310 likes | 875 Views
Digital Switchover:-. By Murray Niman G6JYB. Digital Switchover. Digital Switchover is the adoption of DVB - Digital Video Broadcasting The end of all UHF Analogue Television Every ordinary TV and Video Recorder affected. Function will be lost unless adapted or replaced
E N D
Digital Switchover:- ByMurray Niman G6JYB
Digital Switchover Digital Switchover is the adoption of DVB - Digital Video Broadcasting • The end of all UHF Analogue Television • Every ordinary TV and Video Recorder affected. • Function will be lost unless adapted or replaced • Replacement Sources maybe any combination of Digital Terrestrial, Cable, Satellite, and now Broadband (Homechoice) • Digital Terrestrial Television (DTT) is Freeview (and TopupTV) • Prospect of Freesat from BBC/ITV - not Sky! • UK is over 50% Digital ready - 7 million have Sky, 4 million on Freeview ( growing at 40000 units/wk) - see later for Radio Broadcasting
Digital Around The World • We are not alone . . . • DVB is widespread • US is ATSC • UK takeup is a leader • Berlin already Digital only
Why Switch? • Digital terrestrial transmission allows at least four times the number of services available as analogue on the same bandwidth • Current Analogue TV restricts digital terrestrial coverage and signal strength; 20-25% of households are unable to receive digital terrestrial. These homes will only be able to get digital TV through an aerial when we switch off analogue transmissions • Improved transmission efficiency - services now available on DTT will only use two-thirds of the spectrum currently used in analogue • Spectrum can be released for new services such as for broadcasting, interactive services or mobile communications. Examples: DVB-H, but HiDef-TV unlikely • Broadcasters will save on transmission costs (by ending the duplication and will not have to pay for upgrading the present analogue transmitters which would need major investments to keep running • Estimates of net benefits are in the billions of pounds, and also coincides with lower cost and newer consumer electronics - such as the end of the video tape recording • Its not just a UK thing - we don’t wont to be left behind….
Freeview • Digital Television via your aerial • BBC/CrownCastle/BSkyB joint venture, replaced ITV Digital. • Just needs a DTV Adapter or an iDTV and card compatibility if you want TopupTV • Will be the only TV via an aerial after Analogue shutdown • Channels are transmitted in Multiplexes, interleaved between existing Analogue TV Analogue: 5 Channels (A few sub carriers AM, FM, PM modulation) Freeview: 6 Multichannel Multiplexes, with 4-8 video channels each (1705 subcarriers/COFDM - 18 or 24 Mb/s)
Freeview Video Channels Mux-1 (BBC)Mux-2Mux-A (SDN) BBC-1 ITV-1,2,3 five (Ch5) BBC-2 ITV-News QVC BBC-3/CBBC Ch4 , More-4 Bidup, PriceDrop BBC-News24 E4 ? abc1 (plus TopupTV) Mux-B (BBC)Mux-CMux-D BBC-4/CBeebies UK History TMF BBCi Video(701/2) Sky News The Hits BBC Parliament Sky Sports News FTN / UKBrightIdeas Community Sky Travel Ideal World Over 20 radio stations as well Ofcom has recently designated Mux 1, 2, Bas Public Service Broadcast (PSB) multiplexes - So Ch5 may need to move as part of Switchover
ITV BBC2 CH5 BBC1 CH4 2 1 B D A C London TV Transmitter Powers • Crystal Palace & Croydon (Ch5) • Current Analogue = 1MW Peak, Digital = 20kW (17dB down) • Digital Channels are within enhanced Aerial Group-A • Raising digital powers further would start to interfere with Analogue • Close Analogue, move Digital to Analogue freqs which have international clearance for high power • Digital Powers will be within 6-10dB of current Analogue peaks Analogue Digital
UHF TV Channels: BLUE = Retained for TV RED = Released for Sale GREEN = Radar & Astronomy UHF Spectrum • UHF TV has 48 x 8MHz channels • Band IV 470-598MHz & Band V 598-854 MHz - 384 MHz total bandwidth • TV is regional , but goal is to free common spectrum across the UK • Plan is to release 14 UHF Channels:- 14 x 8 MHz = 112MHz released • Probably done as per below. • Upper Channels are adjacent to 2G Mobile Phones - 3G in future • Subject to confirmation at Europe Conference Implications: Crystal Palace ITV, BBC1, Ch4 can be reused for Full power Digital at 100-250kW, compared to 20kW at present
ITV 2 4 1 Analogue = Blue Digital = Orange 5 B 2 A 1 D C 2 Sudbury • Sudbury - Digital Powers are much lower relative to Analogue • Digital Channels are outside Aerial Group-B - need Group E for ITV/Ch4 • NB Sudbury-B on UHF Ch-68 can clash with Sky Boxes etc • Digital-Only Sudbury would be much higher power and less critical on need for wideband aerials Tx Power, dBW
