UMTS provides higher data rates than previous mobile networks, enabling new services like video telephony and quick data downloads. A killer application is likely to be quick access to location-based information via the internet. At launch, most traffic will be voice using circuit-switched connections, but over time data traffic on packet-switched connections will increase. UMTS defines bearer services to negotiate the quality of service parameters needed by different applications, including four main classes (conversational, streaming, interactive, background) depending on delay sensitivity. The conversational class supports real-time applications like voice and video calls.
WCDMA (Wideband Code Division Multiple Access) is a 3G mobile technology that uses CDMA to allow multiple users to access a wide 5MHz radio channel simultaneously. Key features of WCDMA include fast power control to manage interference between users, and soft/softer handover which allows a mobile to connect to multiple base stations for better call quality as the user moves between cells. WCDMA was developed to provide higher data speeds and capacity over wireless networks compared to 2G technologies like GSM.
This document provides an overview of Wideband Code Division Multiple Access (WCDMA) technology. It discusses how WCDMA evolved from existing GSM and CDMA technologies to provide higher data rates and capacity. Key aspects of WCDMA include efficient power control, soft handover between cells, and the ability to allocate capacity between voice and data services. The document describes the basic architecture of a WCDMA network including the radio access network components like Node B base stations and radio network controllers.
GSM-architecture-Location tracking and call setup- Mobility management- Handover-
Security-GSM SMS –International roaming for GSM- call recording functions-subscriber and
service data mgt –-Mobile Number portability -VoIP service for Mobile Networks – GPRS –
Architecture-GPRS procedures-attach and detach procedures-PDP context procedure-
combined RA/LA update procedures-Billing
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.
This document provides an overview of WCDMA technology. It discusses the evolution of mobile networks from 1G to 3G, highlighting the need for 3G networks to support higher data rates. It introduces UMTS and WCDMA as 3G standards, with WCDMA being the radio access technology used in UMTS networks. Key concepts of WCDMA such as spreading, scrambling, power control and handover are described at a high level. The document also provides basic information on WCDMA channels and packet access.
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.
This document provides an overview of wireless communication and cellular systems. It discusses key concepts such as frequency reuse, cell footprint, handover, interference, and system capacity. It explains how cellular networks divide a service area into smaller cells served by low-power base stations to improve capacity. Neighboring cells are assigned different frequency groups to reduce interference. The same frequencies can be reused in cells far enough apart. Handover allows calls to be transferred between cells as users move. The document also covers channel assignment strategies and methods for expanding system capacity through cell splitting or reducing the frequency reuse factor.
This document provides an introduction to traffic engineering concepts for telecommunication networks. It discusses key topics like traffic statistics, patterns, units of measurement, grade of service, blocking probability, congestion, modeling traffic, network organization, and management. The purpose of traffic engineering is to determine how to provide adequate service to subscribers while making economical use of network resources. It analyzes statistical properties of networks to design efficient models.
WCDMA (Wideband Code Division Multiple Access) is a 3G mobile technology that uses CDMA to allow multiple users to access a wide 5MHz radio channel simultaneously. Key features of WCDMA include fast power control to manage interference between users, and soft/softer handover which allows a mobile to connect to multiple base stations for better call quality as the user moves between cells. WCDMA was developed to provide higher data speeds and capacity over wireless networks compared to 2G technologies like GSM.
This document provides an overview of Wideband Code Division Multiple Access (WCDMA) technology. It discusses how WCDMA evolved from existing GSM and CDMA technologies to provide higher data rates and capacity. Key aspects of WCDMA include efficient power control, soft handover between cells, and the ability to allocate capacity between voice and data services. The document describes the basic architecture of a WCDMA network including the radio access network components like Node B base stations and radio network controllers.
GSM-architecture-Location tracking and call setup- Mobility management- Handover-
Security-GSM SMS –International roaming for GSM- call recording functions-subscriber and
service data mgt –-Mobile Number portability -VoIP service for Mobile Networks – GPRS –
Architecture-GPRS procedures-attach and detach procedures-PDP context procedure-
combined RA/LA update procedures-Billing
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.
This document provides an overview of WCDMA technology. It discusses the evolution of mobile networks from 1G to 3G, highlighting the need for 3G networks to support higher data rates. It introduces UMTS and WCDMA as 3G standards, with WCDMA being the radio access technology used in UMTS networks. Key concepts of WCDMA such as spreading, scrambling, power control and handover are described at a high level. The document also provides basic information on WCDMA channels and packet access.
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.
This document provides an overview of wireless communication and cellular systems. It discusses key concepts such as frequency reuse, cell footprint, handover, interference, and system capacity. It explains how cellular networks divide a service area into smaller cells served by low-power base stations to improve capacity. Neighboring cells are assigned different frequency groups to reduce interference. The same frequencies can be reused in cells far enough apart. Handover allows calls to be transferred between cells as users move. The document also covers channel assignment strategies and methods for expanding system capacity through cell splitting or reducing the frequency reuse factor.
This document provides an introduction to traffic engineering concepts for telecommunication networks. It discusses key topics like traffic statistics, patterns, units of measurement, grade of service, blocking probability, congestion, modeling traffic, network organization, and management. The purpose of traffic engineering is to determine how to provide adequate service to subscribers while making economical use of network resources. It analyzes statistical properties of networks to design efficient models.
This document discusses quality of service (QoS) provisioning in wireless multimedia networks. It describes QoS challenges in wireless networks due to limited bandwidth, unreliable links, and varying channel conditions. It also discusses the characteristics of multimedia services and traffic modeling challenges. The document outlines IEEE 802.11 MAC layer enhancements including the distributed coordination function, point coordination function, and IEEE 802.11e standard for supporting QoS through enhanced distributed channel access and hybrid coordination function. It emphasizes the need for end-to-end QoS, adaptive frameworks, and call admission control for wireless multimedia networks.
A digital switch is a device that handles digital signals generated at or passed through a telephone company central office and forwards them across the company's backbone network. ... A centrex is a digital switch at the central office that manages to switch for the private company from the central office.
Global system for mobile communication Introduction, GSM architecture, GSM interfaces, Signal processing in GSM,
Frame structure of GSM, Channels used in GSM
The document discusses various multiple access techniques used in wireless networks. It describes Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiplexing (OFDM), and Space Division Multiple Access (SDMA). It also covers concepts like duplexing methods, power control, modulation techniques, and the near-far problem in CDMA systems.
The document discusses the transition from GSM networks to 3G networks using UMTS (Universal Mobile Telecommunications System) and W-CDMA (Wideband Code Division Multiple Access) technology. It provides an overview of the 3 steps to transition: from current GSM networks to 2.5G networks with GPRS added, to 3G networks using UMTS and W-CDMA. Key aspects of W-CDMA such as its frequencies, multiple access techniques, and spreading codes used are summarized.
The document provides an overview of the Global System for Mobile Communication (GSM) standard. It describes GSM as an integrated European mobile system that enables international roaming. The key objectives of GSM are outlined as well as the basic system elements, including mobile stations, base station systems, and mobile switching centers. The document also discusses concepts such as frequency reuse, cellular networks, handover, and multiple access methods used in GSM like TDMA.
Successful interference cancellation with Blind Equalization method for MC-CD...IJTET Journal
Abstract— The increasing demand for wireless services has created the need for cost effective transmission techniques that can exploit scarce spectral resources efficiently. Inorder to achieve the high data rates needed to meet the quality of service requirements of future multimedia applications, MC-CDMA has been considered as good air-interface candidate, especially for the downlink. However, the user capacity of MC-CDMA system is essentially limited by interference. This interference can be mitigated by employing precoding techniques, IB-DFE based receivers and other efficient interference suppression techniques. In the proposed system, combined Iterative IA precoding at the transmitter with IB-DFE based processing at the receiver is suggested for MC-CDMA systems. The matrices for this nonlinear space-frequency equalizer are obtained by minimizing the overall MSE of all data streams at each subcarrier.
The document discusses the basic principles of wireless communication, including radio propagation characteristics, spreading technology, channel coding, interleave technology, and modulation. It then focuses on the specific mechanisms used in WCDMA networks, including the data transmission procedure, channel coding methods of convolutional codes and turbo codes, spreading using orthogonal variable spreading factor codes, and modulation techniques.
The document discusses GSM signaling and mobile signaling. GSM signaling defines communications between the mobile and network using different protocols across interfaces. Mobile signaling involves the mobile searching for frequencies, synchronizing, downloading information, selecting a network, and signaling to the network by sending a service request when a call is made.
Co-channel and adjacent-channel interference evaluation of an outdoor telecom...Konstantinos Stamatakis
The objective of the present paper is to evaluate the
impact of adjacent and co-channel interference on the
performance of some standard report systems that exists in an
outdoor telecommunications cabinet - base station (BS) (also
known as KV, from the acronym of the German word
Kabelverzweiger) and devices that technicians frequently use.
Specifically, the interference analyzed is between devices, such as
Bluetooth handset, laptop and measurement tools, that are
usually used during inspections and repairs by technicians and
wireless reporting systems installed inside BS that provide
information about BS’s condition and real time connection with
the help desk back office
GSM-Mobility Management-Call Control
GRPS-Network elements
Radio Resource Management
Mobility Management and Session Management
Small Screen Web Browsing
UTRAN-Core and Radio Network Mobility Management
UMTS Security
This document provides an overview of the Global System for Mobile Communications (GSM). It discusses how GSM uses a combination of Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) to maximize channel usage. It also describes the key components of GSM including the mobile station, base station subsystem, network switching subsystem, and operation and support subsystem. Additionally, it covers functions like frequency reuse, handovers, short message service, speech coding, and call routing in GSM networks.
