This document discusses cellular network planning and optimization, specifically for WCDMA radio resource management (RRM). It covers several key topics:
Quality of Service (QoS) in UMTS is achieved through a system of bearers that negotiate bandwidth and latency requirements between network elements. Radio access bearers connect the user equipment to the core network.
RRM functions like admission control, power control, handover control, and packet scheduling work to guarantee QoS, maintain coverage, and optimize cell capacity in WCDMA networks. Power control is a critical RRM mechanism that uses fast and outer loop techniques to control transmission power and mitigate interference.
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.
The document discusses WCDMA radio network planning and optimization. It covers several key topics:
1. WCDMA fundamentals including network infrastructure, radio interface protocols, link characteristics, and link budget analysis.
2. Radio resource utilization, which involves functions like power control, handover control, congestion control, admission control, and load control.
3. Issues related to coverage and capacity as well as cell deployment and WCDMA radio network planning, including co-planning with GSM networks.
4. Managing co-existing TDD and FDD modes within the network.
This document discusses radio network planning for WCDMA networks. It describes the planning process, which involves initial planning, detailed radio network planning, and network operation and optimization. The initial planning phase involves estimating site density and configurations through radio link budgeting and coverage analysis. Key aspects of WCDMA link budgeting include interference degradation margin, fast fading margin, transmit power increase, and soft handover gain. Detailed planning then refines site locations and configurations based on propagation modeling and traffic forecasts. Network performance is then analyzed and optimized through monitoring key performance indicators.
Admission control guarantees quality of service by controlling the number of users based on interference, capacity, load, and coverage. It selectively denies access requests to limit load. Congestion control resolves overload by delaying packets, removing calls, or moving users between channels. Power control aims to minimize transmit power while maintaining quality by adjusting power levels through inner-loop, outer-loop, and open-loop control. Soft/softer handover combines signals from multiple base stations or sectors to support user mobility and power control.
Voice Over U M T S Evolution From W C D M A, H S P A To L T EPengpeng Song
The document outlines the evolution of voice over UMTS networks from WCDMA to LTE. It discusses AMR voice codec characteristics and implementations of voice over UMTS networks in R99, HSPA+, and LTE standards. Key aspects covered include voice over IMS, circuit switched fallback, header compression, scheduling, and performance metrics like capacity and latency.
The document discusses drive test analysis for mobile networks. It describes the key elements of an effective drive test program including understanding network performance using call and data metrics. The drive test process involves defining test routes and clusters, collecting data, analyzing key performance indicators (KPIs) like call setup success rate and throughput, and troubleshooting issues. Defining test cases, KPIs, and categorizing failures is important for understanding genuine network problems versus measurement errors.
This document discusses optimization of networks using drive testing and TEMS software. It provides information on:
1) How drive testing and TEMS can analyze network performance from a subscriber perspective by recording measurement data.
2) The types of information displayed in TEMS windows including cell identity, signal strength, quality, and timing advance measurements.
3) How to use the TEMS software including default tabs, maps, recording properties, and report generation.
Here you are an interesting explanation about HSPA Technology. The High Speed packet Access is the combination of two technologies, one of the downlink and the other for the uplink that can be built onto the existing 3G UMTS or W-CDMA technology to provide increased data transfer speeds.
The original 3G UMTS / W-CDMA standard provided a maximum download speed of 384 kbps.
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.
The document discusses WCDMA radio network planning and optimization. It covers several key topics:
1. WCDMA fundamentals including network infrastructure, radio interface protocols, link characteristics, and link budget analysis.
2. Radio resource utilization, which involves functions like power control, handover control, congestion control, admission control, and load control.
3. Issues related to coverage and capacity as well as cell deployment and WCDMA radio network planning, including co-planning with GSM networks.
4. Managing co-existing TDD and FDD modes within the network.
This document discusses radio network planning for WCDMA networks. It describes the planning process, which involves initial planning, detailed radio network planning, and network operation and optimization. The initial planning phase involves estimating site density and configurations through radio link budgeting and coverage analysis. Key aspects of WCDMA link budgeting include interference degradation margin, fast fading margin, transmit power increase, and soft handover gain. Detailed planning then refines site locations and configurations based on propagation modeling and traffic forecasts. Network performance is then analyzed and optimized through monitoring key performance indicators.
Admission control guarantees quality of service by controlling the number of users based on interference, capacity, load, and coverage. It selectively denies access requests to limit load. Congestion control resolves overload by delaying packets, removing calls, or moving users between channels. Power control aims to minimize transmit power while maintaining quality by adjusting power levels through inner-loop, outer-loop, and open-loop control. Soft/softer handover combines signals from multiple base stations or sectors to support user mobility and power control.
Voice Over U M T S Evolution From W C D M A, H S P A To L T EPengpeng Song
The document outlines the evolution of voice over UMTS networks from WCDMA to LTE. It discusses AMR voice codec characteristics and implementations of voice over UMTS networks in R99, HSPA+, and LTE standards. Key aspects covered include voice over IMS, circuit switched fallback, header compression, scheduling, and performance metrics like capacity and latency.
The document discusses drive test analysis for mobile networks. It describes the key elements of an effective drive test program including understanding network performance using call and data metrics. The drive test process involves defining test routes and clusters, collecting data, analyzing key performance indicators (KPIs) like call setup success rate and throughput, and troubleshooting issues. Defining test cases, KPIs, and categorizing failures is important for understanding genuine network problems versus measurement errors.
This document discusses optimization of networks using drive testing and TEMS software. It provides information on:
1) How drive testing and TEMS can analyze network performance from a subscriber perspective by recording measurement data.
2) The types of information displayed in TEMS windows including cell identity, signal strength, quality, and timing advance measurements.
3) How to use the TEMS software including default tabs, maps, recording properties, and report generation.
Here you are an interesting explanation about HSPA Technology. The High Speed packet Access is the combination of two technologies, one of the downlink and the other for the uplink that can be built onto the existing 3G UMTS or W-CDMA technology to provide increased data transfer speeds.
The original 3G UMTS / W-CDMA standard provided a maximum download speed of 384 kbps.
Here are the steps to solve this problem:
1) Calculate MAPL using propagation model (Hata, Cost231 etc.)
Given: Carrier freq = 900MHz, BS height = 30m, Tx power = 20W
Using Hata model, calculate MAPL
2) Calculate cell range using MAPL
Cell range = sqrt(MAPL/2)
3) Calculate number of cells required for 100sqkm area
Number of cells = Area/Cell area
Cell area = pi * (Cell range)^2
4) Number of sites = Number of cells
For the given parameters, the calculations would provide the number of sites required.
