Mobile Communications Chapter 4 Wireless Telecommunication Systems Market

Mobile Communications Chapter 4: Wireless Telecommunication Systems Market q GSM q Overview q Services q Sub-systems q Components q DECT q TETRA q UMTS/IMT-2000 q

Mobile phone subscribers worldwide 1200 Subscribers [million] 1000 GSM total 800 TDMA total CDMA total 600 PDC total Analogue total Total wireless 400 Prediction (1998) 200 0 1996 1997 1998 1999 2000 2001 2002 year

CT 0/1 AMPS NMT CT 2 IS-136 TDMA D-AMPS GSM PDC TDMA FDMA Development of mobile telecommunication systems IMT-FT DECT EDGE GPRS IMT-SC IS-136 HS UWC-136 IMT-DS UTRA FDD / W-CDMA IMT-TC UTRA TDD / TD-CDMA IMT-TC TD-SCDMA 1 G IS-95 cdma. One cdma 2000 1 X 2 G 2. 5 G IMT-MC cdma 2000 1 X EV-DO 1 X EV-DV (3 X) 3 G

GSM: Overview GSM q q q q formerly: Groupe Spéciale Mobile (founded 1982) now: Global System for Mobile Communication Pan-European standard (ETSI, European Telecommunications Standardisation Institute) simultaneous introduction of essential services in three phases (1991, 1994, 1996) by the European telecommunication administrations (Germany: D 1 and D 2) seamless roaming within Europe possible today many providers all over the world use GSM (more than 184 countries in Asia, Africa, Europe, Australia, America) more than 747 million subscribers more than 70% of all digital mobile phones use GSM over 10 billion SMS per month in Germany, > 360 billion/year worldwide

Performance characteristics of GSM (wrt. analog sys. ) Communication q mobile, wireless communication; support for voice and data services Total mobility q international access, chip-card enables use of access points of different providers Worldwide connectivity q one number, the network handles localization High capacity q better frequency efficiency, smaller cells, more customers per cell High transmission quality q high audio quality and reliability for wireless, uninterrupted phone calls at higher speeds (e. g. , from cars, trains) Security functions q access control, authentication via chip-card and PIN

Disadvantages of GSM There is no perfect system!! q no end-to-end encryption of user data q no full ISDN bandwidth of 64 kbit/s to the user, no transparent Bchannel reduced concentration while driving q electromagnetic radiation q abuse of private data possible q roaming profiles accessible q high complexity of the system q several incompatibilities within the GSM standards q

GSM: Mobile Services GSM offers q several types of connections l q voice connections, data connections, short message service multi-service options (combination of basic services) Three service domains Bearer Services q Telematic Services q Supplementary Services q bearer services MS TE MT R, S GSM-PLMN Um transit network (PSTN, ISDN) tele services source/ destination network TE (U, S, R)

Bearer Services Telecommunication services to transfer data between access points q Specification of services up to the terminal interface (OSI layers 1 -3) q Different data rates for voice and data (original standard) q q data service (circuit switched) synchronous: 2. 4, 4. 8 or 9. 6 kbit/s l asynchronous: 300 - 1200 bit/s l q data service (packet switched) synchronous: 2. 4, 4. 8 or 9. 6 kbit/s l asynchronous: 300 - 9600 bit/s l Today: data rates of approx. 50 kbit/s possible – will be covered later!

Tele Services I Telecommunication services that enable voice communication via mobile phones q All these basic services have to obey cellular functions, security measurements etc. q Offered services q mobile telephony primary goal of GSM was to enable mobile telephony offering the traditional bandwidth of 3. 1 k. Hz q Emergency number common number throughout Europe (112); mandatory for all service providers; free of charge; connection with the highest priority (preemption of other connections possible) q Multinumbering several ISDN phone numbers per user possible q

Tele Services II Additional services q Non-Voice-Teleservices group 3 fax l voice mailbox (implemented in the fixed network supporting the mobile terminals) l electronic mail (MHS, Message Handling System, implemented in the fixed network) l. . . l l Short Message Service (SMS) alphanumeric data transmission to/from the mobile terminal using the signaling channel, thus allowing simultaneous use of basic services and SMS

Supplementary services Services in addition to the basic services, cannot be offered stand-alone q Similar to ISDN services besides lower bandwidth due to the radio link q May differ between different service providers, countries and protocol versions q Important services q q q q identification: forwarding of caller number suppression of number forwarding automatic call-back conferencing with up to 7 participants locking of the mobile terminal (incoming or outgoing calls). . .

