1、 ETSI TS 101 574 V1.1.1 (2011-11) Access, Terminals, Transmission and Multiplexing (ATTM); System characteristics of receiver equipment installed in headends of integrated broadband cable and television networks intended to receive broadcast signals in the frequency range 470 MHz to 790 MHz Technica
2、l Specification ETSI ETSI TS 101 574 V1.1.1 (2011-11)2Reference DTS/ATTM-003017 Keywords cable, CRS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous
3、-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between su
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6、_support.asp 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 2011. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETS
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8、1.1.1 (2011-11)3Contents Intellectual Property Rights 4g3Foreword . 4g31 Scope 5g32 References 5g32.1 Normative references . 5g32.2 Informative references 5g33 Definitions, symbols and abbreviations . 5g33.1 Definitions 5g33.2 Symbols 6g33.3 Abbreviations . 6g34 Background 6g34.1 Cable System Archit
9、ecture . 6g34.2 Frequency Allocations 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, i
10、ncluding 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
11、) has been produced by ETSI Technical Committee Access, Terminals, Transmission and Multiplexing (ATTM). ETSI ETSI TS 101 574 V1.1.1 (2011-11)51 Scope The present document defines system characteristics of the receiving equipment used in cable headends including but not limited to receiver noise fig
12、ure, antenna gain, signal-to-noise ratio, etc. 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 refe
13、rence 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 guara
14、ntee their long term validity. 2.1 Normative references The following referenced documents are necessary for the application of the present document. Not applicable. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they a
15、ssist the user with regard to a particular subject area. i.1 ETSI TR 102 881 (V1.1.1): “Access, Terminals, Transmission and Multiplexing (ATTM); Cable Network Handbook“. i.2 ETSI EN 300 744: “Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for digital terrestrial t
16、elevision“. i.3 United States Code of Federal Regulations, Title 47, Part 15, Subpart H: “Television Band Devices“. i.4 FCC 10-174: “Second Memorandum Opinion and Order in the Matter of Unlicensed Operation in the TV Broadcast Bands“, September 23, 2010. i.5 ETSI TS 102 639 (April 2009): “Access and
17、 Terminals, Transmission and Multiplexing (ATTM);Third Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems“. 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: cable dro
18、p: small gauge coaxial cable that connects the customer premises to a tap NOTE: This may contain additional information. fibre node: device which performs a media conversion between a fibre link and a coaxial link in an HFC network ETSI ETSI TS 101 574 V1.1.1 (2011-11)6headend: cable operator facili
19、ty where video signals are received and launched into the cable access network tap: device having coaxial cable connections that splits downstream input RF signals among various output connections 3.2 Symbols For the purposes of the present document, the following symbols apply: MHz megahertz dB dec
20、ibel(s)m meter(s) km kilometer(s)dBm decibel referenced to 1 milliwatt kW kilowatt 3.3 Abbreviations For the purposes of the present document, the following abbreviations apply: COFDM Coded Orthogonal Frequency Division Multiplexing DVB-T Digital Video Broadcast - Terrestrial FCC United States Feder
21、al Communications Commission HFC Hybrid Fibre/Coax MVPD Multi-channel Video Programming Distributor NCTA National Cable up to 20 dB with sophisticated antenna configurations Mounting height 20 m 12 m to 35 m 5.1.2 Directional Patterns Figure 2 depicts a sample directional pattern for a log periodic
22、antenna typically used in Cable headend receivers. Figure 2: Sample Antenna Directional Pattern ETSI ETSI TS 101 574 V1.1.1 (2011-11)95.2 Receiver Characteristics Table 2 gives the main parameters required for professional receivers used in Cable headend installations. Table 2: Receiver Characterist
23、ics Parameter Typical Value Value Range Input level -65 dBm to -25 dBm -80 dBm to -10 dBm Modulation COFDM(DVB-T/T2) Noise figure 5 dB 3 dB to 8 dB Suppression of OOB signals 40 dB (for adjacent carriers) 50 dB to 60 dB (for others) 5.3 Resulting Receiver System Characteristics The combination of hi
24、gh gain antennas and professional receiving equipment with high sensitivity and noise performance allow for terrestrial receivers installed at Cable headends to acquire and demodulate TV station signals that are well beyond the service area of the TV transmitter as defined for a residential terrestr
25、ial receiver. An example link budget, which illustrates this point is provided in annex B. 6 Deployment Scenarios System characteristics of headend receivers as analyzed in clause 5 allow Cable headends to be located outside the area in which a TV transmitter is able to serve residential equipment a
26、nd still receive terrestrial broadcasting services. Redistribution of those TV services through the cable television network even further enlarges the geographical area where customers are able to consume the TV service. Figure 3 depicts a typical scenario for cable headend installations in- and out
27、side the residential service area of a terrestrial transmitter. Subscriber X, located outside the GE06 area, consumes the broadcast TV services by way of a professional cable headend receiver, thus extending the serving area of the terrestrial broadcaster. ETSI ETSI TS 101 574 V1.1.1 (2011-11)10Terr
28、estrial Transmitter Cable Headend Cable Headend Cable Headend Residential equipment serving area Professional equipment serving area Cable Headend Figure 3: Cable headends in- and outside the residential equipment serving area of a terrestrial TV transmitter Subscriber X ETSI ETSI TS 101 574 V1.1.1
29、(2011-11)11Annex A (informative): Protection of Cable Headend Receivers In many regions, the terrestrial television broadcast bands are subject to licensing, and license holders are protected from interfering signals within a defined area surrounding the broadcast antenna. The outer boundary of the
