Interleaved UHF spectrum analysis

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1 Interleaved UHF spectrum analysis On behalf of by LS telcom AG, Lichtenau Status: 23/05/2006 (Edited)

2 1 Introduction For 50 given transmitter sites (i.e. the 50 main stations) free capacities within the UHFspectrum had to be investigated. The useable frequency range is within the channel range and which is determined for interleaved digital transmissions. The 50 transmitter sites are arranged in an order of priority (1. Crystal Palace, 2. Sutton Coldfield etc.) with an additionally grouping concerning an analogue aerial group. The new frequency should be within the group given to every transmitter site, where possible: Group Channel Range Useable Channels A B C/D E K ; W ; Table 1: Group and preferred channel range LS telcom AG, Lichtenau,

3 2 Prediction Model Report Spectrum Analysis UHF part 1 The IRT 2D-Model is a well proved and worldwide established propagation model for the VHF and UHF range. It was developed by the IRT (Institut für Rundfunktechnik) in Munich. The IRT is the research and development institute of the German-speaking broadcasting corporations under public law of ARD, ZDF, DLR, ORF (Austria) and SRG (Switzerland). This model was improved regarding the scattered and reflected waves. Especially for wideband transmissions like DAB and DVB-T this leads to more precise results than other available predictions models. 3 Software CHIRplus_BC at Windows XP This software is developed by LS Telcom AG and is used by many networks operators and regulation authorities worldwide. Especially in Europe CHIRplus_BC is the most used planning and coordination software for broadcast planning purposes. 4 Used transmitter and topo data The transmitter database of the existing DVB-T-network in the UK was given by Ofcom and was implemented in the CHIRplus software. All calculations were made on DTM-maps (Digital Terrain Map) with 200 m resolution. Also a morpho-map for the coverage calculations is included. The population analyses were made on a population map with 50 m resolution. LS telcom AG, Lichtenau,

4 5 Method of frequency search Report Spectrum Analysis UHF part 1 First of all a central transmitter database was set up on a server to ensure that all participating computers are using the same databases. Furthermore, a new found frequency has to be included to this database immediately so that it is taken into account at the next frequency search for the next transmitter site. For example, a new found frequency is not useable at another site near to that site and has to be included for the calculations. The frequency search then was started with Crystal Palace which is on top of the priority list. A frequency search carried out with CHIRplus detects all interferers for each channel and lists the results both as a graphical plot and as a list giving all relevant information concerning the status quo of the spectrum at this site, especially the useable field strength for every channel. This information then is used to select the channels for further surveys (coordination calculations). Afterwards, the first ten channels concerning the lowest useable field strength which are within the defined channel area (21-30 and 41-62) are coordinated by the coordination tool within CHIRplus. If there are not two channels of the first ten within the given analogue aerial group, one or two additional frequencies were investigated. This special function determines the needed reductions to fulfil the conditions given by the ITU. In this special case Ofcom defined the value for the maximum increase with 3 db. At the end then a complete antenna pattern is designed automatically with the reductions for a certain tx power. Ofcom defined the maximum reduction value with 15 db. So the goal was to reduce the transmitter power to a value that at the end 15 db reduction was not exceeded. An other criterion are the maximum useable tx power, they was limited by the power of other channels which are used at the same transmitter. After the coordination of 10 frequencies 2 frequencies had to be selected for a coverage analysis. The criteria for that was the possible transmitter power in relation to the corresponding coordination antenna pattern. Furthermore, the given analogue aerial group (A, B, C/D etc.) was taken into account also. If two frequencies would be similar with their power and pattern the one within the right group was selected. In some cases not only two frequencies were investigated but also a third one. This was necessary when several frequencies seemed to be useable and the decision to select the right one was too difficult. The coverage analysis then resulted in two coverage plots for each calculated frequency. One plot shows the coverage situation for the C2E-modulation (64-QAM, Code rate 2/3) and one for A2E-modulation (QPSK, Code rate 2/3). The coverage analyses are base of the location probability of 70%. All new transmitter sites are taken in consideration for coverage analysis (final coverage). LS telcom AG, Lichtenau,

5 A population analysis based on a special population map determines the number of covered inhabitants within the calculated areas. For some of the transmitter sites no useable frequencies could be found because of too high reductions of the antenna pattern. The analysis carried out is shown in the following section for an example site, in this case, Sutton Coldfield. The coverage plots show three thresholds: - Covered: wanted signals are stronger than the sum of the interfering signals + protection ratio - Interfered: wanted signals are below the sum of the interfereing signals + protection ration - Not covered: wanted signals are below minimum field strength LS telcom AG, Lichtenau,

ERP Pattern 64-QAM QPSK successive successive 2,679,599 4,018,097 714.00 51 B 1.

