Gsm rf planning concepts

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Gsm rf planning concepts

  1. 1. RF Network Design Manish Network Planning 1
  2. 2. Introduction • The high level life cycle of the RF network planning process can be summarised as follows :• To help the operator to identify their RF design requirement • Optional Comparative Analysis • Discuss and agree RF design parameters, assumptions and objectives with the customer RF Design requirement • Coverage requirement • Traffic requirement • Various level of design (ROM to detail RF design) RF Design • Issuing of search ring • Cand. assessment • Site survey, design, approval • Drive test (optional) Site Realisation RF Design Implementation 2 • • • • Frequency plan Neighbour list RF OMC data Optimisation
  3. 3. Comparative Analysis • This is an optional step • This is intended to :• • Help an existing operator in building/expanding their network Help a new operator in identifying their RF network requirement, e.g. where their network should be built • For the comparative analysis, we would need to :• • • Identify all network that are competitors to the customer Design drive routes that take in the high density traffic areas of interest Include areas where the customer has no or poor service and the competitors have service 3
  4. 4. Comparative Analysis • The result of the analysis should include :• For an existing operator • • • All problems encountered in the customer’s network All areas where the customer has no service and a competitor does Recommendations for solving any coverage and quality problems • For a new operator • • Strengths and weaknesses in the competitors network Problem encountered in the competitors network 4
  5. 5. RF Network Design Inputs • The RF design inputs can be divided into :• Coverage requirements • Target coverage areas • Service types for the target coverage areas. These should be marked geographically • Coverage area probability • Penetration Loss of buildings and in-cars • Capacity requirements • Erlang per subscriber during the busy hour • Quality of service for the air interface, in terms GoS • Network capacity 5
  6. 6. RF Network Design Inputs • Available spectrum and frequency usage restriction, if any • List of available, existing and/or friendly sites that should be included in the RF design • Limitation of the quantity of sites and radios, if any • Quality of Network (C/I values) • Related network features (FH, DTX, etc.) 6
  7. 7. Coverage Design Inputs by BSNL • Coverage Thresholds • Indoor Coverage : Signal Level measured at street better than –65 dBm. Indoor coverage to be provided in commercial complexes, hotels,technology parks etc. • In Car Coverage: Signal Level measured at street better than –75 dBm. In Car coverage to be provided in residential areas, highways, tourist spots etc. • Outdoor Coverage : Signal level measured at street better than –85 dBm. All remaining areas to be covered with Outdoor coverage. • These are general guidelines for planning , specific areas not provided. 7
  8. 8. Capacity Design Inputs by BSNL • Frequency spectrum available 6.2 MHz (31 channels). • Average traffic per sub for RF design : 50 mErlang. • Synthesizer frequency hopping can be used. • GOS: 2% • Existing network Database • Total No. of sites with configuration • Site details eg location(Lat-Long), Antenna height ,azimuth, etc. 8
  9. 9. RF Network Design • There are 2 parts to the RF network design to meet the :• Capacity requirement • Coverage requirement • For the RF Coverage Design CW Drive Testing Propagation Model Digitised Databases RF Coverage Design Customer Requirements Link Budget 9
  10. 10. CW Drive Testing • CW drive test can be used for the following purposes :• • Propagation model tuning Assessment of the suitability of candidate sites, from both coverage and interference aspect • CW drive test process can be broken down to :Test Preparation • Equipment required • BTS antenna selection • Channel selection • Power setting • Drive route planning • Test site selection Propagation Test • Transmitter setup • Receiver setup • Drive test • Transmitter dismantle Data Processing • Measurement averaging • Report generation 10
  11. 11. CW Drive Testing - Test Preparation • The test equipment required for the CW drive testing :• Receiver with fast scanner • Example : HP7475A, EXP2000 (LCC) etc. • The receiver scanner rate should conform to the Lee Criteria of 36 to 50 sample per 40 wavelength • CW Transmitter • Example : Gator Transmitter (BVS), LMW Series Transmitter (CHASE), TX-1500 (LCC) etc. • Base Station test antenna • DB806Y (Decibel-GSM900), 7640 (Jaybeam-GSM1800) etc. • Accessories • Including flexible coaxial cable/jumper, Power 11