Frequencies management,Channel assignments,
Frequency reuse, System capacity and its improvement: Cell spliting and sectoring, Handoffs & its types, prioritizing handoff, Umbrella cell approach, Cell dragging, Roaming, Co channel and adjacent channel interference, Improving coverage- Repeaters for range extension and microcell zone concept, Examples
Multiple access techniques for wireless communicationDr.Umadevi V
This document discusses multiple access techniques for wireless communication. It begins with an introduction to how multiple access schemes allow efficient sharing of limited radio spectrum among multiple users. It then provides a brief history of wireless communication and pioneers. The document goes on to explain various multiple access techniques in detail including FDMA, TDMA, CDMA, SDMA, and CSMA. It describes their applications, advantages, and disadvantages. Forward and reverse link power control in CDMA is also summarized.
Manideep Srirangam completed an inplant training at BSNL Hyderabad from May 25th to June 6th 2015. The training covered an overview of topics in telecommunication including telecommunication networks, PCM principles and multiplexing, digital switching principles, signaling, latest switches, optical fiber communication, GSM and CDMA technologies, and facilities provided by electronic exchanges such as broadband and DSL technologies. Key concepts covered included time division multiplexing, frequency division multiplexing, digital switching, fiber types, PDH systems, and facilities available to subscribers like call forwarding and call waiting.
The document discusses various types of pulse modulation techniques including pulse amplitude modulation (PAM), pulse width modulation (PWM), pulse position modulation (PPM), and pulse code modulation (PCM). It provides details on the basic principles, components, and advantages of each technique. PCM is described as the digital form of pulse modulation where the analog signal is converted to digital pulses by sampling, quantizing, and encoding the signal. The minimum sampling rate required by the Nyquist theorem and examples of calculating bit rates for PCM are also covered.
Presentation on MULTIPLE ACCESS TECHNIQUES FOR WIRELESS COMMUNICATION By SUPRIYA BHARATI (ME/EC/10006/16) and KHUSHBOO KUMARI (ME/EC/10010/16) Under the Guidance of Dr. Sanjay Kumar Department of Electronics & Communication Engg. (ECE) Birla Institute of Technology, Mesra ,Ranchi-835215 , Jharkhand , India
This document discusses multiple access communication techniques. It introduces frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and space/beam division multiple access (SDMA). FDMA assigns each user a pair of frequencies, TDMA divides bandwidth into time slots and assigns users slots, CDMA allows signals to occupy the same channel using unique codes, and SDMA serves different users using concentrated spot beams. The document provides examples of applications and advantages/disadvantages of each technique.
Crossborder cultural portal in Western Europe provides 3500-4000 events and 7000 guide entries from existing databases and user submissions. The portal reaches over 100,000 people per month, including 9000 website visitors. It is a strategic instrument for crossborder cooperation managed by a coordinating structure and 6 regional administrators from cultural administrations. Challenges include improving content collection and dissemination to bring cultural content to new sectors and audiences while expanding the network of content providers.
This document discusses quality of service (QoS) provisioning in wireless multimedia networks. It describes QoS challenges in wireless networks due to limited bandwidth, unreliable links, and varying channel conditions. It also discusses the characteristics of multimedia services and traffic modeling challenges. The document outlines IEEE 802.11 MAC layer enhancements including the distributed coordination function, point coordination function, and IEEE 802.11e standard for supporting QoS through enhanced distributed channel access and hybrid coordination function. It emphasizes the need for end-to-end QoS, adaptive frameworks, and call admission control for wireless multimedia networks.
A digital switch is a device that handles digital signals generated at or passed through a telephone company central office and forwards them across the company's backbone network. ... A centrex is a digital switch at the central office that manages to switch for the private company from the central office.
Global system for mobile communication Introduction, GSM architecture, GSM interfaces, Signal processing in GSM,
Frame structure of GSM, Channels used in GSM
The document discusses various multiple access techniques used in wireless networks. It describes Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiplexing (OFDM), and Space Division Multiple Access (SDMA). It also covers concepts like duplexing methods, power control, modulation techniques, and the near-far problem in CDMA systems.
The document discusses the transition from GSM networks to 3G networks using UMTS (Universal Mobile Telecommunications System) and W-CDMA (Wideband Code Division Multiple Access) technology. It provides an overview of the 3 steps to transition: from current GSM networks to 2.5G networks with GPRS added, to 3G networks using UMTS and W-CDMA. Key aspects of W-CDMA such as its frequencies, multiple access techniques, and spreading codes used are summarized.
The document provides an overview of the Global System for Mobile Communication (GSM) standard. It describes GSM as an integrated European mobile system that enables international roaming. The key objectives of GSM are outlined as well as the basic system elements, including mobile stations, base station systems, and mobile switching centers. The document also discusses concepts such as frequency reuse, cellular networks, handover, and multiple access methods used in GSM like TDMA.
Successful interference cancellation with Blind Equalization method for MC-CD...IJTET Journal
Abstract— The increasing demand for wireless services has created the need for cost effective transmission techniques that can exploit scarce spectral resources efficiently. Inorder to achieve the high data rates needed to meet the quality of service requirements of future multimedia applications, MC-CDMA has been considered as good air-interface candidate, especially for the downlink. However, the user capacity of MC-CDMA system is essentially limited by interference. This interference can be mitigated by employing precoding techniques, IB-DFE based receivers and other efficient interference suppression techniques. In the proposed system, combined Iterative IA precoding at the transmitter with IB-DFE based processing at the receiver is suggested for MC-CDMA systems. The matrices for this nonlinear space-frequency equalizer are obtained by minimizing the overall MSE of all data streams at each subcarrier.
The document discusses the basic principles of wireless communication, including radio propagation characteristics, spreading technology, channel coding, interleave technology, and modulation. It then focuses on the specific mechanisms used in WCDMA networks, including the data transmission procedure, channel coding methods of convolutional codes and turbo codes, spreading using orthogonal variable spreading factor codes, and modulation techniques.
The document discusses GSM signaling and mobile signaling. GSM signaling defines communications between the mobile and network using different protocols across interfaces. Mobile signaling involves the mobile searching for frequencies, synchronizing, downloading information, selecting a network, and signaling to the network by sending a service request when a call is made.
Co-channel and adjacent-channel interference evaluation of an outdoor telecom...Konstantinos Stamatakis
The objective of the present paper is to evaluate the
impact of adjacent and co-channel interference on the
performance of some standard report systems that exists in an
outdoor telecommunications cabinet - base station (BS) (also
known as KV, from the acronym of the German word
Kabelverzweiger) and devices that technicians frequently use.
Specifically, the interference analyzed is between devices, such as
Bluetooth handset, laptop and measurement tools, that are
usually used during inspections and repairs by technicians and
wireless reporting systems installed inside BS that provide
information about BS’s condition and real time connection with
the help desk back office
GSM-Mobility Management-Call Control
GRPS-Network elements
Radio Resource Management
Mobility Management and Session Management
Small Screen Web Browsing
UTRAN-Core and Radio Network Mobility Management
UMTS Security
This document provides an overview of the Global System for Mobile Communications (GSM). It discusses how GSM uses a combination of Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) to maximize channel usage. It also describes the key components of GSM including the mobile station, base station subsystem, network switching subsystem, and operation and support subsystem. Additionally, it covers functions like frequency reuse, handovers, short message service, speech coding, and call routing in GSM networks.
Frequencies management,Channel assignments,
Frequency reuse, System capacity and its improvement: Cell spliting and sectoring, Handoffs & its types, prioritizing handoff, Umbrella cell approach, Cell dragging, Roaming, Co channel and adjacent channel interference, Improving coverage- Repeaters for range extension and microcell zone concept, Examples
Multiple access techniques for wireless communicationDr.Umadevi V
This document discusses multiple access techniques for wireless communication. It begins with an introduction to how multiple access schemes allow efficient sharing of limited radio spectrum among multiple users. It then provides a brief history of wireless communication and pioneers. The document goes on to explain various multiple access techniques in detail including FDMA, TDMA, CDMA, SDMA, and CSMA. It describes their applications, advantages, and disadvantages. Forward and reverse link power control in CDMA is also summarized.
Manideep Srirangam completed an inplant training at BSNL Hyderabad from May 25th to June 6th 2015. The training covered an overview of topics in telecommunication including telecommunication networks, PCM principles and multiplexing, digital switching principles, signaling, latest switches, optical fiber communication, GSM and CDMA technologies, and facilities provided by electronic exchanges such as broadband and DSL technologies. Key concepts covered included time division multiplexing, frequency division multiplexing, digital switching, fiber types, PDH systems, and facilities available to subscribers like call forwarding and call waiting.
The document discusses various types of pulse modulation techniques including pulse amplitude modulation (PAM), pulse width modulation (PWM), pulse position modulation (PPM), and pulse code modulation (PCM). It provides details on the basic principles, components, and advantages of each technique. PCM is described as the digital form of pulse modulation where the analog signal is converted to digital pulses by sampling, quantizing, and encoding the signal. The minimum sampling rate required by the Nyquist theorem and examples of calculating bit rates for PCM are also covered.
