Publication V by author

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1 Publication V Jyrki T. J. Penttinen DVB H coverage estimation in igly populated urban area. In: Te 58t Annual IEEE Broadcast Symposium (ABS Alexandria, VA, USA October IEEE Broadcast Tecnology Society. 6 pages by autor

2 DVB-H Coverage Estimation in Higly Populated Urban Area Jyrki T.J. Penttinen Nokia Siemens Networks, Spain Abstract Te metodology for te sufficiently accurate DVB-H coverage estimation is one of te most important topics in te network planning of te system. Te final coverage area depends on te planned capacity, i.e. te bit stream per cannel, as well as te number of te cannels. Also te surrounding geograpical area as a big impact on te coverage, as well as te antenna eigt. Tis paper sows a case analysis about te coverage estimation as a basis for te initial radio network planning in large urban environment. Te study was carried out for Mexico City, wic is one of te most populated areas in te world. Keywords DVB-H, radio network planning. INTRODUCTION Te coverage area of a single DVB-H transmitter site depends on te provided capacity and tus on te radio parameters tat provides te required bit pipe. Logically, iger total capacity demand in te given band widt results smaller cell sizes. Te environment as a big impact on te radio wave propagation. According to te Okumura-Hata [8] prediction model, te dense urban area attenuates te signal considerably compared to te oter environment types. Tis paper sows an example of te coverage planning in Mexico City, wic is considered as one of te largest urban and dense urban environments. Despite of te callenges of te presented environment type, te definite advantage of DVB-H can be seen most clearly in tis case as big amount of potential customers can be served in reduced area. In Mexico City alone, te estimated total population is about million from wic te number of te potential customers can be estimated to be considerable. Te study presented in tis paper compares te accuracy and usability of te basic Okumura-Hata model and more indept coverage planning tool wit respective terrain eigt and area type information included. THE PLANNED ENVIRONMENT Mexico City is situated in 1.4 miles (2.2 km of eigt from te sea level, and it is surrounded by te mountains wit about 1.9 miles (3 km of eigt compared to te sea level. Figure 1 sows an overview of te city. As can be observed, te area consists of urban buildings in large area. Figure 1. An overview of Mexico City, near te center area. Te city is in general tigtly built and large in size. Te following Figure 2 sows te area cluster type of Mexico City. As can be seen, te dense urban and urban type is very large wit te respective cluster type proportion of rougly 420 square miles (1000 km 2. residential forest dense urban urban open km Figure 2. Te area type, i.e. cluster map of Mexico City. Tis map sows te area of about miles (50 50 km from wic alf is urban and dense urban area.

3 THEORETICAL COVERAGE ESTIMATION Te assumption for te analysis was to use 16-QAM modulation, wic provides about two times more cannel capacity compared to QPSK. On te oter and, te link budget of 16-QAM produces about 6-7 db smaller coverage tan QPSK. For te sufficiently robust cannel coding and error recovery, te Code Rate (CR of ½ and MPE-FEC rate of ¾ was selected. Wit 16-QAM modulation and 17.5 db C/N requirement, tis results a total cannel capacity of 6.2 Mb/s. Using te basic SFN network, tis combination would be possible to use e.g. for 1 ESG (electrical service guide, about kb/s and for ig quality audio-video cannels of about 450 kb/s eac, or for about 20 good quality A/V cannels of about 250 kb/s eac. In te initial pase of te planning, an Okumura-Hata based roug estimation about te needed amount of sites can be carried out using te respective area correction. For te estimation of te cell size (radius, a link budget is a proper tool. In tis specific case, te link budget sown in Table 1 can be created. Table 1. An example of te DVB-H link budget. General parameters Frequency f MHz Noise floor for 6 MHz bandwidt P n dbm RX noise figure F 5.2 db TX Transmitter output power P TX W Transmitter output power P TX 63.8 dbm Cable and connector loss L cc 3.0 db Power splitter loss L ps 3.0 db Antenna gain G TX 13.1 dbi Antenna gain G TX 11.0 dbd Eff. Isotropic radiating power EIRP 70.9 dbm EIRP W Eff. Radiating power ERP 68.8 dbm ERP W RX Min C/N for te used mode (C/N min 17.5 db Sensitivity P RXmin dbm Antenna gain, isotropic ref G RX -7.3 dbi Antenna gain, 1/2 wavelengt dipole G RX -5.2 dbd Isotropic power P i dbm Location variation for 95% area prob L lv 5.3 db Building loss L b 14.0 db GSM filter loss L GSM 0.0 db Min required received power outdoors P min(out dbm Min required received power indoors P min(in dbm Min required field strengt outdoors E min(out 62.8 dbuv/m Min required field strengt indoors E min(in 76.8 dbuv/m Maximum pat loss, outdoors L pl(out db Maximum pat loss, indoors L pl(in db According to te link budget, te outdoor reception of tis specific case wit 2,400 W transmitter yields a successful reception wen te radio pat loss is equal or less tan db. Te Okumura-Hata model [8] can be applied in order to obtain te cell radius (unit in kilometers in large city type. L( db = lg( f 13.82lg( + [ lg( ] lg( d a( a( MS LC1 MS LC 2 d = 10 L( db BS 2 [ ( ] = 8.29 lg 1.54 MS BS a( 2 [ ( ] 4.97, f 400MHz = 3.2 lg MS 1.10 [ lg( f lg( BS a( MS ] lg( BS i, f MS 200MHz Te following Figure 3 presents te estimated cell range calculated wit te large city model and by varying te transmitter antenna eigt and power level. d (km Cell radius Antenna eigt (m i P=1500W P=2400W P=3400W P=4700W Figure 3. Te cell range calculated wit te Okumura- Hata model for te large city, varying te transmitter power levels. According to te Figure 3, it is clear tat iger te antenna is located and iger te transmitter power is, lower is te transmitter site number. In practice, toug, it is not always possible to obtain te site locations and antenna eigts in te tecnically best locations. Te access for already existing towers migt be limited as well as te available eigts in te towers, and rooftops migt be callenging to obtain. In many cases, te antenna eigt is limited to feet (20 30 m. In some cases, it could be possible to obtain a iger antenna location in broadcast tower near te city center, or even better, in skyscraper s rooftop in te downtown area. On te oter and, te transmitter type is important to select correctly. In case of ig-power transmitter type, te respective power consumption increases. It can be estimated 200