Architecture of the GSM system GSM is a PLMN (Public Land Mobile Network) several providers setup mobile networks following the GSM standard within each country q components q MS (mobile station) l BS (base station) l MSC (mobile switching center) l LR (location register) l q subsystems RSS (radio subsystem): covers all radio aspects l NSS (network and switching subsystem): call forwarding, handover, switching l OSS (operation subsystem): management of the network l

GSM: overview OMC, EIR, AUC HLR NSS with OSS VLR MSC GMSC VLR fixed network MSC BSC RSS

GSM: elements and interfaces radio cell MS BSS MS Um radio cell MS BTS RSS BTS Abis BSC A MSC NSS MSC VLR signaling VLR GMSC HLR IWF O OSS EIR AUC OMC ISDN, PSTN PDN

GSM: system architecture radio subsystem MS network and switching subsystem fixed partner networks MS ISDN PSTN MSC Um BTS Abis EIR SS 7 BTS BSC VLR BTS BSS HLR BSC A MSC IWF ISDN PSTN PSPDN CSPDN

System architecture: radio subsystem MS network and switching subsystem MS Components MS (Mobile Station) q BSS (Base Station Subsystem): consisting of q Um BTS Abis BTS BSC l BTS (Base Transceiver Station): MSC sender and receiver l BSC (Base Station Controller): controlling several transceivers Interfaces A BTS BSS BSC Um : radio interface q Abis : standardized, open interface with 16 kbit/s user channels q A: standardized, open interface with 64 kbit/s user channels q MSC

System architecture: network and switching subsystem network subsystem fixed partner networks ISDN PSTN MSC o MSC (Mobile Services Switching Center): o IWF (Interworking Functions) o o EIR SS 7 Components ISDN (Integrated Services Digital Network) PSTN (Public Switched Telephone Network) PSPDN (Packet Switched Public Data Net. ) CSPDN (Circuit Switched Public Data Net. ) HLR Databases VLR MSC IWF ISDN PSTN PSPDN CSPDN o HLR (Home Location Register) o VLR (Visitor Location Register) o EIR (Equipment Identity Register)

Radio subsystem The Radio Subsystem (RSS) comprises the cellular mobile network up to the switching centers q Components q Base Station Subsystem (BSS): Base Transceiver Station (BTS): radio components including sender, receiver, antenna - if directed antennas are used one BTS can cover several cells l Base Station Controller (BSC): switching between BTSs, controlling BTSs, managing of network resources, mapping of radio channels (Um) onto terrestrial channels (A interface) l l q BSS = BSC + sum(BTS) + interconnection Mobile Stations (MS)

GSM: cellular network segmentation of the area into cells possible radio coverage of the cell q q q idealized shape of the cell use of several carrier frequencies not the same frequency in adjoining cells cell sizes vary from some 100 m up to 35 km depending on user density, geography, transceiver power etc. hexagonal shape of cells is idealized (cells overlap, shapes depend on geography) if a mobile user changes cells handover of the connection to the neighbor cell

Example coverage of GSM networks (www. gsmworld. com) T-Mobile (GSM-900/1800) Berlin Vodafone (GSM-900/1800) e-plus (GSM-1800) O 2 (GSM-1800)

Base Transceiver Station and Base Station Controller Tasks of a BSS are distributed over BSC and BTS q BTS comprises radio specific functions q BSC is the switching center for radio channels

Mobile station Terminal for the use of GSM services q A mobile station (MS) comprises several functional groups q MT (Mobile Terminal): offers common functions used by all services the MS offers l corresponds to the network termination (NT) of an ISDN access l end-point of the radio interface (Um) l q TA (Terminal Adapter): l q terminal adaptation, hides radio specific characteristics TE (Terminal Equipment): peripheral device of the MS, offers services to a user l does not contain GSM specific functions l q SIM (Subscriber Identity Module): l personalization of the mobile terminal, stores user parameters TE TA R MT S Um

