UMTS Technologist, MSc (EE), Radiolinja Antti.Siitonen@radiolinja.fi T-110.300 Telecommunications architectures Lectures on 15.11.2001 Introduction to UMTS 1
Contents 1. Introduction to UMTS 1.1. Standards evolution 1.2. Radio interface in general 1.3. Network architecture 1.4. Mobile handset 2. Services in UMTS environment 2.1. Theoretical bitrates and Quality of Service 2.2. Service capabilities 2.3. Service concepts 3. UMTS protocols 3.1. Protocol architectures in UMTS overview 3.2. Signalling 2
Worldwide Telecommunications Growth millions of customers 1800 1600 1400 1200 1000 800 600 400 200 0 source ETSI GMM report 1996 1998 2000 2002 2004 2006 2008 2010 Fixed Mobile Internet Mobile Internet 3
UMTS Universal Mobile Telecommunications System UMTS = European variation of the WCDMA technology FDD and TDD bands New licences GSM combatible What is new? Wideband data access and multimedia support Open service creation environment Videophone Picture: Nokia 4
3G Standards U M T S Variant Radio access Switching 2G Basis 3G (US) WCDMA, EDGE, CDMA2000 IS-41 IS-95, GSM1900, TDMA 3G (Europe) WCDMA, GSM, EDGE Advanced GSM NSS and packet core 3G (Japan) WCDMA Advanced GSM NSS and packet core GSM 900/1800 PDC UMTS standardization is done in 3GPP = 3rd Generation Partnership Project ETSI = European Telecommunication Standard Institute / Europe ARIB = Association of Radio Industries and Business / Japan CWTS = China Wireless Telecommunication Standard Group / China T1 = Standardisation Committee T1 - Telecommunications /US TTC = Telecommunications Technology Committee /Japan TTA = Telecommunication Technology Association /Korea 5
3GPP Standards Commercial servicescommercial services R3 R4 Commercial services R5 3GPP Release 4 3GPP Release 5 3GPP Release 3 (Release 1999) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 2000 2001 2002 2003 6
UMTS releases Release 3 (Officially named Release 1999) UMTS expansion + EDGE quick start = faster GPRS, faster Circuit Switched Data MultiMediaMessaging (For GPRS also), Adaptive Multirate New radio network for UMTS Release 4 New network architecture: MSC server Location based services (PS), VHE, Camel 3, MAP over IP Release 5 (and Release 6) OSA, MediaGateway, GSN server IPv6 mandatory, IPv4 optional SIP signalling and VoIP Interfaces to other networks (WLAN (HiperLan2).) 7
What is new with UMTS radio? In shot: everything Wideband CDMA - 2 Mbit/s channel bitrate» Soft handover» Cell breathing Both FDD and TDD modes» Frequency Division Duplex» Time Division Duplex New frequencies 2100 MHz = 2,1 GHz Later other frequency bands (900, 1800, 2600...) Cell planning is changed from frequency planning into capacity planning 8
WCDMA - cell breathing 1 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 9
WCDMA- cell breathing 2 More load... 512 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 10
WCDMA- cell breathing 3 Serving 2 Mbit user 2 Mbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 64 kbit/s 11
WCDMA- cell breathing 4 Several 2 Mbit users? 2 Mbit/s 2 Mbit/s 2 Mbit/s 2 Mbit/s 12
WCDMA frequencies (ITU) ITU Allocations Europe 1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz 1880 GSM 1800 DECT IMT 2000 UMTS MSS MSS TDD 1885 1900 1980 2010 2025 2110 2170 2200 IMT 2000 UMTS MSS MSS China IMT 2000 MSS IMT 2000 MSS 1893 1919 Japan Korea North America B PCS IMT 2000 B MSS 1990 MSS IMT 2000 MSS 2160 Reserve MSS MSS = Mobile Satellite Services 1850 1900 1950 2000 2050 2100 2150 2200 2250 MHz FDD 13
WCDMA Frequency use 2 times more effective than GSM 1 WCDMA channel = 28 GSM channels... f GSM 0,2 MHz WCDMA 5MHz 14
UMTS Network release 99 - Based mainly on GSM+GPRS HLR VAS Camel, WAP, MExE, USAT MS 3G MSC SS7 Circuit Switched Domain PSTN GSM GPRS Internet UE UTRA BTS BSC SGSN GGSN LAN Packet Switched Domain UTRA BS RNC BS RNC 15
UMTS Network release 4 Control Switching MSC Server SS7 Media Gateway PSTN MS Media Gateway Circuit Switched Domain GSM GPRS Internet BTS BSC SGSN GGSN LAN UE UTRA Packet Switched Domain RNC BS HSS VAS Camel, WAP, MExE, USAT HSS = Home Subscriber Server 16