4 tat te power consumption migt be about 6 times te produced power level fed to te antenna cable. Also te complexity rises among te iger power levels, and e.g. liquid cooling is needed instead of air cooling, affecting on te maintenance. Tese migt be limitations for te igest power classes wen selecting te optimal power levels. In tis analysis, a 2,400 W transmitter type was selected due to te above mentioned reasons. According to te Figure 3, it provides a cell radius of miles (3 4 km wit te transmitter antenna installed to feet (20 40 m of eigt. As a comparison, te antenna eigt of 330 feet (100 m provides about 4.4 miles (7 km cell radius, and 660 feet (200 m antenna yields about miles (10 11 km radius. If possible to install, one or two ig antenna locations would provide a good basic coverage in te city area wilst te sites wit lower antenna eigts fills te rest of te area. If only te urban and dense urban areas are to be covered, te following teoretical coverage map can be created by selecting 2 sites wit antenna eigt of 660 feet (200 m and cell radius of 6.8 miles (11 km, and te rest of te sites could use antenna eigts of 100 feet (30 m wic provides a cell radius of about 2.2 miles (3.5 km. Te map represents te Okumura-Hata estimated coverage for te outdoor assuming te sites can be selected witout restrictions. km Figure 4. Teoretical coverage plan wen using Okumura-Hata model for te cell radius estimation. Te drawback of te above presented coverage plan is tat te prediction is inaccurate depending on te actual terrain type. Neverteless, it gives an idea about te roug cell number. In any case, tis analysis sows te importance of te antenna eigt as wit only two ig antenna locations, it looks possible to cover about alf of te given area wilst te low antenna locations results a need of about 15 sites. PLANNING TOOL ANALYSIS In order to compare te teoretical Okumura-Hata approac wit te more realistic metods, Nokia NetAct Planner was used as a basis for more in-dept analysis of te coverage planning. Te tool consists of te digital maps of Mexico City, wit respective clutter data. A total of 7 sites were selected for te analysis based on te practical site considerations, i.e. te selected sites could possibly be real candidates wit realistic antenna eigts. Te NetAct consists of several propagation models. Extended Okumura-Hata prediction model wit respective digital cluster maps was used in te analysis. Te initial parameter tuning for te DVB-H plan was made based on te estimated local clutter attenuation factors. Te final clutter values and oter propagation model parameterization for te estimated coverage area sould be adjusted by carrying out field tests as eac area type differs from te oters. Te coverage map was plotted for outdoor and indoor environments based on te previously used DVB-H link budget, taking into account te relevant parameters (bandwidt, modulation sceme, code rate, MPE-FEC rate and receiver antenna gain. Te same 2,400 W transmitter type was used in all te sites like in previous analysis, wit EIRP of about dbm, depending on te site configuration, i.e. cable lengts and losses. In tis analysis, 2 or 3 directional antennas wit te orizontal beam widt of 65 degrees and vertical beam of 27 degrees was used, wit respective antenna gain of 13.1 dbi. In some cases of ig antenna installations, a sligt antenna element downtilting was used in order to optimize te coverage. Oter essential global parameters for te link budget were: Code rate (CR ½, MPE-FEC rate ¾, radio cannel TU6 (wit 30 Hz Doppler, cannel bandwidt 6 MHz and 680 MHz operating frequency. Te average building penetration loss was estimated to be 14 db. Wit te area location probability of 95 %, te link budget yields a minimum requirement of dbm for te received power level in tis specific case. Te following Table 2 presents te selected sites wit te antenna eigt ant, direction (degrees, down-tilt (DT and te final EIRP (dbm values. Te EIRP sown in te Table includes te transmitter filter, cable, connector and power splitter loss. Table 2. Te DVB-H site configuration. Site TX P ant deg DT EIRP Tres Padres 2400 W 60 m 140/220 2/ WTC 2400 W 190 m 0/150/240 2/2/ Iztapalapa 2400 W 30 m 0/120/240 0/0/ Santa Fe 2400 W 20 m 0/120/240 0/0/ Tlalpan 2400 W 20 m 330/90 0/ Vallejo 2400 W 30 m 0/120/240 0/0/ Azteca 2400 W 30 m 120/240 0/0 71.1