Network and switching subsystem NSS is the main component of the public mobile network GSM q q switching, mobility management, interconnection to other networks, system control Components Mobile Services Switching Center (MSC) controls all connections via a separated network to/from a mobile terminal within the domain of the MSC - several BSC can belong to a MSC q Databases (important: scalability, high capacity, low delay) q Home Location Register (HLR) central master database containing user data, permanent and semi-permanent data of all subscribers assigned to the HLR (one provider can have several HLRs) l Visitor Location Register (VLR) local database for a subset of user data, including data about all user currently in the domain of the VLR l

Mobile Services Switching Center The MSC (mobile switching center) plays a central role in GSM q q q switching functions additional functions for mobility support management of network resources interworking functions via Gateway MSC (GMSC) integration of several databases Functions of a MSC q q q q specific functions for paging and call forwarding termination of SS 7 (signaling system no. 7) mobility specific signaling location registration and forwarding of location information provision of new services (fax, data calls) support of short message service (SMS) generation and forwarding of accounting and billing information

Operation subsystem The OSS (Operation Subsystem) enables centralized operation, management, and maintenance of all GSM subsystems q Components q Authentication Center (AUC) generates user specific authentication parameters on request of a VLR l authentication parameters used for authentication of mobile terminals and encryption of user data on the air interface within the GSM system l q Equipment Identity Register (EIR) registers GSM mobile stations and user rights l stolen or malfunctioning mobile stations can be locked and sometimes even localized l q Operation and Maintenance Center (OMC) l different control capabilities for the radio subsystem and the network subsystem

GSM - TDMA/FDMA qu en cy 935 -960 MHz 124 channels (200 k. Hz) downlink fre 890 -915 MHz 124 channels (200 k. Hz) uplink higher GSM frame structures time GSM TDMA frame 1 2 3 4 5 6 7 8 4. 615 ms GSM time-slot (normal burst) guard space tail 3 bits user data S Training S user data 57 bits 1 26 bits 1 57 bits guard tail space 3 546. 5 µs 577 µs

GSM hierarchy of frames hyperframe 0 1 2 2045 2046 2047 3 h 28 min 53. 76 s . . . superframe 0 1 0 2 . . . 1 48 . . . 49 24 50 6. 12 s 25 multiframe 0 1 . . . 0 1 24 2 120 ms 25 . . . 48 49 50 235. 4 ms frame 0 1 . . . 6 7 4. 615 ms slot burst 577 µs

GSM protocol layers for signaling Um Abis MS A BTS BSC MSC CM CM MM MM RR RR’ BTSM LAPDm LAPD radio PCM 16/64 kbit/s BSSAP SS 7 PCM 64 kbit/s / 2. 048 Mbit/s

Mobile Terminated Call 1: calling a GSM subscriber 2: forwarding call to GMSC 3: signal call setup to HLR 4, 5: request MSRN from VLR 6: forward responsible MSC to GMSC 7: forward call to current MSC 8, 9: get current status of MS 10, 11: paging of MS 12, 13: MS answers 14, 15: security checks 16, 17: set up connection HLR 4 5 3 6 calling station 1 PSTN 2 GMSC 10 7 VLR 8 9 14 15 MSC 10 13 16 10 BSS BSS 11 11 12 17 MS

Mobile Originated Call 1, 2: connection request 3, 4: security check 5 -8: check resources (free circuit) 9 -10: set up call VLR 3 4 6 PSTN 5 GMSC 7 MSC 8 2 9 MS 1 10 BSS

MTC/MOC MS MTC BTS MS MOC BTS paging request channel request immediate assignment paging response service request authentication response ciphering command ciphering complete setup call confirmed assignment command assignment complete alerting connect acknowledge data/speech exchange

4 types of handover 1 MS BTS 2 3 4 MS MS MS BTS BTS BSC BSC MSC

Handover decision receive level BTSold HO_MARGIN MS MS BTSold BTSnew

Handover procedure MS BTSold BSCold measurement report result MSC BSCnew BTSnew HO decision HO required HO request resource allocation ch. activation HO command HO request ack ch. activation ack HO access Link establishment clear command clear complete HO complete

Security in GSM Security services q access control/authentication user SIM (Subscriber Identity Module): secret PIN (personal identification number) l SIM network: challenge response method l q confidentiality l q voice and signaling encrypted on the wireless link (after successful authentication) anonymity temporary identity TMSI (Temporary Mobile Subscriber Identity) l newly assigned at each new location update (LUP) l encrypted transmission l 3 algorithms specified in GSM A 3 for authentication (“secret”, open interface) q A 5 for encryption (standardized) q A 8 for key generation (“secret”, open interface) q “secret”: • A 3 and A 8 available via the Internet • network providers can use stronger mechanisms