Core network release 5 (6) PSTN MS IMS = IP Multimedia Subsystem MGW+HSS+CPS SIP-signalling IMS MGW SS7 GSM IP/ATM SGSN GGSN Internet BTS BSC IP/ATM HSS CPS VAS Camel, WAP, MExE, USAT UE UMTS IP/ATM RNC HSS = Home Subscriber Server CPS = Call Processing Server Core Network Packet Switched Domain BS IP RAN 17
Bearer architecture in UMTS TE MT UTRAN CN Iu edge CN Gateway End-to-end Service Local Bearer Service UMTS Bearer Service External Bearer Service Radio Access Bearer Service CN Bearer Service Radio Bearer Service UTRA Bearer Service IU Bearer Service Physical Bearer Service Backbone Bearer Service Backbone Phys. Bearer Service TE = Terminal Equipment, MT = Mobile Termination, UTRAN = UMTS Radio Network, CN = Core Network 18
UMTS Terminal, User Equipment (UE) Mandatory functions: Interface to USIM = Universal Subscriber Identity Module Service provider and network registration and deregistration Location update Originating and receiving connection orinented and connectionless services An unalternable equipment identification (IMEI) Basic identification of the terminal capabilities Emergency calls without USIM Authentication and ciphering algorithm support Optional, but important API, Service related information download, Virtual Home Environment maintenance interface, Secondary IC-card slot 19
Terminal Complexity Comparison MIPS 90 80 70 60 50 40 GSM/EDGE WCDMA 30 20 10 0 Speech 8 kbit/s 144 kbit/s Source: SMG2 evaluion documents by Nokia, Ericsson and Siemens 20
Services in UMTS Environment Content Provider Content Provider Content Provider Service Provider Service Provider Service Provider Carrier Provider Carrier Provider Games End User End User End User Info Services Communication Services 21
Theoretical bitrates Theoretical bitrates seem to remain theory Specified rates are: Circuit Switched bit Packet Switched bit Coverage Type rate (kbit/s) rate (kbit/s) 144 kbit/s 144 kbit/s peak rate Basic coverage,rural/suburban, fast moving vehicles, outdoor 384 kbit/s 384 kbit/s peak rate Extended Coverage, urban, moving vehicles, outdoor 2 Mbit/s 2 Mbit/s peak rate Hot Spot areas, urban, centre, walking speeds, indoor In commercial deployments maximum bit rates are expected to be 384 kbit/s and basic service bit rate 64 kbit/s Indoor coverage for UMTS? One issue is also the availability of high speed terminals 22
Quality of Service Radio capacity optimisation Core Network and UTRAN independent from each other and surrounding networks Transport Network optimisation QoS classes: Conversational class: minimum fixed delay, no buffering, symmetric traffic, guaranteed bit rate = Real Time Traffic Streaming class: minimum variable delay, buffering allowed, asymmetric traffic, guaranteed bit rate = Near Real Time Traffic Interactive class: moderate variable delay, buffering allowed, asymmetric traffic, no guaranteed bit rate = Not Real Time Traffic Background class: big variable delay, buffering allowed, asymmetric traffic, no guaranteed bit rate = Data synchronisation 23
Quality of Service (cont.) QoS parameters in UMTS: Maximum bit rate (kbit/s) Guaranteed bit rate (Kbit/s) Allowed transfer delay (ms) UE UTRAN CN Is QoS class negotiable? UMTS End-to-end Service UMTS Bearer Service: Request for UMTS QoS Class RAB Assignment Request RRM: - Admission Control QoS Negotiation Radio Bearer and Radio Link establishment RAB Assignment Response UMTS Bearer Service with Negotiated QoS RAB = Radio Access Bearer, RRM = Radio Resource Management 24
Quality of Service (cont.) Conversational Streaming Interactive Background Max. Bit < 2048 < 2048 < 2048 < 2048 rate (kbit/s) Guaranteed < 2048 < 2048 N/A N/A Bit rate (kbit/s) Symmetry Symmetric Asymmetric Asymmetric Asymmetric Transfer delay (ms) 100-250 > 250 N/A N/A Challenges: First typical use cases will be in hybrid networks (UMTS/GPRS/GSM), How is this taken into account? How much can content compression and background synchronisation solve user needs? 25
