UMTS and Beyond

Prof. Hamid AghvamiCentre for Telecommunications Research - Kings College LondonWireless Multimedia Communications Ltd

Mobile System GenerationsFirst Generation (1G) mobile systems were designed to offer a single service, i.e., speech.Second Generation (2G) mobile systems were also designed primarily to offer speech with a limited capability to offer data at low rates.Third Generation (3G) mobile systems are expected to offer high-quality multi-media services and operate in different environments.3G systems are referred to as Universal Mobile Telecommunications System (UMTS) in Europe and International Mobile Telecommunications 2000 (IMT2000) worldwide.

UMTS Main Requirements (3 Ms)Multi-media

Multi-environment

Multi-operator Virtual operators

Mobile Multimedia Services

Different Environments for UMTS

Global

Suburban

Macro-Cell

Urban

Micro-Cell

In- Building

Pico-Cell

Home-Cell

Europe has decided to adopt an evolutionary approach for the UMTS core network based on migration from the GSM/GPRS infrastructure.

For the actual air interface, a revolutionary approach has been chosen. That is a new radio air interface for UMTS Terrestrial Radio Access (UTRA).

There is another parallel activity concerning the UMTS air interface using an evolutionary approach (an intermediate approach).First phase of UMTS

Evolution approach based on GSM InfrastructureEvolution ApproachNewRadio Access (UTRAN)

NSS

And

GSNsPSTNN-ISDNB-ISDNIP-based NetworksRadio Access

GSM Infrastructure

Public Network

Dual-mode

Dual-mode

EvolvedGSMRadio Access (GERAN)

In this approach the GSM air interface has evolved within GSM phase 2+ to support higher rate data services. The most important developments in this approach are:1. General Packet Radio Services (GPRS )2. High Speed Circuit Switched Data (HSCSD )3. Enhanced Data Rates for GSM Evolution (EDGE )

It is referred to GSM/EDGE Radio Access Network (GERAN)

Evolutionary approach for the GSM Air Interface

SMSC/VLRGMSCPSTNHLRPDNInternetGGSNSGSNRNCCircuit Switched (GSM)Packet Switched(GPRS)UTRANIu,psIu,csGsCGnGrGcUMTS Phase IDRNCNode BNode BNode BNode BIu,csIu,ps.....

Applications& ServicesLegacy mobile signalling networkOther PLMN MultimediaIP networksGGSN PSTN/legacy/externalSGSNSGSN HSS(HLR)GGSNEIRSGWMRFCSCFMGCFMGWSimplified architecture for the support of IP-based multimedia services in 3GPP release 5Signalling interfaceSignalling and data transfer interfaceGnGpMhCxMmGiMgMcGiGiMrGcMsGnGiGrGfTEMTGERANTEMTUTRANIu-PSUuUmRR

New Functional Entities for the All IP Architecture Call State Control Function (CSCF) executes the call control. It is based on the IETF Session Initiation Protocol (SIP).

Media GateWay (MGW) provides an inter-connection from GGSN to legacy circuit-switched networks such as PSTN.

Media Gateway Control Function (MGCF) controls the MGW.

Media Resource Function (MRF) performs multiparty call and multimedia conferencing functions.

Signalling GateWay (SGW) performs signalling conversion to/from legacy mobile signalling network.

Home Subscriber Server (HSS) is an evolved HLR.

4G ConceptTowards 4G

User centric, user controlled servicesandcontext-aware applications

What does user controlled services mean? The user has freedom and flexibility to select any desired service with reasonable QoS and affordable price, anytime, anywhere using any device in a secure manner4G Concept

What does context-aware applications mean?

A context-aware application means the behaviour of the application adapts itself to user context changes. User context includes: -user profile and preferences. -user device and access network capabilities. -user environment and mobility. 4G Concept

TechnologiesChallenges

Convergence/integration/inter-working of all existing and emerging fixed and mobile (wired and wireless) networks including broadcast

Simple to select and easy to use desired services

Universal and low cost terminals

IP TechnologyAgent TechnologyReconfigurable Technology

Inter-working Concept Integration Concept

Network Level Concepts

Interworking/Integration For the design of next generation wireless networks two different approaches are currently being considered. They are:- Interworking with next generation Internet (tight coupling)- Integration within next generation Internet (very tight coupling) In the first approach, the access network and the core network use different IP protocols and mechanisms and only the core network is considered as a sub-network of the Internet. In the second approach, both the core and access networks use common IP based protocols and mechanisms and the access network is considered as a sub-network of the Internet.

Signalling GatewayWAPAccountingUMTSBroadcast Networks (DAB, DVB-T)Satellite FESGSM / GPRSContext-aware informationCentreWireless LANsSIP Proxy ServerInter-Working

General architecture of the IP-based IMT network platformApplicationsAP1AP2AP3APnMiddlewareIP-based transport NWLocationAccounting/billingMedia conversionDistributionBasic network management sub-layerRRMMMC/SMSecurityQoSService support sub-layerIPIPIPIPRadioRadioRadioIPIPIPISDN/PSTNInternetIntegration

Global coverageNational coverageLocal area coverageWireless LANs DAB and DVB-T, DVB-S2G, 3G and 4G Cellular Personal area coverageHierarchical coverage layers for 4G SatelliteRegional coverageWireless PANs Vertical HandoverHorizontal HandoverIP-based backbone

