This document provides an overview of RF planning fundamentals and the planning process. It discusses the key steps in RF planning including capacity planning, coverage planning, parameter planning, and optimization. It also covers topics like power budget preparation, propagation models, antenna fundamentals, and extending cell range. The planning process aims to provide sufficient network capacity and coverage while efficiently using the available spectrum.
This document contains parameters related to 2G cell configuration for an Axis network with 2247 sites and 19 BSCs. It includes common cell data parameters like AGBLK, MFRMS, ACCMIN, INDOOR_CELL values. It also includes locating cell filter data parameters like BSPWR, BSTXPWR, MSRXMIN, BSRXMIN for path loss calculation. Finally, it contains locating urgency cell data parameters like TALIM, PSSBQ, PTIMBQ, QLIMDL for handling call quality issues. The parameters need to be optimized for Axis' coverage-limited network.
2G / 3G / 4G / IMS / 5G Overview with Focus on Core NetworkHamidreza Bolhasani
The document provides an overview of mobile networks from 2G to 5G, with a focus on the core network. It describes the key network elements and protocols in 2G/3G networks such as BTS, BSC, NodeB, RNC, SGSN, GGSN. Example call flows and scenarios like location update and SMS are reviewed. GPRS network architecture is introduced including the functions of SGSN, GGSN, CG. Finally, it briefly introduces 5G services before concluding.
Go nast3010 e01_1 2_g-3g cell reselection and handover-37Muhammad Ali Suhail
This document discusses 2G-3G cell reselection and handover between 2G and 3G networks. It covers the conditions required for 2G-3G interworking, various reselection and handover strategies, algorithms for cell reselection and handover, and load balancing handover algorithms. The key goals are to understand interworking between 2G and 3G networks and how to perform efficient reselection and handover of calls and data sessions between the two network types.
This document discusses parameters related to idle mode in GSM-GPRS networks. It describes the structure of BSS parameters including those for the BSC, BTS, handover control, power control, and adjacent cells. It then explains various aspects of idle mode including cell selection, cell reselection using criteria C1 and C2, and how parameters like cellReselectOffset and temporaryOffset can influence cell priority. It also covers cell reselection hysteresis and provides an example of how these parameters can be used in a dual-band network to optimize call setup between different layers.
This document provides an overview and detailed descriptions of Circuit Switched Fallback (CSFB) features in an evolved Radio Access Network (eRAN). It describes CSFB procedures for falling back from an LTE network to UTRAN or GERAN networks to support circuit switched services like voice calls. The document includes sections on CSFB architectures, handover decisions and executions, related interfaces, engineering guidelines, parameters and troubleshooting.
The document outlines basic call flows for location updates, mobile originating calls (MOC), mobile terminating calls (MTC), and IP calls. It describes the key steps as:
1) Location update involves identity response, authentication between the SIM and MSC, update location requests, and ciphering.
2) For MOC, the mobile station sends a setup message with the dialed number, the MSC sends a send routing information message to the HLR, and the HLR responds with routing instructions allowing the call to be connected.
3) For MTC, the MSC requests a roaming number from the HLR, the HLR provides a number and the MSC pages the mobile station to alert
This document provides an overview of the key principles and components of a GSM network, including:
- The mobile station consists of the mobile equipment and subscriber identity module.
- The base station subsystem comprises the base transceiver station, which provides radio access, and the base station controller, which manages radio resources.
- The network switching subsystem includes the mobile switching center, home location register, visitor location register, and equipment identity register.
- The network uses several interfaces to connect the different components and allow mobility across the network.
This document contains parameters related to 2G cell configuration for an Axis network with 2247 sites and 19 BSCs. It includes common cell data parameters like AGBLK, MFRMS, ACCMIN, INDOOR_CELL values. It also includes locating cell filter data parameters like BSPWR, BSTXPWR, MSRXMIN, BSRXMIN for path loss calculation. Finally, it contains locating urgency cell data parameters like TALIM, PSSBQ, PTIMBQ, QLIMDL for handling call quality issues. The parameters need to be optimized for Axis' coverage-limited network.
2G / 3G / 4G / IMS / 5G Overview with Focus on Core NetworkHamidreza Bolhasani
The document provides an overview of mobile networks from 2G to 5G, with a focus on the core network. It describes the key network elements and protocols in 2G/3G networks such as BTS, BSC, NodeB, RNC, SGSN, GGSN. Example call flows and scenarios like location update and SMS are reviewed. GPRS network architecture is introduced including the functions of SGSN, GGSN, CG. Finally, it briefly introduces 5G services before concluding.
Go nast3010 e01_1 2_g-3g cell reselection and handover-37Muhammad Ali Suhail
This document discusses 2G-3G cell reselection and handover between 2G and 3G networks. It covers the conditions required for 2G-3G interworking, various reselection and handover strategies, algorithms for cell reselection and handover, and load balancing handover algorithms. The key goals are to understand interworking between 2G and 3G networks and how to perform efficient reselection and handover of calls and data sessions between the two network types.
This document discusses parameters related to idle mode in GSM-GPRS networks. It describes the structure of BSS parameters including those for the BSC, BTS, handover control, power control, and adjacent cells. It then explains various aspects of idle mode including cell selection, cell reselection using criteria C1 and C2, and how parameters like cellReselectOffset and temporaryOffset can influence cell priority. It also covers cell reselection hysteresis and provides an example of how these parameters can be used in a dual-band network to optimize call setup between different layers.
This document provides an overview and detailed descriptions of Circuit Switched Fallback (CSFB) features in an evolved Radio Access Network (eRAN). It describes CSFB procedures for falling back from an LTE network to UTRAN or GERAN networks to support circuit switched services like voice calls. The document includes sections on CSFB architectures, handover decisions and executions, related interfaces, engineering guidelines, parameters and troubleshooting.
The document outlines basic call flows for location updates, mobile originating calls (MOC), mobile terminating calls (MTC), and IP calls. It describes the key steps as:
1) Location update involves identity response, authentication between the SIM and MSC, update location requests, and ciphering.
2) For MOC, the mobile station sends a setup message with the dialed number, the MSC sends a send routing information message to the HLR, and the HLR responds with routing instructions allowing the call to be connected.
3) For MTC, the MSC requests a roaming number from the HLR, the HLR provides a number and the MSC pages the mobile station to alert
This document provides an overview of the key principles and components of a GSM network, including:
- The mobile station consists of the mobile equipment and subscriber identity module.
- The base station subsystem comprises the base transceiver station, which provides radio access, and the base station controller, which manages radio resources.
- The network switching subsystem includes the mobile switching center, home location register, visitor location register, and equipment identity register.
- The network uses several interfaces to connect the different components and allow mobility across the network.
This document provides an overview of optional features for UTRAN UR11.1, including wideband AMR speech support, PS signaling bearers for IMS, cell broadcast service, PS conversational bearers for VoIP, robust header compression, and PS conversational bearers for VoIP over HSDPA. It describes the benefits and technical details of each feature. The document also includes figures illustrating network architectures, protocols, and technical concepts related to the optional features.
The document provides an overview of how to use Actix software to analyze drive test data. It discusses installing Actix, creating workspaces and cell references, loading and analyzing 2G and 3G call log files to view KPIs and generate reports, and using the Spotlight feature for radio network analysis and event-based troubleshooting. The summaries generated focus on the high-level steps and key capabilities of Actix for drive test data analysis.
The document summarizes key LTE parameters including RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, throughput, latency, tracking area code, timing advance, and transmit power. RSRP measures reference signal power and is used for coverage and path loss calculations. RSRQ measures signal quality near cell edges. SINR measures signal quality accounting for interference and noise. CQI indicates downlink channel quality. PCI identifies cells. BLER indicates block error rate. Latency aims to be less than 10ms for user data and 100ms for control signaling. Timing advance synchronizes uplink transmissions accounting for UE distance from the base station.
This document discusses network optimization techniques including:
1. Monitoring key performance indicators (KPIs) such as transmitted carrier power, code tree allocation, and channel element allocation to identify issues.
2. Performing analysis of KPIs to locate root causes of failures in specific network elements or cells.
3. Proposing solutions such as adjusting signal transmission power limits, code tree rearrangement, or adding network capacity to address problems identified through monitoring and analysis.
The document provides an overview and analysis flow for optimizing the performance of a mobile network. It discusses various problems that can occur like low availability of control channels, congestion on signaling and traffic channels, and high drop call rates. For each problem, it lists probable causes and recommends actions to identify the issue and solutions to resolve it, such as adjusting configuration parameters, adding network capacity, or improving frequency planning. MML commands are also provided to check device logs, resources, and performance statistics for troubleshooting purposes.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
This document provides an overview of network drive testing on 2G/3G networks. It discusses the reasons for performing drive tests, including network performance monitoring, maintenance, benchmarking, and addressing customer complaints. It then outlines the modules to be covered in the training, including an overview of 3G systems, drive test concepts, performing outdoor drive tests, and drive test reporting and analysis. Key topics that will be covered include 3G/UMTS architectures, channelization, handover processes, and the parameters measured during 2G and 3G drive tests.
Ericsson 2 g ran optimization complete trainingsekit123
This document provides an overview of Ericsson 2G RAN optimization training. It outlines the purpose of the training, which is to give an overview of Ericsson hardware capabilities and limitations and provide an in-depth introduction to optimization processes and features. The document summarizes key hardware such as BSCs, RBSs, TRUs, and CDUs as well as concepts like channel allocation profiles and quality measurement. It also lists common Ericsson optimization tools.
The document discusses UMTS planning and dimensioning processes. It describes:
1) The overall planning process which includes system dimensioning, radio network planning, pre-launch optimization, performance monitoring, and post-launch optimization.
2) The inputs, assumptions, and steps used for air interface dimensioning which includes uplink and downlink link budget analysis to determine coverage requirements and capacity needs.
3) Traffic modelling and load calculation methods to estimate subscriber traffic per cell based on factors like subscriber density, traffic profiles, and cell area.
The document discusses key concepts and components of GSM and WCDMA mobile networks. It describes the Home Location Register (HLR) and Visitor Location Register (VLR) which store subscriber information and location data. It also mentions the Authentication Center (AUC), Equipment Identity Register (EIR), and Base Station System (BSS). For WCDMA, it outlines the interfaces between network elements like Iu, Uu, Iub, and Iur and discusses radio access bearers, spreading factors, and the use of channel elements for network sizing.
This document discusses cell selection and reselection in GSM networks. It explains:
1) Cell selection is performed when a mobile first turns on to select an initial "camped-on" cell. Reselection occurs when the mobile moves to ensure it remains on the best cell.
2) C1 and C2 criteria are used for selection and reselection. C1 compares signal levels and C2 adds offsets.
3) In the scenario, the mobile selects the 900MHz cell using C1/C2 criteria. To prefer the 1800MHz cell instead, the document suggests using the C2 formula without offsets by setting the penalty time lower.
TEMS tools are used at various stages of radio network design, rollout, operation and improvement. During the design and rollout phase, TEMS is used for network integration testing, initial tuning, and GPRS performance verification. In the operation and improvement phase, it is used for traditional optimization and network feature optimization. TEMS allows measurement of key performance indicators, analysis of issues like low signal strength, interference, handover problems and call setup failures. It helps identify root causes and evaluate potential solutions.