Presentation on MULTIPLE ACCESS TECHNIQUES FOR WIRELESS COMMUNICATION By SUPRIYA BHARATI (ME/EC/10006/16) and KHUSHBOO KUMARI (ME/EC/10010/16) Under the Guidance of Dr. Sanjay Kumar Department of Electronics & Communication Engg. (ECE) Birla Institute of Technology, Mesra ,Ranchi-835215 , Jharkhand , India
This document discusses multiple access communication techniques. It introduces frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and space/beam division multiple access (SDMA). FDMA assigns each user a pair of frequencies, TDMA divides bandwidth into time slots and assigns users slots, CDMA allows signals to occupy the same channel using unique codes, and SDMA serves different users using concentrated spot beams. The document provides examples of applications and advantages/disadvantages of each technique.
Crossborder cultural portal in Western Europe provides 3500-4000 events and 7000 guide entries from existing databases and user submissions. The portal reaches over 100,000 people per month, including 9000 website visitors. It is a strategic instrument for crossborder cooperation managed by a coordinating structure and 6 regional administrators from cultural administrations. Challenges include improving content collection and dissemination to bring cultural content to new sectors and audiences while expanding the network of content providers.
Présentation dans le cadre du launch du portail ticket-saarmoselle.eu auquel plurio.net apporte des contenus.
Präsentation im Rahmen vom Launch des Portals ticket-saarmoselle.eu dem purio.net Inhalte bereitstellt.
Touch of a Button Ltd is an independent technology solutions provider that specializes in designing and installing intelligent systems for buildings. It was established in 2004 and offers professional project management and a full service approach. It has experience delivering complex technology projects for hotels, offices, and luxury homes internationally while maintaining high quality and client service.
Rapport d'activités 2010 du projet plurio.net, cofinancé par le Fonds européen de développement régional dans le cadre du programme INTERREG IVA Grande Région.
Tätigkeitsbericht 2010 des Plurio.net Projekts, gefördert durch den Europäischen Fonds für regionale Entwicklung im Rahmen des Programms INTERREG IVA Großregion.
18 mc arthurglenn-app_presentation_090212rfalletti
This document discusses developing a mobile app for McArthurGlen Designer Outlets. It provides an overview of Publiglobe, the communications agency developing the app. It then discusses the growing smartphone market and how retail can benefit from mobile apps. The proposal is for a personalized app that allows users to plan trips, get location information and create wish lists. Several layout designs are presented, including splash screens, a generic home page, a personalized home page and an outlet page. The goal is to enhance the customer experience through a well-designed, feature-rich mobile app.
Europeana Creative is a project that brings together cultural heritage institutions and creative industries. It aims to encourage creative reuse of digital cultural heritage content from Europe's museums, libraries, and archives. The project includes several key activities: 1) Europeana Labs and a network of living labs for experimenting with content; 2) technical infrastructure and tools for accessing and working with content; 3) a legal framework and business models to allow content reuse; 4) pilot apps and services developed by partners; and 5) open innovation challenges for developers and entrepreneurs. One pilot is the Design Pilot, which includes developing tools for visual searching of content, hosting workshops to stimulate design with digital culture, and creating an interactive Culture Cam installation.
Présentation à l'occasion de la réunion du comité d'accompagnement du projet PLURIO.NET, le 14 janvier 2009 à Luxembourg, Maison de l'Europe
Präsentation anlässlich der Sitzung des Begleitausschusses des Projekts PLURIO.NET, 14. Januar 2009 in Luxemburg, Maison de l'Europe
This document provides an overview of the Europeana Creative project. The project is a collaboration between cultural heritage institutions and creative industries to encourage reuse of digital cultural heritage content. It aims to break down barriers for creative industries by providing access to content, tools, and support for app and game development. The key activities of the project include Europeana Labs for experimenting with content, developing technical infrastructure and licenses, running pilot apps and games, and hosting innovation challenges to find new uses of cultural data. The goal is to inspire creative industries and provide benefits like access to content and audiences.
This document summarizes a presentation given by Craig Fender and Ravindra Punati of eBay on avoiding cascading failures. It provides background on eBay operations, including that eBay connects buyers and sellers. It discusses how complexity in highly available systems can lead to fragility and cascading failures from multilayered dependencies. The presentation addresses preventing cascading failures through failure injection testing to identify weaknesses, monitoring systems to detect failures early, and designing systems with redundancy to allow failures to be isolated. It emphasizes approaches like uniform service deployment to enable automated remediation of atomic failures before they cascade.
20140411 e creative zagreb frank thinnesFrank Thinnes
Europeana Creative is a collaboration of cultural heritage institutions and creative companies from 14 European countries. The project aims to encourage creative reuse of digital cultural content and facilitate partnerships between these sectors. It provides online labs and tools to experiment with content, develops technical infrastructure and legal frameworks, and runs challenges to fund pilot apps and services. The goals are to break down barriers to access cultural heritage materials and enable cross-sector collaboration for mutual benefit. Initial pilots include museum and education games that engage with collections in new ways. Feedback indicates the projects can positively promote destinations for tourism and reach new audiences for museums when they provide surprising and fun experiences for users.
The audiences for TV are fragmenting. The Internet continues to grow, and ad money continues to move online. But technological obstacles and vested interests will probably keep the Internet from becoming what TV was or is.
The document discusses various topics related to management development including:
1) Managerial skills such as observation, implementation of development programs, decision making, and conducting research can be enhanced through development tools that convert abstract ideas into behavior tailored to specific situations.
2) Career planning involves evaluating one's interests and abilities, considering opportunities, and establishing goals and development activities to find career satisfaction.
3) Both individuals and organizations have roles to play in career development, including personal assessments, establishing goals, improving training programs, and special assignments.
Post-merger integration requires leadership from the top to define the new company's culture and roles. An integration manager can help coordinate integration efforts and ensure synergies are captured. When integrating IT systems, companies must find a balance between rapid and slow integration to minimize customer and employee disruption while realizing cost savings.
The document analyzes DLF's corporate governance practices across several attributes. It finds that DLF treats shareholders highly, with a 20.2% ROI and 200% dividend rate, but treats employees below average, with compensation cost reductions despite increased staffing. DLF also treats debtholders, customers, suppliers, and society above average or highly. It has strong credit ratings, customer relationship management systems, joint ventures with suppliers, and corporate social responsibility programs. However, risks include exposure to India's real estate industry and new non-real estate ventures. Overall, DLF receives a corporate governance value rating of 4 out of 10.
IRJET-QOS parameter analysis of UMTS networks based on Handovers and Sectoriz...IRJET Journal
This document analyzes quality of service (QOS) parameters in UMTS networks based on handovers and sectorization. It discusses:
1) Handovers play a major role in continuing services as users move between cell boundaries. Sectorization divides cells into sectors using directional antennas to reduce interference and increase capacity.
2) Simulations are conducted using OPNET to analyze soft and hard handovers as a user moves between sectors. Results show the active cell count changes and cells added and removed from the active set.
3) Analysis of soft and hard handovers using applications like HTTP shows that soft handovers provide better performance with lower object and page response times, ensuring seamless service continuity.
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.
Quality of service performances of video and voice transmission in universal ...journalBEEI
The universal mobile telecommunications system (UMTS) has distinct benefits in that it supports a wide range of quality of service (QoS) criteria that users require in order to fulfill their requirements. The transmission of video and audio in real-time applications places a high demand on the cellular network, therefore QoS is a major problem in these applications. The ability to provide QoS in the UMTS backbone network necessitates an active QoS mechanism in order to maintain the necessary level of convenience on UMTS networks. For UMTS networks, investigation models for end-to-end QoS, total transmitted and received data, packet loss, and throughput providing techniques are run and assessed and the simulation results are examined. According to the results, appropriate QoS adaption allows for specific voice and video transmission. Finally, by analyzing existing QoS parameters, the QoS performance of 4G/UMTS networks may be improved.
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Umts Radio Interface System Planning And OptimizationDavid Rottmayer
The document discusses planning and optimizing UMTS radio networks. It begins with an overview of UMTS network architecture and the differences between UMTS and GSM radio system planning. Key aspects of UMTS planning include coverage and capacity planning occurring simultaneously, as capacity requirements influence coverage. The document then covers WCDMA air interface specifications, propagation environments, and the UMTS radio system planning process. It discusses challenges such as varying traffic levels and distributions. The document provides a typical link budget example and explains transmitter, receiver, and channel parameters considered in UMTS coverage planning.
This document discusses solutions for implementing interactivity in mobile multimedia systems. It outlines the importance of interactivity for mobile applications and services. Some key challenges are large round-trip delays due to retransmissions. Solutions proposed include hybrid-ARQ at the Node B to reduce delays, shorter transmission time intervals, Node B controlled scheduling to adapt faster to channel conditions, and adaptive modulation and coding. These solutions aim to improve system capacity, throughput, and reduce delays to better support interactive applications on mobile devices.
Performance Evaluation of QoS parameters in UMTS Network Using Qualnetijdpsjournal
A UMTS network based on the Wide Band-CDMA technology is a 3rd generation telecommunication system which provides various multimedia applications along with the conventional
telephony service. These various multimedia applications fall into four different categories, which are
differentiated from each other on the basis of required bit rate and delay tolerance etc. parameters. In
order to get best Quality of Service (QoS) for a particular application running on the subscriber
equipment the parameters of the respective category to which the application belong need to be in a
required range. In this work the performance of a UMTS network scenario is evaluated by using various values of the precedence bits of the CBR application. The simulation tool used is QUALNET 5.0. The performance of the scenario according to the respective precedence bits is analyzed by four metrics: average jitter, end to end delay, throughput and UMTS signals received and forwarded to MAC. The comparative analysis of all the four metrics according to the precedence bit values will be carried out and it will be concluded in the last section that which precedence bit gives the best performance for the simulated UMTS network scenario.