5 Te coverage plots indicates te functional areas for 16- QAM in outdoor and indoor environments. As a reference, also QPSK outdoor coverage is presented, wit te colors sown in te following Figure 5. In te following coverage maps, te raster size is miles (5 5 km. Outdoor QPSK coverage Okumura-Hata is not valid in tis case as te radius is more tan 20 km, but e.g. ITU-R P.1546 model yields 9.4 miles / 15 km wit te parameter values of tis example wic is in align wit te estimation sown in te Figure 6. EIRP: 70.5 dbm Ant: 140/220 deg, ~3km above sea level Downtilt: 2/2/2 deg Out door 16-QAM coverage Indoor 16-QAM coverage Figure 5. Te meaning of te plotted colors. Two possibilities were identified for te ig antenna installation; te WTC (skyscraper and Tres Padres (mountain. Te WTC site (wit 623 feet / 190 m antenna eigt provides a good basic coverage wit more tan 6.2 miles / 10 km radius (NetAct in main beam, or 5.5 miles / 8.7 km (Okumura-Hata. It is wort noting, toug, tat te used prediction model does not take into account te variations of te obstacles like detailed building eigts, so tere migt be oles in te presented map especially in te street canyons. EIRP: 69.3 dbm Ant: 0/150/240 deg, 190 m Downtilt: 2/2/2 deg Figure 6. Tres padres site. Tlalpan was planned wit 2 sectors in a tower (antenna in 65 feet / 20 m, wic provides only local coverage. Te outdoor coverage is about 1.9 miles / 3 km (1.8 miles / 2.8 km via Okumura-Hata of radius in te main beam of te antennas. EIRP: 71.3 dbm Ant: 330/90 deg, 20 m Downtilt: 0/0 deg Figure 5. WTC site. Te oter ig antenna site, Tres Padres, was planned wit 2 sectors pointing sout-east and sout-west in ig mountain tower (about 1.9 miles / 3 km from sea level, wilst te average value of te city area is about 1.4 miles / 2.2 km. It provides a large basic coverage. Depending on te obstacles in LOS and observed direction, te outdoor coverage varies witin miles / 5 25 km of radius. Figure 7. Tlalpan site Iztalapa was planned wit 3 sectors in a tower (antenna eigt 100 feet / 30 m. It provides only a local coverage. Depending on te obstacles in LOS, te outdoor coverage is

6 about 2.5 miles / 4 km (1.9 miles / 3.1 km via Okumura- Hata of radius in main beams. EIRP: 69.3 dbm Ant: 0/120/240 deg, 30 m 1.6 miles / 2.5 km (1.6 miles / 2.5 km via Okumura-Hata of radius. Te callenge of tis site is te variations of te mountain eigts nearby. EIRP: 69.5 dbm Ant: 0/120/240 deg, 20 m Figure 8. Iztalapa site. Vallejo contains 3 sectors (antenna eigt 100 feet / 30 m. It provides a local coverage due to te low antenna eigt, but neverteless, it increases te indoor coverage in Tres padres sector. Depending on te obstacles in main beams, te outdoor coverage is about 2.1 miles / 4 km (1.9 miles / 3.1 km via Okumura-Hata of radius. Figure 10. Santa Fe site. Azteca wit 2 sectors (antenna eigt 65 feet / 20 m provides relatively good local coverage in te directions witout obstacles. Depending on te obstacles, te outdoor coverage varies in range of miles / 3 10 km (2.2 miles / 3.6 km via Okumura-Hata of radius. EIRP: 69.3 dbm Ant: 0/120/240 deg, 30 m EIRP: 71.1 dbm Ant: 120/240 deg, 30 m Figure 9. Vallejo site. Santa Fe wit 3 sectors in a tower (antenna eigt 65 feet / 20 m provides relatively small local coverage for te low antenna eigt and non-uniform terrain. Depending on te obstacles in man beams, te outdoor coverage is about Figure 11. Azteca site. Te following Figure 12 presents te complete network coverage wit te 7 sites. Te plot sows te network coverage wit 16-QAM and 95 % area location probability, code rate of ½ and MPE-FEC of 2/3.