This document provides guidelines for optimizing accessibility in Ericsson networks. It discusses key performance indicators (KPIs) for measuring accessibility, including call setup success rate and overall service accessibility. It also analyzes factors that can affect accessibility, such as admission control, processor load, and issues after call admission like congestion. Annexes describe user equipment idle mode procedures and call establishment procedures in detail.
5G Network Architecture, Design and Optimisation3G4G
Presented by Prof. Andy Sutton, Principal Network Architect, Architecture & Strategy, TSO, BT at The IET '5G - State of Play' conference on 24th January 2018
*** SHARED WITH PERMISSION ***
This document outlines the process for mobile originated and terminated calls in 3G networks. It describes the steps for a mobile originating call in 3 parts and a mobile terminated call in 3 parts, including setting up the GTP tunnel for transport. The document breaks down the end-to-end call flows for 3G connections.
This document provides an introduction to 5G technology, including:
- 5G aims to meet growing connectivity needs and fulfill diverse use cases such as drones, augmented reality, and the Internet of Things.
- 5G standards are being developed by 3GPP and ITU, with 3GPP specifying the radio technology beyond LTE known as New Radio (NR).
- 5G requirements defined by 3GPP include high peak data rates, low latency, high reliability, large connection densities, and support for high mobility.
The document provides information on drive testing in GSM networks. Drive testing involves using mobile devices to collect network performance data along predetermined routes. This helps evaluate coverage, availability, capacity, retainability, and call quality from the subscriber perspective. Key aspects discussed include the hardware requirements for drive testing (laptop, data collection software, mobile phones, GPS), different test modes (dedicated call, idle, scan), and important metrics to analyze (Rx level, Rx quality, bit error rate, frame erasure rate, speech quality index). TEMS software is highlighted as a common tool for collecting data and analyzing network performance based on drive test results.
This document provides guidelines for optimizing 3G networks through neighbor optimization and coverage adjustments. The objectives are to have an optimum number of neighbors to clean up pilot pollution, reduce overshooting, increase capacity, and reduce the possibility of soft congestion conflicts. The methodology involves deleting and adding neighbors based on data from the OSS, as well as adjusting antenna tilting. The optimization sequence is outlined, including guidelines for neighbor deletion, addition of different neighbor types, and planning of the SIB11. The end goal is to have fewer than 36 total neighbors and avoid blocking alarms due to too many neighbors.
The GSM network is comprised of the following components:
Network Elements
The GSM network incorporates a number of network elements to support mobile equipment. They are listed and described in the GSM network elements section of this chapter.
GSM subsystems
In addition, the network includes subsystems that are not formally recognized as network elements but are necessary for network operation. These are described in the GSM subsystems (non-network elements) section of this chapter.
Standardized Interfaces
GSM specifies standards for interfaces between network elements, which ensure the connectivity of GSM equipment from different manufacturers. These are listed in the Standardized interfaces section of this chapter.
Network Protocols
For most of the network communications on these interfaces, internationally recognized communications protocols have been used
These are identified in the Network protocols section of this chapter.
GSM Frequencies
The frequency allocations for GSM 900, Extended GSM and Digital Communications Systems are identified in the GSM frequencies section of this chapter.
GSM networks are digital and can cater for high system capacities. They are consistent with the world wide digitization of the telephone network, and are an extension of the Integrated Services Digital Network (ISDN), using a digital radio interface between the cellular network and the mobile subscriber equipment
The GSM system provides a greater subscriber capacity than analogue systems. GSM allows 25 kHz. Per user, that is, eight conversations per 200kHz. Channel pair (a pair comprising one transmit channel and one receive channel). Digital channel coding and the modulation used makes the signal resistant to interference from the cells where the same frequencies are re-used (co-channel interference); a Carrier to Interference Ratio (C/I) level of 9 dB is achieved, as opposed to the 18 dB typical with analogue cellular. This allows increased geographic reuse by permitting a reduction in the number of cells in the reuse pattern. Since this number is directly controlled by the amount of interference, the radio transmission design can deliver acceptable performance.
This document provides an overview of GSM and the basics of 3G mobile networks. It discusses the introduction and features of GSM, the GSM architecture including mobile stations, base station systems, and network switching systems. It then covers GSM interfaces, channelization, handover, and the evolutions of 3G technologies including HSDPA and HSUPA. The benefits of HSPA for 3G are also summarized.
The document outlines the procedure for CDMA network design in 5 stages:
1. Preparations including setting design criteria like coverage reliability, capacity, and soft handoff ratios.
2. RF environment analysis involving region clustering, site surveys, competitor analysis, and link budget analysis.
3. Coverage design for outdoor, indoor, and underground areas.
4. Parameter design including pilot assignment and base station dimensioning.
5. Reporting and dimensioning to determine equipment requirements.
This document describes a project to simulate the planning and design of an LTE cellular network using CellPlanner software. It provides background on LTE technology and the need for network simulation. The objectives are to provide coverage to the given area with a minimum data rate of 10Mbps using non-directional antennas, and above 12Mbps for most areas using directional antennas. Key considerations include the topology, morphology, system parameters, and radio configurations. Simulation results achieved 90% coverage area meeting data rate requirements, with a tradeoff of using more base stations in some difficult terrain areas.
This document provides an overview of optional features for UTRAN UR11.1, including wideband AMR speech support, PS signaling bearers for IMS, cell broadcast service, PS conversational bearers for VoIP, robust header compression, and PS conversational bearers for VoIP over HSDPA. It describes the benefits and technical details of each feature. The document also includes figures illustrating network architectures, protocols, and technical concepts related to the optional features.
The document provides an overview of how to use Actix software to analyze drive test data. It discusses installing Actix, creating workspaces and cell references, loading and analyzing 2G and 3G call log files to view KPIs and generate reports, and using the Spotlight feature for radio network analysis and event-based troubleshooting. The summaries generated focus on the high-level steps and key capabilities of Actix for drive test data analysis.
The document summarizes key LTE parameters including RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, throughput, latency, tracking area code, timing advance, and transmit power. RSRP measures reference signal power and is used for coverage and path loss calculations. RSRQ measures signal quality near cell edges. SINR measures signal quality accounting for interference and noise. CQI indicates downlink channel quality. PCI identifies cells. BLER indicates block error rate. Latency aims to be less than 10ms for user data and 100ms for control signaling. Timing advance synchronizes uplink transmissions accounting for UE distance from the base station.
This document discusses network optimization techniques including:
1. Monitoring key performance indicators (KPIs) such as transmitted carrier power, code tree allocation, and channel element allocation to identify issues.
2. Performing analysis of KPIs to locate root causes of failures in specific network elements or cells.
3. Proposing solutions such as adjusting signal transmission power limits, code tree rearrangement, or adding network capacity to address problems identified through monitoring and analysis.
The document provides an overview and analysis flow for optimizing the performance of a mobile network. It discusses various problems that can occur like low availability of control channels, congestion on signaling and traffic channels, and high drop call rates. For each problem, it lists probable causes and recommends actions to identify the issue and solutions to resolve it, such as adjusting configuration parameters, adding network capacity, or improving frequency planning. MML commands are also provided to check device logs, resources, and performance statistics for troubleshooting purposes.
The document discusses various resources in an LTE network that need to be monitored to ensure capacity and quality of service. It describes several key performance indicators (KPIs) related to resources like connected users, traffic volume, paging messages, processor usage, and provides thresholds and solutions to address issues.
This document provides an overview of network drive testing on 2G/3G networks. It discusses the reasons for performing drive tests, including network performance monitoring, maintenance, benchmarking, and addressing customer complaints. It then outlines the modules to be covered in the training, including an overview of 3G systems, drive test concepts, performing outdoor drive tests, and drive test reporting and analysis. Key topics that will be covered include 3G/UMTS architectures, channelization, handover processes, and the parameters measured during 2G and 3G drive tests.
Ericsson 2 g ran optimization complete trainingsekit123
This document provides an overview of Ericsson 2G RAN optimization training. It outlines the purpose of the training, which is to give an overview of Ericsson hardware capabilities and limitations and provide an in-depth introduction to optimization processes and features. The document summarizes key hardware such as BSCs, RBSs, TRUs, and CDUs as well as concepts like channel allocation profiles and quality measurement. It also lists common Ericsson optimization tools.
The document discusses UMTS planning and dimensioning processes. It describes:
1) The overall planning process which includes system dimensioning, radio network planning, pre-launch optimization, performance monitoring, and post-launch optimization.
2) The inputs, assumptions, and steps used for air interface dimensioning which includes uplink and downlink link budget analysis to determine coverage requirements and capacity needs.
3) Traffic modelling and load calculation methods to estimate subscriber traffic per cell based on factors like subscriber density, traffic profiles, and cell area.
The document discusses key concepts and components of GSM and WCDMA mobile networks. It describes the Home Location Register (HLR) and Visitor Location Register (VLR) which store subscriber information and location data. It also mentions the Authentication Center (AUC), Equipment Identity Register (EIR), and Base Station System (BSS). For WCDMA, it outlines the interfaces between network elements like Iu, Uu, Iub, and Iur and discusses radio access bearers, spreading factors, and the use of channel elements for network sizing.
This document discusses cell selection and reselection in GSM networks. It explains:
1) Cell selection is performed when a mobile first turns on to select an initial "camped-on" cell. Reselection occurs when the mobile moves to ensure it remains on the best cell.
2) C1 and C2 criteria are used for selection and reselection. C1 compares signal levels and C2 adds offsets.
3) In the scenario, the mobile selects the 900MHz cell using C1/C2 criteria. To prefer the 1800MHz cell instead, the document suggests using the C2 formula without offsets by setting the penalty time lower.
TEMS tools are used at various stages of radio network design, rollout, operation and improvement. During the design and rollout phase, TEMS is used for network integration testing, initial tuning, and GPRS performance verification. In the operation and improvement phase, it is used for traditional optimization and network feature optimization. TEMS allows measurement of key performance indicators, analysis of issues like low signal strength, interference, handover problems and call setup failures. It helps identify root causes and evaluate potential solutions.
This document provides guidelines for optimizing accessibility in Ericsson networks. It discusses key performance indicators (KPIs) for measuring accessibility, including call setup success rate and overall service accessibility. It also analyzes factors that can affect accessibility, such as admission control, processor load, and issues after call admission like congestion. Annexes describe user equipment idle mode procedures and call establishment procedures in detail.
5G Network Architecture, Design and Optimisation3G4G
Presented by Prof. Andy Sutton, Principal Network Architect, Architecture & Strategy, TSO, BT at The IET '5G - State of Play' conference on 24th January 2018
*** SHARED WITH PERMISSION ***
This document outlines the process for mobile originated and terminated calls in 3G networks. It describes the steps for a mobile originating call in 3 parts and a mobile terminated call in 3 parts, including setting up the GTP tunnel for transport. The document breaks down the end-to-end call flows for 3G connections.
This document provides an introduction to 5G technology, including:
- 5G aims to meet growing connectivity needs and fulfill diverse use cases such as drones, augmented reality, and the Internet of Things.