6 6 Analysis Example - Sutton Coldfield: Frequency Chan. Group Covered Pop. Covered Pop. ERP Pattern 64-QAM QPSK successive successive 2,679,599 4,018, B 1.26 kw final final 2,679,718 4,017,848 successive successive 827,469 2,278, W final final 729,195 1,981,853 LS telcom AG, Lichtenau,

6.1 Coverage Analysis final channel 51 (Group B) 6.1.1 Coverage Analysis C2

7 6.1 Coverage Analysis final channel 51 (Group B) Coverage Analysis C2 (Modulation 64-QAM; Code rate 2/3) Figure 1: Coverage Plot final Sutton Coldfield channel 51, 64-QAM Coverage Analysis A2 (Modulation QPSK, Code rate 2/3) Figure 2: Coverage Plot final Sutton Coldfield channel 51, QPSK LS telcom AG, Lichtenau,

6.2 Coverage Analysis final channel 29 (Group A) 6.2.1 Coverage Analysis C2

8 6.2 Coverage Analysis final channel 29 (Group A) Coverage Analysis C2 (Modulation 64-QAM; Code rate 2/3) Figure 3: Coverage Plot final Sutton Coldfield channel 29, 64-QAM Coverage Analysis A2 (Modulation QPSK, Code rate 2/3) Figure 4: Coverage Plot final Sutton Coldfield channel 29, QPSK LS telcom AG, Lichtenau,

9 7 Summary (written by Ofcom) For all 50 main stations, the results of the analysis can be summarized as follows: No frequencies were available at six main stations One frequency was available at three main stations Two frequencies were available at the remaining 41 main stations The predicted coverage of a high capacity and a low capacity network using the frequencies found above is given in the table below. Cases 1 and 2 refer to how the best channels are allocated at each site. Case Network Channel Allocation UK Coverage 1 64QAM (hi cap) Best 44 Channels 72% QPSK (low cap) Remaining 41 Channels 67% 2 QPSK (low cap) Best 44 Channels 86% 64QAM (hi cap) Remaining 41 Channels 50% With regards to receive aerials, 29 of the best 44 channels are in the existing aerial group, thus 15 channels are out of group. 16 of the remaining 41 channels are in the aerial group, thus 25 channels are out of group. There are various caveats associated with the coverage predictions as follows: Antenna templates were used in the predictions, incorporating the necessary restrictions for protecting other transmitters from interference. In reality, a practical antenna pattern will be worse than a theoretical template, so coverage will also be worse. The universe in which the additional high and low capacity muxes were planned assumed that the v5.2 UK DSO frequency plan was used for the three PSB and three COM multiplexes; and assumed a particular European interferer scenario (before the GE06 plan was agreed) which is probably now somewhat outdated and optimistic. Both the UK and European DSO plans have developed since this study was done, so specific channels at specific sites may no longer be valid. Nevertheless the general overall conclusion that there is still interleaved spectrum available for other uses (over and above the 3PSB and 3COM muliplexes) is still convincing. A 3dB increase in usable field strength was allowed in order to reasonably find frequencies for the extra high and low capacity muxes. Thus, there may be an impact on the coverage of the three PSB and three COM multiplexes, which will need to be mitigated. 8

