F-6 Prior Coordination Notices F-2 Background NSMA / FCC Technical Standards for Frequency Coordina
15、tion and Notification Procedures G- 1 Introduction. G-2 Frequency Coordination. G-3 Contlicts V TIA TSB 10-F Notice TIA/EIA Engineering Standards and Publications are designed to serve the public interest through climinating misunderstanding between manufacturers and purchasers, facilitating inter-c
16、hangeability and improvement of products, assisting the purchaser in selecting and obtaining with minimum delay the proper products for his particular need. Existence of such Standards and Publications shall not in any respect preclude any member or non-member of TWIA from manufacturing or selling p
17、roducts not conforming to such Standards and Publications, nor shall the existence of such standards and Publications preclude their voluntary use by those other than TIMEIA members, whether the standard is to be used either domestically or internationally. Recommended Standards, Publications and Bu
18、lletins are adopted by TI.A/EI.A in accordance with the American National Standards Institute (ANSI) patent policy, By such action, TIAELA does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Recommended Standard, Publication or Bullet
19、in. Technical Bulletins are distinguished from TIA/EIA Recommended Standards or Interim Standards, in that they contain a compilation of engineering data or information useful to the technical community, and represent approaches to good engineering practices that are suggested by the formulating com
20、mi. - This Bulletin is not intended to preclude or discourage other approaches that similarly represent good engineering practice, or that may be acceptable to, or have been accepted by, appropriate bodies. Parties who wish to bring other approaches to the attention of the formulating committee to b
21、e considered for inclusion in fuane revisions of this Bulletin are earnuraged to do so. It is the intention of the formulating committee to revise and update this Bulletin fi-om time to time as may be occasioned by changes in technology, industry practice, or government regulations, or for other app
22、ropriate reasons. I (Formulated under the cognizance of TIA TR-14.11 subcommittee on “Interference Criteria for Microwave Systems“.) vi TIA ”SB 10-F Preface The first edition of this document, Indusrrial Elecponics Bulletin (EB) IO-A dated July 1972, was proctucedby a working group of committee “R-1
23、4.11 of the Electronic Industries Association (EM), and after consultations with user groups was endorsed by the representatives of the Operational Fixed Microwave Council (OFMC). It was submitted to the FCC as a recommendation of the joint OFMCEIA task force. The second edition, IEB IO-B dated Marc
24、h 1973, added an Appendix on “Interference Calculation Considerations” prepared by the EIA working group as a guide for users. Some values of C/I (unfaded RF carrier-t or upgrade. Standard FCC channel assignments and pairings should always be the goal in new. microwave hops and systems. EIA TSBLO-F
25、94 3234600 0555393 937 TIA TSB 10-F Terms and Definitions Will be added in Bulletin 10-G. Index Will be added in Bulletin 10-G. ix TIA “SB 10-F - Blank Page - a X Section 1 Interference Criteria for Microwave Systems in the Merged Domestic Public Fixed Radio Services and Private Operational-Fixed Mi
26、crowave Service Bands 1.0 Introduction This Bulletin provides methodology and criteria for properly coordinating microwave radio systems in the merged (under FCC ET Docket 92-9) Domestic Public Fixed Radio Services and Private Operational- Fixed Microwave Service (POFMS) bands. These interference cr
27、iteria are based on levels of interference established in Parts 21 and 94 of the FCC Rules and Regulations. The first major section of this Bulletin is Section 2, Technical Considerations for Interference Analysis. Section 2 characterizes the various interfering signals (FM-FDM, FM-Video, Vestigial
28、Sideband Video, and Digital) and explains the considerations in calculating this interference into victim receivers (FM- FDM, FM-Video, Vestigial Sideband Video, and Digital). This edition of the Bulletin includes calculation methods for vestigial sideband AM Video but does not include tables or cal
29、culation methods for other types of vestigial or single-sideband AM interference. Section 3, Applications (Interference Calculations and Measurements), explains the methodology for making coordination calculations and shows sample calculations. The actual criteria for proper coordination are contain
30、ed in Section 4, Technical Considerations for Path Design. Annexes A-D contain additional information for those seeking more detailed background for the formulas and other information in the main ,part of this Bulletin. Annex F specifically addresses PCS- POFMS spectrum sharing considerations. Annex
31、 G discusses frequency coordination and notification procedures. 1-1 Section 1 TIA TSB 10-F - Blank Page - Section 2 Technical Considerations Analysis for Interference 2.0 Introduction This Section of the Bulletin describes in some detail most of the interfering signal types to which a “victim” (int
32、erfered-with) analog or digital microwave receiver might be exposed. The relative vulnerabilities of various analog and digital receivers to interference in main (CO- and adjacent-channel) response windows are characterized in equations and curves. Allowable levels of interference are provided to st
