UMTS : La Convergence des Réseaux Mobiles et d'Internet
Transcript of UMTS : La Convergence des Réseaux Mobiles et d'Internet
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Cellular networks evolution: Cellular networks evolution: from 2G to 3Gfrom 2G to 3G
CEENet 2004: Wireless and Mobile Networking
Budapest (Hungary)
August 20th, 2004August 20th, 2004
Sami TabbaneSami Tabbane
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SummarySummary
2G networks architecture2G networks architecture
2,5G evolution towards third 2,5G evolution towards third generationgeneration
3G services and evolution3G services and evolution
ConclusionsConclusions
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I. 2G networks I. 2G networks architecturearchitecture
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GSM GSM basic basic network network architecturearchitecture
.. < > ^ ... . . .
BTS
BTS
BSC
TRAU
MSC/VLR
PSTN
HLR A
Abis
SS7 Network
EIR
BSS
NSS
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BTSBTS Radio transmission/reception
management (modulation/demodulation, equalisation, interleaving ...)
Physical layer management (TDMA transmission, SFH, coding, ciphering ...)
Link layer management (LAPDm)
Received signal quality and power measures.
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BSCBSC
Radio resource management: channel allocation, BTS measures processing, BTS and MS power control, handover ...
Interfaces management: with the MSC (gathers the traffic towards the MSC) and with the BTSs.
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MSCMSC Management of the communications between the
mobiles and the fixed network. Handover management. Interconnection with the
fixed network (switching features). Management of the visiting
users with the VLR. GMSC function (Gateway
MSC): gateway for the calls
coming/going towards an external network.
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HLR/VLRHLR/VLRHLR (Home Location Register)
Subscribers database:
- Subscription data: IMSI, MSISDN, subscription type (restrictions, supplementary services, ...)
- Location information: mobile VLR number.VLR (Visitor Location Register)
Data: IMSI, MSISDN, TMSI, MSRN, subscription type, location area, ...
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Suscriber Identity ModuleSuscriber Identity Module
Informations: subscriber identity, password (PIN), subscription informations (authorized networks, call restrictions, …), security algorithms, short numbers, last received/dialled numbers, last visited location area, ...
SIM card + GSM terminal = access to GSM services.
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GSM sGSM services characterizationervices characterization
GSM = circuit switched-based technology.
2 types of services (ISDN based classification):
Bearer services: Telecommunications services offering transmission capabilities (bitrate, BER, synchronous/asynchronous mode ...) between network access points.
Teleservices: Telecommunications services offering capacities taking into account the terminal equipment (telephone, SMS, ...).
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Some GSM bearer servicesSome GSM bearer servicesBearer service Target
networkOffered throughputs (bits/sec)
3.1 kHz External to the PLMN
Asynchronous data circuit duplex
PAD circuit asynchronous access
Synchr data circuit duplex.
Alternate speech and data
Speech followed by data
Synchronous packet data duplex
ISDN
PSTN, ISDN
PSPDN
PSTN, ISDN
PSTN, ISDN
ISDN, PSTN
PSPDN
300 to 9600
300, 1200, 1200/75, 2400, 4800, 9600
Idem
1200, 2400, 4800,
9600
2400, 4800, 9600
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GSM teleservicesGSM teleservices
Radiotelephone. Emergency calls.Short message service.Fax. ...- Supplementary services:Calling number identification. Call waiting,Call transfer (on non reply, unconditional, on
busy, ...)Conference call, Closed user group
...
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II. 2,5 G evolution II. 2,5 G evolution towards 3Gtowards 3G
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High Speed Circuit High Speed Circuit Switched Data (HSCSD)Switched Data (HSCSD)
Objective: High bitrates radio bearers.
Introduced in phase 2+ (1997).
Use several time slots per mobile (up to 6).
Bitrates: 19.2 ; 28.8 ; 28.4 ; 48 ; 56 and 64 kb/s.
Asymetric configurations (n slots on the uplink and m slots on the downlink).
Problem: Circuit-switched (cost + capacity).
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Customized Applications for Mobile Customized Applications for Mobile network Enhanced Logic (CAMEL)network Enhanced Logic (CAMEL)
Intelligent network concept CAMEL defines an architecture and mechanisms based on IN.