GSM - authentication SIM mobile network Ki RAND 128 bit AC RAND 128 bit RAND Ki 128 bit A 3 SIM SRES* 32 bit MSC SRES* =? SRES 32 bit Ki: individual subscriber authentication key 32 bit SRES: signed response

GSM - key generation and encryption MS with SIM mobile network (BTS) Ki AC RAND 128 bit A 8 cipher key BSS Ki 128 bit SIM A 8 Kc 64 bit data A 5 encrypted data SRES data MS A 5

Data services in GSM I Data transmission standardized with only 9. 6 kbit/s advanced coding allows 14, 4 kbit/s q not enough for Internet and multimedia applications q HSCSD (High-Speed Circuit Switched Data) mainly software update q bundling of several time-slots to get higher AIUR (Air Interface User Rate) (e. g. , 115. 2 kbit/s using 8 slots, 14. 4 each) q advantage: ready to use, constant quality, simple q disadvantage: channels blocked for voice transmission q

Data services in GSM II GPRS (General Packet Radio Service) q q q packet switching using free slots only if data packets ready to send (e. g. , 115 kbit/s using 8 slots temporarily) standardization 1998, introduction 2001 advantage: one step towards UMTS, more flexible disadvantage: more investment needed (new hardware) GPRS network elements GSN (GPRS Support Nodes): GGSN and SGSN q GGSN (Gateway GSN) q l q SGSN (Serving GSN) l q interworking unit between GPRS and PDN (Packet Data Network) supports the MS (location, billing, security) GR (GPRS Register) l user addresses

GPRS quality of service

GPRS architecture and interfaces SGSN Gn BSS MS Um SGSN Gb Gn HLR/ GR MSC VLR EIR PDN GGSN Gi

GPRS protocol architecture MS BSS Um SGSN Gb Gn GGSN apps. IP/X. 25 SNDCP LLC RLC MAC radio BSSGP FR GTP LLC GTP UDP/TCP BSSGP IP IP FR L 1/L 2 SNDCP Gi

DECT (Digital European Cordless Telephone) standardized by ETSI (ETS 300. 175 -x) for cordless telephones q standard describes air interface between base-station and mobile phone q DECT has been renamed for international marketing reasons into „Digital Enhanced Cordless Telecommunication“ q Characteristics q q q q frequency: 1880 -1990 MHz channels: 120 full duplex mechanism: TDD (Time Division Duplex) with 10 ms frame length multplexing scheme: FDMA with 10 carrier frequencies, TDMA with 2 x 12 slots modulation: digital, Gaußian Minimum Shift Key (GMSK) power: 10 m. W average (max. 250 m. W) range: approx. 50 m in buildings, 300 m open space

DECT system architecture reference model D 4 PA PA D 3 PT VDB D 2 FT local network PT HDB D 1 global network FT local network

DECT reference model C-Plane U-Plane network layer data link control OSI layer 3 data link control OSI layer 2 medium access control physical layer close to the OSI reference model q management plane over all layers q several services in C(ontrol)- and U(ser)plane q application processes management signaling, interworking OSI layer 1

DECT layers I q Physical layer modulation/demodulation q generation of the physical channel structure with a guaranteed throughput q controlling of radio transmission q channel assignment on request of the MAC layer l detection of incoming signals l sender/receiver synchronization l collecting status information for the management plane l q MAC layer maintaining basic services, activating/deactivating physical channels q multiplexing of logical channels q l e. g. , C: signaling, I: user data, P: paging, Q: broadcast segmentation/reassembly q error control/error correction q

DECT time multiplex frame 1 frame = 10 ms 12 down slots slot 0 0 sync A: network control B: user data X: transmission quality 25. 6 kbit/s simplex bearer 32 kbit/s 31 0 0 419 guard 420 bit + 52 µs guard time („ 60 bit“) in 0. 4167 ms D field A field 12 up slots 387 B field 63 0 protected mode unprotected mode 319 0 X field 3 DATA C 64 16 DATA

