The following pages list UK UHF DTT transmitters. These are arranged by region and then grouped into main stations with the relays in alphabetical order. The list includes all main sites (in bold), relays that carry the commercial multiplexes (COM) and other public service multiplexes (PSB) ( Freeview Lite ) of ERP 50 W or more. The list includes the implemented changes for the channel 61:62 800 MHz sell off for LTE, temporary HD and local television multiplex and local TVchannels ('local digital television programme services' or 'L-DTPS') High-definition services are included on both mux BBC B and the temporary HD Muxes. 98
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Key to Digital Television Transmitters Ant: Indicates the op mum aerial group and the signal polarisa on. Note this is based on a er channel 61:62 and takes into account the aerial group amendments. (See page 106). High-defini on services are included on both mux BBC B and the temporary HD Muxes. *Denotes Local Digital Television (L-DTPS) Loca on sites with baseline parameters - final design not yet available. The reference to the local mux L-xxx relates to the par cular loca on eg L-LON for London (see table). Ofcom awarded L-DTPS licenses for the following but technical parameters have yet to be confirmed for Cambridge and Scarborough. Ofcom will also be considering applica ons for local TV licences in Middlesbrough, Mold, Swansea and York in the coming months. 103
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470-606 Mhz 614-790 Mhz E21-E37 E39-E60 Band A B C/D E K W/B T Pre LTE:800 Channels 21-37 35-53 48-68 35-68 21-48 - 21-68 Pre LTE:800 Frequency (MHz) 470-606 582-734 686-854 582-854 470-694 470-854 - Post LTE:800 Channels 21-37 35-53 48-60 35-60 21-48 - 21-60 Post LTE:800 Frequency (MHz) 470-606 582-734 686-790 582-790 470-694 - 470-790 Amplifier Output Capability for Digital Terrestrial Signals A practical guide Many amplifier output capabilities are still given for five analogue channels. To convert to an output rating for six digital multiplexes subtract between 3 and 6 db from the analogue rating. In most cases a 3 or 4 db derating will be sufficient. Derating by 6 db will give additional protection from the effect of intermodulation products. The presence of additional multiplexes at substantially lower powers will not affect this recommendation so far as the high power muxes are concerned, although the operating level may need to be reduced further to protect the low-level multiplexes from intermodulation products arising from the high power ones. A practical check can be carried out by checking the signal quality for each multiplex, preferably in a quantitative way, such as by means of MER measurements. First check the quality at the input to the amplifier (directly from the antenna if possible). Compare this with the output from a suitable test point in the distribution system. The chosen test point should provide signal levels representative with the actual outlet plate levels in the system. If excessive reduction in signal quality (more than 1 or 2 db) is found the cause should be investigated, and may be due to running an amplifier at too high an output level. 105
Duplex Gap Guard Band PMSE 64-QAM 45 dbµv 65 dbµv 23 db 7.5 Mhz 256-QAM 45 dbµv 65 dbµv 26 db 7.9 MHz Recommendations according to DTG 'R-Book 5' & CAI Codes of Practise Cellular Mobile Frequencies Band 2G (GSM) 3G (UMTS) 4G (LTE) Base TX Mobile TX Base TX Mobile TX Base TX Mobile TX LTE-800 791 821 832 862 GSM-900 925 960 880 915 GSM-1800 1805 1880 1710 1785 UMTS-2100 2110 2170 1920 1980 1900 1920 TDD LTE-2600 2620-2690 2500-2570 All frequencies are in MHz. Some 2G spectrum is now in use for 3G and 4G services. TDD = Time-division duplex. Long Term Evolution (LTE)/4G Proximity to DTT DTT LTE Base Station Downlink LTE Consumer Unit Uplink 8MHz 8MHz 8MHz 8MHz 8MHz 8MHz 8MHz 8MHz 8MHz 8MHz 10MHz 10MHz 10MHz 10MHz 10MHz 10MHz 10MHz 470 478 766 774 782 774 782 790 ch ch ch ch ch ch ch ch ch ch 21 22 23... 37 38... 58 59 60 Group A Group T PMSE - programme making and special events 791 796 801 806 811 816 796 801 806 811 816 821 block A 1MHz block B block C block A 41 Mhz Duplex Spacing 832 837 842 847 852 857 837 842 847 852 857 862 block B block C 106
Cases of interference from LTE signals on UHF frequencies will be a problem in many installations, both existing and new. Here are some techniques to mitigate the effects of LTE. Problem The main issue will be with the proximity and the levels of power of the LTE transmissions to the existing DTT network (see LTE/4G to proximity to DTT on previous page). Interference and overload to DTT reception from LTE will be a problem in all areas of the installation. The downlink transmissions from the transmitters will cause problems with interference affecting the reception as well as signal amplification and splitting. There may also be problems from the uplink from LTE consumer mobile devices operating near TVs or other equipment with poorly screened installations and wide band amplifiers. It is important that the correct choices are made when selecting products for installations to make sure they are suitably protected or designed to mitigate the effects of LTE. Cases of interference will increase as the network rolls out (2013-15), the subscribers increase and all 6 LTE blocks (A1-C2) are all in use at full power. How to mitigate the problems Aerials Ensure the correct aerial is selected. Ideally only use CAI benchmarked aerials in the correct groups T and A or select the correct group for the transmitter. Following the power increase post DSO, a distant horizontal DTT can now be used instead of a local transmitter. Could a different transmitter be used to reduce LTE interference? a. Consider the position of the aerial. Can it be re-sited to use the local surroundings as screening? (see fig 1). b. If the LTE is vertically polarised then choose a horizontal transmission. This will give at least 16 db of rejection to the LTE signal. (see fig 2). c. Similarly, if possible, change the aerial group from a higher frequency band to a lower frequency e.g. group CD to B or group B to A. (see fig 3). 107