Separation:
-1- Applications and Services specific features (SCP: Computers for services provision + SMP: Management point for data of one or several SCPs),
-2- Applications comon processing (SSP: Switch for service access)
Objective: Allow roaming subscribers to use their services even though these are specific to their operator.
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CAMEL services introductionCAMEL services introduction
.. < > ̂... . . .
BTS
BTS
BSC
TRAU
MSC/VLR
PSTN
HLR A
Abis
IN Plate-form
SS7 Network
EIR
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SIM ToolkitSIM Toolkit
Principle: The SIM card can initiate actions on the terminal.
Objectives: Allow exchanges between the network and the SIM through SMSs (without displaying them) Value-added services provision.
Examples:
- Reservation in a restaurant (send a menu by the network, manages user choices and the SIM card sends back the reservation in an SMS).
- Menus management (kiosk services ).
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General Packet Radio General Packet Radio Service: 2,5 GService: 2,5 G
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Introduction of packet-switchingIntroduction of packet-switching
Packet switching advantagesPacket switching advantages Transmission of non-periodic and bursty
data (e.g.: mails),Frequent small packets (e.g.: telematic,
billing and micro-payments),Large but unfrequent packets (e.g.: ftp).
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GPRS principlesGPRS principles
Higher bit-rates per TCH (9.05 ; 13.4 ; 15.6 ; 21.4 kb/s),
Higher bit-rates with up to 8 time slots per user,
Channel sharing by active terminals,
Separate allocation of uplink and downlink channels, Separate packet transmission network between the BSC and external packet transmission networks: GSS (based on SGSN and GGSN).
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GGSN (GGSN (Gateway GPRS Support NodeGateway GPRS Support Node)) FunctionsFunctions
Routing: IP router which supports dynamic or static routing, Security: Ciphers the communications towards or from the
mobiles. Mobility management: Use of routing areas. Handover
management between the BSCs and other SGSNs. Authentication: At Attach and inter-SGSN RA updates. Sessions management: At each session, the SGSN activates a
PDP (Packet Data Protocol) context. Billing: Production of the CDRs according to the quantity of
information and the session duration (attachment, duration of active PDP context).
SMS: Supports the Gd interface for the communications with the SMS-GMSC and the SMS-IWMSC.
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GGSN (GGSN (Gateway GPRS Support NodeGateway GPRS Support Node)) functionsfunctions
Routing: IP router which supports dynamic or static routing, Security: Includes firewalls for filtering the packets coming
from external IP networks. Gateway: Allows the connection to other IP or GPRS
networks. Mobility management: Allows the routing of the packets
towards the users SGSNs, according to their mobility. Sessions management: At each session, the GGSN allocates
an IP address to the mobile. Billing: Production of the CDRs according to the quantity
of information and the session duration (attachment, duration of active PDP context).
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GPRS introduction GPRS introduction iin a GSM networkn a GSM network
.. < > ^ ... . . .
BTS
BTS
BSC
PCU
Gb Gs
SGSN Gr, Gd, Gf
Gn
Border Gateway
GGSN
Inter-operator
GPRS backbone
GPRS backbone
Internet PDN
Router LAN
Service plate-form
WAP, WWW, ...
SS7 Network
Gc
Gf EIR
Gr
TRAU
MSC/VLR
PSTN
HLR A
Abis
IN Plate-form
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GSM to GPRS EvolutionGSM to GPRS Evolution
BSS Evolution: - Replace/Upgrade existing elements: BTS, BSC, O&M, Network planning, Links (Abis, Ater, …). - New element: PCU (Packet Controller Unit). NSS Evolution: - A new core network (GSS) dedicated to GPRS: IP/ATM based, network packet nodes (SGSN, GGSN), Internet equipment (DNS servers, Firewalls, …). - Evolution of the network elements: HLR, MSC/VLR, SS7.
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Main Main characteristicscharacteristics
Same physical layer as GSM. Service separated from GSM:
Different fixed networks (new network entities and new protocols).
New mobiles, 3 types: - A: GSM and GPRS at the same
time, - B: GSM or GPRS (« dual mode » in
idle mode), - C: GSM or GPRS a priori.