- 5G standards are being developed by 3GPP and ITU, with 3GPP specifying the radio technology beyond LTE known as New Radio (NR).
- 5G requirements defined by 3GPP include high peak data rates, low latency, high reliability, large connection densities, and support for high mobility.
The document provides information on drive testing in GSM networks. Drive testing involves using mobile devices to collect network performance data along predetermined routes. This helps evaluate coverage, availability, capacity, retainability, and call quality from the subscriber perspective. Key aspects discussed include the hardware requirements for drive testing (laptop, data collection software, mobile phones, GPS), different test modes (dedicated call, idle, scan), and important metrics to analyze (Rx level, Rx quality, bit error rate, frame erasure rate, speech quality index). TEMS software is highlighted as a common tool for collecting data and analyzing network performance based on drive test results.
This document provides guidelines for optimizing 3G networks through neighbor optimization and coverage adjustments. The objectives are to have an optimum number of neighbors to clean up pilot pollution, reduce overshooting, increase capacity, and reduce the possibility of soft congestion conflicts. The methodology involves deleting and adding neighbors based on data from the OSS, as well as adjusting antenna tilting. The optimization sequence is outlined, including guidelines for neighbor deletion, addition of different neighbor types, and planning of the SIB11. The end goal is to have fewer than 36 total neighbors and avoid blocking alarms due to too many neighbors.
The GSM network is comprised of the following components:
Network Elements
The GSM network incorporates a number of network elements to support mobile equipment. They are listed and described in the GSM network elements section of this chapter.
GSM subsystems
In addition, the network includes subsystems that are not formally recognized as network elements but are necessary for network operation. These are described in the GSM subsystems (non-network elements) section of this chapter.
Standardized Interfaces
GSM specifies standards for interfaces between network elements, which ensure the connectivity of GSM equipment from different manufacturers. These are listed in the Standardized interfaces section of this chapter.
Network Protocols
For most of the network communications on these interfaces, internationally recognized communications protocols have been used
These are identified in the Network protocols section of this chapter.
GSM Frequencies
The frequency allocations for GSM 900, Extended GSM and Digital Communications Systems are identified in the GSM frequencies section of this chapter.
GSM networks are digital and can cater for high system capacities. They are consistent with the world wide digitization of the telephone network, and are an extension of the Integrated Services Digital Network (ISDN), using a digital radio interface between the cellular network and the mobile subscriber equipment
The GSM system provides a greater subscriber capacity than analogue systems. GSM allows 25 kHz. Per user, that is, eight conversations per 200kHz. Channel pair (a pair comprising one transmit channel and one receive channel). Digital channel coding and the modulation used makes the signal resistant to interference from the cells where the same frequencies are re-used (co-channel interference); a Carrier to Interference Ratio (C/I) level of 9 dB is achieved, as opposed to the 18 dB typical with analogue cellular. This allows increased geographic reuse by permitting a reduction in the number of cells in the reuse pattern. Since this number is directly controlled by the amount of interference, the radio transmission design can deliver acceptable performance.
This document provides an overview of GSM and the basics of 3G mobile networks. It discusses the introduction and features of GSM, the GSM architecture including mobile stations, base station systems, and network switching systems. It then covers GSM interfaces, channelization, handover, and the evolutions of 3G technologies including HSDPA and HSUPA. The benefits of HSPA for 3G are also summarized.
The document outlines the procedure for CDMA network design in 5 stages:
1. Preparations including setting design criteria like coverage reliability, capacity, and soft handoff ratios.
2. RF environment analysis involving region clustering, site surveys, competitor analysis, and link budget analysis.
3. Coverage design for outdoor, indoor, and underground areas.
4. Parameter design including pilot assignment and base station dimensioning.
5. Reporting and dimensioning to determine equipment requirements.
This document describes a project to simulate the planning and design of an LTE cellular network using CellPlanner software. It provides background on LTE technology and the need for network simulation. The objectives are to provide coverage to the given area with a minimum data rate of 10Mbps using non-directional antennas, and above 12Mbps for most areas using directional antennas. Key considerations include the topology, morphology, system parameters, and radio configurations. Simulation results achieved 90% coverage area meeting data rate requirements, with a tradeoff of using more base stations in some difficult terrain areas.
This document discusses radio frequency (RF) planning for cellular networks. It addresses the key aspects of RF planning including:
1) Providing adequate coverage and capacity while using spectrum efficiently and minimizing the number of cell sites.
2) Conducting a planning process that involves inputs from customers, coverage and capacity planning, parameter planning, and optimization.
3) Setting objectives for coverage, capacity, network growth, and cost-effective design.
Wcdma Radio Network Planning And OptimizationPengpeng Song
The document discusses WCDMA radio network planning and optimization, including key topics such as:
1) Fundamentals of WCDMA link budget analysis and radio interface protocol architecture.
2) Radio resource utilization techniques like power control, handover control, and congestion control.
3) Issues of coverage and capacity planning as well as enhancement methods.
4) The process of WCDMA radio network planning including dimensioning, detailed planning, and optimization aspects to address interference.
Engineer EMERSON EDUARDO RODRIGUES PRESENTA UNA NUEVA VERSION
THERE ONE NEW ONE PRESENTATION FOR 2G AND 3G ENGINEERING FOR LTE AND PSCORE ENGINEER
ITS VERY SUITABLE FOR YOUR RESEARCH AT ALL LEVELS OF RF ENGINEERING AND PS CS
Iaetsd gmsk modulation implementation for gsm in dspIaetsd Iaetsd
This document describes the implementation of a GMSK modulator on a TMS320C6713 digital signal processor. GMSK modulation is used in GSM cellular systems due to its bandwidth efficiency. The author designed a simple algorithm to accurately generate GMSK signals in DSP. Key components included a numerically controlled oscillator and Gaussian low-pass filter implemented as a finite impulse response filter. Simulation results were obtained using Elanix software to verify the GMSK modulator design.
Interplay of Communication and Computation Energy Consumption for Low Power S...ijasuc
The sensor network design approach normally considers the communication energy consumption for
evaluating a communication protocol. This is true for the low power devices such as MICAz/MICA2
which do not consume a lot of energy for the data treatment. However, recently developed sensor devices
for multimedia applications such as iMote2 do consume considerable amount of energy for data
processing. In this article, we consider various scenarios for routing the data in wireless multimedia
sensor networks by considering the local design parameters of devices such as PXA27x and beagleboard.
The proposed routing solution considers node level optimizations such as data compression, dynamic
voltage and frequency scaling (DVFS) for making a routing decision. The proposed approaches have
been simulated to prove the effectiveness of the approach.
1. The document discusses planning a WCDMA network, including dimensioning the network, estimating coverage and capacity, and accounting for uncertainties.
2. Dimensioning involves initially estimating the number of sites and equipment needed based on factors like traffic load and distribution. Coverage is estimated using link budget calculations and propagation models. Capacity is estimated based on load factor calculations that account for interference.
3. Planning must consider uncertainties from factors like user locations, speeds, and data rates that impact coverage and capacity in real networks. Both static and dynamic simulations are used to optimize the network plan.
The document discusses ad hoc and sensor networks. It provides sample questions and answers related to various topics in this area. Some key points covered include:
- Characteristics of wireless channels include path loss, fading, interference, Doppler shift, and transmission rate constraints.
- Shannon's theorem states the maximum possible data rate on a noisy channel as a function of bandwidth and signal-to-noise ratio.
- An ad hoc network is a decentralized type of wireless network without any fixed infrastructure. It is suitable for situations where a wired network cannot be setup.
- Challenging issues in ad hoc network maintenance include medium access, routing, multicasting, transport layer protocols, pricing schemes, and quality of service
Final Performance Evaluation of 3GPP NR eMBB within 5G-PPP consortiumEiko Seidel
The document summarizes simulation results evaluating whether 3GPP NR (5G New Radio) technology meets the ITU-R 5G performance targets. Simulations were conducted for different scenarios like indoor hotspot, dense urban, and rural environments. Key findings include:
- In dense urban scenarios at 4GHz, the minimum requirements for user experience data rate and spectral efficiency were met. However, at 30GHz the requirements could not be fulfilled due to insufficient outdoor-to-indoor coverage.
- Minimum requirements were generally met across scenarios, except for some cases using high frequencies like 30GHz where outdoor-to-indoor links were infeasible.
- Area traffic capacity requirements for indoor hotspots were exceeded in
OPERATORS CAN SAVE $14 MILLION YEARLY THROUGH DATA OFFLOADINGGreen Packet
Of late, network congestion is one of the most talked about topic in the telecoms industry has is attributed to the overwhelming growth in data consumption. There is an assortment of solutions to combat congestion, ranging from high investment to cost-effective and short-term to long-term. In this paper, Greenpacket puts forth a cost-effective, immediate and long-term solution to network congestion – data offloading.
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System Consideration, Design and Implementation of Point To Point Microwave L...ijtsrd
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50509750 fundamentals-of-rf-planning
1. D) Fundamentals of RF Planning
Chapter 1 Introduction to RF Planning
Chapter 2 Propagation-1
Chapter 3 Propagation-2
Chapter 4 Frequency planning
Chapter 5 Antenna Fundamentals
Chapter 6 Advanced RF Planning
Chapter 7 Extending Cell Range
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2. Chapter 1 Introduction to RF Planning
Contents:
Introduction to RF Planning
Objectives
The Planning Process
Aims of the planning process
Basic Planning Process
Power Budget Preparation
Power Budget Preparation
Summary
Objectives:
The aims of this section are to enable the student to:
• Describe basic GSM RF Planning and optimization
• List the important characteristics of a good RF plan
• List the basic steps involved in Cell/RF planning
• Prepare a single Power Budget for both uplink and downlink
The Planning Process
A well planned network not only gives reliable operation, it also provides a cost-effective network coupled
with a high quality of service. There are certain issues that need to be examined to produce an effective
network plan.
These include:
Sufficient capacity support
Efficient use of the available frequency spectrum
The minimum number of sites to provide the required service
Flexibility for future expansion
Adequate coverage in a given area with the minimum of interference.
The first step in any plan will be to assess the requirements of the customer. This information will include:
Business plan
The number of subscribers and their distribution
Grade of service
Local constraints
Available frequency spectrum
Once the planned system is implemented, all assumptions need to be validated by following an
optimisation process.
The planning process can be simplified into 4 main headings:
Capacity planning
Coverage planning
Parameter planning
Optimisation
Figure 1-1 illustrates a simplified diagram which itemises the planning process.
Figure 1-2 illustrates a basic outline of the optimisation process.
NOTE The information given in Figure 1-2 under ’Recommendations’ is not in any particular order of
application.
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4. Aims of the planning process
Once the planning and optimisation processes have been carried out, the following aims should have been
met:
Coverage as per expectations and customer request.
Co-channel and Adjacent channel interference levels as predicted and within limits.
Minimum adjustments required to antennas during the optimisation process.
Planning process should be well structured and optimisation restricted to the final stages of
implementation and the commissioning of new sites.
Expansion of the system should be easy and require minimum disruption and changes to the network.
Basic Planning Process
In order to provide the basic elements of a well planned network (good coverage and adequate capacity),
the planner needs to know the customer’ s expectations.
