1、ETSI TR I O1 205 1.1.2 (2001-07) Technical Report Digital Video Broadcasting (DVB); LMDS Base Station and User Terminal Implementation Guidelines for ETSI EN 301 199 2 ETSI TR 101 205 V1.1.2 (2001-07) Reference RTWJTC-DVB-119 Keywords broadcasting, digital, DVB, interaction, TV, video ETSI 650 Route
2、 des Lucioles F-O6921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 O0017 - NAF 742 C Association but non lucratif enregistre la Sous-prfecture de Grasse (06) No 7803/88 Important notice Individual copies of the present document can be downloaded
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5、able at If you find errors in the present document, send your comment to: editoretsi .fr 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. O European Telecommunications Standar
6、ds Institute 2001. O European Broadcasting Union 2001. All rights reserved. ETSI 3 ETSI TR 101 205 V1.1.2 (2001-07) Contents Intellectual Property Rights 5 Foreword 5 Introduction 5 1 2 3 4 4.1 4.2 4.3 5 5.1 5.1.1 5.1.2 5.2 5.3 6 6.1 6.1.1 6.2 6.2.1 6.2.2 6.2.3 6.2.4 7 7.1 7.1.1 7.1.2 7.2 7.2.1 7.2.
7、2 Scope 7 References 7 Abbreviations . 7 Actual and Future Relations between LMDS and other Network Scenarios . 8 Satellite Segments as an example . 8 CATV Networks as an example . 8 Terrestrial Networks as an example . 8 Use of the LMDS Spectral Resource . 9 Capacity Comparison of the different Ser
8、vices . 9 Re - Broadcasting of a second space segment . 10 Bandwidth On-Demand . 11 The Implementation of Return Channels for User Interaction . 11 LMDS Channel Use 12 Modulation and Channel Coding 12 Definition of a Possible Spectrum Structure . 13 The First Way To Exploit the Resource at 40 GHz 13
9、 Re - Broadcasting of a first satellite space segment . 10 Channel Characteristics at 40 GHz . 12 Alternative Use of the Resource . 14 Other RF Resources . 15 Mesh Systems 15 Propagation Parameters and Cell Size . 16 Atmospherical Attenuation . 16 Reflection/Refraction . 17 Link Budget 18 General 18
10、 Basic Relations 18 The Propagation of Millimetric Waves . 16 7.2.2.1 C/N Margin 18 7.2.2.2 Antennas 19 7.2.2.2.1 Antenna of the User Terminal 19 7.2.2.2.2 Antenna of the Base Station . 20 7.2.2.3 Waveguides 22 7.2.2.4 Low Noise - Amplifier 22 7.2.3 Link Budget/Details . 23 7.2.3.1 Downstream . 23 7
11、.2.3.3 Codec Influence 26 Specification of Power and Frequency Resource 26 7.3.1 Downstream . 26 7.3.2 Upstream . 27 7.3.3 Power Control 27 7.3.4 Frequency Control . 29 7.3.5 Other Modulation Schemes 29 8 Cell Cluster Structures and Cell Planning 30 8.1 Cluster Structures 30 8.2 Cell Planning . 32 7
12、.2.3.2 Upstream 25 7.3 ETSI 4 ETSI TR 101 205 V1.1.2 (2001-07) 9 Connectivity to other Networks . 33 10 Backbones 34 11 Radiation Safety . 34 Annex A: Recommended Frequency Raster 36 History . 46 ETSI 5 ETSI TR 101 205 V1.1.2 (2001-07) Intellectual Property Rights IPRs essential or potentially essen
13、tial 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 O00 3 14: “Intellectual Property Rights (IPRs); Essential, orpotentially Essential, IPRs notjed
14、 to ETSI in respect OfETSIstandards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (htt:/!wvw.etsi ordj r). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to th
15、e existence of other IPRs not referenced in ETSI SR O00 3 14 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by Joint Technical Committee (JTC) Broadcast of the European Broadcasting
16、 Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). NOTE: The EBU/ETSI JTC Broadcast was established in 1990 to Co-ordinate the drafting of standards in the specific field of broadcasting and related fields. Since 19
17、95 the JTC Broadcast became a tripartite body by including in the Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and television receivers. The EBU is a professional association of broadcasting organizations whose work includes the Co-ordination of its
18、 members activities in the technical, legal, programme-making and programme-exchange domains. The EBU has active members in about 60 countries in the European broadcasting area; its headquarters is in Geneva. European Broadcasting Union CH-I218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21
19、11 Fax: +41 22 717 24 81 Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations in the television industry. Its aim is to establish the framework for the introduction of MPEG-2 based digital television services. Now comprising over 200 organi