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Services Services classificationclassification
Services
Service type Sub-types Characteristics
Point-to-Point (PtP)
PtP – Connectionless Network Service (CNLS)
Data packet transfer between two points via a connection-less service (e.g. Internet) or via connection oriented service (e.g. X25)
PtP – Connection Oriented Network Service (CONS)
Data packet transfer from a point towards a geographical area (group of cells)
Point-to-Multipoint (PtM)
PtM – Multicast (PtM-M)
Multicast service (cf. IP)
PtM – IP Multicast (IP – M)
Data packet transfer towards a predefined group of users in a geographical area
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Enhanced Data rates for Enhanced Data rates for the GSM Evolution: 3Gthe GSM Evolution: 3G
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Enhanced Data rates for GSM Evolution Enhanced Data rates for GSM Evolution (EDGE)(EDGE)
Objective:Increase the data bitrates (GPRS EGPRS). Bitrates:
- 473 kb/s for the terminals of 100 km/h maximum. - 80-130 kb/s on average.
- 144 kb/s for the terminals of 250 km/h maximum. Means:-1- New modulation (8-PSK).-2- Link adaptation. New mobiles, upgrade/replacement of TRXs
and capacity enhancement (Abis, …).
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EDGE introductionEDGE introduction
.. < > ^ ... . . .
BTS
BTS
BSC
PCU
Gb Gs
SGSN Gr, Gd, Gf
Gn
Border Gateway
GGSN
Inter-operator
GPRS backbone
GPRS backbone
Internet PDN
Router LAN
Service plate-form
WAP, WWW, ...
SS7 Network
Gc
Gf EIR
Gr
TRAU
MSC/VLR
PSTN
HLR A
Abis
IN Plate-form
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III. 3G services and III. 3G services and evolutionevolution
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Internet and GSMInternet and GSM
0
200
400
600
800
1000
1200
1996 1997 1998 1999 2000 2001 2003
Mill
ion
s o
f u
se
rs
GSMInternet
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Motivations for a new Motivations for a new systemsystem
Convergence: computer, telecommunications and audio applications.
Present services: Mainly voice (> 70 % of cellular operators revenues).
Extend to data and combination of voice/data. New frequency bands (WARC 92). Migration (operators and providers) towards
more diverse and developed applications and services.
Technological progress (networks, systems, DSP, …)
Definition and development of new systems.
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Development initial planningDevelopment initial planning 1998-1999 Radio interface definition
2000 First demonstrations of 3G systems
May 2000 IMT-2000 specifications validation by ITU-R
2000-2001 3G licenses allocation in Europe
Mid-2001 First 3G networks opened in countries such as Japan, based on first 3G specifications
Mid-2002 3G terminals available (first specifications)
2002 3G pilot networks in Western Europe.
2002-2003 3G applications development
Mid-2004 3G commercially available
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UMTS main UMTS main features (1)features (1)
Integration of existing mobile services (cellular, cordless, paging, PMR, …) and introduction of service portability (Virtual Home Environment, …).
Choice among various terminals and service providers.
Flexible terminals supporting several radio interfaces (software radio).
Global roaming for terminals and services.
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UMTS main UMTS main features (2)features (2)
Voice quality similar to that of fixed networks.
Satellites services for areas non covered by terrestrial BTS.
UMTS frequency spectrum: 1885-2025 MHz and 2110-2200 MHz.
Security and anti-fraud techniques against access to data by non-authorized persons or entities.
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1997 2000 2005
Uplink
Downlink
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UMTS main UMTS main features features (3)(3)
Wideband multimedia mobile services: 2 Mb/s for indoor, reduced mobility (10 km/h), 384 kb/s for urban outdoor (120 km/h), 144 kb/s for rural outdoor, important mobility (500 km/h). Variable quality of service (BER between 10-3 and 10-
6, delays between 30 and 300 ms). Asymetric and variable bitrate transmission. Multiples services per user: Speech : 8 kb/s, Data : 2,4 at 6x64 = 384 kb/s, Video : 384 kb/s, Multimedia.
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Objectives and Objectives and Features (1)Features (1)
Wideband. Service integration. Packet access. Techniques for capacity
enhancement: multi-user detection, interference cancellation, adaptive antennas, MIMO, … Inter-system (GSM – 3G) and
inter-frequencies (hierarchical networks) handover.