These may be specified as number of subscribers for a given coverage area or a set number of sites in an
area for example.
Armed with either of these, the planner can then begin to assess the number sites required (for a given
number of subscribers), or the capacity capabilities (if given a number of sites).
Certain assumptions are made for the planning process:
25 mE average traffic per subscriber
Grade of Service (air interface) 2%
Mobile to Mobile traffic 10% (Mobile originated & Mobile terminated)
Mobile to PSTN traffic 70% (Mobile originated)
Land to Mobile traffic 20% (Mobile terminated)
Average Call duration 90 secs
Traffic Capacity of 1 carrier with 7 TCHs:
2.94E (approximately 118 subscribers). A 1/1/1 site will have capacity of approximately 350 subscribers.
Traffic capacity of 2 carriers with 14 TCHs: 8.2E (approximately 330 subscribers).
A 2/2/2 site will have a capacity of about 990 subscribers.
As an example, if the customer has given the maximum number of sites for a city as 20, then the capacity
of those sites would be as follows:
For a 1/1/1 site:
350 subscribers per site - 350 x 20 = 7000 subscribers
For a 2/2/2 site:
990 subscribers per site - 990 x 20 = 19800 subscribers
If the customer specified capacity required was for 10000 subscribers, then to support these subscribers
using 1/1/1 sites, the planner would calculate 29 sites would easily support the subscribers.
For a network utilising 2/2/2 sites, 11 sites would support the 10000 subscribers. The actual deployment of
the sites and their configuration would depend on the subscriber distribution within the coverage area.
Table 1-1 illustrates how subscribers/erlangs may be distributed over a given area.
Subscriber Distribution
Table 1-1 Subscriber Distribution
Area Type Traffic
%
Erlangs Subscribers 1/1/1 Sites 2/2/2 Sites
Urban - High
Density
20 50 2000 6 2
Urban 30 75 3000 9 3
Industrial 15 37.5 1500 5 2
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5. Suburban 25 62.5 2500 8 3
Highways 5 12.5 500 2 1
Quasi-open 5 12.5 500 2 1
Totals 100 250 10000 32 12
If it is decided that the sites whose traffic is _ 20% will be 2/2/2 configuration and the rest will be 1/1/1,
then the total sites would be:
8 @ 2/2/2 + 9 @ 1/1/1 = 17 sites
It is possible to calculate an approximate area covered for a given number of sites. For instance, a cell with
a 1km radius can give coverage for about 3sq.km. Therefore, if we needed to provide coverage for a city
with an area of 250sq. km, then we would require approximately 84 sites.
The number of sites could be reduced if the less busy areas of the city were covered utilising larger cells
with the more dense capacity areas using smaller cells.
Any area can be divided into one or more of the following areas:
Urban
Suburban
Quasi-Open
Open
Water
Once sample site areas (areas selected which take into account all types of clutter) have been chosen
several basic steps then need to be carried out:
Site surveys - assessing building heights and construction obstructions, foliage, orientation of sectors,
local legal requirements.
Preparation of power budgets.
Propagation tests - using drive tests to obtain data for the site to calculate coverage probabilities.
Propagation model adjustment - using drive test results to modify propagation model for more accurate
prediction.
Power Budget Preparation
One of the first steps in the planning process is the production of a power budget for both uplink and
downlink. Table 1-2 shows a power budget spreadsheet using typical values.
The following however should be noted:
BTS receiver sensitivity is quoted at -107dBm, but it could be as good as 110dBm
MS receiver sensitivity is quoted at -102dBm, but could be as good as 105dBm
The actual peak power of a MS is typically 31-32dBm even though the peak power is stated at 33dBm,
this means that the uplink power budget is normally 1-2dB worse than in Table 1-2.
Diversity gain, although nominally quoted at 3dB, could be anything from 0-4dBm depending upon
environment, MS location, diversity type, etc.
The maximum permitted path loss (MPL) in the downlink is 2dB more than the uplink allowable loss. This
may mean reduction of BTS output by 2dB to maintain system balance.
If the difference was only 1dBm, then the BTS cannot be adjusted down to obtain system balance because
it can only be adjusted in 2dB steps. In this case, the lower value of MPL would be taken as the design
parameter.
The majority of the system losses/gains are the same because they are equipment related.
Fade margin is a function of the area coverage probability. If it is 4dB for 90% coverage, then the minimum
isotropic receive Power that is required for 90% coverage probability outdoors is -92dBm. Fade Margin is
discussed in a later section.
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6. Power Budget Preparation
The allowable path loss calculated in the power budget is the absolute maximum permissable and includes:
Free Space Loss
Clutter Factors
Coverage Confidence Level (Probability of coverage of the area)
If the actual loss value is better than that calculated, then the cell size is adequate to give the performance
predicted.
With the cell commissioned, drive test readings can be taken to give actual signal strengths. With these
values, statistical tools can then be employed to produce coverage probabilities and the required Fade
Margin.
By using these values in the Power Budget, the processes can be repeated until the system is ’ fine tuned’ to
produce the radius and performance required.
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7. Power Budget will be discussed again in the Propagation Models section.
Summary
RF planning can be broken down into several basic steps and requires understanding of the following:
Propagation Models
Coverage requirements
Link (Power) Budgets
Antenna factors
Frequency Planning and re-use
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8. Chapter 2 Propagation-1
Contents:
Propagation – 1
Objective
Radio Signal Propagation
Multipath Environment
Knife-Edge Diffraction
Cell Defination
Urban Propagation Environment
Building Penetration
Propagation Models
Okumura-Hata Model
Hata’ s Propagation Formula
Corrections to Okumura-Hata Model
Cost 231-Hata Propagation Model
Example 1
Cell Radius
Example 2
Example 3
Walfisch-Ikegami Model
Line-Of-Sight Propagation
Non Line-Of-Sight Propagation
Non Line-Of-Sight Propagation (cont’ d)
Microcellular Environment
Fresnel Zones
Example 4
Ray Tracing Model
Propagation Model Selection
Objectives:
The aims of this section are to enable the student to show basic knowledge of, and calculate:
• Radio propagation in fre space
• Fresnel zones and their effect
• Effects of the environment on radio propagation
• Building losses and In-Building coverage
• Path loss in different propagation environments and the use of relevant
propagation models in prediction
• Macro and Micro cellular principles
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10. Multipath Environment
In a mobile environment, there is seldom a direct line of sight between the mobile and the BTS. Hence the
pure free space path loss calculated as per the formula given in the previous page is not directly applicable.
The signal almost always arrives via multiple paths at the receiver end, be it a mobile or the BTS as shown
in Figure 2-2.
The multi path is due to reflection, diffraction and scattering of radio waves. The extent of these effects
depends on the type and the total area of the obstruction. For instance, a
plain surface will cause maximum reflection whilst a sharp edge like the corner of a
building will cause scattering of signals known as ’ Knife-Edge Diffraction’.
Knife-Edge Diffraction
Propagation over rough terrain is dependant on the size of objects encountered over that terrain with respect
to the frequency used.
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11. If the wavelength of the signal is much less than the size of the object, then waves will be reflected.
If the wavelength of the signal is much greater than the size of the object, the effect will be minimal.
Values in between these extremes will have variable effect on propagation. The signals will tend to ’ curve’
around the objects.
Figure 2-3 shows the effect on the signal of Knife-Edge Diffraction.
Knife-Edge Diffraction
Cell Definition
A cell is a geographical area, which is covered by radio signals. Conventionally, a practical cell is
considered to have an irregular shape, with uniform Receive Signal Strength (RSS) all around. This is
shown in Figure 2-4 (a).
However, it is convenient to assume a regular shape for analytical and planning purposes. Ideally a cell
should be circular in shape Figure 2-4 (b) with varying signal strengths all around. From a geometrical
point of view this can be approximated by a hexagon, with different RSS values on the sides. As illustrated
in Figure 2-4 (c).
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12. Urban Propagation Environment
Of all the types of propagation environment considered in a mobile communications network, the most
common, and also most unpredictable is the Urban environment. The Urban environment consists of many
types of ’ obstruction’ . The predominant features are the buildings within the area. As well as the effects of
the environment (buildings, foliage etc.) on external propagation levels, account must be taken of the effect
the construction of the buildings has on signal levels inside the buildings themselves.
Building Penetration
The attenuation given by a building is simply the difference between signal level outside the building and
the level inside.
The attenuation afforded by a building will depend on several factors:
Construction materials
Thickness of walls
Size of the building
Angle of arrival of the signals
Typically, signal values can vary by as much as -40dB to 80dB depending on the various factors.
Generally speaking, a building with a wall facing the signal origin will offer less penetration loss than one
which is at an angle to the signal source.
Also, Doors and windows will offer less resistance to RF signals than walls and will thus provide a better
penetration of RF signals.
Another factor which can contribute to the degradation of signals within a building is the amount of
furnishing within it. A fully furnished building can give 2-3dB more attenuation than one which is empty.
Figure 2-5 gives some typical values for varying building types and uses.
NOTE The values given are for illustration purposes only and are not definitive.
Building Attenuation
Type of Building Attenuation
in dBs
Farms, Wooden Houses, Sport Halls 0-3
Small offices, Parking lots, Independent
houses, Small apartment blocks
4-7
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13. Row houses, Offices in containers,
Offices, Apartment blocks
8-11 dB
Offices with large areas 12 -15 dB
Medium Factories, workshops without
roof top windows
16 -19
Halls of metal, without windows 20 -23
Shopping malls, ware houses, buildings
with metal/glass
24 -27
Figure 2-5
Propagation Models
Propagation models are effectively a set way of applying an environment’ s characteristics to calculations to
produce a prediction of signal levels within that environment.
Models are created for different environments by carrying out tests at selected frequencies, over varying
distances and times and with varying antenna heights.
The data retrieved from these tests is then analyzed using mathematical tools and a curve is produced.
Imperical formulae to match these curves are then generated and used as propagation models.
Common propagation models are
Log-Distance model
Longley-Rice Model (Irregular terrain)
Okumura
Hata
Cost 231 - Hata (Similar to Hata; used for 1500-2000MHz frequencies)
Walfish-Ikegami Cost 231
Walfisch-Xia JTC
XLOS (Motorola Proprietary)
Deterministic Microcell Model (DMM)
Bullington
Du Path loss model
Diffracting screens model
Of all the models listed, the Hata and Walfisch-Ikegami models are agreed to be the most important.
Motorola’ s NetPlan uses the proprietary XLOS model as well as the Deterministic Microcell Model
(DMM).
Any given model is only as accurate as the information provided to it and assuming it is used in the correct
environment for which it is intended.
For example, the Hata model is suitable for use in Urban/Suburban areas. While the Walfisch-Ikegami is
more suited to the dense urban Microcell type areas.
In the following pages, the common models will be examined in more detail.