20、zations from more than 25 countries around the world, DVB fosters market-led systems, which meet the real needs, and economic circumstances, of the consumer electronics and the broadcast industry. Introduction LMDS as a system concept is also well-known under the expressions of “Wireless Cable“, “MW
21、S“ (Multimedia Wireless Systems“) and “Last Mile Distribution System“. It is important to state here that LMDS shall in many cases be an extension to: Satellite Cable 0 Terrestrial Data Framing structure, channel coding and modulation for 11/12 GHz satellite services“. la1 ETSI EN 301 199 (V1.2.1):
22、“Digital Video Broadcasting (DVB); Interaction channel for Local Multi-point Distribution Systems (LMDS)“. Electronics Framing structure, channel coding and modulation for cable systems“. ETSI ES 200 800: “Digital Video Broadcasting (DVB); DVB interaction channel for Cable TV distribution systems (C
23、ATV)“. CEPT/ERC/REC 13-04: “Preferred frequency bands for fixed wireless access in the frequency range between 3 and 29.5 GHz“. 71 SI 91 3 Abbreviations For the purposes of the present document, the following abbreviations apply: AGC AWGN BWS DTH EIRP GPS LMDS LNA MWS NVoD Automatic Gain Control Add
24、itive White Gaussian Noise Broadband Wireless Systems Direct-To-Home Effective Isotropic Radiated Power Global Positioning System Local Multipoint Distribution System Low Noise Amplifier Multimedia Wireless Systems Near Video on Demand (= Time shifted equal contents) ETSI 8 ETSI TR 101 205 V1.1.2 (2
25、001-07) 4 Actual and Future Relations between LMDS and other Network Scenarios 4.1 Satellite Segments as an example Nowadays the best-known satellite systems for TV transmission are the so-called geo-stationary satellite networks permitting the simple DTH distribution by using a 60 cm dish antenna f
26、or multi-program reception. The dominating frequency band is the so-called Ku band (10,7 GHz to 12,75 GHz down link) in Europe. Usual satellite segments are operating within this resource. These systems have similar transponder carrier positions and also the usable bandwidth is in most cases the sam
27、e. Frequency re-use is achieved in a simple way by polarization and the directivity of the receive antenna. It is reasonable to expect that the number of satellite systems will increase rather than decrease in addition to the fact that new multi media applications will occupy a part of the whole sat
28、ellite scenario with the consequence that the terrestrial last-mile scenario has to cope with this. E.g. the useful bit-rate I per transponder is given by: n 188 m 204 I=R XX-X- with Rsy being the symbol rate, n/m depicting the convolutional code rate and 188/204 being the Reed-Solomon code rate in
29、EN 300 421 i (DVB-SAT). E.g. if the convolutional code rate is set to 3/4 and the symbol rate is 27,5 MSy/s we obtain a useful bit-rate of 38 Mbit/s. 4.2 CATV Networks as an example CATV networks are determined by the QAM modulation in TV and by the in-band down-streams. This has to be noted when su
30、pplying the last mile with cable born contents. The frequency resource occupies approximately 800 MHz. The scenario of re-modulating satellite channels to cable is well-known and is done at IF. Thus no additional exotic equipment but rather truly off-the-shelf re-modulators can be implemented. E.g.
31、the bit-rate for an in-band downstream and QAM is given by: 188 I = Rsy x Zd(A4) x - 204 with Rsy again being the symbol rate. Now ld(m) expresses the number of bits used by an M-ary QAM alphabet (EN 300 429 7 applies in this case). E.g. the symbol rate is given with 6,95 MSy/s (in an 8 MHz CATV cha
32、nnel) and the constellation shall be 64 QAM we also obtain a useful bit-rate of 38 Mbit/s. Thus a satellite channel like above can be re-modulated into this CATV channel or, similarly this cable downstream channel can be re-modulated into an LMDS embedded downstream of 27,5 MSy/s. 4.3 Terrestrial Ne
33、tworks as an example Terrestrial digital TV networks are operated using the so-called COFDM on-air. Despite this the “last mile“ is bridged in most cases by the terrestrial service itself and situations are imaginable which require a re-modulation to LMDS. ETSI 9 ETSI TR 101 205 V1.1.2 (2001-07) E.g
34、. the bit-rate for terrestrial TV channels is given by: with: Ri,: The useful net data rate (Mbit/s); Rs : The symbol rate; b: The number of bits per subcarrier; CRcoNv: The inner (convolutional) code rate; CRRs: The outer (Reed-Solomon) code rate, 188/204 = 0,9216; TU: The duration of the useful sy
35、mbol part; T,: The entire symbol duration, including guard interval. E.g. if the symbol rate is 6,75 MSy/s (fitting into one 8 MHz UHF channel), the convolutional code rate is 3/4 , the modulation is QAM (4 bitdsubcarrier) we obtain a useful net bit rate of 14,93 Mbit/s. The maximum possible DVB-T d