DECT layers II q Data link control layer creation and keeping up reliable connections between the mobile terminal and basestation q two DLC protocols for the control plane (C-Plane) q connectionless broadcast service: paging functionality l Lc+LAPC protocol: in-call signaling (similar to LAPD within ISDN), adapted to the underlying MAC service l q several services specified for the user plane (U-Plane) l l l null-service: offers unmodified MAC services frame relay: simple packet transmission frame switching: time-bounded packet transmission error correcting transmission: uses FEC, for delay critical, time-bounded services bandwidth adaptive transmission „Escape“ service: for further enhancements of the standard

DECT layers III q Network layer similar to ISDN (Q. 931) and GSM (04. 08) q offers services to request, check, reserve, control, and release resources at the basestation and mobile terminal q resources q necessary for a wireless connection l necessary for the connection of the DECT system to the fixed network l q main tasks call control: setup, release, negotiation, control l call independent services: call forwarding, accounting, call redirecting l mobility management: identity management, authentication, management of the location register l

Enhancements of the standard Several „DECT Application Profiles“ in addition to the DECT specification q GAP (Generic Access Profile) standardized by ETSI in 1997 assures interoperability between DECT equipment of different manufacturers (minimal requirements for voice communication) l enhanced management capabilities through the fixed network: Cordless Terminal Mobility (CTM) DECT Common Portable Part basestation Air Interface fixed network l GAP DECT/GSM Interworking Profile (GIP): connection to GSM q ISDN Interworking Profiles (IAP, IIP): connection to ISDN q Radio Local Loop Access Profile (RAP): public telephone service q CTM Access Profile (CAP): support for user mobility q

TETRA - Terrestrial Trunked Radio Trunked radio systems q q q many different radio carriers assign single carrier for a short period to one user/group of users taxi service, fleet management, rescue teams interfaces to public networks, voice and data services very reliable, fast call setup, local operation TETRA - ETSI standard q q q q formerly: Trans European Trunked Radio offers Voice+Data and Packet Data Optimized service point-to-point and point-to-multipoint ad-hoc and infrastructure networks several frequencies: 380 -400 MHz, 410 -430 MHz FDD, DQPSK group call, broadcast, sub-second group-call setup

TDMA structure of the voice+data system hyperframe 0 1 2 . . . 57 58 59 61. 2 s 15 16 17 1. 02 s multiframe 0 1 2 . . . CF frame 0 0 1 slot 2 3 509 56. 67 ms 14. 17 ms Control Frame

UMTS and IMT-2000 Proposals for IMT-2000 (International Mobile Telecommunications) UWC-136, cdma 2000, WP-CDMA q UMTS (Universal Mobile Telecommunications System) from ETSI q UMTS UTRA (was: UMTS, now: Universal Terrestrial Radio Access) q enhancements of GSM q EDGE (Enhanced Data rates for GSM Evolution): GSM up to 384 kbit/s l CAMEL (Customized Application for Mobile Enhanced Logic) l VHE (virtual Home Environment) l fits into GMM (Global Multimedia Mobility) initiative from ETSI q requirements q min. 144 kbit/s rural (goal: 384 kbit/s) l min. 384 kbit/s suburban (goal: 512 kbit/s) l up to 2 Mbit/s urban l

Frequencies for IMT-2000 1850 1900 ITU allocation (WRC 1992) Europe China 1950 IMT-2000 GSM DE 1800 CT GSM 1800 Japan T D D North America 1900 T D D MSS 2000 2200 MHz MSS UTRA MSS FDD IMT-2000 MSS cdma 2000 MSS W-CDMA MSS 1950 2100 2150 IMT-2000 cdma 2000 MSS W-CDMA PCS 1850 2050 MSS UTRA MSS FDD IMT-2000 PHS 2000 rsv. 2050 2100 2150 MSS 2200 MHz

IMT-2000 family Interface for Internetworking IMT-2000 Core Network ITU-T GSM (MAP) Initial UMTS (R 99 w/ FDD) IMT-2000 Radio Access ITU-R ANSI-41 (IS-634) IP-Network Flexible assignment of Core Network and Radio Access IMT-DS IMT-TC IMT-MC IMT-SC IMT-FT (Direct Spread) (Time Code) (Multi Carrier) (Single Carrier) (Freq. Time) UTRA FDD (W-CDMA) 3 GPP UTRA TDD (TD-CDMA); TD-SCDMA 3 GPP cdma 2000 UWC-136 (EDGE) UWCC/3 GPP DECT 3 GPP 2 ETSI