  12. 12. CW Drive Testing - Test Preparation • Base Station Antenna Selection • The selection depends on the purpose of the test • For propagation model tuning, an omni-directional antenna is preferred • For candidate site testing or verification, the choice of antenna depends on the type of BTS site that the test is trying to simulate. • For Omni BTS : • Omni antennas with similar vertical beamwidth • For sectorised BTS • Utilising the same type of antenna is preferred • Omni antenna can also be used, together with the special feature in the post processing software like CMA (LCC) where 12
  13. 13. CW Drive Testing - Test Preparation • Test Site Selection • For propagation model tuning, the test sites should be selected so that :• They are distributed within the clutter under study • The height of the test site should be representative or typical for the specific clutter • Preferably not in hilly areas • For candidate site testing/verification, the actual candidate site configuration (height, location) should be used. • 13 For proposed greenfield sites, a “cherry-picker” will
  14. 14. CW Drive Testing - Test Preparation • Frequency Channel Selection • The necessary number of channels need to be identified from the channels available • With input from the customer • The channels used should be free from occupation • From the guard bands • Other free channels according to the up-todate frequency plan • The channels selected will need to be verified by conducting a pre-test drive • It should always precede the actual CW drive test to verify the exact free frequency to be used • It should cover the same route of the actual propagation test 14
  15. 15. CW Drive Testing - Test Preparation • Transmit Power Setting • For propagation model tuning, the maximum transmit power is used • For candidate site testing, the transmit power of the test transmitter is determined using the actual BTS link budget to simulate the coverage • On sites with existing antenna system, it is recommended that the transmit power to be reduced to avoid interference or intermodulation to other networks. • The amount of reduction is subject to the possibility if separating the test antenna from the existing antennas 15
  16. 16. CW Drive Testing - Test Preparation • Drive Route Determination • The drive route of the data collection is planned prior to the drive test using a detail road map • Eliminate duplicate route to reduce the testing time • For propagation model tuning, each clutter is tested individually and the drive route for each test site is planned to map the clutter under-study for the respective sites. • It is important to collect a statistically significant amount of data, typically a minimum of 300 to 400 data points are required for each clutter category • The data should be evenly distributed with respect to distance from the transmitter • In practice, the actual drive route will be modified according to the latest development which was not shown on the map. The actual drive route taken should be marked on a map for record 16 purposes.
  17. 17. CW Drive Testing - Propagation Test • Transmitter Equipment Setup • Test antenna location • Free from any nearby obstacle, to ensure free propagation in both horizontal and vertical dimension • For sites with existing antennas, precaution should be taken to avoid possible interference and/or intermodulation • Transmitter installation • A complete set of 360º photographs of the test location (at the test height) and the antenna setup should be taken for record 17
  18. 18. CW Drive Testing - Propagation Test • Scanning Receiver Setup - HP 7475A Receiver Example HP 7475A Receiver 18
  19. 19. CW Drive Testing - Propagation Test • Scanning Receiver Setup • The scanning rate of the receiver should always be set to allow at least 36 sample per 40 wavelength to average out the Rayleigh Fading effect. • For example: scanning rate = 100 sample/s • test frequency = 1800 MHz • therefore, to achieve 36 sample/40 wavelength, 40 × 0.1667 = the max. speed is 18.52 m / s = 66.67 km / h = • • 36/100 It is recommended that :• Beside scanning the test channel, the neighbouring cells is also monitored. This information can be used to check the coverage overlap and potential interference • Check the field strength reading close to the test antenna before starting the test, it should 19 approach the scanning receiver saturation