33、andardize the interference analysis. No matter how complex the total interference analysis, it always examines some number of individual potential exposures each of which must be resolved independently. Each such exposure involves one transmilter and one receiver, and the question to be answered is:
34、 “Does this transmitter interfere with . this receiver?” The question can be broken into two parts: 1. How much interference can the victim receiver tolerate before performance is unacceptably degraded? 2. Will the interference level fiom this transmitter into this receiver exceed the acceptable val
35、ue? In order to be able to resolve interference situations to the satisfaction of all parties concerned, it is necessary to have general agreement among users and frequency planners on the objectives, parameters, and calculation methods to be used. It is the purpose of this Bulletin to provide this
36、information. The tables, curves and equations in this Bulletin deal with the first of the above two questions. They provide performance objectives and interference criteria for interference situations most likely to be encountered. The principles used for deriving these values can also be extended t
37、o cover other situations as the need arises. The second question is addressed by interference level calculation methods state in Section 3 of this Bulletin. 2.1 Receiver Spurious Response Interference Windows The kinds of low level interference treated in this Bulletin are what might be called recei
38、ver “main response” interferences. Interference between two different systems, and overshoot and adjacent path types of intra-system interference, are ordinarily the only types that need to be considered. However there are also several analog and digital receiver “spurious response” windows especial
39、ly sensitive to higher level intrahop and intrastation interference sources. The more significant of these spurious receiver responses, in descending order of importance, are: 2-1 Section 2 TIA TSB 10-F F0 F0 F0 where: f mice the IF (the image frequency, one or the other depending on local oscillato
40、r position), f one-half the IF (one or the other depending on local oscillator position), and f IF (one or the other, since balanced mixers should “notch out” FM-FDM and reduce digital signal interference on the local oscillator frequency) “F,” is the wanted RF carrier frequency and “IF” is its firs
41、t IF frequency. An interfering signal in any of these spurious response windows may produce baseband noise in an FM-FDM receiver, tonal interference in a video receiver, and threshold degradation in a digital receiver, the amount depending on relative strengths of the wanted and unwanted signals at
42、the receiver mixer. Receiver RF filtering ahead of the mixer provides protection against these types of interference by attenuating the unwanted signal but allowing the wanted signal to pass. Microwave receivers in communication systems can be assumed to have sufficient attenuation to make spurious
43、response insignificant as far as interhop interference is concerned because of the relatively small levels of these distant unwanted signals. In fie case of a local (intrastation) interfering transmitter, however, the unwanted signal can be of far higher magnitude. It is therefore undesirable to ass
44、ign a transmitter to a frequency on or adjacent to a collocated receivers spurious response window especially if operating over, or to a lesser extent in close physical proximity to, the receive antenna. Also, intrastation DACI (direct adjacent channel interference) may generate intelligible (and th
45、erefore very disturbing) crosstalk between FM-FDM systems, if a very high level interfering signal falls on the victim receivers RF filter skirt, via the “slope detection” FM to AM conversion mechanism. DAC1 may occur at “bucking” stations where the FCCs high-low band separation of transmit and rece
46、ive frequencies is violated and an interfering transmitter and its antenna are very near (perhaps 20 MHz and 6 m) a collocated victim receiver and its antenna. Another type of intrastation spurious interference can occur when the outputs of two or more transmitters “mix” at bi-metallic or corrosion
47、points in common radio branching networks, waveguides, or antenna feeds to create RF intermodulation products, the most important being 2A-B and (in multiline systems) A+B-C third order products. These conversion products can increase noise in FM-FDM links and degrade analog and digital receiver thr
48、esholds in multiline systems where two or more transmitters (A, B, etc.) operate on the same antenna with their corresponding receivers. Unless separate transmit and receive antennas are used, a common practice in some long-haul systems, frequencies should be chosen so these products do not fall on
49、or near (perhaps within *20 MHz) of any receiver frequency. Receiver spurious response considerations play an important part in the development of suitable frequency plans. The FCC has established standard frequency plans and T-R separations which take these responses into account which, if followed, should make them unimportant. If nonstandard plans are used, spurious response as well as main response interferences should be studied for each case. Multiline systems are susceptible to additional sources of potential self-interference such as direct adjacent channel interference