Common Propagation Models
Log Distance model
Longley-Rice Model (Irregular terrain)
Okumura
Hata
Cost 231 - Hata (Similar to Hata; used for 1500-2000MHz
frequencies)
Walfish-Ikegami Cost 231
Walfisch-Xia JTC
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14. XLOS (Motorola Proprietary)
Deterministic Microcell Model (DMM)
Bullington
Du Path loss model
Diffracting screens model
Okumura-Hata Model
In the early 1960’ s a Japanese engineer named Okumura carried out a series of detailed propagation tests
for land-mobile radio services at various different frequencies. The frequencies were 200 MHz in the VHF
band and 453, 922, 1310, 1430 and 1920 MHz in the UHF band. The results were statistically analyzed and
described for distance and frequency dependencies of median field strength, location variabilities and
antenna height gain factors for the base and mobile stations in urban, suburban and open areas over quasi-
smooth terrain.
The correction factors corresponding to various terrain parameters for irregular terrain, such as rolling hills,
isolated mountain areas, general sloped terrain and mixed land-sea path were defined by Okumura.
As a result of these tests carried out primarily in the Tokyo area, a method for predicting field strength and
service area for a given terrain of a land mobile radio system was defined.
The Okumura method is valid for:
frequency range of 150 to 2000 MHz
distances between the base station and the mobile stations of 1 to 100 km
base station effective antenna heights of 30 to 100 m.
MS antenna height assumed as 1.5m
The results of the median field strength at the stated frequencies were displayed graphically. Different
graphs were drawn for each of the test frequencies in each of the terrain environments (eg. urban, suburban,
hilly terrain etc.) Also shown on these graphs were the various antenna heights used at the test transmitter
base stations. The graphs show the median field strength in relation to the distance in km from the site.
Figure 2-6 illustrates some of the resultant curves that were produced. As this is a graphical representation
of results it does not transfer easily into a computer environment. However, the results provided by
Okumura are the basis on which path loss prediction equations have been formulated. The most important
work has been carried out by another Japanese engineer named Hata. Hata has taken Okumura’ s graphical
results and derived an equation to calculate the path loss in various environments. These equations have
been modified to take into account the differences between the Japanese terrain and the type of terrain
experienced in Western Europe.
Hata’s Propagation Formula
Hata used the information contained in Okumura’ s propagation loss report of the early 1960’ s, which
presented its results graphically, to define a series of empirical formulas to allow propagation prediction to
be done on computers. The propagation loss in an urban area can be presented as a simple formula of:
A + B log 10 R
where: is:
A frequency function
B antenna height function
R the distance from the transmitter.
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15. Hata, using this basic formula which is applicable to radio systems is the UHF and VHF frequency ranges,
added an error factor to the basic formula to produce a series of equations to predict path loss. To facilitate
this action Hata has set a series of limitations which must be observed when using this empirical calculation
method:
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22. Non Line-Of-Sight Propagation
Here, we assume that the BTS antenna is above roof level for any building within the cell and that there is
no line of sight between the BTS and the mobile. We define the following parameters with reference to
Figure 2-9: w the distance between street mobile and building hm mobile antenna height hB BTS antenna
heights hr height of roof.
hB difference between BTS height and roof top.
hm difference between mobile height and rooftop.
Under non line of sight propagation conditions, for the sake of simplicity, we assume that the environment
has buildings of uniform height. For a mobile on the street, the signal undergoes diffraction from rooftops
and also multiple diffraction due to the surrounding buildings.
The total path loss is given by:
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26. Fresnel Zones
We know that radio signals get diffracted when they encounter an obstacle. We can imagine the signal to
travel with spherical wave fronts. Looking at the cross section, Fresnel Zones are a set of concentric circles,
which are loci of all points having the same signal strength. The Fresnel zones are apart from each other.
Figure 2-12‘ illustrates the nature of Fresnel Zones.
The radius of the Fresnel Zone is dependent on frequency and antenna height. For a given antenna height
the signal will propagate further before the FIRST Fresnel Zone touches the ground.
Also, the diffraction is maximum when the difference between the direct ray and the diffracted ray is /2.
Therefore we can write that
where d0 is the break point.
The path loss slope is similar to LOS path loss within the break point. Diffractions and
Multi path phenomena usually happen beyond this point.
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27. Ray Tracing Model
The propagation of radio waves could be studied by using either Statistical Prediction algorithms or
Deterministic models. The latter are more accurate than the former, but require large computation time.
Deterministic models relate the propagation parameters to the physical structure of the buildings, such as
the wall orientation, materials used, their refraction and diffraction coefficients etc. The statistical models
on the other hand only look at the path losses based on measurements made between buildings.
The Ray tracing model of the NetPlan is one such Deterministic model. It treats the walls, roofs and floors
as black mirrors. Losses in the path between transmitters and receivers are calculated using the mechanisms
of direct transmission, reflection and diffraction.
In small areas with “soft” walls (few metallic frames, unglazed surfaces), direct transmission and reflection
are the most predominant mechanisms. Larger micro cell environments where buildings provide a canyon
for propagation, diffraction is the major mechanism of propagation.
When the beam strikes a wall, part of it gets reflected and the rest goes ‘through’ the wall. There are
multiple reflections within the wall as shown in Figure 2-14. The ray tracing is performed by studying the
wave’ s arrival time, intensity, phase and direction of impact. The intensity of each beam is a function of
wall material, thickness and incident angle.
NetPlan provides conductivity constants for various types of materials used in buildings. Diffraction is the
predominant mode of propagation when the beam strikes the corner of a building. Further discussions on
the ray-tracing model are beyond the scope of our
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28. Propagation Model Selection
Table 2-1 shows table giving general usage of the various propagation models. It is by no means exhaustive
and is only intended as a guideline for model selection. The model chosen will be dictated by conditions
specific to the area to be planned for.
Propagation Model Selection
Table 2-1
Environment Type Model
Dense Urban
Street Canyon propagation Walfisch-Ikegami, LOS
Non LOS conditions, Microcells Walfisch-Ikegami COST
231
Macrocells, antenna above rooftop Okumura-Hata
Urban
Urban areas Walfisch-Ikegami
Mix of buildings of varying heights,
vegetaion and open areas
Okumura-Hata
Suburban
Business and residential areas, open
areas
Okumura-Hata
Rural
Large open areas, fields, difficult
terrain with obstacles
Okumura-Hata
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29. Chapter 3 Propagation-2
Contents:
Propagation – 2
Objectives
Radio Link Design
Calculation of Mobile Receiver Sensivity
Example 5
Signal Variations
Probability Density Functions (PDFs) of Signals
Variation of Gaussian Curve for Varying values of s
Calculation of Standard Deviation
Example 6
Example 6
Confidence Intervals
The Concept of Normalized Standard Deviation
Example 7
Calculation of Edge Probability and Fade Margin
Example 8
Example 9
Example 10
In-Building Margins
Example 11
Example 12
Fussy Logic Vs Fuzzy Logic
Coverage Plots
Cell Planning and C/I
Example 13
Co-Channel interference C/I – Omni Cells
Co-Channel interference C/I-Sectored Cells
Adjacent Channel Interference
Objectives:
The aims of this section are to enable the student to show basic knowledge of, and calculate:
Explain the need for radio link design and calculate acceptable path loss for a given
power budget
Explain and calculate Fade Margin and signal variation
Explain and calculate Probability Density Functions (PDF) of signals
Calculate Standard Deviation
Explain and calculate Normal Distribution and confidence intervals
Explain and calculate Edge Probability
Calculate In-Building coverage
Explain coverage plots
Explain and calculate C/I ratio for both Co-channel and Adjacent channel
Interference
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30. Radio Link Design
The primary objective of Radio Link Design is to provide RF coverage over a desired area with a good deal
of certainty. In practical terms it involves preparation of a Power budget, which takes into account the
receiver’ s sensitivity, BTS transmit power, path losses etc.
The link budget we studied in Chapter 1 could be described by a Level diagram shown in Figure 3-1.
From the diagram we can write an expression for the maximum allowable path loss as:
LPmax = PT – Pmob.rec + GT + GR – (LFT + LFR + FM)
Where, LFT and LFR are feeder and connector losses at the transmitter and receiver respectively. FM is the
fade margin.
In RF design, the key factors are the relationship between Path Loss and Coverage area as well as how to
arrive at the Fade Margin.
Calculation of Mobile Receiver Sensitivity
The mobile should get a minimum signal which is above the thermal noise, with a specified Carrier to
Noise ratio. It should also have adequate cushion to take care of any degradation in the performance of the
RF circuitry due to aging, temperature variations etc.
The noise level at the receiver is calculated as follows:
NR = kTB
Where: k is: the Boltzmann’ s constant = 1.38 x 10- 20 (mW/Hz/0Kelvin.)
T the receiver noise temperature in degrees Kelvin.
B the receiver bandwidth in Hz.
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33. Variation of Gaussian Curve for varying values
The normal or the Gaussian distribution depends upon the value of Standard Deviation. We get a different
curve for each value of ó. The total area under the normal curve is unity.This is illustrated in Figure 3-5.
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36. Area under Normal Curve
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37. NOTE We added 0.5 to 0.4474 because, the condition that the RSS is better than –92dBm is true for the
entire right hand side of the normal curve.
Calculation of Edge Probability and Fade Margin:
We define the following parameters:
Propagation Index:
This is the attenuation constant .
This can be theoretically computed by using the formulae applicable for the specific propagation model
chosen for the cell site.
Or we can obtain RSS at various points at a desired distance from the BTS using drive tests and plot RSS
vs distance. From the plot we can obtain the propagation constant.
Area Probability:
This is the fraction of the total area within which the RSS will be above a specified threshold.
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41. Example 9
For the RSS calculated in Example 8, prepare a power budget for the uplink and down links. RSS required
is – 92.425 dBm. This is taken as the sensitivity limit of the mobile.
Example 9
For the RSS calculated in Example 8, prepare a power budget for the uplink and down links. RSS required
is – 92.425 dBm.
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44. Table 3-5
Area 75%
coverage
50%
coverage
Central business
area
20 dB 15 dB
Residential area 15 dB 12 dB
Industrial Area 12 dB 10 dB
In Car 6 to 8 dB
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45. If the minimum RF signal strength for 90% coverage on the street is –92dBm, then, for 75% in building
coverage in a central business area, we should have a signal level of –72dBm on the street. This will
provide –92dBm inside the building.
When we take in to account the building penetration loss as explained in the previous page, the cell radius
will be reduced.
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46. Fussy Logic Vs Fuzzy Logic
Up to now, all the models that we have studied are purely empirical. The formulae we used do not at all
take care of all possible environments. Hence only an iterative process could achieve the accuracy of
planning based on these models. We also have computer tools to do the job of performing the elaborate and
complex
calculations, given the parameters and assumptions. Fuzzy Logic could be useful for experienced planners
in making right guesses!
Certain assumptions can be made:
Divide the environment into 5 categories;
Free Space
Rural
Suburban
Urban
Dense Urban.
We assign specific attenuation constant values to each category, say, 0, 1 4.Fuzzy Logic helps us to
guess the right value for , the attenuation constant for an environment which is neither rural nor suburban
nor urban but a mixture, with a strong resemblance to one of the major categories.
The following simple rules could be used:
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47. Coverage Plots
By using computers, we can calculate the coverage probabilities at various points from the BTS and plot
Coverage Contour plots. Figure 3-9 shows a single coverage plot for a cell site and Figure 3-10 a composite
coverage plot for a locality respectively.