  20. 20. CW Drive Testing - Propagation Test • Drive Test • Initiate a file to record the measurement with an agreed naming convention • Maintain the drive test vehicle speed according to the pre-set scanning rate • Follow the pre-plan drive route as closely as possible • Insert marker wherever necessary during the test to indicate special locations such as perceived hot spot, potential interferer etc. • Monitor the GPS signal and field strength level throughout the test, any extraordinary reading should be inspected before resuming the test. • Dismantling Equipment • It is recommended to re-confirm the transmit 20 power (as the pre-set value) before dismantling
  21. 21. Measurement Data Processing • Data Averaging • This can be done during the drive testing or during the data processing stage, depending on the scanner receiver and the associated postprocessing software • The bin size of the distance averaging depends on the size of the human made structure in the test environment • Report Generation • For propagation model tuning, the measurement data is exported into the planning tool (e.g. Asset) • Plots can also be generated using the processing tool or using MapInfo • During the export of the measurement data, it is important to take care of the coordinate 21
  22. 22. Propagation Model • Standard Macrocell Model for Asset • Lp (dB) = K1 + K2 log(d) + K3 Hm + K4 log(Hm) + K5 log(Heff) • + K6 log(Heff) log(d) + K7 Diffraction + Clutter factor • where Lp, Diffraction, Clutter factor are in dB • d, Hm, Heff are in m • It is based on the Okumura-Hata empirical model, with a number of additional features to enhance its flexibility • Known to be valid for frequencies from 150MHz to 2GHz • Applies in condition :• Base station height : 30 - 200 m • Mobile height : 1 - 10 m • Distance : 1 - 20 km • An optional second intercept and slope 22 (K1, K2) for the
  23. 23. Morphology Class Morphology Classification Dense Urban Urban Dense Suburban Light Suburban Rural Definition A mixture of 8-15 storey commercial bldgs/residential apartments/shopping complexes and 15-25 storey skyscrapers. Bldgs are densely packed. Major roads are at least 4 lanes wide and minor roads are 2 lanes wide. There is very little or no trees. A mixture of 4-6 storey shophouses densely packed and 6-15 storey commercial bldgs/residential apartments/shopping complexes. Compared to dense urban, the bldgs are not as tall or as densely packed. Major roads are at least 4 lanes wide and minor roads are 2 lanes wide. There is very little or no trees. Typically 4 storey shophouses densely packed. There are occasional 6 to 12 storey bldgs. Usually a busy town in between cities. Roads are 2 to 4 lanes wide. Light foliage. Typically less than 4 storey shophouses lined along highway/main road. The shophouses form 1 or 2 tier from the road and the houses are not densely packed. Usually at the outer fringe of a town. Light to moderate foliage. Along highway where there are isolated houses or open ground. 23
  24. 24. Link Budget Link Budget Element of a GSM Network BTS Antenna Gain LNA (optional) Feeder Loss ACE Loss Diversity Gain BTS Transmit Power BTS Receiver Sensitivity Max. Path Loss Fade Margin Penetration Loss MS Antenna Gain, Body and Cable Loss Mobile Transmit Power 24 Mobile Receiver Sensitivity
  25. 25. Link Budget • BTS Transmit Power • Maximum transmit power • GSM900 and 1800 networks use radios with 46dBm maximum transmit power • ACE Loss • Includes all diplexers, combiners and connectors. • Depends on the ACE configuration • The ACE configuration depends on the number of TRXs and combiners used No of TRXs 1 or 2 1 or 2 3 or 4 3 or 4 Network ACE Configuration GSM900 GSM1800 GSM900 GSM1800 2 antennas per cell, diplexer 2 antennas per cell, diplexer 2 antennas per cell, diplexer + hybrid combiner 2 antennas per cell, diplexer + hybrid combiner 25 Downlink ACE Loss (dB) 1.0 1.2 4.4 4.4
  26. 26. Link Budget • Mobile Transmit Power • GSM900 : Typical mobile class 4 (2W) • GSM1800 : Typical mobile class 1 (1W) Class 1 2 3 4 5 GSM 900 (Watt/dBm) 8 / 39 5 / 37 2 / 33 0.8 / 29 GSM 1800 (Watt/dBm) 1 / 30 0.25 / 24 4 / 36 - • Mobile Receiver Sensitivity • The sensitivity of GSM900 and GSM1800 mobile = -102 dBm 26