7 Figure 12. Te complete network coverage prediction. RESULTS Te cell size estimation obtained by calculating wit pure Okumura-Hata prediction model as relatively good average correlation wit te results tat can be obtained wit NetAct Planner wen te general limits of te models are taken into account. Te results of te NetAct Planner sows tat te used prediction takes well into account te terrain eigts and cluster types, wic would be callenging to do wit using only teoretical Okumura-Hata approac. Wen sufficiently good line of sigt is found in te planned sector, te useful cell size may be considerably better tat obtained wit te use of Okumura-Hata. Te number of identified site number was relatively low in te NetAct analysis. More sites are obviously needed if te same area sould be covered as sown in Okumura-Hata analysis in Figure 4. By observing te Figure 12, about 4 6 additional sites migt be necessary for te full coverage. Okumura-Hata estimated well te relatively low antenna installation sites, but te model estimated te coverage area of te ig WTC site in pessimistic way wic affects on te final estimation of te sites. It is wort noting tat especially te indoor coverage in selected areas requires te use of repeater type of solution, e.g. in sopping centers and oter centralized locations, were te potential customers are typically using te service. CONCLUSIONS Te results of te case analysis sows tat te teoretical Okumura-Hata prediction model wit DVB-H link budget gives a good first-and estimate about te cell sizes and tus about te needed amount of te sites in te planned area. Taking into account te caracteristics of te model, tis metod can be applied especially in te initial pase of te network planning. Due to te restrictions of te Okumura-Hata ranges as te antenna eigt and maximum estimated cell radius are considered, te metodology applies for te relatively decent radiating power levels. Wen te cell radius exceeds te maximum predictable value of 12.4 miles / 20 km, as te case is for te Tres Padres site, te model is not feasible and adjusted models sould tus be used. Especially for te ig antenna locations, one of te most logical models at te moment is te ITU recommendation P.1546, wic is based on te curve mapping and is valid practically for all te environments were DVB-H can be constructed. On te oter side, te power levels are limited due to te EMC and uman exposure regulation resulting sufficiently small cell ranges in order to be estimated wit Okumura-Hata in mayor part of te cases in urban areas. Te advanced planning tool wit respective digital maps including te terrain eigt and correct cluster attenuation information is essential in te detailed network planning. It is also wort noting tat te predictions presented in tis paper gives indication only about te coverage areas. Especially in te case of Single Frequency Network, te correct balancing of te FFT size and Guard Interval values is important in order to avoid too ig level of te possible inter-symbol interferences in large single frequency network areas. Te results sows tat te coverage estimation presented in tis paper can be used in te first pase of te DVB-H radio network planning for te initial estimation of te transmitter sites. As te clutter types vary in practice, te more detailed prediction estimations wit respective model tuning via te field tests are tus needed in te following pases. REFERENCES [1] Limits of Human Exposure to Radiofrequency Electromagnetic Fields in te Frequency Range from 3 khz to 399 GHz. Safety Code 6. Environmental Healt Directorate, Healt Protection Branc. Publication 99-EHD-237. Minister of Public Works and Government Services, Canada ISBN p. [2] DVB-H Implementation Guidelines. Draft TR V1.2.2 ( European Broadcasting Union. 108 p. [3] Jukka Henriksson. DVB-H standard, principles and services. HUT seminar T Helsinki, Presentation material. 53 p [4] Editor: Tibault Bouttevin. Wing TV. Services to Wireless, Integrated, Nomadic, GPRS-UMTS&TV andeld terminals. D8 Wing TV Measurement Guidelines & Criteria. Project report. 45 p. [5] Gerard Faria, Jukka A. Henriksson, Erik Stare, Pekka Talmola. DVB- H: Digital Broadcast Services to Handeld Devices. IEEE p. [6] William C.Y. Lee. Elements of Cellular Mobile Radio System. IEEE Transactions on Veicular Tecnology, Vol. VT-35, No. 2, May pp [7] Myron D. Fanton. Analysis of Antenna Beam-tilt and Broadcast Coverage. ERI Tecnical Series, Vol 6, April p. [8] Masaaru Hata. Empirical Formula for Propagation Loss in Land Mobile Radio Services. IEEE Transactions on Veicular Tecnology, Vol. VT-29, No. 3, August p. [9] Recommendation ITU-R P Metod for point-to-area predictions for terrestrial services in te frequency range 30 MHz to 3000 MHz p.