This document outlines the process of cellular network planning and optimization. It discusses collecting radio network data through drive testing, analyzing network performance, and proposing solutions to issues or meet key performance indicators. The objectives of optimization are finding and correcting problems, meeting contract quality criteria, and iterative improvement of overall network quality without degrading other areas. Methodologies proposed include problem analysis, drive testing, simulation, and exporting data to map software to identify solutions.
The key performance indicators for measuring 3G cell performance include accessibility metrics like RRC success rate, RAB success rate, and CSSR. Retainability is measured by dropped call rates for speech, video, and packet switched connections. Mobility is measured by handover success rates between cells and between 3G and 2G networks. Factors that affect HSDPA throughput include downlink power, the number of downlink codes allocated for HSDPA, and transport channel capacity. Tuning parameters like increasing the number of HSDPA codes or changing the scheduling algorithm can improve HSDPA throughput.
The document discusses various parameters used in LTE drive testing including:
- RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, and throughput which provide information on signal strength, quality, and performance. Phone-based drive testing allows monitoring of these parameters and correlation with data performance. MIMO and handovers between LTE and other technologies can also be evaluated. Key metrics include coverage, capacity, and end-user experience.
This presentation provides an overview of several radio features in UMTS networks, including admission control, congestion control, power control, channel type switching, adaptive multi-rate switching, and open loop transmit diversity. Admission control guarantees quality of service by controlling the number of users. Congestion control resolves overload situations through call removal or delaying packets. Power control aims to minimize transmit power while maintaining link quality. Channel type switching optimizes channel usage for bursty traffic. Adaptive multi-rate switching adapts bit rates for coverage and capacity. Open loop transmit diversity provides coverage and capacity gains through additional diversity.
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.
3 g huawei ran resource monitoring and management recommendedMery Koto
The document discusses monitoring resources in a Huawei WCDMA network to avoid congestion and blockages. It describes monitoring resources at the NodeB and cell levels like CE cards, licenses, OVSF codes, power levels, and Iub bandwidth. Counters are presented to monitor traffic, KPIs, resource usage, and rejections due to congestion. The resource consumption of different services is also analyzed to understand network characteristics and identify if resources are sufficient for desired services.
In this project, we are implementing a tool for calculating number of base stations required to meet LTE network coverage and capacity requirement. Coverage planning includes link budget analysis for calculating MAPL and then determining cell radius using RF propagation models. Capacity planning cares about service models and traffic models for calculating required throughput in the network, In addition, it is concerned with calculating cell throughput.
This document provides an overview of radio resource management for cellular networks. It discusses topics like call signaling, traffic channel allocation algorithms, interference level measurements, prioritized allocation, queuing parameters and processes for entering and leaving the queue. The document is copyrighted material from Nokia Siemens Networks and cannot be copied or shared without their permission.
The document provides an overview of the UMTS radio path and transmission. It discusses key topics such as the WCDMA air interface, radio resource management, and channelization and scrambling codes. The objectives are to explain terms related to the UMTS air interface such as carrier, spreading, and scrambling codes. It also aims to describe the structure of the UMTS air interface and key functions in radio resource management.
GSM Network Analysis and KPI Optimisation discusses key performance indicators (KPIs) for optimizing GSM networks. It describes the architecture of GSM networks including mobile stations, base station subsystems, switching subsystems and operation support subsystems. It then covers various GSM concepts like channels, frame structure, bursts and call flows. The document outlines different types of KPIs like accessibility, retainability and speech quality for both voice and data services. Finally, it discusses how to optimize specific KPIs like blocking, dropping and handover success rates by checking network parameters and using tools like OSS, MRR and NCS reports.
This document provides an overview of a training course on 3G UMTS networking. The course covers topics such as the physical layer, connection establishment, measurements, mobility management, and the UTRAN control protocol. It describes the UMTS network architecture including the core network domains and interfaces. It also discusses radio access network components like the RNC and Node B, as well as key aspects of the WCDMA air interface such as duplexing modes, spreading codes, and handover types. Finally, it introduces concepts like quality of service management in UMTS networks.
This document discusses radio resource optimization parameters in GSM networks. It covers topics like idle parameter optimization, power control, handover control, radio resource administration, measurement processing, signaling channel mapping, traffic channel mapping, paging parameters, access grant channel parameters, frequency reuse, and frequency hopping techniques. Diagrams and examples are provided to illustrate concepts like TDMA frame structure, logical and physical channel organization, and capacity calculations.
The document provides guidance on optimizing key performance indicators (KPIs) such as call setup success rate (CSSR). It discusses analyzing CSSR by examining its components like SDCCH drop rate. A high SDCCH drop rate can be caused by hardware issues, interference, or transmission problems. The document recommends checking specific counters and alarms to determine the root cause, and describes potential fixes like moving SDCCH channels or adjusting parameters. Overall, the document outlines a process for identifying underperforming cells, analyzing relevant KPIs and counters, and addressing issues to improve network optimization.
The document discusses various channels used in GSM networks. It describes physical channels that transfer bits between network elements and logical channels distinguished by the nature of carried information. It provides details on different types of logical channels including traffic, broadcast, common control and dedicated control channels. It also explains concepts like bursts, frames, multiframe structures and how they are used to organize speech and data on traffic channels.
The document provides an overview of GSM RF interview questions and answers. It covers topics such as the three services offered by GSM (teleservices, bearer services, and supplementary services), spectrum allocation for GSM-900 and DCS-1800, carrier frequencies and separation, ciphering and authentication algorithms, equalization, interleaving, speech coding, channel coding, frequency reuse, cell splitting, interfaces (Um, Abis, A), LAPD and LAPDm, WPS, MA, MAIO, frequency hopping types, DTX, DRX, gross data rate, Erlangs and grade of service, coverage differences between GSM900 and DCS1800, time advance, location area and location update
The document discusses the requirements and configuration of Inter Frequency Load Balancing (IFLB) in LTE networks. IFLB aims to balance traffic load across cells on different frequencies by offloading user equipment between those cells. Key steps in IFLB include determining cell load, exchanging load information, selecting offload candidates, and handing users over to target cells if their signal quality is sufficient. The document provides guidance on setting parameters that control IFLB behavior and thresholds.