  27. 27. Link Budget • Diversity Gain • Two common techniques used :• Space • Polarisation • Reduce the effect of multipath fading on the uplink • Common value of 3 to 4.5 dB being used • BTS Receiver Sensitivity • Depends on the type of propagation environment model used, most commonly used TU50 model • BTS :• Receiver Sensitivity for GSM900 = -107 dBm 27
  28. 28. Link Budget • Feeder Loss • Depends on the feeder type and feeder length • The selection of the feeder type would depends on the feeder length, I.e. to try to limit to feeder loss to 3 -4dB. • BTS Antenna Gain • Antenna gain has a direct relationship to the cell size • The selection of the antenna type depends on :• The morphology classes of the targeted area and coverage requirements • Zoning and Local authority regulations/limitations • Common antenna types used :28 • 65º, 90º, omni-directional antennas with
  29. 29. Link Budget • Slow Fading Margin • To reserve extra signal power to overcome potential slow fading. • Depends on the requirement of coverage probability and the standard deviation of the fading • A design can take into consideration :• both outdoor and in-building coverage, which utilises a combined standard deviation for indoor and outdoor (Default value = 9dB) • Only outdoor coverage (Default value = 7dB) • Pathloss slope used, 45dB/dec (Dense Urban), Cell Area Outdoor slow fade margin 42dB/dec Combined (outdoor & (Urban), 38dB/dec (Suburban) and Coverage (dB) 33dB/decindoor) slow fade margin (Rural) Probability (dB) (%) 85 90 95 DU 2 5 9 U 3 6 9 SU 3 6 9 RU 4 6 10 DU 1 3 6 U 1 3 6 SU 2 4 7 29 RU 2 4 7
  30. 30. Link Budget • Penetration Loss • • • Penetration loss depends on the building structure and material Penetration loss is included for in-building link budget Typical value used for Asia-Pacific environment (if country specific information is not available) :• Dense Urban : 20 dB • Urban : 18 dB • Suburban : 15 dB • Rural : 9 dB • Body Loss • Typical value of 3dB body loss is used • MS Antenna Gain • A typical mobile antenna gain of 2.2 30 dBi is used
  31. 31. Link Budget • Link Budget Example (GSM900) UPLINK MS Transmit Power Cable Loss MS Antenna Gain Body Loss Penetration Loss Slow Fade Margin Max. Path Loss BTS Antenna Gain LNA Gain Feeder Loss ACE Loss Diversity Gain BTS Receiver Sensitivity 33 dBm 0 dB 2.2 dBi 2 dB W X Y 18 dBi 0 dB 2 dB 0 dB 4 dB -107 dBm DOWNLINK BTS Transmit Power ACE Loss Feeder Loss LNA Gain BTS Antenna Gain Max. Path Loss Slow Fade Margin Penetration Loss Body Loss MS Antenna Gain Cable Loss Diversity Gain MS Receiver Sensitivity 31 46 dBm Z 2 dB 0 dB 18 dBi Y X W 2 dB 2.2 dBi 0 dB 0 dB -102 dBm
  32. 32. Antenna • Antenna Selection • Gain • Beamwidths in horizontal and vertical radiated planes • VSWR • Frequency range • Nominal impedance • Radiated pattern (beamshape) in horizontal and vertical planes • Downtilt available (electrical, mechanical) • Polarisation • Connector types (DIN, N) • Height, weight, windload and physical dimensions 32
  33. 33. Antenna • The antenna selection process • Identify system specifications such as polarisation, impedance and bandwidth • Select the azimuth or horizontal plane pattern to obtain the needed coverage • Select the elevation or vertical plane pattern to be as narrow as possible, consistent with practical limitations of size, weight and cost • Check other parameters such as cost, power rating, size, weight, mounting capabilities, wind loading, connector types, aesthetics and reliability to ensure that they meet system requirements 33
  34. 34. Antenna • System Specification • Impedance and frequency bandwidth is normally associated with the communication system used • The polarisation would depends on if polarisation diversity is used • Horizontal Plane Pattern • Three categories for the horizontal plane pattern :• Omnidirectional • Sectored (directional) • Narrow beam (highly directional) • Elevation Plane Pattern • Choosing the antenna with the smallest elevation plane beamwidth will give maximum gain. However, beamwidth and size are inversely related • Electrical down tilt • Null filling 34
  35. 35. Nominal RF Design Link Budget Propagation model Coverage requirements Site radius Nominal RF Design (coverage) Maximum path loss Typical site configuration • Transmit Power • Antenna configuration (type, height, azimuth) • Site type (sector, omni) Traffic requirements • Standard hexagon site layout • Friendly, candidate sites • Initial site survey inputs Traffic requirements • Recalculate the site radius using the number of sites from the traffic requirement • Repeat the nominal RF design Coverage site count Traffic site count Traffic > Cov. Cov. > Traffic 35 Nominal site count