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54. Table 3-6
N D/R = 3N C/I = 10log [1/6(D/R)3.5]
3 3 8.917dB
4 3.46 11.08dB
7 4.58 15.35dB
9 5.19 17.25dB
12 6 19.45dB
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56. Chapter 4 Frequency planning
Contents:
Frequency Planning
Objectives
Frequency Planning and Re-use Patterns
TCH re-use planning example
Directional Re-use
Objectives:
State the reasons for good frequency planning
Explain the concept of manual frequency planning
Explain the concept of automatic frequency planning
Describe the concept of frequency reuse patterns
Explain directional frequency reuse
Frequency Planning and Re-use Patterns
The ultimate goal of frequency planning in a GSM network is attaining and maintaining the highest
possible C/I ratio everywhere within the network coverage area. A general requirement is at least 12 dB C/I,
allowing tolerance in signal fading above the 9dB specification of GSM.
The actual plan of a real network is a function of its operating environment (geography, RF, etc.) and there
is no universal textbook plan that suits every network. Nevertheless, some practical guidelines gathered
from experience can help to reduce the planning cycle time.
Rules for synthesizer frequency hopping (SFH)
As the BCCH carrier is not hopping, it is strongly recommended to separate bands for
BCCH and TCH, as shown below
This has the benefits of:
_ Making planning simpler
_ Better control of interference
If microcells are included in the frequency plan, the band usage shown below is
suggested.
Practical rules for TCH 1x3 re-use pattern
BCCH re-use plan: 4x3 or 5x3, depending on the bandwidth available and operating environment.
Divide the dedicated band for TCH into 3 groups with an equal number of frequencies (N). These
frequencies will be the ARFCN equipped in the MA list of a hoUse an equal number of frequencies in all
cells within the hopping area. The allocation of frequencies to each sector is recommended to be in a
regular or continuous sequence (see planning example).pping system (FHI).
The number of frequencies (N) in each group is determined by the design loading factor (or carrier-to-
frequency ratio). A theoretical maximum of 50% is permitted in 1x3 SFH. Any value higher than 50%
would practically result unacceptable quality.
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57. Some commonly used loading factors (sometimes termed as fractional load factors) are 40%, 33%, 25%,
etc.
No more than 48 frequencies in a cell with multiple carriers with GPRS timeslots
Use the same HSN for sectors within the same site. Use different HSNs for different sites. This will help
to randomize the co-channel interference level between the sites.
Use different MAIOs to control adjacent channel interference between the sectors within a site
TCH re-use planning example
Bandwidth: 10 MHz
S Site configuration: Mix of 2-2-2, 3-3-3 and 4-4-4
S Loading factor: 33%
S Environment: Multi layer (micro and macro co-exist)
The spectrum is split as shown below
A total of 49 channels are available and the first and last one are reserved as guard bands. Thus, there are
47 usable channels. 12 channels are used in the BCCH layer with a 4x3 re-use pattern.Based on 33%
loading and a 4-4-4 configuration, N is calculated as N = 3 / 0.33 = 9 hopping frequencies per cell. Thus, a
total of 27 channels are required for the hopping TCH layer. The remaining 8 channels are used in the
micro layer as BCCH. One of the possible frequency and parameter setting plans is outlined in the table
Table 4-1.
Table 4-1
ARFCN HSN MAIO
Sector A 21, 24, 27, 30, 33, 36,
39, 42, 45
Any from
{1, 2, ..... 63}
0, 2, 4
Sector B 22, 25, 28, 31, 34, 37,
40, 43, 46
Same as above 1, 3, 5
Sector C 23, 26, 29, 32, 35, 38,
41, 44, 47
Same as above 0, 2, 4
The above MAIO setting will avoid all possible adjacent channel interference among sectors within the
same site. The interference (co or adjacent channel) between sites will still exist but it is reduced by the
randomization effect of the different HSNs
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58. .
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59. Practical rules for TCH 1x1 re-use pattern
1x1 is usually practical in rural area of low traffic density, where the average occupancy of the hopping
frequencies is low. With careful planning, it can be used in high traffic areas as well.
BCCH re-use plan: 4X3 or 5X3, depending on the bandwidth available and operating environment.
The allocation of TCH frequencies to each sector is recommended to be in a regular or continuous
sequence.
Use different HSNs to reduce interference (co and adjacent channel) between the sites.
Use the same HSNs for all carriers within a site and use MAIOs to avoid adjacent and co--channel
interference between the carriers. Repeated or adjacent MAIOs are not to be used within the same site to
avoid co-channel and adjacent channel interference respectively.
A maximum loading factor of 1/6 or 16.7% is inherent in a continuous sequence of frequency allocation.
Since adjacent MAIOs are restricted, the maximum number of MAIOs permitted is:
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60. In a 3 cell site configuration, the logical maximum loading factor is 1/6 or 16.7%.
The following figure illustrates how co-channel and adjacent channel interference can be avoided:
Rules for baseband hopping (BBH)
All the rules outlined for SFH are generally applicable to BBH. As the BCCH is in the hopping frequency
list, a dedicated band separated from TCH may not be essential. An example of frequency spectrum
allocation is shown below
Directional Re-use
In a sectored site, a group of channels (ARFCNs) is transmitted in the direction of antenna orientation. This
is based on a tricellular platform consisting of 3 identical cells as shown in Figure 4-1.Every cell is
considered as an OMNI logically. The cells are excited from the corners, separated by 1200. The axes of
the diagram represent the 3 directions of reuse. These are designated as {f(00) }, { f(1200) } and
{ f(2400) }
Because we use directional antennae, the worst co channel interference will be from only one interfering
station in the same direction.
We form a generic combination of the tri-cell pattern using 7 such patterns, as shown in Figure 4-2.
From this, we can see that each of the three axes has three parallel layers. This results in a total of six or
multiples of six frequency groups. While assigning frequencies to individual cells we have to take the
directions of reuse in
to account.
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62. Chapter 5 Antenna Fundamentals
Contents:
Antenna Fundamentals
Objectives
Antenna Considerations
Antenna Location
Combating Multipath Fading
Space Diversity
Antenna Spacings
Polarisation Diversity
Antenna Configurations
Air Combining System
Antenna Specifications
Downtilt
Example 16
Downtilt Notch
Objectives :
The objectives of this section are to enable the student to:
Explain the factors to be considered regarding antenna selection
Describe the advantages and disadvantages of certain antenna locations
Explain antenna diversity
Describe different antenna configurations
Explain the various specifications given for antennas
Explain downtilt
Antenna Considerations
The primary objective for a proper antenna location and choice of an appropriate diversity scheme is to
provide a uniform coverage within the cell area and minimum interference to and from other BTS antennae.
Choice of antenna location ( cell site ) is based on proper containment of coverage and alignment of the
sites in to a specific hexagonal pattern. The choice may be limited due to availability of space, links to BSC
etc.
Containment of Coverage in Urban/Suburban areas:
In Urban areas, the following conditions usually exist:
Several Sites may be needed
Frequency re use is unavoidable
In-building penetration is a must
Large coverage obtained by keeping an antenna at a height may not satisfy in-building coverage
requirements.
In fact, one can rely on the buildings to serve as radio path shields, limiting the coverage area. Also the
reflections from the buildings provide coverage to areas which would not have been possible in the normal
LOS mode. (Street Canyons). These additional paths consequently increase in-building penetration also.
Antenna Considerations
Uniform Coverage in the cell
Alignment with hexagonal pattern
Space availability
Connectivity to BSC/MSC
Urban areas may have the following conditions:
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63. • Several Sites may be needed
• Frequency re use is unavoidable
• In-building penetration is a must.
• Buildings act as RF shield and contain coverage.
• Buildings reflect signals and provide coverage to areas where
• LOS would have failed.
• Such additional paths improve in-building penetration.
• Antenna at a very high point may not meet In-building coverage requirements.
Antenna Location
The location of an antenna needs to be chosen not only for coverage needs, but also to ensure that the
minimum interference to and from other sites is acheived.
Choice of location is driven by proper containment of coverage and site alignment within the confines of
the specified pattern.
In urban areas, there are certain conditions which prevail:
Several sites will be required
The re-use of frequencies is common
In-building penetration needs to be provided
Merely placing an antenna at the highest point is not the answer to providing best coverage.
As well as giving a source of interference ot other sites in the coverage area, in-building coverage will not
be fully acheived as succesfully as more specific solutions.
Figure 5-1 illustrates the possibilities of antenna location within a built-up area. In the first case, whilst a
large area is covered by the high mounted antenna, interference control is difficult and in-building coverage
is limited.
In the second instance, the buildings act as a natural containment for the propagation, and can also give
coverage in areas that would otherwise be considered ’ dead spots’ . In-building coverage is also improved
in this scenario. In Figure 5-2, location of the antenna at a high point within a suburban environment will
be more beneficial than in a city environment and cause less of an interference problem.
Antenna Location
Location of antennae at high points needs careful examination of site coverage, type of area etc.
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64. Combating Multipath Fading
We have the following techniques by which the effects of Multi path fading can be minimized:
In the Time Domain: Interleaving
In the Frequency Domain: Frequency Hopping
In the Spatial Domain: Space Diversity
In the Polarisation Domain: Polarisation Diversity.
Of the 4 different schemes listed above, the last two techniques are related to antenna systems.
In general, a diversity antenna system provides a number of receive paths ( normally 2). The diverse output
from each path is combined by the receiver to give a signal of sufficient S/N.
Thus a Diversity antenna System essentially has:
Two or More antennae
A combiner circuitry.
Another major requirement of Diversity antenna systems is that the signals arriving at the different receive
paths/ports should have very low correlation. This is because if a signal is fading at one port, the chances of
it happening in the other port should be LOW. This is the basis of Diversity.
Antenna Diversity
A Diversity antenna System essentially has:
Two or More antennae
A combiner circuitry
Space Diversity
There are 3 ways in which Space Diversity could be realized:
Horizontal Separation
Vertical Separation
Composite Separation
Figure 5-4 shows the three different configurations for spatial diversity
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65. Antenna Spacings:
The separation between antenna is a function of the correlation coefficient. To achieve a desired correlation
coefficient, say <0.7, different configurations need different spacings. Figures given in Table 5-1 are for
minimum required separation. If space is not a constraint, larger separation is always recommended.
Horizontal separation is preferred because it provides low correlation values.
However, horizontal separation suffers from angular dependence (as in Figure 5-4). Vertical separation
does not suffer much from angular dependence. It also requires minimum supporting fixtures and does not
occupy a lot of space. But, as the distance increases, the correlation between the RF signals at the antenna
points increases rapidly, thereby negating the very advantage of space diversity.
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66. View Angles
Figure 5-5
Space Diversity can be achieved using:
2 antennae systems
3 antennae systems
The 2 antennae system is preferred where the space for the antenna structure is limited or where the
operators want to use less number of antennae.
The 3 antennae system provides very good spatial separation between the two receive antennae and avoids
the use of Duplexers. This reduces the risk of generating inter modulation products.
Figure 5-6 shows the use of two antennas for space diversity, and Figure 5-7 shows configuration for three
antenna configurations.