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Objectives and Objectives and Features Features (2)(2)
Main challenge: Merge mobile phone radio coverage to Internet and other multimedia applications. 3G systems must provide: Flexible multimedia services management, Internet access, Flexible services support, Packet access at an interesting cost for « Best Effort » services. Most of multimedia applications accessible through Internet:
3G access = Mobile Internet.
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Introduction of Introduction of UMTSUMTS
RNC
Node B
Iub
Iub
Iu
UMTS Core Network
UE
Node B
UMTS Radio Access Network
GPRS/EDGE Radio Access Network
GPRS core network
Internet
NSS
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Zone 4Global
Zone 1in building
Zone 2Urban
Zone 3Suburban
UTRA/TDD
UTRA/FDD
GSM
MSS
3G environment and multi-mode terminals 3G environment and multi-mode terminals (UMTS Forum)(UMTS Forum)
Basic terminalPDA
Audio/video terminal
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Evolution from 2,5G to Evolution from 2,5G to 3G networks3G networks
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UMTS R99 main featuresUMTS R99 main features
UMTS Core Network
UE
UTRAN
Services
New radio access system (WCDMA-based): higher bitrates, HO with GSM
Camel, GPRS-based core network with improvements (security, GTP, …)
OSA (Open Systems Architecture), USSD (Unstructured Supplementary Service Data), MMS, LCS (cell level), streaming, GSM services (SMS-PtP/CB), SMS, VHE
EMS, MMS, MExE (Mobile Execution Environment, terminals classified by classmark), SAT (SIM Application Toolkit, interoperability
between all USIM and UE), VHE
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UMTS R4 FeaturesUMTS R4 Features
UMTS Core Network
UE
UTRAN
Services
New TDD access mode, evolution of UTRAN transport (IP introduction), radio interface improvement (e.g. UTRA repeaters ), RAN improvements (e.g. overhead compression)
Packet transport improvement in the core network, TrFO (Transcoder Free Operation), Tandem Free
between 2G and 3G
Authentication algorithm, VHE and OSA evolutions, LCS support in circuit and packet domains (OTDOA and A-GPS)
MExE release 4, MMS r4, SMS/EMS improvements, Terminal Local Model-USAT Local (allows USIM applications to access other devices
with Bluetooth),
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UMTS R99/R4 and UMTS R99/R4 and GSM/GPRSGSM/GPRS
UMTSRadio
GSMRadio
PSTN/ISDN
PublicIPGGSN
VMSC
VLR
SGSN
GPRSVLR
HLRCAMEL
PS
CS
GMSC
Core Network
IP/ATM Core
Network(s)
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UMTS R5 FeaturesUMTS R5 Features
UMTS Core Network
UE
UTRAN
Services
HSDPA (bitrates between 1 and 5 Mb/s), Smart antennas, IP transport in UTRAN (IP-
RAN) with DiffServ introduction, SIP (call control), End-to-end QoS improvements, IuFlex (traffic load
sharing between core nodes
IMS (VoIP, chatt, jeux, white shared board, flexible billing, …), OSA improvements (VAS offered by third parties, VHE easier),
Extended streaming (optimisation, 2 and 3D graphics, MIDI audio, …)
Wideband AMR (wider bandwidth for voice), GTT (Global Text Telephony, real time text
communication), LCS improvements with A-GPS, MMS/EMS improvements
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UMTS Core Network
UMTS Radio Access Network
GPRS/EDGE Radio Access Network
GPRS core network
Internet
NSS
IP Multimedia System
Introduction of Introduction of IMSIMS
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UMTS R6 FeaturesUMTS R6 Features
UMTS Core Network
UE
UTRAN
Services
Infrastructure sharing, QoS/IP, ... WLAN (loose coupling) with AAA function reuse, access with USIM
MBMS (multimedia broadcast service), IMS phase 2 (independant access from the radio access UMTS, GERAN,
WLAN), Presence and Instant Messaging, Push-To-Talk
SES (Speech Enhanced Services): distributed voice recognition, MIMO (multiple antennas in the
terminals), Terminal management (configuration, performances, downloading)
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E-GGSN
E-SGSN
RNC
RNC
E-GGSN
Roadmap to All-IP Networks - 3GPP R6+Roadmap to All-IP Networks - 3GPP R6+
PS + IM DomainAll-IP
IPv4 & IPv6 Networks
IP inUTRAN
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UMTS features and sub-systems for service provisionUMTS features and sub-systems for service provision
Introduction of IPDevelopment of multimedia IP services with hardware and software componants integration
Customization User framework portability
Provision by third parties
Services development by external applications and contents providers
Terminal related
Adaptation of the service to the user terminal according to its characteristics, task sharing with the network
MeXE Mobile eXecution
Environment
VHE Virtual Home Environment
OSA Open Service
Access
IMS IP Multimedia
Service
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IMS - IP Multimedia ServiceIMS - IP Multimedia Service
Principles
Drawbacks
QoS characteristics differentiation for voice or video associated with a multimedia session (streaming, IM, etc.)