  36. 36. Nominal RF Design • Calculation of cell radius • A typical cell radius is calculated for each clutter environment • This cell radius is used as a guide for the site distance in the respective clutter environment • The actual site distance could varies due to local terrain • Inputs for the cell radius calculation :• Maximum pathloss (from the link budget) • Typical site configuration (for each clutter environment) • Propagation model 36
  37. 37. Nominal RF Design • There are different level of nominal RF design :• Only using the cell radius/site distance calculated and placing ideal hexagon cell layout • Using the combination of the calculated cell radius and the existing/friendly sites from the customer The site distance also depends on the required capacity •In most mobile network, the traffic density is highest within the CBD area and major routes/intersections •The cell radius would need to be reduce in this area to meet the traffic requirements •BASED ON THE SITE DISTANCE & THE COVERAGE REQUIREMENTS CELL COUNT BASED ON COVERAGE IS CALCULATED. 37
  38. 38. Nominal RF Design • Cell count based on traffic is derived based on capacity inputs:• Capacity requirements • GOS • Spectrum availability • Freq. Hopping techniques • If the total sites for the traffic requirement is more than the sites required for coverage, the nominal RF design is repeated using the number of sites from the traffic requirement • Recalculating the cell radius for the high traffic density areas • The calculation steps are :• Calculate the area to be covered per site • Calculate the maximum cell radius • Calculate the site distance 38
  39. 39. Site Realisation • After completion of Nominal design based on cell count ( coverage & capacity requirements ) , search rings for each cell site issued. • Nominal design is done , with the existing network in place ( existing BTS ) . Existing site location remain unchanged , azimuth , tilts as per the new design requirements. • Based on the search ring form physical site survey is undertaken. 39
  40. 40. Site Realisation Search Ring Form BSNL Circle:Haryana City / SSA: Site Id: Site Name: Morphology Type: Spheroid: Krishna Nagar Quasi Open , Industrial WGS-84 Coordinates: (GPS) deg min sec Latitude: 18 o 39 ' 49.3 ''N Longitude: 73 o 47 ' 36.7 ''E Site AGL (m): 30 Search Radius:50 m Antenna Type: 65 deg Vertical polarised Antenna Orientation(Deg) Sector1 Sector2 350 120 Sector3 240 Search Ring Form • Site ID • Site Name • Latitude/Longitude • Project name • Issue Number and date • Ground height • Clutter environment • Preliminary configuration • Number of sector • Azimuth • Antenna type • Antenna height Coverage Objectives: Krishna Nagar, Jotiba Nagar, Shambaji Nagar, Yamuna Nagar Comments Issue Date: Revision No. : R1.1 Name & signature of RF Coordinator • Location Map & SR radius • Search ring objective • Approvals 40
  41. 41. Site Realisation Suitable Y Candidates? Release of Search Ring Y Candidates Approved? N N N Next candidate Problem identifying candidate N Caravan next candidate Exhausted candidates N Y Discuss alternative with customer N Exhausted candidates Driveby, RF suggest possible alternative N Issue design change All parties agreed at Caravan Arranged Caravan Cell split required Y Candidate approved? Y Y Additional sites required N Y 41 Y Produce Final RF Design
  42. 42. Site Realisation • Candidate Assessment Report-Site Survey Forms • Site survey Forms for all suitable candidates for the search ring • For each candidates :• Location (latitude/longitude) • Location map showing the relative location of the candidates and also the search ring • Candidate information (height, owner etc) • Photographs (360º set, rooftop, access, building) • Possible antenna orientations • Possible base station equipment location • Information for any existing antennas • Planning reports/comments (restrictions, possibilities of approval etc.) 42
  43. 43. Site Realisation-Site Survey Form TECHNICAL SITE SURVEY FORM Date June 12, 2004 BSNL Circle • Final RF Configuration Form Bihar CITY / SSA Site ID BHPAT-09 BSNL/ NBSNL Site Name Patna 09 Owner Name Address & Contact No. • Construction Container/Room Tower Type GBT / Rooftop Bldg. Hgt 10 m. Tower Hgt 6 m. Antenna Ht 20 m. Coordinate LAT 26° 21' 25.9" N LONG 85° 48 ' 31.2" E GSM ANTENNA : TYPE AZ M-TILT SECTOR 1 AP909014-2 85° +1.9 SECTOR 2 AP909014-2 185° +0.7 SECTOR 3 AP909014-2 307° +1.3 Spheroid: Candidate No. Assess: Accept/ Reject Priority Morphology/Clutter Site Blockage if Any Remark Nokia Representative BSNL Survey Team Representative Name: Name: Signature: Signature: Base Station configuration • Azimuth • Antenna height • Antenna type • Down tilt • Antenna location • Feeder type and length • BTS type • Transmit power • Transceiver configuration 43