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67. Figure 5-7
Polarisation Diversity
Operating Principles (see Figure 5-8):
A plane polarised wave has two components namely Vertical and Horizontal components. The two fields
exhibit a good degree of de correlation. This means that dual polarization can be used as a diversity system.
A Dual- Polarisation antenna consists of 2 sets of radiating elements which radiate, or in reciprocal, receive,
2 orthogonal fields. The antenna has 2 input connectors which separately connect to each set of the
elements. The antenna has therefore the capability to transmit and receive two orthogonally polarised fields
simultaneously.
Figure 5-9 shows the two types of Dual-Polarisation antennas.
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68. Advantages of Dual Polarisation:
Reduced support structure for the antenna
Reduced weight
Slim Towers and hence quicker construction and low cost.
Cost of One dual polarised antenna is generally lower than the cost of two space diversity antennae.
Choice of Dual Polarisation type:
H/V type:
As most mobiles are held at an angle of 450, H/V is more likely to cause balanced signals at the two
branches.
The diversity performance is less dependent on the mobile’ s location.
Slant type:
Correlation between the two elements is angular dependent.
Unbalanced signals at the two arms of the receive antenna, since one of the signals could be at the same
angle as the mobile.
Antenna Configurations
Figure 5-10 shows both the single and double antenna systems.
One Antenna System:
Needs a Duplexer for the port Transmitting and Receiving.
Needs a Duplexer or an External Filter for the receive only arm.
The filter can be avoided if the isolation between the two ports Is better than 30 dB.
Two Antenna System:
Receiving antenna is the Dual Polarised antenna.
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69. Transmitting antenna is the conventional vertical poalrised antenna.
Both transmit and receive antennae should have identical characteristics such as beam width, gain etc.
Transmit antenna is usually mounted below the receive antenna. As most of the systems have down tilts,
keeping the transmit antenna below the receive antenna minimizes shadowing of the receive antenna by the
transmitter.
Air Combining System
This enables both the ports of the antenna to simultaneously transmit and receive. The air combining
system requires a duplexer. The system has the following advantages:
It reduces combining losses.
Ideal for SFH as it minimizes the losses caused by hybrid combiners.
Enhances isolation, because of the Duplexer.
The use of the duplexer increases the risk of high inter-modulation products. It is essential to choose low
inter-mod product duplexers for this configuration. Figure 5-11 shows the configuration using the Air
Combining system.
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72. Figure 5-13
Downtilt
When the main radiation lobe of the antenna is intentionally adjusted above or below its plane of
propagation, the result is known as a “beam tilt”. When tiled downward, we get the “Down Tilt”.
Down tilt can be done in 2 ways:
Electrical Down tilt
Mechanical Down tilt.
Mechanical Downtilt
Mechanical down tilt is done by physically changing the antenna position. A common method is by the use
of scissor-type mounting brackets.
Figure 5-14 illustrates the effect of Mechanical downtilt on the pattern. As can be seen from the diagram,
mechanical downtilt not only causes the main lobe of the antenna to be lowered, but it also causes the back
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73. lobe to be raised by the same degree. This can cause interference problems and therefore is not always the
best solution. Lowering the Site power may be a better answer for instance.
Electrical Downtilt
Electrical down tilt is achieved by changing the phase value of the RF signal at the inputs of a phased array.
It is normally factory set and can be field-adjusted by changing externally the phasing cables supplied by
the manufacturer. Figure 5-15 shows an example of the effect of using different length phasing cables.
Figure 5-16 shows an the resultant coverage changes for differing values of electrical downtilt.
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74. The down tilt required at a given site depends on the coverage planned. With reference to Figure 5-17, it
can be seen that the coverage diminishes rapidly outside the main lobe of the transmitted signal.
Keeping the interference objective in mind, it is preferable to limit the outer edge of the main lobe to the
cell radius. In general down tilt angles greater than 7-10 degrees are not recommended. Also not more than
2 degrees difference in down tilt angles between any two adjacent sectors in a given site is desirable.
The down tilt angle for a cell may be calculated from geometry. It is given by the equation:
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75. Typical vertical beam width of an antenna is 10-12 degrees.
Example 16
Downtilt Notch
When the antenna is physically down tilted, a notch at the centre of the horizontal beam pattern is produced.
This notch becomes larger as the down tilt angle increases.This notch can be effectively used to control
interference as shown in Figure 5-19
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77. Chapter 6 Advanced RF Planning
Contents:
Objectives
Introduction
Planning Steps
Other Considerations
Customer Requirements
Surveys
In-Building Coverage
RF Propagation Tests
Planning Tool Preparation and Model Calibration
Model Calibration
Link Budget and Other Steps
Coverage Esstimation
Capacity Considerations
Fine Tuning
Site Selection
Objectives:
The aims of this section are to enable the student to:
List the various steps involved in the RF Planning process
Explain each of the steps of the planning process
State other factors to be considered in the planning process
State customer requirements
Explain the use of Drive Tests
Explain the use of Planning tools
Describe the customisation of planning models
Perform an RF Planning exercise
Introduction
Chapter 1 introduced the planning and optimisation process in general terms. This chapter looks at each
step of the process in detail. The planning processes will be referenced to an imaginary city known
as ’ Utopia’ .
Planning Steps
The first step is to understand the customer requirements in terms of:
Coverage levels
In-building coverage expectations
Proposed roll out plans
Start-up number of sites which the operator may have in mind.
The next step is to Survey the city of Utopia to understand
Traffic pattern and distribution
Probable growth areas
High business areas etc.
Conducting Propagation tests for in-building coverage and on street signal level estimates.
From the survey data the planning tool is set up and run. Then a draft plan is prepared by dividing the city
into a number of regions like Busy business area with Excellent outdoor coverage, medium in-building
coverage, good in-building coverage etc. For each of these classifications, a simple link budget along with
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78. an appropriate propagation model, the number of sites required per region. The draft plan is then reviewed
with the customer and fine tuned.
Planning Steps
1. Understand Customer requirements
Coverage requirements
In-building coverage expectations
Initial Roll out plans
Pre determined number of sites ?
2. Survey:
Traffic Distribution and Pattern
Growth areas
High density business/residential areas
Propagation tests for in-building coverage estimates and model calibrations.
3. Prepare Planning Tool
Get Digitized maps
Load maps in the Planning tool.
Use survey data and run the programme.
4. Draft Plan:
Divide city in to number of regions-
Busy business areas
Areas that need excellent in-building coverage
Medium in-building coverage areas
Use appropriate model and link budgets to calculate the number of sites required per region.
5. Fine Tune Plan:
Perform more drive tests, confirm plan predictions.
Review plan with customer and fine tune the plan.
Other Considerations
The planning exercise depends on the type of site under consideration- is it a macro site ( large area ) or a
mini site? Is it a micro cell or a pico cell? This is to a large extent defined by the traffic growth projections,
amount of spectrum available, coverage required at the time of launch and capacity planned for the first 3-5
years of operation. To start with Macro cells may be designed to give maximum coverage with limited
number of sites. As the traffic and capacity increase, cells may be split, or new cells may be added to get
more focussed coverage. Tall sites are modified by reducing antenna
heights to get better coverage and minimize interferences.
Other Considerations
Site Selection- Cell Types:
Macro ( Large Cells)
Mini
Micro
Pico
Depends on:
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79. Traffic Growth Projections
Site Density required
Spectrum Availability
Coverage needed at launch
Macro Sites to start with:
Maximum Coverage
Fewer Sites.
Hence lower initial investment.
During Growth phase:
Split Cells
Add New Cells
Modify “ tall” sites by reducing antenna height.
All this gives increased capacity and better in- building coverage.
On going activities:
Optimization techniques
Capacity enhancements
Frequency Hopping techniques
Customer Requirements
The success of the planning process depends on how well we understand what the customer wants.It would
be a good idea to have a questionnair answered by the customer.
Some of the important questions should include precise boundary limits for the network (does the Govt.
have any special conditions?), areas in which medium in-building coverage is considered adequate, areas
where excellent coverage is needed, what are the potential growth areas, what are the implementation
strategies and specific requirements if any.
Is there any limit on the initial investment for the customer?
What is the minimum the customer is willing to support with reference to the competition?
It is important to understand these customer requirements so that the draft plan will be in tune with what the
customer wants and fine tuning becomes easier.
Customer Requirements
What are the boundaries for the network?
Are there any special pockets to be covered due to Govt. requirements?
What are the areas in which medium to average in-building coverage is acceptable?
What are the areas where excellent in building coverage is needed?
Areas with high growth potential
New colonies under development
High revenue areas
Shopping malls, office complexes, industrial estates etc.
Initial implementation Strategy:
High usage, high revenue users first?
High end residential and business areas?
Street Coverage first?
Special areas like 5 Star hotels, Commercial buildings
with fine in-building coverage?
High way coverage critical?
Total coverage on day one?
Number of sites more than the competition? Etc etc.
Any budget limitations?
Give an ideal plan to start with.
Let the customer cut corners.
Not an easy job!!
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80. Surveys
This is basically a scouting exercise. It is better to spend at least a week in each city/locality. It helps in
identifying the network requirements for the city/location. Keep an open eye for the major traffic routes,
main roads, the general city layout, types of buildings, location of major hotels, shopping centres, airport,
railway station, typical consumer behaviour, telephone density, number of restaurants, bars and clubs, parks
and open areas, any historical buildings, old buildings, congested localities with narrow streets, any lakes,
‘ nullahs’ ( narrow canals/waterways ) and so on.
In-Building Coverage
Identify different types of buildings in the city, such as hotels, restaurants, commercial buildings, shopping
malls residential and so on. Select a few buildings in each type and conduct propagation tests. Receive
signal strength is noted at the entrance ( on the road) of the buildings and inside- more importantly in the
basement and ground floor.
This is because the in building coverage is usually less only in these areas. As we go higher up in the
building, the coverage usually improves.
With reference to the signal strength in the road, the building penetration loss can then be computed.
Repeat the process for all buildings and for all categories of buildings. This will give an estimate of
building loss for the locality under consideration.
In-Building Coverage
_ Classify Buildings –
Hotels/Restaurants
Commercial
Industrial
Residential
Shopping malls/markets
Propagation tests in a number of buildings in each variety.
RF signal on the road Vs. inside building gives building
penetration loss.
Repeat tests in as many buildings as possible to get an
estimate of building loss for the area.
In-building coverage affected mostly in ground
floor/basements.
Typical Values: ( examples only )
Hotels/Restaurants 15 dB
Commercial bldgs 20 dB
Shopping malls 15 dB
Industrial Estates 12-15 dB
Residential buildings 15-20 dB
Old/Historical buildings 25-30 dB.
RF Propagation Tests
RF survey is done by performing drive tests within the proposed cell site area. For a new network, we set
up a test transmitter at a chosen point and measure RF signal strengths at various points. In an existing
network, the drive test is used to collect data from the network itself.
A typical RF propagation kit is listed in Table 6-1.
Table 6-1
Battery powered
Transmitter
10 or 20 watts output; frequency
in GSM 900/1800 MHz bands.
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81. Portable mast Adjustable up to 5m. With 1m
antenna on top, effective height
above ground is 6m.