30、protected area is known as the broadcast contour for the station. The licensing authority seeks to assign frequency licenses to stations to ensure that receiver locations within the broadcast contour for each station are assured that they can receive the stations signal without disruptive interferen
31、ce from other users of that frequency or adjacent frequencies. In order to achieve this, the licensing authority ensures that other licensees for that frequency and the adjacent frequencies are a sufficient distance away from the broadcast contour of the station in question. For each frequency in th
32、e broadcast band, the result from a geographic perspective can be a set of “islands“ of licensed use within a sea of “white space“. Conversely, any selected geographical location may be within the broadcast contour for some number of stations, each transmitting on its licensed frequency, and the rem
33、aining frequencies are essentially unused. In certain regions these unused frequencies, or “white spaces“ are currently planned to be used for radiocommunications, primarily for data services. Such usage is expected to be unlicensed on a non-exclusive and non-protected basis. Therefore it will be su
34、bject to rules that, for example, require users to avoid frequencies that are in use by the licensed broadcasters. In the United States, for example, the US Federal Communications Commission (FCC) has defined rules allowing unlicensed “Television Bands Devices“ (TVBDs) to operate on most frequencies
35、 of the television broadcast band, providing that they consult a “geo-location database“ in order to determine which frequencies are available for use in their present location. The geo-location database therefore contains data about the licensed users of the television band, along with the geograph
36、ical information about the broadcast contour for each licensee. In addition, the FCC has allowed that certain other areas can be protected via registration with the geo-location database. For example, the FCC has allowed that performance venues that use low-power wireless microphones can be register
37、ed. Furthermore, certain professional sites which receive broadcast transmissions, but which fall outside the broadcast contour for a licensed terrestrial broadcaster, can be registered and provided with a protection contour in order to assure continued reliable use of the terrestrial broadcast sign
38、al. The FCC has determined that such sites, which include cable headends, shall be protected as follows i.3, (Part 15, Section 712, paragraph b): “TV translator, Low Power TV (including Class A) and Multi-channel Video Programming Distributor (MVPD) receive sites. MVPD, TV translator station and low
39、 power TV (including Class A) station receive sites located outside the protected contour of the TV station(s) being received may be registered in the TV bands database if they are no farther than 80 km outside the nearest edge of the relevant contour(s). Only channels received over the air and used
40、 by the MVPD, TV translator station or low power/Class A TV station may be registered. TVBDs may not operate within an arc of 30 degrees from a line between a registered receive site and the contour of the TV station being received in the direction of the stations transmitter at a distance of up to
41、80 km from the edge of the protected contour of the received TV station for co-channel operation and up to 20 km from the registered receive site for adjacent channel operation, except that the protection distance shall not exceed the distance from the receive site to the protected contour. Outside
42、of this 30 degree arc, TVBDs may not operate within 8 km from the receive site for co-channel operation and 2 km from the receive site for adjacent channel operation. For purposes of this section, a TV station being received may include a full power TV station, TV translator station or low power TV/
43、Class A TV station.“ ETSI ETSI TS 101 574 V1.1.1 (2011-11)12Additionally, the FCC has allowed for operators of existing sites located more than 80 km from the edge of the broadcast contour to apply for a waiver of the rules, so that those sites can be registered in the geo-location database as well
44、i.4: “42. We recognize that there are cable headends that receive TV station signals located at distances beyond 80 km from the edge of a television stations protected service contour and understand NCTAs concern for possible disruption service to cable subscribers. These same considerations would a
45、pply to other MVPDs and to TV translator, low power TV and Class A TV stations that re-transmit programming from another TV station. We do not believe that the requested change would have significant impact on the availability of TV white space because these facilities are generally in remote areas
46、where many channels will be available for white space devices. However, we also recognize that parties may wish to have an opportunity to review such requests to confirm the assessment. We are therefore providing that current MVPD operators, TV translator, low power TV and Class A TV stations with r
47、eceive sites located beyond the 80 km co-channel protection distance in the rules may apply for a waiver of that distance during a period that will end 90 days after the effective date of the rules adopted herein. Such waiver requests would also involve shifting the 20 km adjacent channel protection
48、 distance so that it is measured from the actual receive site. We will then issue a public notice requesting comment on requests we receive and issue decisions. MVPD operators and TV translator, low power TV and class a TV stations that commence operation in the future with receive sites located bey
49、ond the co-channel and adjacent protection distances may apply for a waiver of those distances within 90 days of commencing operation. Following receipt of such request(s), we will then issue a public notice asking for comment on the request(s) and issue decision(s).“ Figure A.1 illustrates the protection regions defined by the FCC for professional receive sites. Figure A.1: Adjacent and Co-channel Protection Regions Defined by the US Federal Communications Commission ETSI ETSI TS 101 574 V1.1.1 (2011-11)13Annex B (informative): Example Link Budget Calcula