Timetable for TV Switchover • Planning started years ago. ‘The Digital Television Project’ in DCMS • Will occur on a phased region by region basis. More detail in 2005 • Each TV Region will be given a 2 year warning, then phased switch switchover over 6months, probably starting with BBC2 • Probable start is 2007 in the Border/Tyne Tees TV region • Government has not officially confirmed the start date, but their agents have set the backstop deadline ! • Ofcom has issued DRLs - Digital Replacement Licences to all broadcasters which oblige them to be Digital Only by Dec-31 2012 • SwitchCo being formed by Ofcom along with huge PR budget • In Wales one area has already switched . . . • Timetable can be subject to politics - General Elections etc
Wales - The Ferryside Trial • Started Nov-2004 • Local relay for 250 homes converted to digital • Free boxes given to assess how well householders can install use, record • Analogue endsFeb 2005
Switchover Detail • Full Freeview is currently on 80 Transmitters at low power • Requirement is for similar 95%+ coverage - compared to the patchy 75% for Freeview at present • Transmitter powers will rise to within 6 or 10dB of analogue • Plan is that all 1154 transmitters will carry at least the three Public Service Broadcast (PSB) Muxes 1, 2, B. • Ch5 will probably be moved from Mux-A to Mux 2 or B • The 80 main transmitters and ~130 relays will have all 6 Muxes • Most relays will only have 3 PSB Muxes • Plans/Benchmarking for boxes, aerials, cable etc done
Hi Definition TV • Enhanced or Hi-Definition is 720 or 1080 lines:- • Freeview Plans are for Standard TV - not Hi-Def. But widescreens are supported • Hi-Def easier by Satellite & Cable as huge Bandwidth needed • BBC has asked for use of released Spectrum for Hi-Def • WARNINGS: • Sky Hi-Def in 2006 will encrypt signal on new interconnects so many new widescreen and flat panel TVs with Scart-only connections may be incompatible - no raw video! • DVD Disks will be superceded by Bluray or HD-DVD soon as well
Approved Aerials as at 9-Dec-2004 • Only certain aerials are approved for DTT • Approved Aerials have this Logo from the Confederation of Aerial Industries (CAI) • Beware of the Cowboys ! • Gain Standard: 1=Highest4=Lowest Antiference Ltd XG10EW Standard 2 Blake UK Ltd DMX10A Standard 1 DMX05WB Standard 2 DMX10WB Standard 2 DML26WB Standard 4 SR10WB Standard 3 SR13WB Standard 3 SR18WB Standard 3 VW5WB Standard 3 VW10WB Standard 2 Fracarro (UK) Ltd BLU420F Standard 2 BLU220+ Standard 3 Delta 500 Standard 3 Delta 800 Standard 2 LP45N Standard 4 Masterplug Ltd AERO6 Standard 2 AERO15 Standard 3 AERO16 Standard 2 Maxview Aerials ASY18W Standard 3 Philex Electronic 27869R Standard 3 Televès UK Ltd X43 Ref 8044 Standard 2 DAT45 Standard 2 Infinito 1126 Standard 3 Triax UK Ltd Unix 52 CDW Standard 2 Vision V10-LP SUPER Standard 4 V10-321 CDW Standard 3 V10-481 CDW Standard 2
Cables & Connections • Only CT100, 125 and 165 is approved - CAI have a Cable list as well. • Good quality double-screened coaxial cable of a type approved under the CAI cable benchmarking scheme is recommended for the aerial downlead and for all RF connections between equipment within the household. • Inferior cable with poor screening, often referred to as “low loss”, should be avoided as it will almost certainly result in an increased susceptibility to impulse interference. • Unless the level of the signal on a down lead is very high, it is strongly recommended that a replacement cable of an approved type should always be fitted. • Coaxial fly leads should conform to BS EN 60966-2-4:1997. • “F” connections should be crimped type taking care to choose the appropriate “F” connector to match the diameter of the coaxial cable.
TV-Anytime Recording . . . • Ideally Recorders need their own tuner so it can record whilst you watch something else • Trend will be to Disc based recording - either DVD or Hard Drive • Some Freeview boxes feature hard drives like SkyPlus • Many DVD recorders are Analogue only tuners! • Issue with Programme Delivery Control - PDC is Analogue only • Freeview Recorders can use Programme Guide and Signal Info • Look for full 8 Day EPG support. Many boxes haven’t had their software updated for full EPGs . . . . . . and in the near future this:
So, Be Careful . . . • You need to think about digital switchover today as it will happen in the lifetime of any new TV or video recorder that you buy now. • Equipment only qualifies for Logo if it is 2K/8K carrier compatible etc- ITV Digital boxes do not qualify - were 2000 carrier only • Modern hardware has a 8000 carrier COFDM receiver (eg for better interference immunity, SFN TV relays) • Use cheap adapters if unsure of software support. • Switch to Digital before you get Switched Off !