The document is a seminar report on Wideband Code Division Multiple Access (WCDMA) technology. It discusses the basics of WCDMA, including that it uses code division multiple access to separate users and spread signals over a wide 5MHz bandwidth. It also covers WCDMA specifications, generation, spreading principles, power control, handovers, and advantages such as service flexibility and spectrum efficiency.
This document discusses WCDMA RF optimization processes, policies, and case studies. It describes the three steps of the WCDMA RF optimization process: single station check, base station group optimization, and whole network optimization. It then discusses common RF problems, analysis, and optimization policies for issues like call drops, discontinuity, and access failures. Finally, it presents five case studies of WCDMA network optimization including issues like handover problems, coverage gaps, high site interference, and neighbor cell list configuration errors.
The document describes various signaling messages used in different layers and interfaces of the GSM network, including:
1. Radio Resource (RR) messages for channel establishment, ciphering, handover, channel release, paging, and system information on the Um interface.
2. Messages for BTS Management (BTSM) on the Abis interface for radio link management, channel management, and TRX management.
3. Base Station System Application Part (BSSAP) messages on the A interface for resource management between the BSC and MSC.
4. Mobile Application Part (MAP) messages involving mobility services, call handling services, and short message services between entities in the core network.
This document provides an overview of 3rd generation WCDMA/UMTS wireless networks. It describes the evolution from 2G to 3G networks and the key aspects of WCDMA/UMTS architecture, including the air interface, radio access network, core network and radio resource management functions such as admission control, load control, packet scheduling, handover control and power control. The document also briefly discusses additional topics such as radio network planning issues, high speed data packet access, and a comparison of WCDMA and CDMA2000.
Maria D'cruz_WCDMA UMTS Wireless NetworksMaria D'cruz
The document provides an overview of WCDMA/UMTS architecture and radio resource management. It describes the evolution from 2G to 3G networks and the standardization of WCDMA. The key aspects of WCDMA air interface, UTRAN architecture, core network functionality, and radio resource management techniques like admission control, load control, packet scheduling, handover control and power control are summarized. Diagrams illustrate the system architecture and information flow between network elements.
Here are the steps to solve this problem:
1) Calculate MAPL using propagation model (Hata, Cost231 etc.)
Given: Carrier freq = 900MHz, BS height = 30m, Tx power = 20W
Using Hata model, calculate MAPL
2) Calculate cell range using MAPL
Cell range = sqrt(MAPL/2)
3) Calculate number of cells required for 100sqkm area
Number of cells = Area/Cell area
Cell area = pi * (Cell range)^2
4) Number of sites = Number of cells
For the given parameters, the calculations would provide the number of sites required.
This document outlines the process of cellular network planning and optimization. It discusses collecting radio network data through drive testing, analyzing network performance, and proposing solutions to issues or meet key performance indicators. The objectives of optimization are finding and correcting problems, meeting contract quality criteria, and iterative improvement of overall network quality without degrading other areas. Methodologies proposed include problem analysis, drive testing, simulation, and exporting data to map software to identify solutions.
The key performance indicators for measuring 3G cell performance include accessibility metrics like RRC success rate, RAB success rate, and CSSR. Retainability is measured by dropped call rates for speech, video, and packet switched connections. Mobility is measured by handover success rates between cells and between 3G and 2G networks. Factors that affect HSDPA throughput include downlink power, the number of downlink codes allocated for HSDPA, and transport channel capacity. Tuning parameters like increasing the number of HSDPA codes or changing the scheduling algorithm can improve HSDPA throughput.
The document discusses various parameters used in LTE drive testing including:
- RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, and throughput which provide information on signal strength, quality, and performance. Phone-based drive testing allows monitoring of these parameters and correlation with data performance. MIMO and handovers between LTE and other technologies can also be evaluated. Key metrics include coverage, capacity, and end-user experience.
This presentation provides an overview of several radio features in UMTS networks, including admission control, congestion control, power control, channel type switching, adaptive multi-rate switching, and open loop transmit diversity. Admission control guarantees quality of service by controlling the number of users. Congestion control resolves overload situations through call removal or delaying packets. Power control aims to minimize transmit power while maintaining link quality. Channel type switching optimizes channel usage for bursty traffic. Adaptive multi-rate switching adapts bit rates for coverage and capacity. Open loop transmit diversity provides coverage and capacity gains through additional diversity.
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.
3 g huawei ran resource monitoring and management recommendedMery Koto
The document discusses monitoring resources in a Huawei WCDMA network to avoid congestion and blockages. It describes monitoring resources at the NodeB and cell levels like CE cards, licenses, OVSF codes, power levels, and Iub bandwidth. Counters are presented to monitor traffic, KPIs, resource usage, and rejections due to congestion. The resource consumption of different services is also analyzed to understand network characteristics and identify if resources are sufficient for desired services.
In this project, we are implementing a tool for calculating number of base stations required to meet LTE network coverage and capacity requirement. Coverage planning includes link budget analysis for calculating MAPL and then determining cell radius using RF propagation models. Capacity planning cares about service models and traffic models for calculating required throughput in the network, In addition, it is concerned with calculating cell throughput.
This document provides an overview of radio resource management for cellular networks. It discusses topics like call signaling, traffic channel allocation algorithms, interference level measurements, prioritized allocation, queuing parameters and processes for entering and leaving the queue. The document is copyrighted material from Nokia Siemens Networks and cannot be copied or shared without their permission.
The document provides an overview of the UMTS radio path and transmission. It discusses key topics such as the WCDMA air interface, radio resource management, and channelization and scrambling codes. The objectives are to explain terms related to the UMTS air interface such as carrier, spreading, and scrambling codes. It also aims to describe the structure of the UMTS air interface and key functions in radio resource management.
GSM Network Analysis and KPI Optimisation discusses key performance indicators (KPIs) for optimizing GSM networks. It describes the architecture of GSM networks including mobile stations, base station subsystems, switching subsystems and operation support subsystems. It then covers various GSM concepts like channels, frame structure, bursts and call flows. The document outlines different types of KPIs like accessibility, retainability and speech quality for both voice and data services. Finally, it discusses how to optimize specific KPIs like blocking, dropping and handover success rates by checking network parameters and using tools like OSS, MRR and NCS reports.