Improving quality of service using ofdm technique for 4 th generation networkeSAT Journals
This document summarizes a research paper that compares the performance of 32QAM and 64QAM digital modulation techniques when used with OFDM for 4G networks. It finds that 32QAM has better performance with lower bit and packet loss over 64QAM. Specifically, when transmitting 1920 bits over an AWGN channel, 32QAM had 65 bit losses and 0 packet losses, while 64QAM had 80 bit losses and 0.04167 packet losses. Therefore, the document concludes 32QAM can be more efficiently used than 64QAM for digital transmission in 4G networks when combined with OFDM modulation.
Improving quality of service using ofdm technique for 4 th generation networkeSAT Publishing House
This document summarizes a research paper that compares the performance of 32QAM and 64QAM digital modulation techniques when used with OFDM for 4G networks. It finds that 32QAM has better performance with lower bit and packet loss over 64QAM. Specifically, when transmitting 1920 bits over an AWGN channel, 32QAM had 65 bit losses and 0 packet losses, while 64QAM had 80 bit losses and 0.04167 packet losses. Therefore, the document concludes 32QAM can be more efficiently used than 64QAM for digital transmission in 4G networks when combined with OFDM modulation.
The document provides an overview of wireless data communications technologies including wide area cellular services, wireless LANs, and satellite integrated wireless services. It summarizes key aspects of these technologies such as cellular network principles, GSM network architecture, GPRS and EDGE integration, 3G UMTS standards, CDMA basics, Wi-Fi, Bluetooth, and issues with wireless LAN and 3G integration.
An Overview of Wireless Data Communicationsgo2project
The document provides an overview of wireless data communications technologies including wide area cellular services, wireless LANs, and satellite integrated wireless services. It summarizes key aspects of these technologies such as cellular network principles, GSM network architecture, GPRS and EDGE integration, wireless LAN standards, and issues with early implementations of WAP and Bluetooth. It also discusses drivers for the evolution to 3G networks and applications platforms for cellular networks.
Quality of Service in bandwidth adapted hybrid UMTS/WLAN interworking networkTELKOMNIKA JOURNAL
Integration of Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN) result in ubiquitous connection for end users. In the integrated network, ensuring the quality of service to users and enhancing capacity of network are prominent issues. Bandwidth adaptation technique is one of the solutions to overcome these issues. Bandwidth adaptation based on per flow and per class schemes were proposed for loosely coupled interworking network. In this paper, hybrid coupled UMTS and WLAN interworking network is analyzed with bandwidth adaptation based on per flow and per class schemes and the performances have been compared. Simulation result shows that the proposed hybrid coupled interworking network with bandwidth adaptation based on per class scheme performs better with enhanced quality of service and network capacity.
This document provides a rough guide to understanding 3G/HSPA concepts for RF engineers. It begins with general information on 3G networks and UMTS. It then discusses technical concepts such as spreading codes, scrambling codes, and processing gain. It explains how spreading spreads the baseband signal over the frequency band and hides it below the noise floor, allowing recovery via despreading. The document also covers HSPA technologies and their advantages over prior 3G standards.
This document provides a rough guide to understanding 3G/HSPA concepts for RF engineers. It begins with general information on 3G networks and UMTS. It then discusses technical concepts such as spreading codes, scrambling codes, and processing gain. It explains how spreading spreads the baseband signal over the frequency band and hides it below the noise floor, allowing recovery via despreading. The document also covers HSPA technologies and their advantages over prior 3G standards.
This document provides a rough guide to understanding 3G/HSPA concepts for RF engineers. It begins with general information on 3G networks and UMTS. It then discusses technical concepts such as spreading codes, scrambling codes, and processing gain. It explains how spreading spreads the baseband signal over the frequency band and hides it below the noise floor, allowing recovery via despreading. The document also covers HSPA technologies and their advantages over prior 3G standards.
DWDM is a fiber optic transmission technique that uses different wavelengths of light to transmit multiple data signals simultaneously over the same fiber. This allows network capacity to be dramatically increased to meet rapidly growing bandwidth demands. DWDM provides a flexible solution to fiber exhaust and allows different data formats like IP, ATM, and SONET to be transported over a single optical network. By assigning each signal a unique wavelength, DWDM can multiply the capacity of existing fiber infrastructure.
Mobile operators face challenges in meeting increasing bandwidth demands for mobile broadband services using their existing backhaul networks. This includes supporting multiple technologies over leased lines or self-built networks while keeping costs low. Transport providers see an opportunity in the growing backhaul market but must ensure their wholesale services meet stringent performance criteria for timing, quality of service, and other metrics required by mobile operators. Key technical challenges include synchronizing timing over packet networks and supporting various cellular protocols.
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.
This paper focuses on layer aspects of mobile computing. While transmission over different wires typically does Not cause Interface; this is an important topic in wireless transmission. Now days people are hang on the mobile concepts of Techniques. The wireless transmission was used in all fields in whole world. Even in homes we are using Wireless Equipments such as radio, television, etc. ATM is a technology designed for the high-speed transfer of voice, video, and data through public and private networks using cell relay technology. ATM is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T) standard. ATM technology is used in every walks of life of human and in latest equipments. The practice of maximizing the uses of ATM technology has to be exercised by creating wide network in our world. Therefore, this paper is about the aspects of (TRAFFIC-CONTRACTS) from ATM technology, which are necessary for Understanding the problems of higher layers and the complexity needed to handle transmission impairments. Most people are using ATM technology but they won’t have an idea upon it. But in this world we are using the ATM technology with satellite
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/how-axelera-ai-uses-digital-compute-in-memory-to-deliver-fast-and-energy-efficient-computer-vision-a-presentation-from-axelera-ai/
Bram Verhoef, Head of Machine Learning at Axelera AI, presents the “How Axelera AI Uses Digital Compute-in-memory to Deliver Fast and Energy-efficient Computer Vision” tutorial at the May 2024 Embedded Vision Summit.
As artificial intelligence inference transitions from cloud environments to edge locations, computer vision applications achieve heightened responsiveness, reliability and privacy. This migration, however, introduces the challenge of operating within the stringent confines of resource constraints typical at the edge, including small form factors, low energy budgets and diminished memory and computational capacities. Axelera AI addresses these challenges through an innovative approach of performing digital computations within memory itself. This technique facilitates the realization of high-performance, energy-efficient and cost-effective computer vision capabilities at the thin and thick edge, extending the frontier of what is achievable with current technologies.
In this presentation, Verhoef unveils his company’s pioneering chip technology and demonstrates its capacity to deliver exceptional frames-per-second performance across a range of standard computer vision networks typical of applications in security, surveillance and the industrial sector. This shows that advanced computer vision can be accessible and efficient, even at the very edge of our technological ecosystem.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
In the realm of cybersecurity, offensive security practices act as a critical shield. By simulating real-world attacks in a controlled environment, these techniques expose vulnerabilities before malicious actors can exploit them. This proactive approach allows manufacturers to identify and fix weaknesses, significantly enhancing system security.
This presentation delves into the development of a system designed to mimic Galileo's Open Service signal using software-defined radio (SDR) technology. We'll begin with a foundational overview of both Global Navigation Satellite Systems (GNSS) and the intricacies of digital signal processing.
The presentation culminates in a live demonstration. We'll showcase the manipulation of Galileo's Open Service pilot signal, simulating an attack on various software and hardware systems. This practical demonstration serves to highlight the potential consequences of unaddressed vulnerabilities, emphasizing the importance of offensive security practices in safeguarding critical infrastructure.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Discover top-tier mobile app development services, offering innovative solutions for iOS and Android. Enhance your business with custom, user-friendly mobile applications.
Conversational agents, or chatbots, are increasingly used to access all sorts of services using natural language. While open-domain chatbots - like ChatGPT - can converse on any topic, task-oriented chatbots - the focus of this paper - are designed for specific tasks, like booking a flight, obtaining customer support, or setting an appointment. Like any other software, task-oriented chatbots need to be properly tested, usually by defining and executing test scenarios (i.e., sequences of user-chatbot interactions). However, there is currently a lack of methods to quantify the completeness and strength of such test scenarios, which can lead to low-quality tests, and hence to buggy chatbots.
To fill this gap, we propose adapting mutation testing (MuT) for task-oriented chatbots. To this end, we introduce a set of mutation operators that emulate faults in chatbot designs, an architecture that enables MuT on chatbots built using heterogeneous technologies, and a practical realisation as an Eclipse plugin. Moreover, we evaluate the applicability, effectiveness and efficiency of our approach on open-source chatbots, with promising results.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
The expansion of AI services necessitates enhanced computational capabilities on edge devices. Temporal Event Neural Networks (TENNs), developed by BrainChip, represent a novel and highly efficient state-space network. TENNs demonstrate exceptional proficiency in handling multi-dimensional streaming data, facilitating advancements in object detection, action recognition, speech enhancement and language model/sequence generation. Through the utilization of polynomial-based continuous convolutions, TENNs streamline models, expedite training processes and significantly diminish memory requirements, achieving notable reductions of up to 50x in parameters and 5,000x in energy consumption compared to prevailing methodologies like transformers.
Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
The Microsoft 365 Migration Tutorial For Beginner.pptxoperationspcvita
This presentation will help you understand the power of Microsoft 365. However, we have mentioned every productivity app included in Office 365. Additionally, we have suggested the migration situation related to Office 365 and how we can help you.
You can also read: https://www.systoolsgroup.com/updates/office-365-tenant-to-tenant-migration-step-by-step-complete-guide/
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
zkStudyClub - LatticeFold: A Lattice-based Folding Scheme and its Application...Alex Pruden
Folding is a recent technique for building efficient recursive SNARKs. Several elegant folding protocols have been proposed, such as Nova, Supernova, Hypernova, Protostar, and others. However, all of them rely on an additively homomorphic commitment scheme based on discrete log, and are therefore not post-quantum secure. In this work we present LatticeFold, the first lattice-based folding protocol based on the Module SIS problem. This folding protocol naturally leads to an efficient recursive lattice-based SNARK and an efficient PCD scheme. LatticeFold supports folding low-degree relations, such as R1CS, as well as high-degree relations, such as CCS. The key challenge is to construct a secure folding protocol that works with the Ajtai commitment scheme. The difficulty, is ensuring that extracted witnesses are low norm through many rounds of folding. We present a novel technique using the sumcheck protocol to ensure that extracted witnesses are always low norm no matter how many rounds of folding are used. Our evaluation of the final proof system suggests that it is as performant as Hypernova, while providing post-quantum security.
Paper Link: https://eprint.iacr.org/2024/257
"Choosing proper type of scaling", Olena SyrotaFwdays
Imagine an IoT processing system that is already quite mature and production-ready and for which client coverage is growing and scaling and performance aspects are life and death questions. The system has Redis, MongoDB, and stream processing based on ksqldb. In this talk, firstly, we will analyze scaling approaches and then select the proper ones for our system.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Driving Business Innovation: Latest Generative AI Advancements & Success Story
Umts services
1. 2
UMTS Services and Applications
Jouni Salonen, Antti Toskala and Harri Holma
2.1 Introduction
The best known new feature of UMTS is higher user bit rates: on circuit-switched connections 384 kbps, and on packet-switched connections up to 2 Mbps, can be reached.
Higher bit rates naturally facilitate some new services, such as video telephony and quick
downloading of data. If there is to be a killer application, it is most likely to be quick
access to information and its filtering appropriate to the location of a user: see Figure 2.1.
Often the requested information is on the Internet, which calls for effective handling of
TCP/UDP/IP traffic in the UMTS network. At the start of the UMTS era almost all traffic
will be voice, but later the share of data will increase. It is, however, difficult to predict
the pace at which the share of data will start to dominate the overall traffic volume. At
the same time that transition from voice to data occurs, traffic will move from circuitswitched connections to packet-switched connections. At the start of UMTS service not
all of the Quality of Service (QoS) functions will be implemented, and therefore delaycritical applications such as speech and video telephony will be carried on circuit-switched
bearers. Later, it will be possible to support delay-critical services as packet data with
QoS functions.
Compared to GSM and other existing mobile networks, UMTS provides a new and
important feature, namely it allows negotiation of the properties of a radio bearer.
Attributes that define the characteristics of the transfer may include throughput, transfer
delay and data error rate. To be a successful system, UMTS has to support a wide range
of applications that possess different quality of service (QoS) requirements. At present it
is not possible to predict the nature and usage of many of these applications. Therefore it
is neither possible nor sensible to optimise UMTS to only one set of applications. UMTS
bearers have to be generic by nature, to allow good support for existing applications
and to facilitate the evolution of new applications. Since most of the telecommunications
applications today are Internet or N-ISDN applications, it is natural that these applications
and services dictate primarily the procedures for bearer handling.
WCDMA for UMTS, edited by Harri Holma and Antti Toskala
2002 John Wiley & Sons, Ltd
2. 12
WCDMA for UMTS
Figure 2.1. One of the concept phones for UMTS
2.2 UMTS Bearer Service
UMTS allows a user/application to negotiate bearer characteristics that are most appropriate for carrying information. It is also possible to change bearer properties via a bearer
renegotiation procedure in the course of an active connection. Bearer negotiation is initiated by an application, while renegotiation may be initiated either by the application or by
the network (e.g. in handover situations). An application-initiated negotiation is basically
similar to a negotiation that occurs in the bearer establishment phase: the application
requests a bearer depending on its needs, and the network checks the available resources
and the user’s subscription and then responds. The user either accepts or rejects the offer.
The properties of a bearer affect directly the price of the service.
The bearer class, bearer parameters and parameter values are directly related to an
application as well as to the networks that lie between the sender and the receiver. The
set of parameters should be selected so that negotiation and renegotiation procedures
are simple and unambiguous. In addition, parameters should allow easy policing and
monitoring. The format and semantics will take into account the existing reservation
protocols such as RSVP and those used in GPRS. Furthermore, the QoS concept should
be flexible and versatile enough to allow bearer negotiation in the future with as yet
unknown applications.
The layered architecture of a UMTS bearer service is depicted in Figure 2.2; each
bearer service on a specific layer offers its individual services using those provided by
3. UMTS Services and Applications
13
UMTS
TE
MT
UTRAN
CN Iu
EDGE
NODE
CN
Gateway
TE
End-to-End Service
TE/MT Local
Bearer Service
External Bearer
Service
UMTS Bearer Service
Radio Access Bearer
Service
Radio Bearer
Service
Iu Bearer
Service
UTRA
FDD/TDD
Service
CN Bearer
Service
Backbone
Network
Service
Physical Bearer
Service
Figure 2.2. Architecture of a UMTS bearer service
the layers below. As can be seen from the figure, the UMTS bearer service plays a major
role in end-to-end service provisioning [1].
2.3 UMTS QoS Classes
In general, applications and services can be divided into different groups, depending on
how they are considered. Like new packet-switched protocols, UMTS attempts to fulfil
QoS requests from the application or the user. In UMTS four traffic classes have been
identified:
—
—
—
—
conversational,
streaming,
interactive, and
background classes.
The main distinguishing factor between these classes is how delay-sensitive the traffic
is: the conversational class is meant for very delay-sensitive traffic, while the background
class is the most delay-insensitive. The UMTS QoS classes are summarised in Table 2.1.
The conversational and streaming classes are typically transmitted as real-time connections over the WCDMA Release’99 air interface, while the interactive and background
classes are transmitted as non-real-time packet data using packet scheduling. The packet
scheduling in WCDMA is described in detail in Chapter 10.
4. 14
WCDMA for UMTS
Table 2.1. UMTS QoS classes
Traffic class
Conversational
class
Fundamental Preserve time
characteristics relation (variation)
between
information
entities of the
stream
Example of
the
application
Conversational
pattern (stringent
and low delay)
Voice,
videotelephony,
video games
Streaming class
Interactive class
Background
Preserve time
relation (variation)
between
information
entities of the
stream
Request response
pattern
Destination is not
expecting the data
within a certain
time
Streaming
multimedia
Web browsing,
network games
Preserve data
integrity
Preserve data
integrity
Background
download of
emails
2.3.1 Conversational Class
The best-known application of this class is speech service over circuit-switched bearers.
With Internet and multimedia, a number of new applications will require this type, for
example voice over IP and video telephony. Real-time conversation is always performed
between peers (or groups) of live (human) end-users. This is the only type of the four
where the required characteristics are strictly imposed by human perception.
Real-time conversation is characterised by the fact that the end-to-end delay is low and
the traffic is symmetric or nearly symmetric. The maximum end-to-end delay is given by
the human perception of video and audio conversation: subjective evaluations have shown
that the end-to-end delay has to be less than 400 ms. Therefore the limit for acceptable
delay is strict, as failure to provide sufficiently low delay will result in unacceptable
quality.
2.3.1.1 AMR Speech Service
The speech codec in UMTS will employ the Adaptive Multi-rate (AMR) technique. The
multi-rate speech coder is a single integrated speech codec with eight source rates: 12.2
(GSM-EFR), 10.2, 7.95, 7.40 (IS-641), 6.70 (PDC-EFR), 5.90, 5.15 and 4.75 kbps. The
AMR bit rates can be controlled by the radio access network. To facilitate interoperability
with existing cellular networks, some of the modes are the same as in existing cellular
networks. The 12.2 kbps AMR speech codec is equal to the GSM EFR codec, 7.4 kbps is
equal to the US-TDMA speech codec, and 6.7 kbps is equal to the Japanese PDC codec.
The AMR speech coder is capable of switching its bit rate every 20 ms speech frame
upon command. For AMR mode switching in-band signalling is used.
The AMR coder operates on speech frames of 20 ms corresponding to 160 samples at
the sampling frequency of 8000 samples per second. The coding scheme for the multi-rate
coding modes is the so-called Algebraic Code Excited Linear Prediction Coder (ACELP).
The multi-rate ACELP coder is referred to as MR-ACELP. Every 160 speech samples,
the speech signal is analysed to extract the parameters of the CELP model (LP filter
coefficients, adaptive and fixed codebooks’ indices and gains). The speech parameter bits
5. UMTS Services and Applications
15
delivered by the speech encoder are rearranged according to their subjective importance
before they are sent to the network. The rearranged bits are further sorted based on their
sensitivity to errors and are divided into three classes of importance: A, B and C. Class
A is the most sensitive, and the strongest channel coding is used for class A bits in the
air interface.