  44. 44. Traffic Engineering Spectrum Reuse factor Available Traffic Requirement Maximum number of TRX per cell Channel loading No of TCH available Subscriber supported Traffic offered 44
  45. 45. Traffic Engineering • Traffic Requirement • The Erlang per subscriber • Grade of Service ( GoS ) • GoS is expressed as the percentage of call attempts that are blocked during peak traffic • Most cellular systems are designed to a blocking rate of 1% to 5% during busy hour 45
  46. 46. Traffic Engineering • Frequency Reuse • In designing a frequency reuse plan, it is necessary to develop a regular pattern on which to assign frequencies • The hexagon is chosen because it most closely approximated the coverage produced by an omni or sector site • Common reuse factor : 4/12, 7/21 46
  47. 47. Traffic Engineering • Channel Loading • As the number of TRX increases, the control channels required increases accordingly • The following channel loading is used for conventional GSM network • For services such as cell broadcast, additional control channels might be required Number of TCH Number of TRX Control Channels 1 2 3 4 5 6 7 8 Combined BCCH/SDCCH 1 BCCH, 1 SDCCH 1 BCCH, 2 SDCCH 1 BCCH, 2 SDCCH 1 BCCH, 3 SDCCH 1 BCCH, 3 SDCCH 1 BCCH, 3 SDCCH 1 BCCH, 3 SDCCH 7 14 21 29 36 44 52 60 47
  48. 48. Traffic Engineering • After determining the number of TCH available and the traffic requirements, the traffic offered is calculated using the Erlang B table • For example, for a 2% GoS and 3 TRX configuration, the traffic offered is 14 Erlang • If the traffic per subscriber is 50mE/subscriber, then the total subscribers supported per sector = 280 • For a uniform traffic distribution network, the number of sites required for the traffic requirement is :Total subscribers Total sites = Subscriber supported per site 48
  49. 49. Traffic Engineering • Erlang B Table N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 1% 1.20% 1.50% 0.01 0.01 0.02 0.15 0.17 0.19 0.46 0.49 0.54 0.87 0.92 0.99 1.36 1.43 1.52 1.91 2 2.11 2.5 2.6 2.74 3.13 3.25 3.4 3.78 3.92 4.09 4.46 4.61 4.81 5.16 5.32 5.54 5.88 6.05 6.29 6.61 6.8 7.05 7.35 7.56 7.82 8.11 8.33 8.61 8.88 9.11 9.41 9.65 9.89 10.2 10.4 10.7 11 11.2 11.5 11.8 12 12.3 12.7 12.8 13.1 13.5 13.7 14 14.3 14.5 14.8 15.2 2% 0.02 0.22 0.6 1.09 1.66 2.28 2.94 3.63 4.34 5.08 5.84 6.61 7.4 8.2 9.01 9.83 10.7 11.5 12.3 13.2 14 14.9 15.8 3% 0.03 0.28 0.72 1.26 1.88 2.54 3.25 3.99 4.75 5.53 6.33 7.14 7.97 8.8 9.65 10.5 11.4 12.2 13.1 14.0 14.9 15.8 16.7 5% 0.05 0.38 0.9 1.52 2.22 2.96 3.74 4.54 5.37 6.22 7.08 7.95 8.83 9.73 10.6 11.5 12.5 13.4 14.3 15.2 16.2 17.1 18.1 7% 0.1 0.5 1.1 1.8 2.5 3.3 4.1 5 5.9 6.8 7.7 8.6 9.5 10.5 11.4 12.4 13.4 14.3 15.3 16.3 17.3 18.2 19.2 10% 0.11 0.6 1.27 2.05 2.88 3.76 4.67 5.6 6.55 7.51 8.49 9.47 10.5 11.5 12.5 13.5 14.5 15.5 16.6 17.6 18.7 19.7 20.7 15% 0.18 0.8 1.6 2.5 3.45 4.44 5.46 6.5 7.55 8.62 9.69 10.8 11.9 13 14.1 15.2 16.3 17.4 18.5 19.6 20.8 21.9 23 20% 30% 40% 50% 0.25 0.43 0.67 1 1 1.45 2 2.73 1.93 2.63 3.48 4.59 2.95 3.89 5.02 6.5 4.01 5.19 6.6 8.44 5.11 6.51 8.19 10.4 6.23 7.86 9.8 12.4 7.37 9.21 11.4 14.3 8.52 10.6 13 16.3 9.68 12 14.7 18.3 10.9 13.3 16.3 20.3 12 14.7 18 22.2 13.2 16.1 19.6 24.2 14.4 17.5 21.2 26.2 15.6 18.9 22.9 28.2 16.8 20.3 24.5 30.2 18 21.7 26.2 32.2 19.2 23.1 27.8 34.2 20.4 24.5 29.5 36.2 21.6 25.9 31.2 38.2 22.8 27.3 32.8 40.2 24.1 28.7 34.5 42.1 25.3 30.1 36.1 44.1 49
  50. 50. Traffic Engineering • If a traffic map is provided, the traffic engineering is done together with the coverage design • After the individual sites are located, the estimated number of subscribers in each sector is calculated by :• Calculating the physical area covered by each sector • Multiply it by the average subscriber density per unit area in that region • The overlap areas between the sectors should be included in each sector because either sector is theoretically capable of serving the area • The number of channels required is then determined by :• Calculating the total Erlangs by multiplying the area covered by the average load generated per subscriber during busy hour • Determine the required number of TCH and then the required number of TRXs • If the number of TRXs required exceeded the number 50 of TRXs supported by the available spectrum, additional