This document provides an overview of a training course on 3G UMTS networking. The course covers topics such as the physical layer, connection establishment, measurements, mobility management, and the UTRAN control protocol. It describes the UMTS network architecture including the core network domains and interfaces. It also discusses radio access network components like the RNC and Node B, as well as key aspects of the WCDMA air interface such as duplexing modes, spreading codes, and handover types. Finally, it introduces concepts like quality of service management in UMTS networks.
This document discusses radio resource optimization parameters in GSM networks. It covers topics like idle parameter optimization, power control, handover control, radio resource administration, measurement processing, signaling channel mapping, traffic channel mapping, paging parameters, access grant channel parameters, frequency reuse, and frequency hopping techniques. Diagrams and examples are provided to illustrate concepts like TDMA frame structure, logical and physical channel organization, and capacity calculations.
The document provides guidance on optimizing key performance indicators (KPIs) such as call setup success rate (CSSR). It discusses analyzing CSSR by examining its components like SDCCH drop rate. A high SDCCH drop rate can be caused by hardware issues, interference, or transmission problems. The document recommends checking specific counters and alarms to determine the root cause, and describes potential fixes like moving SDCCH channels or adjusting parameters. Overall, the document outlines a process for identifying underperforming cells, analyzing relevant KPIs and counters, and addressing issues to improve network optimization.
The document discusses various channels used in GSM networks. It describes physical channels that transfer bits between network elements and logical channels distinguished by the nature of carried information. It provides details on different types of logical channels including traffic, broadcast, common control and dedicated control channels. It also explains concepts like bursts, frames, multiframe structures and how they are used to organize speech and data on traffic channels.
The document provides an overview of GSM RF interview questions and answers. It covers topics such as the three services offered by GSM (teleservices, bearer services, and supplementary services), spectrum allocation for GSM-900 and DCS-1800, carrier frequencies and separation, ciphering and authentication algorithms, equalization, interleaving, speech coding, channel coding, frequency reuse, cell splitting, interfaces (Um, Abis, A), LAPD and LAPDm, WPS, MA, MAIO, frequency hopping types, DTX, DRX, gross data rate, Erlangs and grade of service, coverage differences between GSM900 and DCS1800, time advance, location area and location update
The document discusses the requirements and configuration of Inter Frequency Load Balancing (IFLB) in LTE networks. IFLB aims to balance traffic load across cells on different frequencies by offloading user equipment between those cells. Key steps in IFLB include determining cell load, exchanging load information, selecting offload candidates, and handing users over to target cells if their signal quality is sufficient. The document provides guidance on setting parameters that control IFLB behavior and thresholds.
The document is a seminar report on Wideband Code Division Multiple Access (WCDMA) technology. It discusses the basics of WCDMA, including that it uses code division multiple access to separate users and spread signals over a wide 5MHz bandwidth. It also covers WCDMA specifications, generation, spreading principles, power control, handovers, and advantages such as service flexibility and spectrum efficiency.
This document discusses WCDMA RF optimization processes, policies, and case studies. It describes the three steps of the WCDMA RF optimization process: single station check, base station group optimization, and whole network optimization. It then discusses common RF problems, analysis, and optimization policies for issues like call drops, discontinuity, and access failures. Finally, it presents five case studies of WCDMA network optimization including issues like handover problems, coverage gaps, high site interference, and neighbor cell list configuration errors.
The document describes various signaling messages used in different layers and interfaces of the GSM network, including:
1. Radio Resource (RR) messages for channel establishment, ciphering, handover, channel release, paging, and system information on the Um interface.
2. Messages for BTS Management (BTSM) on the Abis interface for radio link management, channel management, and TRX management.
3. Base Station System Application Part (BSSAP) messages on the A interface for resource management between the BSC and MSC.
4. Mobile Application Part (MAP) messages involving mobility services, call handling services, and short message services between entities in the core network.
This document provides an overview of 3rd generation WCDMA/UMTS wireless networks. It describes the evolution from 2G to 3G networks and the key aspects of WCDMA/UMTS architecture, including the air interface, radio access network, core network and radio resource management functions such as admission control, load control, packet scheduling, handover control and power control. The document also briefly discusses additional topics such as radio network planning issues, high speed data packet access, and a comparison of WCDMA and CDMA2000.
Maria D'cruz_WCDMA UMTS Wireless NetworksMaria D'cruz
The document provides an overview of WCDMA/UMTS architecture and radio resource management. It describes the evolution from 2G to 3G networks and the standardization of WCDMA. The key aspects of WCDMA air interface, UTRAN architecture, core network functionality, and radio resource management techniques like admission control, load control, packet scheduling, handover control and power control are summarized. Diagrams illustrate the system architecture and information flow between network elements.
This presentation covers:
What is a Radio Resource Unit ?
Why do we need RRM ?
Need of RRM in WCDMA ?
RRM algorithms Objectives
Different RRM functions : Handover, Power control, Admission Control, Code Management
UMTS system architecture, protocols & processesMuxi ESL
This document provides an overview of UMTS system architecture and protocols. It discusses:
- The logical architecture of UTRAN including RNC and Node-B elements.
- Interfaces between network elements are clearly specified to allow interoperability between equipment from different manufacturers.
- The main functions of the RNC include radio resource management, call management, and connection to the core network.
- Protocols in UTRAN include RRC for radio resource control, RLC for radio link control, and MAC for medium access control.
The document summarizes the key concepts in planning and deploying a 3G WCDMA mobile network. It describes the network architecture including nodes like RNC, Node B and interfaces. It also explains radio network planning phases and considerations like frequency planning, link budget calculations, coverage and capacity planning. The document discusses technologies like HSDPA that enhance data capabilities and presents LinkIT, a planning tool developed to understand network planning mathematics.
UMTS-WCDMA is a 3G mobile communication standard that uses CDMA technology. It uses wideband CDMA with a chip rate of 3.84 Mcps for its air interface along with orthogonal variable spreading factor codes. The standard defines protocols and procedures for cell search, handover, uplink and downlink physical channels, and support for multirate services through variable spreading factors. Long term targets for UMTS-WCDMA evolution include higher data rates up to 100 Mbps for full mobility and 1 Gbps for low mobility, as well as improved spectral efficiency.
- The document analyzes the effect of varying antenna gain and sectorization on site requirements for an LTE radio access network.
- It models three site layouts: single omni-directional antenna sites, 3-sector sites with directional antennas per sector, and 6-sector sites.
- Link budget calculations are performed for different clutter types to estimate the number of sites needed to cover the deployment area under each configuration.