Separation of the planes IP data and session control (SIP)
Independant from the access network
Introduction of multimedia services with QoS managementIntegration with other networks (WLANs, fixed, CDMA2000, …)Flexible billing: billing / service, connectivity, QoS, time, destination
Advantages
IMS for mobile networks GPRS, EDGE, UMTS & CDMA2000
Non real time services IP multimedia applications plate-
form IETF specifications based
IMS extended to wideband fixed networks (xDSL, WLAN, cable, …)
Supports services convergence on fixed and mobile networks (conversion
CS voice traffic in IP)
R6R5
Implementation of many equipments, softwares, interfaces, protocols, which may cause integration, interworking and optimisation problems
Ex.: S-CSCF (Call Status Control Function); SIP AS (SIP Application Server); OSA SCS (Service Capability Server); IM-SSF (Inter-working Module); CSE (Camel Service Environment); HSS (Home Subscriber Server)
Security and QoS with Internet interconnection
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CompoComponnants ants andand interactions interactions betweenbetween IMS IMS andand otherother networksnetworks
ApplicationServers
(SIP, OSA, CAMEL)
SessionControl
MediaControl
IMS
User Data
MediaGateway
PSTN
Packetnetwork
ISUP
Packet SupportNode
Backbone IP PacketGateway
RNC
RAN
Core packet
SIP
SIP
MediaGateway
PCM
AMR
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VHE VHE - - Virtual Home EnvironmentVirtual Home Environment
Principles
•PSE (Personal Service Environment) portability between networks and terminals: user – services interaction modes, multiple subscriptions management (pro/perso), multiple terminals and preferences according to the location.
•Same features always available to the user: interface and services customization, whatever the network and the terminal.
• Independancy relatively to the network (roaming) and the terminal
Applications
VAB Virtual Address
Book
Use of many types of terminals to
access and update user data
Customer Care service
Support to the users: interactive
tutorials, problems detection and
solutions proposal, on-line assistance,
…
Calender multiparty application
Coordinated calendar
management among remote users: answers
collection, meeting dates
determination, …
Multimedia Delivery service
Adaptation of the video to the user
terminal
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OSA OSA - - Open Service AccessOpen Service Access
Supervision of the services and contents by the operator QoS management by external providers for offered services
Principles
Drawbacks
Introduction of SCF (Service Capability Features) to provide applications with service features: call control, user location,…
Access to network features which application developpers will use to develop or improve services
Introduction of services by third parties through standardized interfaces and applications
Easier introduction of application and service providers
Advantages
VPN, teleconferencing, LBS Applications implemented in one
or many application serversApplications
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MExE - Mobile Execution EnvironmentMExE - Mobile Execution Environment
Définition, standardisation and implementation of these terminal classes
Principles
Drawbacks
Standardised execution environment for the mobiles
Negociation of the features between UE and MExE server during service initiation or dynamically
Execution of service applications inside the UE or in the MExE server
MExE defines the classmarks to support various terminals (Classmark 1: WAP environment, Classmark 2: PersonalJava, Classmark 3: J2ME CLDC MIDP environment )
Adaptation of the services to user terminalsAdvantages
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UUSIMSIM characteristics characteristics
64K, 128K, eventually 1MoCapacities
Operator and user profiles management through radio interface (OTA, Over The Air): VAS real-time implementation, with updates and applets downloading, file management, …
Profile management
Point-to-point messages exchange security provision in OTA
Security
Pro-active SIM card for execution of features; management of UE by USIM and thus by the operatorSIM Application
Toolkit (STK)