Licensing Example: UMTS in Germany, 18. August 2000 UTRA-FDD: q Uplink 1920 -1980 MHz q Downlink 2110 -2170 MHz q duplex spacing 190 MHz q 12 channels, each 5 MHz q UTRA-TDD: q 1900 -1920 MHz, q 2010 -2025 MHz; q 5 MHz channels q Coverage: 25% of the population until 12/2003, 50% until 12/2005 q Sum: 50. 81 billion €

UMTS architecture (Release 99 used here!) UTRAN (UTRA Network) Cell level mobility q Radio Network Subsystem (RNS) q Encapsulation of all radio specific tasks q UE (User Equipment) CN (Core Network) Inter system handover q Location management if there is no dedicated connection between UE and UTRAN q Uu UE Iu UTRAN CN

UMTS domains and interfaces I Home Network Domain Cu USIM Domain Mobile Equipment Domain Uu Access Network Domain Iu Zu Serving Network Domain Yu Transit Network Domain Core Network Domain User Equipment Domain Infrastructure Domain User Equipment Domain q Assigned to a single user in order to access UMTS services Infrastructure Domain Shared among all users q Offers UMTS services to all accepted users q

UMTS domains and interfaces II Universal Subscriber Identity Module (USIM) Functions for encryption and authentication of users q Located on a SIM inserted into a mobile device q Mobile Equipment Domain Functions for radio transmission q User interface for establishing/maintaining end-to-end connections q Access Network Domain q Access network dependent functions Core Network Domain Access network independent functions q Serving Network Domain q l q Network currently responsible for communication Home Network Domain l Location and access network independent functions

Spreading and scrambling of user data Constant chipping rate of 3. 84 Mchip/s Different user data rates supported via different spreading factors q higher data rate: less chips per bit and vice versa User separation via unique, quasi orthogonal scrambling codes users are not separated via orthogonal spreading codes q much simpler management of codes: each station can use the same orthogonal spreading codes q precise synchronisation not necessary as the scrambling codes stay quasiorthogonal q data 1 data 2 data 3 data 4 data 5 spr. code 1 spr. code 2 spr. code 3 spr. code 1 spr. code 4 scrambling code 1 sender 1 scrambling code 2 sender 2

OSVF coding 1, 1, 1. . . 1, 1, -1, -1 1, 1, -1, -1, 1, 1 1 X 1, -1, 1, -1 X, -X SF=2 n . . . 1, 1, -1 X, X SF=n 1, 1, -1, 1, 1, -1 . . . 1, -1, -1, 1 1, -1, -1, 1, 1, -1, 1. . . 1, -1, -1, 1, 1, -1 SF=2 SF=4 SF=8

UMTS FDD frame structure Radio frame 10 ms 0 1 2 . . . 12 13 14 Time slot 666. 7 µs Pilot TFCI FBI TPC uplink DPCCH 2560 chips, 10 bits 666. 7 µs uplink DPDCH Data 2560 chips, 10*2 k bits (k = 0. . . 6) 666. 7 µs Data 1 TPC TFCI Data 2 Pilot downlink DPCH DPDCH DPCCH 2560 chips, 10*2 k bits (k = 0. . . 7) Slot structure NOT for user separation but synchronisation for periodic functions! W-CDMA • 1920 -1980 MHz uplink • 2110 -2170 MHz downlink • chipping rate: 3. 840 Mchip/s • soft handover • QPSK • complex power control (1500 power control cycles/s) • spreading: UL: 4 -256; DL: 4 -512 FBI: Feedback Information TPC: Transmit Power Control TFCI: Transport Format Combination Indicator DPCCH: Dedicated Physical Control Channel DPDCH: Dedicated Physical Data Channel DPCH: Dedicated Physical Channel

UMTS TDD frame structure (burst type 2) Radio frame 10 ms 666. 7 µs 0 1 2 Time slot Data Midample 1104 chips 2560 chips . . . Data GP 1104 chips 12 13 14 Traffic burst GP: guard period 96 chips TD-CDMA • 2560 chips per slot • spreading: 1 -16 • symmetric or asymmetric slot assignment to UL/DL (min. 1 per direction) • tight synchronisation needed • simpler power control (100 -800 power control cycles/s)