This document summarizes Sharanjit Kaur's industrial training presentation at MTNL. It introduces MTNL and provides an overview of topics covered during training, including switching, signaling, broadband, and transmission. It then describes projects undertaken and steps to improve quality of service in 3G networks, including checking equipment, monitoring KPIs, increasing bandwidth, and performing drive tests using the TEMS Investigation tool.
This document provides a summary of an industrial training presentation at MTNL. It introduces MTNL and describes key topics covered during the training, including switching, signaling, broadband, and transmission. It discusses these topics in detail and provides examples of projects undertaken and steps that can be taken to improve quality of service in 3G networks. The document concludes with a summary of field training experiences at different MTNL locations.
This presentation describes about UMTS major components Key features, NodeB, RNC, GGSN,MSC, SGSN,VLR,HLR, Charging function, UMTS base stations and info about UMTS number allocated for MS.
Third Generation (3G) wireless systems focused on improving speed and effectiveness of critical communication over 3G standards - W-CDMA, UMTS, and CDMA2000. 4G provides even higher broadband speeds for live streaming, video conferencing, and location-based services. The document compares capabilities and standards of 3G and emerging 4G wireless technologies.
Optimization channal contral power in live umts networkThananan numatti
Abstract— The proposed approach to improvement on the
UMTS (Universal Mobile Telecommunications System)
network radio, there are many ways we propose another way of
reducing power control channel slightly to provide improved
signal quality, which is a measure of quality is EcIo (energy per
bit) / (Own cell interference +. Noise density) principle when the
power control channel down a bit to make the quality better,
because the denominator less energy than ever before, and open
the extra capacity in the network in the body, this is the reason
for the optimization this principle can be applied in a live
network.
It is important to maintain signal quality are durable and
resistant to interference. Probability to the good benefits for
imply network must be physical tuning coverage complete before
and area dense urban or urban is good to the imply this
parameter. For area rural should not imply because the cell edge
a foot print coverage is too large . However this paper presents a science so that the results can be applied to real work.
1. The 3G network consists of the User Equipment (UE) or mobile phone and the UMTS Terrestrial Radio Access Network (UTRAN) which includes base stations and network intelligence.
2. The UE and UTRAN contain four main layers - physical, MAC, RLC, and RRC layers. The RRC layer handles functions like broadcasting information, establishing connections, and controlling quality of service.
3. Below the RRC layer is the RLC layer, which is focused on data transfer functions like segmentation and reassembly. The MAC layer handles logical channels and prioritization, while the physical layer handles radio functions.
Dar es Salaam institute of Technology (DIT) provides training on digital networks including 3G and 4G mobile technologies. 3G networks introduced higher speed packet data and mobile multimedia services compared to previous generations. UMTS/WCDMA is an IMT-2000 3G standard that supports voice and fast packet data through technologies like HSDPA and HSUPA which enable peak downlink rates of 14.4 Mbps and uplink rates of 5.8 Mbps. HSPA+ further increases speeds through MIMO and higher order modulations.
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.
The document discusses HSDPA (High Speed Downlink Packet Access), a 3G mobile telecommunications standard that allows networks to have higher data transfer speeds and capacity. Key points:
- HSDPA was introduced in 2005 and allows peak data rates of 14.4 Mbps compared to 2 Mbps for standard WCDMA. It uses shared channel transmission, fast scheduling, adaptive modulation/coding, and HARQ.
- Planning HSDPA deployment requires analyzing existing network performance, dimensioning configurations, parameter planning, and performance monitoring. Critical aspects include carrier configuration, hardware capacity, transmission capacity, and coverage strategy.
- HSDPA improves on WCDMA through features like shared channel transmission, channel
This document contains questions and answers about LTE (Long Term Evolution) technology. Some key points covered include:
- OFDMA is used for downlink and SC-FDMA is used for uplink to overcome high PAPR issues.
- CDS dynamically schedules radio resources, modulation, coding and power control based on channel quality and traffic load.
- MIMO uses multiple antennas to increase data rates up to a maximum of 8x8 MIMO.
- The LTE network architecture includes the eNB, MME, S-GW and P-GW connected by various interfaces like S1, S6a, S5 etc.
- Security in LTE is based on
WCDMA uses direct sequence spread spectrum technology where user data is multiplied by pseudo-random codes to spread it across a wide bandwidth. This processing gain allows multiple users to transmit simultaneously while maintaining sufficient signal to interference ratios. Power control is used to ensure each user transmits with the minimum necessary power level to reduce interference. Admission control and power control work together to manage system capacity and maintain quality of service as user numbers and noise levels change.
Similar to Cellular network planning_and_optimization_part7 (20)
3. 3
TE MT UTRAN CN Iu
EDGE
NODE
CN
Gateway
TE
UMTS
End-to-End Service
TE/MT Local
Bearer Service
UMTS Bearer Service External Bearer
Service
UMTS Bearer Service
Radio Access Bearer Service CN Bearer
Service
Backbone
Bearer Service
Iu Bearer
Service
Radio Bearer
Service
UTRA
FDD/TDD
Service
Physical
Bearer Service
Radio Access Bearer
UE BS, RNC
4. 4
Radio Access Bearer
Main task of the UTRAN is to create and maintain RAB for
communication between UE and CN.
RAB is build up in order to give for CN elements an illusion
about fixed communication path to UE.