OTA based on SMS transport, then via other bearers (CSD, GPRS, UMTS)
Operations
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Interactions Interactions forfor service service provision in UMTSprovision in UMTS
IMSMultimedia IP
servers
Application and
Content providers
Application servers BDD & user profiles
(PSE, VHE, …) OSA
RAN
(CAC, LC)
QoS management
USAT, MeXE, OTA, CAMEL, LCS, …
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Services evolution in UMTS R99/R4/R5/R6 Services evolution in UMTS R99/R4/R5/R6 networksnetworks
Release Services
R99 MMS, streaming, LCS (cell), MExE, SAT, VHE,
R4 TrFO, VHE, OSA, LCS in PS and CS,
R5 VoD, IMS, HSDPA, Wideband AMR, GTT
R6 MBMS, IMS phase 2
Evolution of the services (voice and interpersonal services)
Voice
SMS/MMS
Voice
Messaging
Videotelephony
Voice/Videotelephony
Instant Messaging/Presence
Rich Call Services
Messaging
Voice/Videotelephony
IM/Presence
Messaging
RCS
LCS
GTT
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QoS and planning QoS and planning problems in UMTSproblems in UMTS
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QoS QoS problems iproblems in UMTSn UMTS
Necessary definition of end-to-end QoS management functions No 3GPP specifications for QoS in PS and in IMS Implementation choice depends on the operator preferences,
the network, the service model, equipment providers, … Resources negociated between operators through DiffServ,
DSCP at network borders
QoS guaranteed in CS but not in IP: QoS problems similar in UMTS as in any IP network
QoS provision in IP ?
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QoS QoS provision iprovision in UMTSn UMTS
Radio access
RSVP, overprovisionning, DiffServ/ IntServ, MPLS In R5, definition of 5 signalling scenarios for end-to-end QoS:
-3 with PDP/DiffServ interworking,
-2 with RSVP signalling
Core network
CAC - Call Admission Control
•RNC: admits or rejects new users or new RAB (Radio Access Bearers) according to network load, users priorities and resource availability
•Used at network UE access: RAB reconfiguration or allocation and HO according to the events
•UL channel interference and DL power related
Load/Congestion Control
• RNC: supervises, detects and manages congestion situations during users connection
• Load reduction via queueing mechanisms,, by delaying the packets of the best effort traffic
• Mechanisms not standardised, designed by the equipment vendors and optimised by the operators
• Principles: CAC based on the interference level, on the admission politics/load factor, etc.
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Cell breathing phenomena
Cas 1 : 10 utilisateurs Cas 2 : 20 utilisateurs
-10 < C/I < -5 dB -15 < C/I < -10 dB
-15 < C/I < -50 dB cellu les
Case 1: 20 users Case 2: 10 users
Radio phenomenaRadio phenomena
cells
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Capacity, cell radius and Capacity, cell radius and noise risenoise rise
R
Charge de la cellule = 20 % de la capacité maximum
Niveau d’interférence = y dB
R
R’
Charge de la cellule = 50 % de la capacité maximum
Noise Rise = 2 dB
Niveau d’interférence = y + 2 dB R
R et R’ sont les rayons des cellu les dans les deux situations de charge
Cell load = 20% of the maximum capacity
Interference level= y dB
R and R’ are the cell radius in the 2 load
situations
Cell load = 50% of the maximum capacity
Interference level= y + 2 dB
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WCDMA systems and planningWCDMA systems and planning
• Interaction between coverage and capacity (estimation of interference level, relation between user number and cells bitrates),
• Multi-services aspect (differents services with different Eb/N0),
• Power control (minimum transmission power of the MSs and BTSs, difference between UL and DL),
• Rake receiver and Soft HO.
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ConclusionsConclusions
UMTS introduces:
an environment to develop and provide services: wideband, flexible, customized, accessible from outside, open on Internet, … with Internet and computer-related technologies.
Richer and wideband servicesRicher and wideband services
But:
More complexity (design, planning, integration, deployment, security, optimisation, operation).