10 Annex A Individual Site Results Table 1. Results assuming best 44 Channels & QPSK modulation Site Gross Pop in 1000s Max ERP Range kw Antenna Restrictions Local Aerial Group households Angus to 10 Yes In Group Beacon Hill Belmont 2, to 100 Yes Out of Group Bilsdale 1,342 1 to 10 Yes In Group Black Hill Blaenplwyf to 100 Yes In Group Bluebell Hill to 1 Yes Out of Group Bressay 8 1 to 10 No Out of Group Brougher Mountain to 100 Yes In Group Caldbeck to 10 Yes Out of Group Caradon Hill to 100 Yes In Group Carmel Chatton to 100 Yes Out of Group Craigkelly to 10 Yes Out of Group Crystal Palace 5, to 100 Yes In Group Darvel to 10 Yes In Group Divis to 100 Yes In Group Dover to 10 Yes In Group Durris to 100 Yes In Group Eitshal to 100 No In Group Emley Moor 1, to 1 Yes Out of Group Hannington to 10 Yes In Group Heathfield to 10 Yes Out of Group Huntshaw Cross to 1 Yes In Group Keelylang Hill to 100 Yes In Group Knockmore 42 1 to 10 Yes Out of Group Limavady to 100 Yes In Group Llanddona to 100 Yes Out of Group Mendip Midhurst to 10 Yes In Group Moel y Parc Oxford to 1 Yes In Group Pontop Pike to 10 Yes In Group Presely to 100 Yes In Group Redruth to 10 Yes Out of Group Ridge Hill Rosemarkie to 100 Yes In Group Rowridge to 100 Yes In Group Rumster Forest to 100 Yes Out of Group Sandy Heath 1, to 100 Yes Out of Group Selkirk 67 1 to 10 Yes In Group Stockland Hill to 10 Yes In Group Sudbury to 100 Yes In Group Sutton Coldfield 1,703 1 to 10 Yes In Group A1

11 Site Gross Pop in 1000s households Max ERP Range kw Antenna Restrictions Report Spectrum Analysis UHF part 1 Local Aerial Group Tacolneston to 100 Yes Out of Group The Wrekin to 10 Yes In Group Torosay 10 1 to 10 Yes In Group Waltham 2, to 100 Yes In Group Wenvoe 1, to 100 Yes Out of Group Winter Hill 1, to 1 Yes In Group Table 2. Results assuming remaining 41 Channels & QPSK modulation Site Gross Pop in 1000s Max ERP Range kw Antenna Restrictions Local Aerial Group households Angus to 10 Yes In Group Beacon Hill Belmont 2, to 100 Yes Out of Group Bilsdale 1,255 1 to 10 Yes In Group Black Hill Blaenplwyf to 100 Yes Out of Group Bluebell Hill to 1 Yes Out of Group Bressay 7 1 to 10 No In Group Brougher Mountain to 100 Yes In Group Caldbeck to 10 Yes Out of Group Caradon Hill Carmel Chatton to 1 Yes Out of Group Craigkelly to 10 Yes Out of Group Crystal Palace 3, to 100 Yes Out of Group Darvel to 1 Yes Out of Group Divis to 100 Yes Out of Group Dover to 10 Yes In Group Durris to 10 Yes Out of Group Eitshal to 100 No Out of Group Emley Moor 1,300 1 to 10 Yes Out of Group Hannington to 10 Yes In Group Heathfield to 10 Yes In Group Huntshaw Cross to 1 Yes In Group Keelylang Hill to 100 Yes Out of Group Knockmore 41 1 to 10 Yes Out of Group Limavady 39 1 to 10 Yes In Group Llanddona to 100 Yes In Group Mendip Midhurst to 10 Yes Out of Group Moel y Parc Oxford to 10 Yes Out of Group Pontop Pike to 10 Yes In Group Presely to 10 Yes Out of Group Redruth to 10 Yes Out of Group Ridge Hill Rosemarkie to 100 Yes In Group Rowridge to 10 Yes In Group A2

12 Site Gross Pop in 1000s households Max ERP Range kw Antenna Restrictions Report Spectrum Analysis UHF part 1 Local Aerial Group Rumster Forest to 100 Yes Out of Group Sandy Heath 1, to 100 Yes Out of Group Selkirk 46 1 to 10 Yes In Group Stockland Hill to 10 Yes In Group Sudbury to 100 Yes Out of Group Sutton Coldfield to 1 Yes Out of Group Tacolneston to 100 Yes Out of Group The Wrekin to 1 Yes In Group Torosay 8 1 to 10 Yes Out of Group Waltham 1, to 100 Yes Out of Group Wenvoe Winter Hill A3

Spectrum Efficiency in Scotland. Study Proposal. National Grid Wireless. Prepared for: Ofcom Prepared by: National Grid Wireless.

Spectrum Efficiency in Scotland Study Proposal National Grid Wireless Prepared for: Ofcom Prepared by: National Grid Wireless 1 EXECUTIVE SUMMARY... 3 2 INTRODUCTION... 4 3 METHODOLOGY... 4 4 CHANGES TO