The network builds up the end-to-end QoS connection from
small pieces, which compose a complete chain without
bottlenecks
These pieces are called Bearers
When the connection is set up, the network elements
negotiate the QoS requirements of the bearers set up
between them
The result is a compromise, in which the QoS requirements
and network’s capacity is taken into account
5. 5
UMTS QoS Classes
File downloading, e-mailsBackground class
Web surfingInteractive class
Real-time streaming videoStreaming class
Speech and video callsConversational
class
Example applicationTraffic Class
6. 6
UMTS QoS Classes
Big variable delay, buffering allowed,
asymmetric traffic, no guaranteed bit
rate
Background class
Moderate variable delay, buffering
allowed, asymmetric traffic, no
guaranteed bit rate
Interactive class
Minimum variable delay, buffering
allowed, asymmetric traffic,
guaranteed bit rate
Streaming class
Minimum fixed delay, no buffering,
symmetric traffic, guaranteed bit rate
Conversational class
PropertiesTraffic Class
7. 7
UMTS QoS Parameters
QoS of some services are not
negotiable (speech), packet data
services admit various QoS classes
QoS negotiable
Set the limits for delay (>80ms)Allowed transfer
delay
Defines the bit rate that the UMTS
bearer must carry between its end
points
Guaranteed bit rate
Defines the maximum bit rate when
delivering information between end
points of UMTS bearer (<2Mbps)
Maximum bit rate
ExplanationParameter
8. 8
QoS Negotiation
UE UTRAN
(NB, RNC)
CN
UMTS bearer service: Request for UMTS QoS Class
RAB assignment request
QoS negotiationRadio bearer and radio
link establishment
UMTS Bearer service with negotiated QoS
E2E service request
Maximum bit rate
Guaranteed bit rate
Transfer delay
QoS negotiable (y/n) Maximum bit rate
Guaranteed bit rate
Transfer delay
QoS negotiable (y/n)
RRM: Admission control
RAB assignment response
9. 9
In early UMTS Release 99 all
conversational and streaming class
traffic were offered over the CS
bearer
Voice
RT multimedia (e.g videotelephony)
In early Release 99 only Interactive
and background class traffic
utilisises the PS bearer
Release 4 capable networks
introduce some streaming class
traffic on PS bearer as well
Release 5 brings along a full
portfolio of PS bearers also utilised
for conversational traffic
QoS in UMTS
10. 10
The QoS over the air interface is implemented by matching each
radio bearer with a transport channel whose format set defines the
QoS parameters
The mapping is performed during the establishment of the RAB
RNC performs the mapping of RAB characteristics to actual resource
requirements (vendor dependent)
Example of mapping for web service, which belongs to the interactive
class
Parameters Interactive Class Radio Resource mapping
Maximum bit rate 128 kbps SF=16
Maximum SDU size 1500 Map to Transport formats
Residual BER 10^-6 1/3 turbo encoder
Transfer Delay NA Interleaver = 40 or 80 msec
Guaranteed bit rate 64 kbps
Delivery order yes Use Acknowledged RLC
SDU Error Ratio 1 %
Set appropriate threshold for outer
loop power control
Delivery of erroneous SDU No Use Acknowledged RLC
SF=16
QoS in UMTS
11. 11
Operators can define the wanted QoS profile (in
HLR) per subscriber
Users can be categorised (QoS differentiation) for
various tariffing schemes
Traffic handling priorities can be set (THP)
Business Remote office Basic free time
Traffic class All four allowed All four allowed
Only converational
(voice calls) and
background
Max bit rate 400 kbps 800 kbps 64 kbps
Guaranteed bit rate 384 kbps 64 kbps 12 kbps
Allowed THPs
THP 1 (e.g. for e-mail
downloads)
THP 2 (e.g. for file
transfer) THP 3
QoS in UMTS
14. 14
General
Radio Resource Management (RRM) is
elementary part of WCDMA.
RRM is responsible for efficient utilization of the
air interface resources it is needed to
Guarantee Quality of Service (QoS)
Maintain the planned coverage area
Optimize the cell capacity
The importance of RRM is mostly due to the
features of the UMTS system; interference
limited nature and adaptive services
15. 15
Introduction to RRM/objectives
Cell coverage Cell capacity
QoS
OPTIMISATION
Objectives of RRM
• Ensure planned coverage for
each service
• Ensure required connection
quality
• Ensure planned max blocking
• Optimise the usage of system
capacity resources
17. 17
Introduction to RRM/Logical model
MS
Node B RNC
• Power Control
• Power Control
• Load Control
• Power Control
• Load Control
• Handover Control
• Admission Control
(also in SGSN)
• Packet Scheduler
18. 18
RRM algorithms
Family of RRM algorithms:
Power control
Fast power control (Node B, UE)
Outer loop power control (RNC)
Handover control (RNC)
Admission control (RNC)
Load control (RNC)
Fast load control (Node B)
Packet scheduling (RNC)
20. 20
Power control
Objectives
Maintain the link quality in uplink and in downlink by controlling
the transmission powers
Prevents near-far effect
Minimise effects of fast and slow fading
Minimises interference in network
Accuracy of the power control is important
No time-frequency separation of users, all use the same
bandwidth
Inaccuracy in power control immediately lifts the network’s
interference level, which correspondingly lowers the capacity
Due to users mobility the speed of power control is also a
critical issue
21. 21
Near-far problem in uplink
There can large path loss difference between UE1 (cell
centre) and UE2 (cell edge)
If both UEs are transmitting with the same power then UE1
will block UE2 (and other cell edge users too)
Power control will drive transmission powers of UE1 and UE2
to the minimum level that is required to meet QoS
In Node B received powers from UE1 and UE2 will be the
same for same services
UE1
UE2
22. 22
Power control
Power Control on the common channels ensures that their
coverage is sufficient both to set up UE-originating and UE-
terminating calls.
Power Control on the dedicated channels ensures an agreed
quality of connection in terms of Block Error Rate (BLER), while
minimizing the impact on other UEs.
Uplink Power Control increases the maximum number of
connections that can be served with the required Quality of Service
(QoS), while reducing both the interference and the total amount of
radiated power in the network.
Downlink Power Control minimizes the transmission power of the
NodeB and compensates for channel fading. Minimizing transmitted
power maximizes the downlink capacity.
23. 23
Power control
Main power control approaches
Fast power control:
Aim is to compensate the effect of fast fading
Gain from fast power control is largest for slowly
moving UEs and when fading is flat, i.e. there is
multi-path diversity
Fast power control drives the received power to a
target SIR. This value is discussed more closely in
connection with dimensioning.
Outer loop power control
Adjust the target SIR according to service QoS.
24. 24
PC mechanism
Outer loop PC:
RNC adjust the
target SIR in order
to meet target
BLER
Fast PC: Node B
command terminal to
change transmit
power in order to meet
target SIR
Received SIR
Outer loop power control
Fast power control
25. 25
Uplink outer loop PC
The goal is to control the target SIR in order to sustain
the wanted QoS with minimum transmit power
The target BLER is defined with the admission control
algorithm
The uplink algorithm is controlled in RNC
Update frequency from 10 Hz up to 100 Hz
Outer loop power control will raise or lower the target
SIR according to step size, which is defined by radio
network planning.
The equipments’ performance defines the minimum
value for target SIR
26. 26
Downlink outer loop PC
Implemented in UE to set SIR target on DL
traffic channels
Quality target: BLER of each transport channel
as set by RNC
Admission control determines the value of DL
BLER.
No SIR target change if NodeB power reaches
maximum or network congestion occurs.