36、ata rate is at 64 QAM, CRcoNv = 7/8 and a guard interval of 1/32 indicated with 31,67 Mbit/s. In this maximum case one LMDS channel of e.g. 38 Mbit/s is filled with exactly one DVB-T channel. But due to the bad link budget for DVB-T this is expected to occur very seldom. On the other hand, the minim
37、um DVB-T data rate can be at CRcoNv = 1/2, QPSK modulation and a guard interval of 1/4 indicated with 4,98 Mbit/s. This means that the LMDS modulation scheme is wide enough also to contain one or more DVB-T channels within one of its channels. 5 5.1 Use of the LMDS Spectral Resource Capacity Com par
38、ison of the different Services As described above the re-broadcast satellite or cable or terrestrial born TV channels would previously dominate the resource use. On the other hand the user of the last mile system really does not want a separate satellite antenna incorporating additional switching -
39、and maintenance problems. Additionally the realization of interaction would become rather complicated. This means as a consequence that re-broadcasting will be a basic element of the last-mile scenario even when, at first, interaction is not demanded (MVDS). First, as an example, a possible bandwidt
40、h application is demonstrated which is possible to become a main candidate also for the last mile scenario. ETSI 10 ETSI TR 101 205 V1.1.2 (2001-07) 5.1 .I Re - Broadcasting of a first satellite space segment Low Band (SUBSEG. 1D - 1B) H - Polar: Low Band (SUBSEG. 1D - 1B) V - Polar: Sum: 2GHz 10,7
41、. 11,7 GHz, sum: 1 GHz, 10,7 . 11,7 GHz, sum: 1 GHz, High Band (SUBSEG. 1E - 1G) H - Polar: High Band (SUBSEG. 1E - 1G) V - Polar: Sum: 2GHz 11,7 . 12,75 GHz, sum: 1 GHz, 11,7 . 12,75 GHz, sum: 1 GHz, As a whole: 4 GHz 5.1.2 Re - Broadcasting of a second space segment Low Band (SAT type 1,2,4, SUBSE
42、GMENT 1/11) H - Polar: 10,7 . 11,7 GHz, sum: 1 GHz, Low Band (SAT type 1,2,4, SUBSEGMENT 1/11) V - Polar: 10,7 . 11,7 GHz, sum: 1 GHz, High Band (SAT type 2,3,4, SUBSEGMENT I) H - Polar: 11,7 . 12,75 GHz, sum: 1 GHz, High Band (SAT type 2,3,4, SUBSEGMENT I) V - Polar: 11,7 . 12,75 GHz, sum: 1 GHz, A
43、s a whole: 4 GHz This means, that if todays satellite space segments are reproduced by LMDS one would obtain 2 GHz per segment and polarization. However, the problem is now being discussed at the European regulation offices to extend the range of 40,5 GHz - 42,5 GHz to 43,5 GHz. This could, as one s
44、cenario, enable one fll satellite segment re-broadcasting together with return channels for a sufficient number of subscribers. Table 1 shows an example of simulcasting a satellite transponder (“Backhaul Source“, German Content) which is after transconversion laid upon one of the 40 GHz downstream c
45、hannels. In this case the transponder “65“ is alternatively shared by NVoD services and car race events (“Formel 1 Konfiguration“) consuming certain highlighted bit rates. The NVoD services consist of time-shifted videos (feed 1 to 5) with 4,22 Mbit/s, the car race contents reveal different views of
46、 the race scenery like “Supersignal“ (= Overview), “Cockpit“ etc. with less compressed (5,44 Mbit/s) pictures. Tables like “Renndaten“ (= race results) only carry very slow motion contents and are compressed to 2,44 Mbit/s. It is clearly shown that the whole data transport stream composes up to 38 M
47、bit/s at a convolutional FEC of 3/4 and a symbol rate of 27,5 Msy/s including Operating System Downloads for different set top boxes and data overheads for System Information (SI) and, optionally, Conditional Access (CA). In both cases a residual bandwidth (“Restbandbreite“) is open for additional s
48、ervice insertion, intermediately filled with stuffing bytes. ETSI 11 ETSI TR 101 205 V1.1.2 (2001-07) Table 1 : Satellite Re-Broadcast Thus an LMDS base station can act as a satellite-like device providing the transmission service for different providers by using a plenty of backhaul sources. 5.2 Ba
49、ndwidth On-Demand Another possible spectrum use may be the broadcast of content to a user individually. This option is feasible because of the frequency re-use from one cell to another: the goal of this mode may be to use the resource most efficiently when e.g. contents being demanded very seldom can be transmitted via an individual small- bandwidth carrier instead of broadcasting the content to everybody. The remaining resource can then be used for other applications to provide contents. For this either individually a server is necessary in the base station or th