Service capabilities Principle: Connections are separated from service maintaining Network components called service capabilities = service platforms Initially identified service capabilities (Release 99) WAP Server / WAP Gateway - Mobile browser capabilities Positioning servers - UE position information, Location Based Services Mobile Station Application Execution Environment - Provides information to other services about UE information handling capabilities UMTS SIM Application Toolkit (USAT) - SIM card handling tools Customised Applications for Mobile network Enhanced Logic (CAMEL) - Service interconnection point (Service control, implementation and provisioning) 26
Service capabilities (cont.) In Release 4 there are new possibilities for service creation OSA = Open Service Architecture Common centralized point for Service Creation = Service Creation Environment (SCE) All capabilities implemented are accessible via APIs Practically CAMEL is required for effective service creation Possibility to make the services roam between networks Challenge: Will the operators open the networks for open service creation? 27
Location Communication Services There are different methods to provide UE position information to services or users Cell ID based positioning Round-Trip Time (RTT) based positioning Timing Advance, Received Signal Strength (TA/Rx) Time-of-Arrival (TOA) positioning Time Difference of Arrival (TDOA) positioning Enhanced Observed Time difference (E-OTD) Angle of Arrival (AOA) positioning Reference Node Based Positioning (RNBP) Assisted Global Positioning System (Assisted GPS) 28
Accuracy of different positioning systems Always an estimate Different methods for different usage Most accurate isn t always the best choise GPS E-OTD TA/Rx Cell-ID 10m 100m 1 km 10 km Accuracy 29
UMTS System architecture for LCS LCS Ext. Client MS HLR GMLC VAS Camel, WAP, MExE, USAT 3G MSC Circuit Switched Domain SS7 PSTN GSM GPRS Internet BTS BSC SGSN GGSN LAN UE UTRA Packet Switched Domain BS SRNC/SMLC LCS Internal Client SMLC = Serving Mobile Location Centre GMLC = Gateway Mobile Location Centre 30
MExE Terminals will have different capabilities - how to tell to the service which are the current capabilities? Mobile Application Execution Environment (MExE) was introduced to handle terminal capabilities MExE Classmark 1: Numeric keypad, limited screensize, fixed character amounts (WAP type Terminal) MExE Classmark 2: Colour screen, full keypad, wide application support (JAVA supporting terminal) MExE Service Environment: Set of supported services Personalisation database - interacts with USIM 31
USAT USIM Application Toolkit Extension to GSM SIM Application Toolkit to support USIM properties Applications executed in USIM Most likely to be closed environment - operators are in control of USAT applications 32
CAMEL SCE Customised Applications for Mobile network Enhanced Logic - Developed to provide automatic roaming with full service set - Mobility and Service Portability on top of IN Circuit Switched Call Control Subscriber Location and State Retrieval GPRSinterworking CAMEL - functioning environment Subscription Data Handling SMS - MMS Mobility Management 33
Virtual Home Environment Idea: To have the same, personalised individual interface through the terminal regardless of the UMTS network the user is attached to Requirements for Release 99 based network are based on CAMEL Subscriber profiles are handled in MExE Service Environment Location Based Services information can be transferred through CAMEL Provisioned services and their usage information is transferred between Networks through CAMEL Number portability can be handled through CAMEL Question: Would this be easier in All IP environment? 34
Service Concepts GSM inherited Services supported in R99 are quite BASIC: Voice FAX Alternate FAX/Voice Circuit Switched Data Bearer services Supplementary Services USSD (Unstructured Supplementary Service Data) MMS Packet Switched Services are actually same as in GPRS, but Bigger bit rate Smaller delay 35
UMTS Security There are three key principles behind 3G security: 3G security will build on the security of second generation systems. Security elements within GSM and other secondgeneration systems that have proved to be needed and robust shall be adopted for 3G security. 3G security will improve on the security of second generation systems - 3G security will address and correct real and perceived weaknesses in second generation systems. 3G security will offer new security features and will secure new services offered by 3G. 36