27. 27
Transmit Power Control (TPC)
Ideal fast power control invert the channel
In practice power control accuracy is reduced by
feedback errors,
Better figure, PC headroom etc
Fast fading channel
Transmitted power
Note: It is usual to talk about ‘fast power control’ when power control is build up
to mitigate fast fading. Transmit power control is WCDMA specific term
28. 28
Uplink TPC
Update rate 1.5 kHz => fast enough to track and
compensate fast fading up to x km/h mobile speed
If received SIR > target SIR in Node B => UE is
commanded to decrease its transmit power. Similarly UE
is commanded to increase its transmission power if
received SIR < target SIR
Network planning defines the step size. Usual step size
values are between 0.5dB and 2dB.
Soft handover:
UE can receive contradictory PC commands from different
node Bs
UE transmission power will be increased if all node B’s ask for
it and decreased if at least one node B demands it
29. 29
Downlink TPC
Similar as UL TPC:
UE measures SIR on DL DPCCH during the pilot
period (or use CPICH)
UE maintains the QoS by sending fast power control
commands (TPC bits) requesting power adjustment
Power offsets can be used in DL in order to improve
control reliability. Offsets are network parameters that
can be set in planning phase
30. 30
TPC characters
Main interference migitation means in UMTS
TPC (1500Hz) is able to follow fast fading up to ~50km/h MS speed, after
that the fading dips are averaged out
In high MS speeds TPC can have even negative impact
TPC lowers the required Eb/No, not so much tx-powers directly
• Concerns in practise:
•In SHO, DL powers can drift apart due to the inaccurate reception of uplink PC
commands → Degraded SHO performance in case drift prevention not working
•In SHO, DL PC commands cannot be combined in RAKE (because they
contain different information). Data bits however can be combined → Worse
reability for PC commands.
=> Can be improved by allocating more power to CCHs
•Building corners in the urban areas
• Average TPC headroom (4dB) must be assumed to pathloss.
33. 33
WCDMA Handover control
Hard HO (HHO)
All the old radio links of an UE are released before the new radio links
are established.
Real time bearers: short disconnection in transmission.
Non real time bearers: HHO is lossless.
Shared & common channels used for hard handover (cell reselection)
Soft HO (SHO).
MS always keeps at least one radio link to UTRAN.
Soft HO: MS is simultaneously controlled by two or more cells belonging to
diffetrent BTS of the same RNC or to different RNC.
Softer HO. MS is controlled by at least two cells under one BTS.
Dedicated channels (Cell_DCH state) used for SHO
Handover can be either network or UE initiated
Serving RNC makes the decisions in both cases
34. 34
WCDMA Handover control
Core network
RNC1 RNC2 RNC3 RNC4 BSC
Node B Node B Node B Node B Node B BTS
Iur
Combining (Softer HO)
Soft Handover
Softer Handover
Soft Handover Hard Handover
Hard Handover Hard Handover
35. 35
Hard handovers
Intra & Inter-frequency HHO’s
Usually triggered to maintain mobility
Not recommended in WCDMA unless there is an urgent need,
because
Hard HO increases interference easily, since the real-time user
is disconnected temporarily and the used power must be re-
evalueted
This decreases the capacity in heavy traffic situations and can
worsen the near-far effect
Absence of Iur (connection between RNC’s) will cause hard HOs
Compressed mode used in HOs between carriers and systems
In compressed mode UE stop UL transmission for few milliseconds
within a radio frame (10ms) in order to enable measurements of
different carriers/systems
36. 36
Inter frequency handover
IFHO can be used in planning to
provide coverage (micro ֏ macro cell)
provide capacity (reduce cell loading)
2nd carrier can be enabled on cell basis
Not so straightforward to perform in UE due to need of
compressed mode
Most Network vendors’ equipment supports IFHO
IFHO is generally seen as a means of optimisation as the
traffic evolves, but can be used also e.g. to provide
indoor coverage
37. 37
Soft Handover (SHO)
SHO helps avoid near-far effect for real-time connection
For high mobility users shadow fading + (slow) hard
handovers would create near-far situations
SHO is an essential interference mitigation tool in
WCDMA
38. 38
DOWNLINK:
SHO utilises two separate codes in DL (RAKE fingers in UE are
assigned for reception)
Maximum ratio combining done in UE for the signals
Produced gain 1-3 dB, however...
Gain depends on the difference of the signals’ strength
Gain depends on channel conditions and accuracy of the received
channel estimate → In some circumstanses the gain can be lost!
The more multipath diversity is available the less SHO gain is
achived
Soft Handover
39. 39
UPLINK:
More complex situation than in DL
During softer HO, same procedure in node B’s RAKE than in DL case
Produced gain 1-3 dB
Better performance in terms of strenght differences, since the signals
come from the same source
During Soft HO, the combining of signals is done in the RNC
Selection combining performed for baseband signal
Based on selecting the frame with better FER or BER
Better frame send to be used in open loop PC (target SIR estimation)
Gain achieved through more stable UE tx-powers (1-2dB)
→ No actual gain to the radio link
Softer/Soft Handover
40. 40
The cells in a WCDMA RAN are, from UE point of view, divided in
different mutual excluding sets defined by 3GPP:
Active Set
The cells involved in soft handover and measured by the UE
Monitored Set
The cells only measured by the UE and not part of the Active Set. The
monitored set can consist of intra-frequency, Inter-Frequency and Inter-RAT
cells
The cells measured by the UE are the sum of the Active Set and the
Monitored Set.
The number of Intra-frequency cells in the Monitored Set + the Active
Set cells is limited by 3GPP to 32.
The number of Inter-Frequency cells in the Monitored set is limited to
32.
The number of Inter-RAT cells in the Monitored set is limited to 32.
Soft Handover
41. 41
Active Set
As UE moves, node Bs are continuously added to and removed from the
active set. When added, they are also updated to the neighbor cell list.
UE measures the monitored set of cells and Handover Control evaluates if
any node B should be added to, removed from or replaced in the active set
Maximum Active Set Size parameter
is used to determine the maximum allowed number of SHO
connections (varies between 1-5, typical default 3)
Too high value decreases capacity (signalling increases and multiple
connections occur too often)
Too low value degreases the SHO performance (best candidate cells may
be excluded in some situations)
Soft Handover
42. 42
The handover measurements for Intra-Frequency HO are based on
P-CPICH Ec/Io
Ec/Io is the received signal code power divided by the total received
power. It is calculated from signal before the signal de-spreading
operation while Eb/No is calculated after de-spreading.