The complexity of the problem: user prospectiveFrom a user prospective

Multiple Heterogeneous network operatorspart of

Multiple user environments accessed using

Multiple heterogeneous devices owned by

heterogeneous users

From a network prospective

Multiple Heterogeneous network operators

providing Multiple services

through multiple access networks

tousers with heterogeneous devicesThe complexity of the problem: network prospective

A Heterogeneous Network Architecture

Inter-working between two radio access networks Open coupling

Inter-working between two radio access networks Loose coupling

Inter-working between two radio access networks Tight coupling

Inter-working between two radio access networks Very tight coupling

Inter-working examples - caching

Content DeliveryNotification

Content: video clip(15MB)Service: Music ClipsCompany: MTV

Please select delivery options Send to PDA (5 eur) 15min Send to office PC (10 eur) 7min Send to STB (20 eur)-2minDelivery options

Network provides device delivery optionsincluding cost and delivery times

User selects desired destination

Slide:*-40Inter-working examples user centric

Load balancing i.e. Using DVB to multicast or broadcast to large number of users

Handovers i.e. Users in train moving outside the coverage of a networkSlide:*-40Inter-working examples network centric

Network SelectionMost Appropriate Network Selection Criteria User Context Service Type Available Resources- Data rate- QoS- Environment (When and Where)- Mobility- User preferences

Convergence

Convergence of Cellular Mobile Networks and WLANsBenefitsFor cellular mobile operators Higher bandwidths. Lower cost of networks and equipment. The use of licence-exempt spectrum. Higher capacity and QoS enhancement. Higher revenue.For users Access to broadband multimedia services with lower cost and where mostly needed (e.g. in Central Business Districts and Business Customer Premises). Inter-network roaming.

ConvergenceConvergence of Mobile Communications and BroadcastingDriversFrom broadcaster point of view Introducing interactivity to their unidirectional point-to-multipoint broadcasting systems. That is, a broadband downlink based on DAB/DVB-T and a narrowband uplink based on 2G/3G cellular systems. From the cellular mobile operator point of view Providing a complementary broadband downlink in vehicular environments to support IP-based multi-media traffic which is inherently asymmetrical.

ConvergenceBenefits Broadcasters will benefit from the use of cellular mobile systems to adapt the content of their multi-media services more rapidly in response to the feedback from customers. Cellular operators will benefit from offering their customers a range of new broadband multi-media services in vehicular environments. Users will benefit from faster access to a range of broadband multi- media services with reasonable QoS and lower cost.

IP Layer Model

Additional IP Functions Mobility Management Quality of Service AAA IP Sec Ad-Hoc Routing etc. Native IP Functions: Routing Addressing Packet Formatting and Handling Lower LayersHigher LayersIP Network LayerIP Convergence LayerData Interface

Error Control Buffer Management QoS Support Segmentation/Reassembly Header Compression Multicast SupportControl Interface

Configuration Management Address Management QoS Control Handover Control Idle Mode Support Security ManagementIP Layer Model for WLANs

IP Layer Model The functionalities and structure of the IP layer model are not sufficient and/or efficient to achieve the requirements of future inter-worked or integrated networks. No fundamental changes have been made in the design of IPV6. The question is: Are some radical changes needed to the IP layer model in order to offer better solutions to the convergence issue? If yes, what are the consequences and implications?

An agent is a software component (object) that is situated within an execution environment (e.g. computers) and acts autonomously on behalf of a user or process and has specific goal.Agent Definition

Agent Technology Mandatory features Reactive: senses changes in the environment and reacts in accordance. Autonomous: has control over its own actions Goal-driven: is pro-active Optional features Collaborative: communicates/negotiates with other agentsMobile: travels from one host to another Learning: adapts in accordance with previous experience Believable: appears believable to the end-user.

Mobile vs. Static AgentsClientServerClientServerrequestrespondrequestrespondSoftware components that can migrate under their own control from host to host in a network or between networks

Mobile Agents Mobile agents have already been used for network monitoring and service delivery including education at a distance. In an ever-increasing world of service providers and service packages, a user demands a simple approach to the selection of the desired service and its delivery mechanism in real-time with least effort. This can be achieved through the use of mobile agents. The use of mobile agents can also overcome the constraints imposed on applications by the limited processing power and speed of mobile terminals.

An open question:

Static or mobile agents for wireless networks?What are the pros and cons?Agent Technology

Re-configurable TechnologyWhat does Reconfiguration mean?Reconfiguration refers to the software re-definition and/or adaptation of every element within each layer of the communication chain.Baseband ProcessingUserDataRF Front End

Re-configurable TechnologyBenefits Users Operators Manufacturers- Select network depending on service requirements and cost.- Connect to any network Worldwide roaming.-Access to new services.- Respond to variations in traffic demand (load balancing).- Incorporate service enhancements and improvements.- Correction of software bugs and upgrade of terminals.- Rapid development of new personalised and customised services- Single platform for all markets.- Increased flexible and efficient production.

Re-configuration ProceduresReconfigurationTriggerMode IdentificationMode NegotiationSoftware DownloadMode Switch DecisionMode MonitoringReconfigure TerminalInitiated by network operator or userDownload software modules that are required for the target modeWhat networks are available?What is the most suitable network (based on QoS, user preferences etc.)?Decision on preferred mode

Re-configurable TechnologyCHALLENGES Regulatory and Standardisation issues. Business models. User preference profiles. Inter-system handover mechanisms and criteria. Software download mechanisms. Flexible spectrum allocation and sharing between operators. Enabling Technologies (RF and antenna elements, ADC/DAC etc.)

Conclusion