UMTS Security (cont.) High Level objectives of security: To ensure that information generated by or relating to a user is adequately protected against misuse or misappropriation; Environments are adequately protected against misuse or misappropriation; To ensure that the security features standardised are compatible with worldwide availability. (There shall be at least one ciphering algorithm that can be exported on a worldwide basis (in accordance with the Wassenaar agreement)); To ensure that the security features are adequately standardised to ensure world-wide interoperability and roaming between different serving networks; To ensure that the level of protection afforded to users and providers of services is better than that provided in contemporary fixed and mobile networks (including GSM); To ensure that the implementation of 3GPP security features and mechanisms can be extended and enhanced as required by new threats and services. 37
Protocol architectures in UMTS UE BS RNC MSC/SGSN GMSC/GGSN System Network Layer Radio Network Layer Transport Network Layer User & Control planes are parallel User Plane Control Plane 38
Transport Network Protocol Architecture UE R99 BS RNC MSC/SGSN Uu Iub/Iur Iu D/Gr HLR RLC RLC SCCP SCCP SCCP SCCP MAC MAC ATM or IP ATM or IP MTP MTP WCDMA Physical Layer Physical Layer (PDH or SDH) UE RLC MAC Control plane protocols in transport network BS RNC SGSN Uu Iub/Iur Iu Gn RLC MAC AAL (n) or GTP-U ATM or UDP/IP AAL (n) or GTP-U ATM or UDP/IP AAL (n) or GTP-U ATM or UDP/IP GGSN AAL (n) or GTP-U ATM or UDP/IP WCDMA Physical Layer Physical Layer (PDH or SDH) User plane protocols in transport network RLC = Radio Link Control, MAC = Medium Access Control, SCCP = Signalling Connection Control Part 39
Protocol layers Physical layers MAC RLC WCDMA Physical Layer PDH or SDH Physical Layer Set of logical channels Radio Link Control» eg. Segmentation and reassembly, Error correction,.. UMTS is primarly specified to use ATM as Layer3-protocol IP is defined for user data and there is an IP option for signalling transport 40
System Network Protocols Mobility Management -protocol (MM) Between UE and MSC Basic mechanisms for Mobility management and authentication functions GPRS Mobility Management -protocol (GMM) Mobility mangement for Packet Switched domain Call Control -protocol (CC) Between UE and MSC Basic Mechanisms for Call Control in Circuit Switched domain Session Management -protocol (SM) Between UE and SGSN Supplementary Services -protocol (SS) Between UE and MSC Additional services in Circuit Switched domain 41
Role of IP in UMTS evolution User Traffic & Services Traffic Control Traffic Transport R99 User Traffic & Services Traffic Control Traffic Transport R4 User Traffic & Services Traffic Control Traffic Transport R5/6 Role of IP 42
All-IP In UMTS R5 IPv6-support mandatory IPv4-support optional Signalling Interface to external networs via SIP Towards PSTN SIP over IP is translated to SS7 Call Control - signalling (eg. ISUP) IPSec is needed to ensure integrity of SIP-sessions» Still no decision of end-to-end multimedia session ciphering 43
SIP services Session Initiation Protocol based signalling VoIP Instant messaging Presence information Browser sessions SIP based services (examples) Rich Call Multimedia conference/chat 44
IP Multicast Architecture Multicast connections example: 5 users, 1 group. RNC RNC SGSN RNC RNC SGSN GGSN IP Multicast Network RNC GGSN RNC SGSN RNC SGSN Radio Bearer (Broadcast) Multicast_RAB Multicast_GTP_Tunnel IP Multicast 45
UMTS for mobile operator New investments to the network New set of subscribers and services Several service networks - serveral service mechanisms New security challenges in IP: Everything cannot be blocked out, IP has more flexibility Number of IP connected devices will be greater than number of individuals in the network IS THERE GOOD ALTERNATIVES? - For Mobile use, not yet. - For Wireless Connectivity, yes there is. To be continued in the next lecture.. 46