UTRAN architecture RNS UE 1 Node B Iub RNC: Radio Network Controller RNS: Radio Network Subsystem Iu RNC CN UE 2 Node B UE 3 Iur Node B Iub RNC Node B RNS UTRAN comprises several RNSs Node B can support FDD or TDD or both RNC is responsible for handover decisions requiring signalingto the UE Cell offers FDD or TDD

UTRAN architecture RNS UE Node B RNC: Radio Network Controller RNS: Radio Network Subsystem Iub RNC Node B Iu UTRAN comprises several RNSs Node B can support FDD or TDD or both CN Iur Node B Iub RNC Node B RNS RNC is responsible for handover decisions requiring signaling to the UE Cell offers FDD or TDD

UTRAN functions Admission control Congestion control System information broadcasting Radio channel encryption Handover SRNS moving Radio network configuration Channel quality measurements Macro diversity Radio carrier control Radio resource control Data transmission over the radio interface Outer loop power control (FDD and TDD) Channel coding Access control

Core network: protocols VLR MSC GSM-CS backbone RNS GMSC PSTN/ ISDN GGSN PDN (X. 25), Internet (IP) HLR RNS Layer 3: IP Layer 2: ATM Layer 1: PDH, SONET UTRAN SGSN GPRS backbone (IP) SS 7 CN

Core network: architecture BTS Abis BSS BSC Node BTSB VLR Iu MSC GMSC PSTN Iu. CS Au. C EIR HLR GR Node B Iub RNC RNS SGSN Iu. PS Gn GGSN Gi CN

Core network The Core Network (CN) and thus the Interface Iu, too, are separated into two logical domains: q Circuit Switched Domain (CSD) Circuit switched service incl. signaling q Resource reservation at connection setup q GSM components (MSC, GMSC, VLR) q Iu. CS q q Packet Switched Domain (PSD) GPRS components (SGSN, GGSN) q Iu. PS q Release 99 uses the GSM/GPRS network and adds a new radio access! Helps to save a lot of money … q Much faster deployment q Not as flexible as newer releases (5, 6) q

UMTS protocol stacks (user plane) UE Uu UTRAN Iu. CS 3 G MSC apps. & protocols Circuit switched RLC MAC radio UE Packet switched apps. & protocols IP, PPP, … PDCP Uu SAR AAL 2 ATM UTRAN Iu. PS 3 G SGSN Gn IP tunnel 3 G GGSN IP, PPP, … GTP RLC GTP UDP/IP MAC AAL 5 L 2 radio ATM L 1 PDCP GTP UDP/IP

Support of mobility: macro diversity Multicasting of data via several physical channels Enables soft handover q FDD mode only q Uplink UE Node B simultaneous reception of UE data at several Node Bs q Reconstruction of data at Node B, SRNC or DRNC q Node B RNC CN Downlink Simultaneous transmission of data via different cells q Different spreading codes in different cells q

Support of mobility: handover From and to other systems (e. g. , UMTS to GSM) q This is a must as UMTS coverage will be poor in the beginning RNS controlling the connection is called SRNS (Serving RNS) RNS offering additional resources (e. g. , for soft handover) is called Drift RNS (DRNS) End-to-end connections between UE and CN only via Iu at the SRNS Change of SRNS requires change of Iu q Initiated by the SRNS q Controlled by the RNC and CN q Node B UE Node B Iub CN SRNC Iur DRNC Iu

Example handover types in UMTS/GSM UE 1 Node B 1 UE 2 UE 3 UE 4 RNC 1 3 G MSC 1 Iu Node B 2 Iur Iub Node B 3 RNC 2 3 G MSC 2 BTS BSC 2 G MSC 3 Abis A

UMTS services (originally) Data transmission service profiles Service Profile High Interactive MM High MM Bandwidth Transport mode 128 kbit/s Circuit switched 2 Mbit/s Packet switched Medium MM 384 kbit/s Circuit switched Switched Data 14. 4 kbit/s Circuit switched Simple Messaging 14. 4 kbit/s Packet switched Voice Bidirectional, video telephone Low coverage, max. 6 km/h asymmetrical, MM, downloads SMS successor, E-Mail 16 kbit/s Circuit switched Virtual Home Environment (VHE) Enables access to personalized data independent of location, access network, and device q Network operators may offer new services without changing the network q Service providers may offer services based on components which allow the automatic adaptation to new networks and devices q Integration of existing IN services q