  51. 51. SWAP PLAN • Why do we need a swap plan? To reduce mix of different vendor BTS within a large city / area • Reduce Inter MSC HO. • Better maintenance efficiency Swap Strategy • No. of existing BTS sites with configuration known • No. of new sites with configuration known. 51
  52. 52. For Example BSNL UP(W) Circle 52
  53. 53. UP(W) Circle Network Diagram Harya na a Sa h ranp ur Uttaranch al Muzaffarnagar NCR Ghaziabad Delhi Harya na Nep al Moradabad Noida Bulandshahr Mathura l i g a r A Nokia BTS Bij nor M ut e er h R p am ur Bareilly Budaun All DHQ on Nokia Pilbhit Etah Rajasth an Agr a Mainpuri Ericcsson BT UP ( E ) Et ah aw 53
  54. 54. UP(W) Circle Network Distribution  Major Cities /SSA’s to be deployed on Nokia BTS          DHQ of all SSA’s Meerut Agra Mathura Noida Ghaziabad Muzaffarnagar Aligarh Bulandshahar  SSA’s except DHQ’s deployed on Ericsson BTS           Bijnor Bareilly Moradabad Etah Etawah Rampur Pilbhit Badaun Mainpuri Saharanpur 54
  55. 55. HW & Rly Plan for UPW NH58 Harya na Saharanpur Uttaranch al Muzaffarnagar Bijnor Meerut Ghaziabad Del hi NH02 Harya na Moradabad Noi da Rampur Bulandshahar Pilbhit Badaun Bareilly Nep al 69 Ericsson HW Site 56 Nokia HW Site National HW Aligarh Etah Mathura Railways State Highway Agra Rajasth an Mainpuri UP ( E ) District Border NH-91 Etawah NH03 NH24 55
  56. 56. SWAP SUMMARY Sl NO SSA PH-IV PLANNED NOKIA SWAP NOKIA WITH ERICSSON EXISTING ERICSSON SWAP ERICSSON WITH NOKIA TOTAL NOKIA TOTAL ERICSSO N Highways Nokia GRAND TOTAL A B C D E F G H (A+D-B) (C-D+B) (E+F+G) 1 Agra 74 2 43 37 109 8 8 125 2 Aligarh 40 4 27 19 55 12 1 68 3 Badaun 16 10 11 3 9 18 1 28 4 Bareilly 45 11 27 17 51 21 2 74 5 Bijnor 39 32 16 3 10 45 0 55 6 Bulandshahar 27 3 17 12 36 8 1 45 7 Etah 17 12 10 3 8 19 3 30 8 Etawah 29 21 16 4 12 33 0 45 9 Ghaziabad 27 1 15 9 35 7 0 42 10 Mainpuri 22 17 12 2 7 27 0 34 11 Mathura 34 1 22 17 50 6 7 63 12 Meerut 68 5 30 26 89 9 11 109 13 Moradabad 73 35 33 16 54 52 9 115 14 Muzaffarnagar 48 10 17 13 51 14 3 68 15 Noida 12 0 8 6 18 2 0 20 16 Pilbhit 11 6 6 2 7 10 5 22 17 Rampur 20 13 11 3 10 21 0 31 18 Saharanpur 31 18 16 9 22 25 5 52 Total 633 201 337 201 633 337 56 1026 56
  57. 57. UP(W) Circle 24volt BTS Distribution • Before Swap 24volt’s ( 40 ) BTS status • Agra – 9 • Aligarh – 2 • Bareilly – 5 • Mathura – 2 • Meerut – 3 • Moradabad – 6 • Saharanpur – 4 • Bijnor – 2 • Bulandshahar – 2 • Etah – 1 • Etawah – 3 • Pilibhit – 1  After Swap 24volt’s ( 40 ) BTS status  Agra – 1  Moradabad – 16  Saharanpur – 1  Bijnor – 17  Etah – 1  Etawah – 3  Bulandshahr – 1  Out of 40 sites 31 have been swapped to  Bijnor – 16  Moradabad – 15  Out of 40 sites 9 left as it is ( No Swap )  Agra - 1  Moradabad – 1  Saharanpur – 1  Bijnor – 1  Bulandshahr – 1  Etah – 1  Etawah – 3 57
  58. 58. Advanced Network Planning Steps 58
  59. 59. Parameter Planning • Parameter planning means creating a default set of BSS parameters. • The most important parameters to plan for: • frequencies • BSIC • LAC • handover control parameters • adjacent cell definitions. 59
  60. 60. BSS Parameter • Relevant BSS parameter for NW planning • frequency allocation plan • transmit power • definition of neighbouring cells • definition of location areas • handover parameters • power control parameters • cell selection parameters 60
  61. 61. Handover Types • Intracell timeslot • Intercell same cell, other carrier or between cells (normal case) • Inter-BSC between BSC areas • Inter-MSC between MSC areas • Inter- PLMN e.g. between AMPS and GSM systems intracell intercell inter-BSC 61
  62. 62. Handover Criteria 1. Interference, UL and DL 2. Bad C/I ratio 3. Uplink Quality 4. Downlink Quality 5. Uplink Level 6. Downlink Level 7. Distance 8. Rapid Field Drop 9. MS Speed 10. Better Cell, i.e. periodic check (Power Budget, Umbrella Handovers) 11. Good C/I ratio 12. PC: Lower quality/level thresholds (DL/UL) 13. PC; Upper quality/level thresholds (DL/UL) 62
  63. 63. Location Area Design 1/2 • Location updating affects all mobiles in network • LocUp in idle mode • LocUp after call completion major road Location area 2 • Location updating causes signalling and processing load within the network (international LocUpdate !) • Avoid oscillating LocUpdate • Trade-off between Paging load and Location Update signalling Location area 1 63