Mitigating 4G/LTE (Long Term Evolution) fig 1 fig 2 fig 3 Signal Distribution (Passive and Active) Gain is only needed for channels 21-60. Gain above this will only amplify the LTE interference. Integral filtering of the LTE signal is good practice but only if the filtering is working from 790 MHz and can help to reduce the overall problem. Correctly designed filtration which is integrated into the products can provide LTE protection. Only use products that conform to the EMC standard EN 50083-2. Filters High filter rejection of the LTE bands will cure the majority of interference problems from both LTE transmitters and mobile user equipment. Band-stop filters or Overlap Blocking filter (see page 46-47) can be used as appropriate to attenuate unwanted signal. See page 58 for details on filters. Filters can also be incorporated into other equipment such as amplifiers to mitigate the problem. Cables, outlet plates and fly leads All these items can be susceptible to LTE if not correctly shielded. Fit only high quality cables. The use of CAI benchmarked cable is recommended. Ensure any fly leads conform to EN 609266-2-5:2009 for IEC leads or EN 609266-2-6:2009 for F type. Only fit outlet plates that conform to the EMC standard EN 50083 2 -. See www.ltefiltering.co.uk for updates. www.ltefiltering.co.uk 108
at800 is a trademark of Digital Mobile Spectrum Limited (DMSL). They are funded by and represent the UK mobile operators who will be launching 4G mobile services at 800 MHz, EE, Telefónica UK (O2), Three and Vodafone. The role is to make sure that television reception still available when 4G mobile services at 800 MHz are launched. Web: www.at800.tv 109
Product Index Product Index is for ease of reference from the Product Code to the relevant page in the Product Guide. The x in a Product Code denotes there are a number of variants with different suffix numbers or letters. pro pro pro pro pro pro 110
Creating an account The login link is on the top right of each screen. To request a password complete the login process and select "trade". The sales department will verify and setup your correct account access. Viewing your account details Once logged in click on Your Account at the top of the screen. From here you can perform a number of functions: View your web order history, with one-click reordering of complete orders View your web order history, with one-click reordering of complete orders. View your company and personal information and change your password. View products you marked as favourites and booked marked, making it easy to reorder them. Fast reordering of previously purchased individual products. List a printable standard order form of item bought to use a re-stocking list. Create and save orders and carts for ease of re-ordering. Finding products The new site gives you a number of ways to find products: Dropdown menu or side bar: Both of these expand to show all product categories. Previously viewed products this shows the last three products you viewed, with one click taking you through to the product page. Featured products, listed on the home page. Product search, top right of each page. This powerful search gives you live search results as you type either keywords or product numbers. New products are listed at the bottom of each page and the top menu. Finding technical information At the bottom of each product page there are tabs detailing specific features, any downloads (manuals etc) and related products. There are also various technical documents, which are available from the Technical dropdown menu at the top of the page. Website - Key Direct Links The website continues to be enhanced offering improved navigation, support for mobile browsing etc to ensure that product and range changes are passed on to the trade. See the following short links. Latest news: www.blake-uk.com/news LTE FAQ: www.ltefiltering.co.uk Twitter: twitter.com/blakesaerials PROception Brand: www.proception.co.uk New products: www.blake-uk.com/new Product Guide: www.blake-uk.com/productguide Register for updates: www.blake-uk.com/register. 2014 111
PRO ception Protection from LTE is a trade mark of ETSI Aerials Brackets & Installation Equipment Bespoke Design Service AV TV Wall Mounts Coaxial Connectors & Adaptors PROception RF Signal Distribution PROception HDMI Signal Distribution LTE Filtering Products Installation Fixings & Fixtures UK R&D... ever expanding range. See www.blake-uk.com/new Register for updates at www.blake-uk.com/register BLAKE UK LTD 177/187 Rutland Road, Sheffield, S3 9PT. T: +44 (0) 114 223 5000 F: +44 (0) 114 223 5001 E: sales@blake-uk.com W: www.blake-uk.com Latest news: http://www.blake-uk.com/news Twitter: @blakesaerials