During a normal telephone conversation, the participants alternate so that, on the average, each direction of transmission is occupied about 50% of the time. The AMR has
three basic functions to utilise effectively discontinuous activity:
• Voice Activity Detector (VAD) on the TX side.
• Evaluation of the background acoustic noise on the TX side, in order to transmit
characteristic parameters to the RX side.
• The transmission of comfort noise information to the RX side is achieved by means
of a Silence Descriptor (SID) frame, which is sent at regular intervals.
• Generation of comfort noise on the RX side during periods when no normal speech
frames are received.
DTX has some obvious positive implications: in the user terminal battery life will
be prolonged or a smaller battery could be used for a given operational duration. From
the network point of view, the average required bit rate is reduced, leading to a lower
interference level and hence increased capacity.
The AMR specification also contains error concealment. The purpose of frame substitution is to conceal the effect of lost AMR speech frames. The purpose of muting the
output in the case of several lost frames is to indicate the breakdown of the channel to
the user and to avoid generating possibly annoying sounds as a result of the frame substitution procedure [2] [3]. The AMR speech codec can tolerate about a 1% frame error
rate (FER) of class A bits without any deterioration of speech quality. For class B and C
bits a higher FER is allowed. The corresponding bit error rate (BER) of class A bits will
be about 10−4 .
The bit rate of the AMR speech connection can be controlled by the radio access
network depending on the air interface loading and the quality of the speech connections.
During high loading, such as during busy hours, it is possible to use lower AMR bit rates
to offer higher capacity while providing slightly lower speech quality. Also, if the mobile
is running out of the cell coverage area and using its maximum transmission power,
a lower AMR bit rate can be used to extend the cell coverage area. The capacity and
coverage of the AMR speech codec is discussed in Chapter 12. With the AMR speech
codec it is possible to achieve a trade-off between the network’s capacity, coverage and
speech quality according to the operator’s requirements.
Release 5 contains enhancement of the AMR technology, the Adaptive Multi-Rate
Wideband (AMR-WB) speech codec. The term wideband comes from the sampling rate,
which has been increased from 8 kHz to 16 kHz, thus resulting to the 14 bit samples
with 16000 samples/s sampling rate. This allows covering twice the audio bandwidth
compared to the classical telephone voice bandwidth of 4 kHz. The end result is a clear
improvement in voice and audio quality. The data rates range from 23.85 kbps down
6. 16
WCDMA for UMTS
to 6.6 kbps. Further details of the AMR-WB can be found from [4]. In case of packet
switched streaming AMR-WB is part of Release 4 already.
2.3.1.2 Video Telephony
Video telephony has similar delay requirements to speech service. Due to the nature of
video compression, the BER requirement is more stringent than that of speech. UMTS
has specified that ITU-T Rec. H.324M should be used for video telephony in circuitswitched connections and Session Initiation Protocol (SIP) for supporting IP multimedia
applications, including video telephony.
Multimedia Architecture for Circuit Switched Connections
Originally Rec. H.324 was intended for multimedia communication over a fixed telephone
network, i.e. PSTN. It is specified that for PSTN connections, a synchronous V.34 modem
is used. Later on, when wireless networks evolved, mobile extensions were added to the
specification to make the system more robust against transmission errors. The overall
picture of the H.324 system is shown in Figure 2.3 [5].
H.324 consists of the following mandatory elements: H.223 for multiplexing and H.245
for control. Elements that are optional but are typically employed are H.263 video codec,
G.723.1 speech codec, and V.8bis. Later, MPEG-4 video and AMR were added as optional
codecs into the system. The recommendation defines the seven phases of a call: set-up,
speech only, modem training, initialisation, message, end, and clearing. Level 0 of H.223
multiplexing is exactly the same as that of H.324, thus providing backward compatibility
Scope of Rec. H.324 M
Video I/O
equipment
Video codec
H.263 or MPEG-4
Simple Profile
Audio I/O
equipment
Speech codec
G.723.1
or AMR
User data
application T.120
etc.
Data protocols
V.14, LAPM, etc.
Receive path
delay
H.223
Multiplexing/
demultiplexing
Level 0
Level 1
Level 2
System control
Modem V.34
V.8/V.8bis
for PSTN
Corresponding
interface for
wireless
network
H.245 control
System control
User
interface
SRP/LAPM
procedures
Modem
control
V.25ter
Figure 2.3. Scope of ITU Rec. H.324
PSTN,
Wireless circuit
switched
network (GSM,
WCDMA, ...)
7. UMTS Services and Applications
17
with older H.324 terminals. With a standardised negotiation procedure the terminal can
adapt to the prevailing radio link conditions by selecting the appropriate error resiliency
level.
V.8bis contains procedures for the identification and selection of common modes of
operation between data circuit-terminating equipment (DCE) and between data terminal equipment (DTE) over general switched telephone network and leased point-to-point
telephone types. The basic features of V.8bis are as follows:
• It allows a desired communication mode to be selected by either the calling or the
answering station.
• It allows terminals to automatically identify common operating modes (applications).
• It enables automatic selection between multiple terminals that share a common telephone circuit.
• It provides user-friendly switching from normal voice telephony to a modem-based
communication mode.
The capabilities exchange feature of V.8bis permits a list of communication modes, as well
as software applications, to be exchanged between terminals. Each terminal is therefore
able to establish the modes of operation it shares with the remote station. A capability
exchange between stations thus ensures, a priori, that a selected communication mode is
possible. Attempts to establish incompatible modes of operation are thus avoided, which
speeds up the application level connection.
As with the mode selection procedure, a capabilities exchange may be performed either
at call set-up, automatically under the control of either the calling or the answering station,
or during the course of telephony. In the latter case, on completion of the information
exchange, the communication link may be configured either to return to voice telephony
mode or to adopt immediately one of the common modes of communication.
V.8bis has been designed so that, when a capabilities exchange takes place in telephony
mode, and the capabilities exchanged are limited to standard features, the interruption in
voice communications is short (less than approximately 2 seconds) and as unobtrusive as
possible.
In order to guarantee seamless data services between UMTS and PSTN, the call control
mechanism of UMTS should take the V.8bis messages into account. V.8bis messages
should be interpreted and converted into UMTS messages and vice versa.
One of the recent developments of H.324 is an operating mode that makes it possible
to use an H.324 terminal over ISDN links. This mode of operation is defined in Annex D
of the H.324 recommendation and is also referred to as H.324/I. H.324/I terminals use the
I.400 series ISDN user-network interface in place of the V.34 modem. The output of the
H.223 multiplex is applied directly to each bit of the digital channel, in the order defined
by H.223. Operating modes are defined bit rates ranging from 56 kbps to 1920 kbps, so
that H.324/I allows the use of several 56 or 64 kbps links at the same time.
H.324/I provides direct interoperability with H.320 terminals, H.324 terminals on the
GSTN (using GSTN modems), H.324 terminals operating on ISDN through user substitution of I.400 series ISDN interfaces for V.34 modems, and voice telephones (both GSTN
and ISDN). H.324/I terminals support H.324/Annex F (= V.140) which is for establishing
8. 18
WCDMA for UMTS
communication between two multiprotocol audio-visual terminals using digital channels
at a multiple of 64 or 56 kbps [6].
Multimedia Architecture for Packet Switched Connections
In the beginning of 3GPP standardization there were two competing standard proposals
for IP multimedia: ITU-T H.323 and IETF’s SIP. After thorough evaluation, SIP was
selected and forms now basis for IP multimedia signalling in UMTS. SIP is part of IETF
Multimedia Architecture (see Figure 2.4), which covers several areas:
• SIP (Session Initiation Protocol): Signalling protocol to be used instead of
H.323/H.245.
• SAP (Session Announcement Protocol): Multicast announcement protocol (advertises
Internet A/V sessions such as pop concerts, lectures, etc.). Current MBone is based
on this.
• SDP (Session Description Protocol): Text-based syntax to describe sessions (replaces
ASN.1/BER in H.323).
• RTSP (Real Time Streaming Protocol): Protocol for controlling remote servers (e.g.
VOD servers to play a file).
RTP is used for media encapsulation and RTCP for control information delivery and lip
sync purposes. Multiparty application sharing is also possible: at least shared workspace
Scope of IETF
Multimedia terminal
Video I/O
equipment
Video codec
H.261, H.263,
H.263+, MobiVideo
RTP-capsulation,
receive path delay
RTCP sender
reports (optional)
Audio I/O
equipment
Audio codec
G.711, G.722,
G.723.1,
G.728, G.729, EFR
RTP-capsulation,
receive path delay
RTCP sender
reports (optional)
TCP/IP driver
User data
application T.120
etc.
Security (optional)
SIP
System control
User interface
SDP
SAP
RTCP (optional)
RSVP (optional)
Figure 2.4. IETF Multimedia architecture
Packet
network
9. UMTS Services and Applications
19
and a network text editor have been developed. Both approaches are based on reliable
multicast.
SIP provides the necessary protocol mechanisms so that end systems and proxy servers
can provide services:
—
call forwarding, call-forwarding no answer;
—
call-forwarding busy;
—
call-forwarding unconditional;
—
other address translation services;
—
callee and calling number delivery, where numbers can be any (preferably a unique)
naming scheme;
—
personal mobility, i.e., the ability to reach a called party under a single, locationindependent address even when the user changes terminals;
—
terminal-type negotiation and selection.