Transmit antenna High gain Omni or directional
antenna as required.
Receiver (TEMS
mobile),
Hand held mobile phone with
RS232 connection to a lap top.Or,
an accurate portable RF
sensitivity meter/ CW receiver if
model calibration is required.
Positioning System GPS system,with PCMCIA card
Computer Lap top PC with TEMS software
and GPS software.
Cables & accessories: Calibrated cable lengths (10m) of
low loss feeder with known
attenuation values; 12 Volts
battery with appropriate cable to
connect to transmitter.
Power meter
VSWR meter
Planning Tool Preparation and Model Calibration
The concepts of RF planning were covered in Section 3. It is possible to do this planning for a number of
sites by manually handling the propagation test results.
However, to do iterative operations and get a coverage map it is essential to use planning tools to automate
the process.
There are many planning tools available to day:
NetPlan ( Motorola)
PlaNet (MSI)
CellCad (LCC)
Odyssey (Aethos)
Asset (Aircon)
Planning tool Requirements:
The planning tool must be easy to use, should be compatible with tools like the TEMs, should be
economical and require minimum hardware.
Obtain Maps:
It is important to have the map of the city/area under consideration. Such map information could be
obtained as paper copies from authorized sources or from a satellite image. The latter option is very
expensive. The maps could be obtained from the local authorities. Where contour maps are required they
could be obtained from the Survey of India department. The maps should be preferably on 1:50000 or
1:25000 scale. Normally the data would be in 50m resolution. Less than this is not suitable for macro cell
designs as it calls for large memory requirements for the planning tool.For micro cells, less than 30 m
resolutions can be considered, where a “ Ray Tracing Tool” is used.The geographical data of the area is
digitized under 3 different categories:
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82. _ Land Use
_ Digital Terrain Map (DTM)
_ Vectors ( Roads, Railway tracks etc).
Planning tool preparation and Model Calibration:
There are many planning tools available to day:
NetPlan (Motorola)
PlaNet (MSI)
CellCad (LCC)
Odyssey (Aethos)
Asset (Aircon)
A planning tool should be:
Easy to Use
Compatible with tools like TEMs
Minimum Hardware requirements
Economical.
Maps collected from authorized sources.
1:50000 or 1:25000 scale
50 m resolution for macro cells.
Less than 30 m resolution possible for Micro cell planning using “ Ray Tracing Tool”.
Maps are digitized under 3 categories:
Land Use
Digital Terrain Map ( DTM )
Vectors ( Roads, Railways etc).
Most Planning tools use corrections for the land use or clutter.
The propagation model can be tuned by assigning values to:
Clutter factor (gain or loss due to clutter)
Clutter heights (for diffraction modelling)
Different types of clutter are defined in these models/tools:
Dense Urban
Urban
Suburban
Suburban with Dense Vegetation.
Rural
Industrial Area
Utilities (marshalling yards, docks, container depots etc )
Open area
Quasi Open area
Forest
Water
Too many clutter type definitions complicate the planning process. 10 to 15 is typical DTM.
Provided by the map vendor
Provides Contour information as a digital map.
Vectors
Highways
Main Roads
Railways
Canals/Water ways
Coast line
Rivers
Each category is digitized as separate layers Displayed separately if required. Map information is set up in
the planning tool. Model Calibration carried out.
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83. Model Calibration
Typically RF propagation tests are conducted for 5-8 proposed BTS sites covering as much of the area as
possible. Efforts should be made to include all types of clutters during the propagation test. Almost all the
planning tools have provision for changing the clutter values to match the propagation test results. They all
have different directory structures and means of handling the geographical data. As an example, the PlaNet
has a procedure for tuning the Macro Cell models. NetPlan has a Custom Path Loss Model which enables
the planer to play with the values of various types of clutter and fine tune the model. For the sake of
illustration, an excerpt from the “ User Reference Guide” of PlaNet is placed as an Annexure.
All tools have provision for manipulating clutter values.
Different tools have different Directory structures and means of handling geographical data. Macro Cell
Tuning procedure described in “ User Reference Guide” of PlaNet kept in Annexure for illustration
purposes.
The procedure mainly talks about ensuring correct data header files to include:
BTS location
EIRP of BTS
Antenna Type
BTS antenna height
Description of surrounding area.
Procedure uses a general core model equation:
The equation has constants k1 to k6 and a constant for clutter, kclutter.
Initial values for the constants are set as per the model chosen (say Okumara-Hata).
PlaNet programme is run repeatedly to make RMS error values for all data files ZERO or a minimum.
For each run of the programme, the values of k1 to k6 are manipulated.
This completes Model calibration.
Link Budget and Other Steps
Once the geographical data is entered in to the planning tool, a coverage map is required to be generated for
each site.
The most important step is then to prepare a Link Budget for the site under consideration. Some of the key
points to be considered are:
What is the desired probability of the receive signal strength at the mobile, within the entire coverage
area? ( usually 90 or 95% and is decided in consultation with the customer).
What is the expected in-building coverage?
What is the probability on the “ EDGE” of the coverage area that the receive signal strength is sufficient
for the mobile to make and hold a call?
What is the fade margin available?
What is the maximum permissible path loss ( from the Link Budget)
What is the radius of the cell?
What are the areas of different types of coverage planned for? For example Main business area could be
100 sq. Km and the suburban area could be 200 sq. Km and so on.
How many sites are required for each type of area? ( from coverage point of view)
Is the number of sites calculated as above adequate for capacity?
Decide on more sites for capacity.
Link Budgets and Other Steps
Key Points to be considered:
Coverage Probability
Expected in-building coverage?
Edge Probability
Fade Margin required
Maximum permissible path loss (from the Link Budget)
What is the radius of the cell?
Number of Sites required (from coverage point of view)
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84. Is the number of sites calculated as above adequate for capacity?
Decide on more sites for capacity.
Coverage Estimation
Having calculated the Maximum permissible path loss, the cell radius can be determined as explained in
Section 2.
For a given cell radius, we can calculate the estimated coverage area based on the formula:
The site separation distance D = (3N) R. ( R is the radius of the cell, same as d)
For a given area, we can then calculate the number of sites required.
Number of Sites = Total Area / Cell area.
Capacity Considerations
Having determined the number of sites, it is then required to check if the capacity requirements are also met.
This depends on the spectrum available, which will decide the site configurations. The availability of other
features like frequency hopping etc is also to be taken into account. If capacity requirements are not met,
then more sites may have to be added. If the number of sites as calculated above is not acceptable to the
customer, then a second round of calculations may be required, assuming 50% in building coverage in
place of 75%.
Fine Tuning
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85. Having prepared the preliminary cell plan, the planning tool can be used for returning coverage predictions.
These will be more accurate than the rough models used for estimating the site density.Typically this
activity will go through a number of iterations in consultation with the customer.
Search Areas:
Based on the final plan, “ search areas” are issued for each site location. In addition to the rough location,
information like latitude and longitude of the place, approximate antenna heights, specific areas if any and
the size of the search areas also needs to be given. The search area size would depend upon the criticality of
the site. As per the information given by the RF planner, site acquisition teams scout for suitable buildings.
Site Selection
The choice of a site location depends on factors like the antenna heights above ground as well as above
clutter. A generic rule of thumb could be used depending upon the type of area under consideration.
Central business area:
Here the search area size is very critical, usually within 100m
the antenna should be at or slightly above the average surrounding clutter height
All near field obstructions should be avoided
Antenna orientation may be along major roads
Try and mount antennas close to solid structures like a lift motor room, this minimizes back lobe
radiation effects
As far as possible avoid towers on building tops as this might cause interference to
neighboring cells.
Residential/Suburban areas:
Here the site separations may be larger than the first case and to that extent the location of the site is also
less critical. Search areas are typically 200 m
Antenna height should be 3 to 5 metres above the average clutter height
Try and locate sites close to major routes or at large junctions
Back lobe radiation is less critical, though it is desirable to avoid it.
Industrial areas:
A suitable location as much at the centre of the area as possible should be selected.
Quasi Open areas:
Search areas can be bigger, say, about 500 m
Propagation is more dependent on the terrain than on the clutter. Hence more care is needed in hilly areas
Use of towers is common
Antenna orientation is not a critical factor. Availability of infrastructure like land, power etc is important.
High ways:
Search areas are along the road and are close
High gain antennas required
Tall sites are suggested. More are needed in hilly areas.
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86. Chapter 7 Extending Cell Range
Contents:
Extending Cell Range
Objectives
Extending Cell Range
Increasing BTS Transmit EIRP
Air Combining Techniques
Improving BTS Sensitivity
Objectives :
Explain the reason for extending the range of cells
Explain the various methods used for range extension
Discuss the results of the various methods
Extending Cell Range
Most operators are nowadays looking for achieving maximum coverage with a minimum or optimum
number of sites. This requirement becomes significant especially in the 1800 MHz band. For in these
frequencies, the path loss in more and cell sizes are much smaller than GSM 900 frequencies. Hence to get
more coverage, the number of sites increases.
Extending the range of each cell helps in reducing the number of sites required. The range of a cell depends
upon the BTS transmit power, BTS receive sensitivity and the mobile’ s receive sensitivity. If we can
improve these parameters, the cell can be ‘extended’.
Increasing BTS Transmit EIRP
To maximize BTS o/p power, single carrier cells can be used, this will avoid the combination losses of
multiple carrier cells.
The output power at the top of the cabinet could be set to 40Watts, giving an increase in signal strength of 3
dB.
Another way to maximize Tx and Rx signals is to implement low loss feeder cables. A typical 7/8”
Andrews coaxial cable has an attenuation of 3.92 dB/100mt. If a 1-5/8” Andrews cable with an attenuation
of 2.16 dB/100mt is used, then an increase of 1.6 dB can be obtained per 100m.
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87. Air Combining Techniques
For sites with 2 or more carriers we can enhance the EIRP of the BTS by using air combining techniques.
By using duplexers, this can be achieved with 2 or 3 antennae as shown in Figure 7-1. For sites with 2
carriers we can enhance the EIRP of the BTS by using air combining techniques. When applied to
Polarization antennae, we can get air combining using a single antenna or with 2 antennae as shown in
Figure 7-2.
Figure 7-2
Improving BTS Sensitivity
BTS sensitivity can be improved by:
Better devices in the BTS receiver
Using Mast-head amplifiers with very low Noise figures.
Better RF cables.
Figure 7-3, Figure 7-4 and Figure 7-5 show relationship between sensitivity vs range; Tx EIRP vs range;
sensitivity and BTS EIRP vs range respectively.
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88. Extending the receiver sensitivity of the BTS has certain advantages:
• On the BTS receiver side, we can improve the receiver sensivitiy by using Mast Head Amplifiers.
• Mast-head amplifiers (MHAs)/Tower Mounted Amplifiers (TMAs) stretch the BTS receiver
sensitivity to – 110 dBm as against the standard –107 or –108 dBm.
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89. This results in better coverage probability. Experiments with MHAs have shown that quality of coverage
has improved-
• In areas with 50% probability to approximately 70% probability.
• In areas with 70% probability to approximately 85% probability.
• In areas with 85% probability to approximately 95% probability.
• In areas with 95% probability to approximately 98% probability.
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