Ec/Io can be be determined for the signal ”in the air”
Eb/No depends on the service (bit rate, CS/PS, receiving end) and
Ec/Io is service independent
The accuracy of the Ec/Io measurements is essential for HO
performance
Depends on filtering lenght and mobile speed
Filter length for slowly moving & stationary UE’s should be just
long enough to avoid Fast Fading errors
Too long filter length for will cause HO delays to fast moving UE
Soft Handover
43. 43
Event based triggered measurements and reporting
Basic reporting events 1A, 1B and 1C (Ref.
3GPP)
1A: Primary CPICH enters the reporting range
1B: P-CPICH leaves the reporting range
1C: Non-active P-CPICH becomes better than an active P-
CPICH
1D: Change of current best cell with new P-CPICH
Handover decision
Done by RNC based on measurements and available
resources
Soft Handover
44. 44
Picture of events 1A and 1B. Example: The terminal sends an event 1A
report to the RNC, if the new cell belongs to the monitored cells list and
Active Set is not full. Then new cell is proposed to be added to the Active
Set. If the Active Set is full, the cell is proposed as a replacement of the
worst cell in the Active Set (1C)
Soft Handover
45. 45
Picture of event 1C. Example: The terminal sends an event 1C report to
the RNC if the new cell belongs to the monitored cells list and Active Set
is not full. Then new cell is proposed to be added to the Active Set. If the
Active Set is full, theen new cell is proposed as a replacement of the
worst cell in the Active Set
Soft Handover
46. 46
Picture of event 1D. Example: The terminal sends an event 1D report to
the RNC if the cell belongs to the monitored cells list and Active Set is
not full. Then cell is proposed to be added to the Active Set. If the Active
Set is full, the cell is proposed as a replacement of the strongest cell in
the Active Set
Soft Handover
48. 48
Inter-Frequency Handover is a hard handover where the UE is
ordered by the network to tune to another frequency.
This means that there will be small interuptions in the data flow to
and from the UE
• When Inter-Frequency HO is
considered, first the UE
measures the conditions to start
Compressed Mode
• Usually Ec/Io of current carrier
• Events 2d and 2f defined for
IFHO
• Time to trigger used
Inter-Frequency HO (IFHO)
49. 49
Soft handover
window
21
Soft handover
margin, which is
defined by
radio network
planning
Received signal
level in
Node B
SHO margin in planning tools
Some 3G planning tools use one single SHO planning parameter (=SHO margin/SHO gain)
Default Value varies between 2 and 6 dB
Value for this parameter should be defined as:
Reporting range1a + Reporting range1b
2
Handover margin =
50. 50
HO related topics in network planning
Network topology: How sites are located relative
to each other, how many sectors/site
Node B antenna radiation patterns
Overlapping patterns => more softer HOs
Antenna tilt => Number of potential Node B’s in Active
Set
Path loss and shadow fading characteristics
The average number of Node B’s that a UE can
synchronise to
HO parameter adjustments is part of the network
optimization
52. 52
Congestion and Admission Control
Congestion/Load Control’s general responsibility is to
remain the network in a stable state and prevent
overloading
Congestion/Load control is in close co-operation with
functions of admission control and packet scheduler
Load control operates in RNC:
Admission
control
Packet
scheduler
Load control
Information of network
loading level
Loading status
NRT (Non-Real Time
traffic) load
53. 53
Admission control
If air interface loading is allowed to increase too much the
coverage of the cell will be reduced below the planned
value.
Admission control decides whether to accept the terminal’s
request for new radio access bearer by calculating how
much interference new bearer would create to the cell in
both UL and DL
Congestion control
Responsible of returning the network back into desired
target load in case of overload
Target load is set in network planning and overload should
be an exceptional situation
Admission and Congestion Control
54. 54
Load
Interference power
Maximum interference level defined by radio network planning
?
Estimated growth in
interference when new UE
arrives to the cell
New bearer’s
load factor
Maximum load level
defined by radio
network planning
There are predefined UL
and DL thresholds for
interference power.
Thresholds are set in
network planning.
If either UL or DL
threshold is exceeded the
RAB is not admitted.
For decision AC may
derive the transmitted bit
rate, processing gain,
radio link initial quality
parameters, target BER,
BLER, Eb/No, SIR target.
Admission Control
55. 55
In case of congestion the use of resources are scaled down to reach
normal loading status
The priorisation and order of congestion control actions is based on
vendor algorithms.
Actions that can be carried out in order to decrease the load
Deny power control commands received from UE
Reduce the UL Eb/No target used in UL fast power control
Reduce the throughput of packet data traffic
Handover to other WCDMA carrier or to GSM
Decrease bit rates in real time services
Drop low priority data calls
Congestion control
56. 56
Determines the available radio resources for NRT radio bearers
Share the available radio resources between NRT radio bearers.
Monitor the allocations for NRT radio bearers.
Initiate the switching between common, shared and dedicated
channels when necessary.
Monitor the system loading.
Perform load control actions for the NRT radio bearers when
necessary.
Packet scheduler
57. 57
Capacity can be divided between
non-controllable and controllable
traffic
Load caused by real time traffic,
interference from other cell users
and noise together is called non-
controllable load
The part of the available capacity
that is not used for non-controllable
load can be used for NRT radio
bearers on best effort basis (=
controllable load).
PS is implemented for dedicated
(DCH) as well as common control
transport channels (RACH/FACH).
PS takes care of filling the
controllable capacity with NRT
traffic
• The amount of scheduled capacity depends on:
• UE and BTS capabilities,
• the current load in the cell,
• the availability of physical resources.
Packet Scheduler
58. 58
For dimensioning purposes radio
network planning can define packet
access features per service, e.g.by
next parameters:
Amount of packet bursts per session
Reading time between bursts
Size of packets
Arrival rate packets
Amount of packets per burst
Number of retransmission
Packet Scheduler
59. 59
Load
InterferenceAdmission
control
Congestion
control
Packet Scheduler
Target level for
interference
Target level for
interference+offset
Threshold
Maximum level
Decrease bit rates
and NRT Bearers
are dropped
Overload actions
No actions
New RT bearers are
admitted normally
NRT bearers are
increased
NRT load is not
increased, but bit rate
changes are allowed
No actions
No new bearers are
admitted
Preventive load
control actions
Decrease bit ratesNo new bearers are
admitted
Control summary