Callers can be given a choice how to reach the party, e.g., via Internet telephony, mobile
phone, an answering service, etc.:
—
—
—
—
terminal capability negotiation;
caller and callee authentication;
blind and supervised call transfer;
invitations to multicast conferences.
Extensions of SIP are available to allow third-party signalling, for example for clickto-dial services, fully meshed conferences and connections to multipoint control units
(MCUs), as well as mixed modes and the transition between them. SIP is addressingneutral, with addresses expressed as URLs of various types such as SIP, H.323 or
telephone (E.164). SIP is independent of the packet layer and requires only an unreliable
datagram service, as it provides its own reliability mechanism [7] [8] [9].
Figure 2.5 shows one of the concept phones for video telephony.
2.3.2 Streaming Class
Multimedia streaming is a technique for transferring data such that it can be processed
as a steady and continuous stream. Streaming technologies are becoming increasingly
important with the growth of the Internet because most users do not have fast enough
access to download large multimedia files quickly. With streaming, the client browser or
plug-in can start displaying the data before the entire file has been transmitted.
For streaming to work, the client side receiving the data must be able to collect the data
and send it as a steady stream to the application that is processing the data and converting
it to sound or pictures. Streaming applications are very asymmetric and therefore typically
withstand more delay than more symmetric conversational services. This also means that
they tolerate more jitter in transmission. Jitter can be easily smoothed out by buffering.
Internet video products and the accompanying media industry as a whole is clearly
divided into two different target areas: (1) Web broadcast and (2) video streaming ondemand. Web broadcast providers usually target very large audiences that connect to a
10. 20
WCDMA for UMTS
Figure 2.5. 3G concept phone for video telephony
highly performance-optimised media server (or choose from a multitude of servers) via
the actual Internet, which at present is very slow. The on-demand services are more
often used by big corporations that wish to store video clips or lectures to a server
connected to a higher bandwidth local intranet—these on-demand lectures are seldom
used simultaneously by more than hundreds of people.
Both application types use basically similar core video compression technology, but the
coding bandwidths, level of tuning within network protocol use, and robustness of server
technology needed for broadcast servers differ from the technology used in on-demand,
smaller-scale systems. This has led to a situation where the few major companies developing and marketing video streaming products have specialised their end-user products to
meet the needs of these two target groups. Basically, they have optimised their core products differently: those directed to the ‘28.8 kbps market’ for bandwidth variation-sensitive
streaming over the Internet and those for the 100–7300 kbps intranet market.
At the receiver the streaming data or video clip is played by a suitable independent
media player application or a browser plug-in. Plug-ins can be downloaded from the Web,
usually free of charge, or may be readily bundled to a browser. This depends largely on
the browser and its version in use—new browsers tend to have integrated plug-ins for
the most popular streaming video players.
In conclusion, a client player implementation in a mobile system seems to lead to an
application-level module that could handle video streams independently (with independent
connection and playback activation) or in parallel with the browser application when the
service is activated from the browser. The module would interface directly to the socket
11. UMTS Services and Applications
21
interface of applied packet network protocol layers, here most likely UDP/IP or TCP/IP
[10] [11].
2.3.3 Interactive Class
When the end-user, either a machine or a human, is on line requesting data from remote
equipment (e.g. a server), this scheme applies. Examples of human interaction with the
remote equipment are Web browsing, database retrieval, and server access. Examples
of machine interaction with remote equipment are polling for measurement records and
automatic database enquiries (tele-machines).
Interactive traffic is the other classical data communication scheme that is broadly
characterised by the request response pattern of the end-user. At the message destination
there is an entity expecting the message (response) within a certain time. Round-trip delay
time is therefore one of the key attributes. Another characteristic is that the content of
the packets must be transparently transferred (with low bit error rate).
2.3.3.1 Computer Games
Playing a computer game interactively across the network is one example of applications
that can be seen to be part of the interactive class. However, depending on the nature
of a game, i.e. how intensive data transfer is, it may rather belong to the conversational
class due to high requirements for the maximum allowed end-to-end delay. Games usually
deploy Java 2 Micro Edition (J2ME) technology.
2.3.4 Background Class
Data traffic of applications such as e-mail delivery, SMS, downloading of databases and
reception of measurement records can be delivered background since such applications
do not require immediate action. The delay may be seconds, tens of seconds or even
minutes. Background traffic is one of the classical data communication schemes that is
broadly characterised by the fact that the destination is not expecting the data within a
certain time. It is thus more or less insensitive to delivery time. Another characteristic is
that the content of the packets does not need to be transparently transferred. Data to be
transmitted has to be received error free.
Multimedia Messaging Service (MMS) is an extension of successful Short Messaging
Service (SMS). As the name suggests, MMS contains not only text, but several elements
such as text, voice, animated GIF images, JPG images, MIDI ringing tones and applications. Since MMS uses MIME encapsulation, any element that has its own MIME type can
be sent as MMS. In addition to multimedia elements, MMS contains presentation information that conforms to Synchronised Multimedia Integration Language (SMIL). When
SMIL is used for the presentation of multimedia messages on mobile terminals, the size
of the window will be limited by the resolution and appearance of the terminal display.
The layout of a multimedia message represents the content as created by the originator
and thus it may well be possible that the original layout does not fit into the display of
the receiving terminal. Therefore the receiving terminal must be capable of replacing the
layout section with a terminal specific one where the size and the position of the text and
image regions are appropriately defined.
12. 22
WCDMA for UMTS
MMS is jointly standardized by 3GPP and WAP Forum. 3GPP is responsible for general
requirements, architecture and functionality [14] [15] whereas WAP Forum focuses on
transport protocol [16] [17]. MMS transport is done using WAP transport and any bearer
capable of WAP can be used. Thus, MMS is bearer independent, e.g. MMS is not limited
to only GSM or WCDMA. WAP Wireless Session Protocol WSP is used for message
transport from phone to MMSC and from MMSC to phone. In addition WAP push features
are used to deliver the message from server to recipient. Shortly, sending MMS from an
MMS client to an MMS client consists of the following phases:
• Client Sending MMS to MMS Server
• MMS Server Sending Notification to recipient Client (WAP push message using SMS
as bearer)
• Client Fetching MMS from MMS Server
• MMS Server Sending Delivery Report to Client
If the recipient client is switched off, the line is busy, the terminal is out of the
coverage area, or for some other reason is not able to retrieve the message soon after
the notification, then the MMS is stored in MMSC and can be fetched later. When a
certain time has elapsed (configurable by the operator), MMS is removed from MMSC
and moved to more permanent storage area that can be accessed via Web or WAP. User
can then later delete, forward, save, or retrieve un-fetched messages [18] [19].
It is easy to predict that once terminals have built-in cameras and large colour displays
(see Figure 2.6), MMS will soon take off MMS will soon take off and provide huge
possibilities for both operators and service providers.
Figure 2.6. Nokia 7650 is one example of Multimedia Messaging terminals
13. UMTS Services and Applications
23
2.4 Service Capabilities with Different Terminal Classes
In WCDMA the same principle as with GSM with Terminal class mark is not used.
WCDMA terminals shall tell the network, upon connection set up, larger set of parameters indicating the radio access capabilities of the particular terminal. These capabilities
determine e.g. what is the maximum user data rate supported in particular radio configuration, given independently for the uplink and downlink directions. To provide guidance
on which capabilities should be applied together, reference terminal radio access capability combinations have been specified in 3GPP standardisation, see [20]. The following
reference combinations have been defined for Release’99:
• 32 kbps class: This is intended to provide basic speech service, including AMR speech
as well as some limited data rate capabilities up to 32 kbps
• 64 kbps class: This is intended to provide speech and data service, with also simultaneous data and AMR speech capability
• 128 kbps class: This class has the air interface capability to provide for example video
telephony or then various other data services
• 384 kbps class is being further enhanced from 128 kbps and has for example multicode
capability which points toward support of advanced packet data methods provided in
WCDMA
• 768 kbps class has been defined as an intermediate step between 384 kbps and 2 Mbps
class
• 2 Mbps class: This is the state of the art class and has been defined for downlink
direction only
These classes are defined so that a higher class has all the capabilities covered by a lower
class. It should be noted that terminals may deviate from these classes when giving their
parameters to the network, thus 2 Mbps is possible for the uplink also though not covered
by any of the classes directly.
3GPP specifications include performance requirements for the bit rates up to 384 kbps,
for more details see Section 12.5. Therefore, it is expected that terminals up to 384 kbps
will be available in the initial deployment phase.
High Speed Downlink Packet Access, HSDPA, further enhances the WCDMA bit
rate capabilities. HSDPA terminal capabilities are defined in 3GPP Release 5 and extend
beyond 10 Mbps. HSDPA is covered in detail in Chapter 11.
2.5 Location Service in WCDMA
2.5.1 Location Services
Location-based services and applications are expected to become one of the new dimensions in UMTS. A location-based service is provided either by a teleoperator or by a
third party service provider that utilises available information on the terminal location.
The service is either push (e.g. automatic distribution of local information) or pull type
14. 24
WCDMA for UMTS
Figure 2.7. 3G concept phone showing location-based service
(e.g. localisation of emergency calls). Other possible location-based services are discount
calls in a certain area, broadcasting of a service over a limited number of sites (broadcasting video on demand), and retrieval and display of location-based information, such
as the location of the nearest gas stations, hotels, restaurants, and so on. Figure 2.7 shows
an example. Depending on the service, the data may be retrieved interactively or as
background. For instance, before travelling to an unknown city abroad one may request
night-time download of certain points of interest from the city. The downloaded information typically contains a map and other data to be displayed on top of the map. By clicking
the icon on the map, one gets information from the point. Information to be downloaded
background or interactively can be limited by certain criteria and personal interest.