  64. 64. Location Area Design 2/2 • Different MSC can not use the same LAC. • Location areas are important input for transmission planners • should be planned as early as possible. • Never define location area borders along major roads! • Dual band or microcellular networks require more attention on LAC planning • co-located DCS and GSM cells are defined to the same LAC • same MSC to avoid too much location updates which would cause very high SDCCH blockings 64
  65. 65. Network Optimisation 65
  66. 66. What is network optimisation? 66
  67. 67. Network Optimisation is: • Improving network quality from a subscribers point of view. • Improving network quality from an operators point of view. 67
  68. 68. What is network quality? 68
  69. 69. Overall Network Quality • H/W Failure • Network Configuration • Network Traffic • Spectrum Efficiency O P E R A T O R C U S T O M E R NETWORK • Coverage yes/no • Service Probability • Quality • Call Set Up Time • Call Success Rate • Call Completion Rate SERVICES • Mail Box, Data, Fax, etc. • Customer Care MOBILE • Faulty H/W or S/W • Mobile Quality • Misuse of Equipment COST H/W Costs Subscription/Airtime costs Additional Services Costs Network Equipment Costs Maintenance Costs Site Leasing Costs Transmission Link Costs 69
  70. 70. Tools for Optimisation Cell Planning Tools • Prediction • Simulation Network Measurement Tools • Propagation • Drive test Network Management System • Network configuration • BSS parameter data • Network performance 70
  71. 71. Performance Feedback • Network is under permanent change • ==> detect problems and symptoms early! OMC It´s far too late when customers complain! field tests customer complaints 71
  72. 72. Optimize compared to what? 72
  73. 73. Key Performance Indicators, KPI • KPIs are figures used to evaluate Network performance. • post processing of NMS data or • drive test measurements data • Usually one short term target and one long term target. • check the network evolution and which targets are achieved • KPIs calculated with NMS data • network performance on the operator side. • KPIs from drive test • performance on the subscribers side • Usually turn key projects are evaluated according to some predefined 73KPIs
  74. 74. Network Performance Evaluation with NMS • The most reliable KPIs to evaluate the network performance with NMS are: • SDCCH and TCH congestion • Blocking percentage [%] • Drop call rate [%] • Handover failure and/or success rate • Call setup success rate • Average quality DL and UL • The targets are always defined by the customer but the following figures can be considered as satisfactory results: • Item limit Target Lowest acceptable • Dropped calls: <2 % 4 % • Handover success >98 % 96 % • Good Qual samples (0..5) >98 % 95 % 74
  75. 75. Drive Test Measurements • Evaluate network performance from the subscriber point of view • KPIs information: • DL quality, call success rate, handover success rate, DL signal level • not statistically as reliable as NMS information • Added value of drive test measurement : • find out the geographical position of problems like bad DL quality to look for a possible interference source in the area • compare the performance of different networks • display the signal level on the digital maps to individuate areas with lack of coverage eventually improve the propagation model • verify the neighbour list parameter plan 75
  76. 76. Optimisation Process • There are not strict processes for optimization because the activity is driven by the network evolution. 76
  77. 77. Optimisation Process: Young Network Case • In a young network the primary target is normally the coverage. • In this phase usually there is a massive use of drive test measurement • check the signal and • the performance of the competitors MMAC GPS NMS X 77
  78. 78. Optimisation Process: Mature Network Case • In a mature network the primary targets are quality indicators • drop call rate, average quality, handover failures. • Important use the information from NMS • a general view of the network performance. • Drive test measurements are still used • but not in a massive way • in areas where new sites are on air • where interference and similar problems are pointed out by NMS data analysis. Drop Call Rate (%) 3.5 3 2.5 Call Bids / 10000 2 Average 1.5 Busy Hour 1 0.5 0 Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed 78

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