Radio Switchover- the end of AM & FM ?In the UK Digital Radios Sales outstrip analogue by £valueOne million DAB radios so far sold in the UK and rising rapidly
Radio Switchover may also include some limited use of DRM RDS, Popular in Cars, is NOT Digital Radio merely Enhanced Analogue FM Digital Radio The UK is a leader in deploying Eureka-147:- - Digital Audio Broadcasting - DAB
DAB in Chelmsford Area • Coverage improved significantly in 2004 • Good aerials can also pick up London & Kent giving 50+ stations • Current Multiplexes are 11B: 218MHz to 12D:229MHz • National Multiplexes don’t need retuning - they are Single Frequency Networks - SFNs • Proposed new frequency blocks are 10A: 209MHz to 11A:217MHz
Buying DAB • Considerable choice in shops and prices are dropping • Check DAB specs for frequency band coverage • Is it all Band III or just UK only • Does it support L-Band (not crucial) • Can its firmware be updated (Some have USB ports) • Future EPG and Graphics may need software updates • Integration with MP3 players, mobile phones • Pause/Record/Playback live radio now featuring
DAB Spectrum • DAB Coverage currently 85% but has gaps esp. for regional services • DAB currently uses 7 Blocks (11B-12D) in Band-III • Ofcom Consultation on 15-Dec-2004 to displace PMR to release 4 or 5 additional blocks: 10A to 11A - will pressure other VHF/UHF allocations • Deadline for responses is 7-Mar-2005 • L-Band also available for DAB but not in use in the UK • BBC Submission requested extra space for quality not quantity • BBC suggest to start preparation for a Switchover Review in 2008 • Need to review status of Long Wave for National Emergencies • NB Issue with DAB L-Band vs Worldspace • Worldspace: 1467-1492 MHz • DAB L-Band: 1452-1490 MHz
TLAs - Three Letter Acronyms • TLAs:- • PSB - Public Service Broadcasting • DTT - Digital Terrestrial Television • DRLs - Digital Replacement Licences • SFN - Single Frequency Network - BBC/National DAB is a SFN • DVB-T, DVB-H - Digital Video Broadcasting • DAB-S, DAB-T - Digital Audio Broadcasting (Satellite, Terrestrial) • SFR - Spectrum Framework Review • ACC - Adaptive Cruise Control, - uses SRR and LRR • SRR/LRR - Short /Long Range Car Radar on 79 or 24GHz • UWB - Ultra Wideband • SDR - Software Defined Radio • BPL - Broadband over Power Lines - USA • PLT - Power Line Telecoms - UK
Threats to Amateur Radio • Most attention so far on Broadband over Powerlines • BPL - Broadband over Power Lines - USA • PLT - Power Line Telecoms - UK • Data can be Voice, Internet TV • In use by Southern Electric • Raises noise floors etc over most of HF bands • Now a whole new set of threats is on us now. . . • Ofcom - no amateurs, purely commercial, attracted by £1m/MHz
Ofcom Spectrum Framework Review • Spectrum Framework Review (Deadline Feb-15) • Advocates total disregard of all international rules in the interest of national flexibility • Suggest that 60% of all spectrum is tradable • Is in favour of Software/Cognitive Radio that could potentially operate on top of amateurs without warning • Proposes to withdraw from CB, Amateur, Maritime licensing • Proposes to simplify access to entrants - barely after new licence structure is in place • Has caught RSGB totally off guard, with a weaker structure • All amateurs and clubs are urged to reply • Original Documents on www.ofcom.org.uk • Easier to download from www.essexrepeatergroup.org.uk
Ofcom Car Radar Review • 77GHz already used for Adaptive Cruise Control - ACC • New Consultation in Dec-2004 on 79GHz and 24 GHz bands for Car Short Range Radar - in Primary Amateur Bands • For Parking, Pedestrian/Crash Avoidance, Lane Control, Platooning etc • Ofcom did not check their own docs and stated that no one used these bands at all! • - correction now issued! • BUT DEADLINE IS JAN-14!
References • Ofcom: www.ofcom.org.uk • Digital Television Project: www.digitaltelevision.gov.uk • Freeview: www.freeview.co.uk • BBC Digital: www.bbc.co.uk/digital/ • Digital Television Group (DTG): www.dtg.org.uk(Better for Postcode searches than Freeview) • Confederation of Aerial Industries (CAI): www.cai.org.uk • TV Anytime: www.tv-anytime.org • Digital Spy: www.digitalspy.co.uk (Terrestrial Section) • Newsgroups: uk.tech.digital-tv, uk.tech.broadcast, alt.radio.digital
TV Transmitter Frequencies/Powers • Note-1: Power levels not directly comparable, but Frequencies can be an issue • Note-2: Some parts of Essex can also receive Bluebell Hill in Kent TV Aerial Groups:- A: 21-37 Red B: 35-53 Yellow C/D: 48-68 Green E: 35-68 Brown K: 21-48 Grey W: 21-68 Black