The location information can be input by the user or detected by the network or
mobile station. The network architecture of the location services is discussed in Chapter 5.
Release-99 of UMTS specifies the following positioning methods:
— the cell coverage-based positioning method,
— Observed Time Difference Of Arrival—Idle Period DownLink (OTDOA-IPDL),
— network-assisted GPS methods.
These methods are complementary rather than competing, and are suited for different
purposes. These approaches are introduced in the following sections.
2.5.2 Cell Coverage Based Location Calculation
Cell coverage based location method is a network based approach, i.e., it does not require
any new functionalities in the mobile. The radio network has the location information with
15. UMTS Services and Applications
25
Mobile in idle or URA_PCH state
Mobile location is known with an
accuracy of location/registration area
Mobile in cell_DCH or
cell_FACH or cell_PCH state
Mobile location is known with an
accuracy of one cell
Forced
location
update
Location area
Round trip
time estimate
Figure 2.8. Location calculation with cell coverage combined with round trip time
a cell level accuracy when the mobile has been allocated a dedicated channel or when
the mobile is in cell FACH or cell PCH states. These states are introduced in Chapter 7.
If the mobile is in idle state, its location with cell accuracy can be obtained by forcing
the mobile to cell FACH state with a location update as illustrated in Figure 2.8.
The accuracy of the cell coverage based method depends heavily on the cell size. The
typical cell ranges in the urban area are below 1 km and in the dense urban a few hundred
meters providing fairly accurate location information.
The accuracy of the cell coverage based approach can be improved by using the round
trip time measurement that can be obtained from the base station. That information is
available in cell DCH state and it gives the distance between the base and the mobile
station.
2.5.3 Observed Time Difference of Arrival, OTDOA
The OTDOA method is based on the mobile measurements of the relative arrival times of
the pilot signals from different base stations. At least three base stations must be received
by the mobile for the location calculation as shown in Figure 2.9. A measurement from
two base stations defines a hyperbola. With two measurement pairs, i.e. with three base
stations, the location can be calculated.
In order to facilitate the OTDOA location measurements and to avoid near-far problems, WCDMA standard includes idle periods in downlink, IPDL. During those idle
periods the mobile is able to receive the pilot signal of the neighbour cells even if the
best pilot signal on the same frequency is very strong. Typical frequency of the idle periods is 1 slot every 100 ms, i.e. 0.7% of the time. The IPDL-OTDOA measurements are
shown in Figure 2.10.
16. 26
WCDMA for UMTS
A pair of base stations defines a
hyperbola. Two pairs (= three base
stations) gives the location.
Figure 2.9. Location calculation with three base stations
Pilo
IPDL = idle periods in
downlink signal
t sig
nal
Location measurement
unit in base stations
Arrival
time t3
Arrival
time t1
Arrival
time t2
Figure 2.10. IPDL (Idle Period Downlink)—OTDOA (Observed Time Difference of Arrival)
The network needs to know the relative transmission times of the pilot signals from
different base stations to calculate the mobile location. That relative timing information
can be obtained by
1.
OTDOA measurements by the location measurement unit at the base station. The
base station measures the relative timing of the adjacent cells. The measurement is
similar to the OTDOA measurements by the mobile.
2.
GPS receiver at the base station.
The accuracy of the OTDOA measurements can be in the order of tens of meters in
very good conditions when several base stations in line-of-sight can be received by the
mobile. In practise, such ideal measurement conditions are not typically available in
cellular networks. The accuracy depends on the following factors
17. UMTS Services and Applications
27
—
Number of base stations that the mobile can be receive. Minimum three is required.
If more base stations can be received the accuracy is improved.
—
Relative locations of the base stations. If the base stations are located in different
directions from the mobile, the accuracy is improved.
—
Line-of-sight. If there is a line-of-sight between the mobile and the base station, the
accuracy is improved.
The requirement of receiving at least three base stations is challenging in the cellular
networks. The target of the network planning is to create clear dominance areas of the
cells and to avoid unnecessary overlapping of the cells. That approach maximizes the
capacity. The clear dominance areas and limited cell overlapping reduces the probability
of accurate OTDOA measurements as it is difficult to receive at least three pilot signals.
Figure 2.11 shows the probability of mobile receiving several pilot signals in realistic
network scenarios. The probability of receiving at least three pilots is 74% in Figure 2.11.
IPDL allows to receive the strongest pilot and the second strongest with 100% probability,
but it is challenging to receive at least three pilots with very high probability. The required
pilot Ec /I0 was −18 dB in these simulations and fully loaded network was assumed. The
results show that IPDL greatly improves the performance of OTDOA: without IPDL the
probability of receiving at least three pilots would be only 31%. The results also show
that it is difficult to obtain very high probability of OTDOA measurements. The accuracy
can be improved by combining OTDOA with cell coverage based location method.
2.5.4 Assisted GPS
Most accurate location measurements can be obtained with integrated GPS receiver in
the mobile. The network can provide additional information, like visible GPS satellites,
60%
Without IPDL
Percentage of Area
50%
With IPDL
40%
OTDOA
measurements
can be done with
≥3 pilots
30%
20%
10%
0%
1
2
3
4
5
6
7
Number of Pilots
Figure 2.11. Probability of receiving several pilot signals [21]
18. 28
WCDMA for UMTS
GPS
satellite
GPS
satellite
GPS
satellite
GPS signal
GPS
receiver in
the mobile
Assistance
data
Reference GPS
receiver in the
radio network
Figure 2.12. Assisted GPS
reference time and Doppler, to assist the mobile GPS measurements. The assistance data
improves the GPS receiver sensitivity for indoor measurements, makes the acquisition
times faster and reduces the GPS power consumption. The principle of assisted GPS is
shown in Figure 2.12.
A reference GPS receiver in every base station provides most accurate assistance data
and most accurate GPS measurements by the mobile. The assisted GPS measurements can
achieve accuracy of 10 meters outdoors and a few tens of meters indoors. That accuracy
meets also the FCC requirements in USA. If the most stringent measurement probabilities
and accuracies are not required, the reference GPS receiver is not needed in every base
stations, but only a few reference GPS receivers are needed in the radio network. It
is also possible to let the mobile GPS make the measurements without any additional
assistance data.
2.6 Concluding Remarks
In this chapter we have briefly looked at UMTS from the perspective of services and
applications. The list is by no means complete, but hopefully it helps readers to understand
the variety of different services and gives some flavour of what we will see just a few years
from now. UMTS provides high bit rates for both circuit-switched and packet-switched
connections, effective bearer handling, multicall, and many other new features to make it
possible to create new applications in a cost-efficient manner.
References
[1]
[2]
[3]
[4]
3GPP, Technical Specification Group Services and System Aspects, QoS Concept (3G TR
23.907 version 1.3.0), 1999.
3GPP, Mandatory Speech Codec Speech Processing Functions, AMR Speech Codec: General
Description (3G TS 26.071 version 3.0.1), 1999.
3GPP, Mandatory Speech Codec Speech Processing Functions, AMR Speech Codec: Frame
Structure General Description (3G TS 26.101 version 1.4.0), 1999.
3GPP, Technical Specification Group Services and System Aspects, Speech Coded speech
processing functions, AMR Wideband Speech Codec, General Description, (3G TS 26.171
version 5.0.0), 2001.
19. UMTS Services and Applications
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
29
3GPP, Technical Specification Group Services and System Aspects, Codec for Circuit
Switched Multimedia Telephony Service: General Description (3G TS 26.110 version 3.0.1),
1999.
ITU-T H.324, Terminal for Low Bitrate Multimedia Communication, 1998.
3GPP, Service Requirements for the IP Multimedia (3GPP TS 22.228), 2002.
3GPP, IP Multimedia Subsystems (3GPP TS 23.228), 2002.
Handley, M., et al., SIP: Session Initiation Protocol, RFC2543, IETF, 1999.
Honko, H., Internet Video Prestudy, 1997.
3GPP, Transparent end-to-end packet switched streaming service (3GPP TS 26.233), 2001.
3GPP, Technical Specification Group (TSG) RAN, Working Group 2 (WG2), Stage 2 Functional Specification of Location Services in URAN (3G TR 25.923 version 1.4.0), 1999.
3GPP, Technical Specification Group Services and System Aspects, Location Services
(LCS), Service description, Stage 1 (3G TS 22.071 version 3.1.0), 1999.
3GPP, Multimedia Messaging Service (3GPP TS 22.140), 2001.
3GPP, MMS Architecture and functionality (3GPP TS 23.140), 2001.
WAP-205-MmsArchOverview, 2001.
WAP-206-MmsMessagingService, 2001.
WAP-207-MmsInetInterworking, 2001.
WAP-208-MmsRelayRelayProtocol, 2001.
3GPP, Technical Specification Group (TSG) RAN, Working Group 2 (WG2), UE Radio
Access Capabilities, 3G TS 25.306 version 3.0.0, 2000.
Johnson, C., Joshi, H. and Khalab, J. “WCDMA Radio Network Planning for Location Services and System Capacity”, IEE 3G2002 conference in London, 9th May.