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Mobile Communications Chapter 4: Wireless Telecommunication Systems

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1 Mobile Communications Chapter 4: Wireless Telecommunication Systems
Universität Karlsruhe Institut für Telematik Mobilkommunikation SS 1998 Mobile Communications Chapter 4: Wireless Telecommunication Systems Market GSM Overview Services Sub-systems Components DECT TETRA UMTS/IMT-2000 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

2 Mobile phone subscribers worldwide
Universität Karlsruhe Institut für Telematik Mobile phone subscribers worldwide Mobilkommunikation SS 1998 200 400 600 800 1000 1200 1996 1997 1998 1999 2000 2001 2002 year Subscribers [million] GSM total TDMA total CDMA total PDC total Analogue total Total wireless Prediction (1998) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

3 Development of mobile telecommunication systems
Universität Karlsruhe Institut für Telematik Development of mobile telecommunication systems Mobilkommunikation SS 1998 CT0/1 FDMA AMPS CT2 NMT IMT-FT DECT IS-136 TDMA D-AMPS EDGE IMT-SC IS-136HS UWC-136 TDMA GSM GPRS PDC IMT-DS UTRA FDD / W-CDMA IMT-TC UTRA TDD / TD-CDMA CDMA IMT-TC TD-SCDMA IS-95 cdmaOne IMT-MC cdma2000 1X EV-DO cdma2000 1X 1X EV-DV (3X) 1G 2G 2.5G 3G Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

4 Universität Karlsruhe Institut für Telematik
GSM: Overview Mobilkommunikation SS 1998 GSM ( ) 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: D1 and D2)  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 million subscribers (Dec 2003) more than 73% of all digital mobile phones use GSM over 10 billion SMS (Short Message Service) per month in Germany, > 360 billion/year worldwide Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

5 Performance characteristics of GSM (wrt. analog sys.)
Universität Karlsruhe Institut für Telematik Performance characteristics of GSM (wrt. analog sys.) Mobilkommunikation SS 1998 Communication mobile, wireless communication; support for voice and data services Total mobility international access, chip-card enables use of access points of different providers Worldwide connectivity one number, the network handles localization High capacity better frequency efficiency, smaller cells, more customers per cell High transmission quality high audio quality and reliability for wireless, uninterrupted phone calls at higher speeds (e.g., from cars, trains) Security functions access control, authentication via chip-card and PIN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

6 Universität Karlsruhe Institut für Telematik
Disadvantages of GSM Mobilkommunikation SS 1998 There is no perfect system!! no end-to-end encryption of user data no full ISDN bandwidth of 64 kbit/s to the user, no transparent B-channel (ISDN bearer – ISDN channel that carries the main data) reduced concentration while driving electromagnetic radiation abuse of private data possible roaming profiles accessible high complexity of the system several incompatibilities within the GSM standards Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

7 Universität Karlsruhe Institut für Telematik
GSM: Mobile Services Mobilkommunikation SS 1998 GSM offers several types of connections voice connections, data connections, short message service multi-service options (combination of basic services) Three service domains Bearer Services - data Telematic Services - voice Supplementary Services – short message service (SMS) bearer services MS GSM-PLMN transit network (PSTN, ISDN) source/ destination network TE MT TE R, S Um (U, S, R) tele services Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

8 Universität Karlsruhe Institut für Telematik
Bearer Services Mobilkommunikation SS 1998 Telecommunication services to transfer data between access points Specification of services up to the terminal interface (OSI layers 1-3) Different data rates for voice and data (original standard) data service (circuit switched) synchronous: 2.4, 4.8 or 9.6 kbit/s asynchronous: bit/s data service (packet switched) asynchronous: bit/s Today: data rates of approx. 50 kbit/s possible – will be covered later! Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

9 Universität Karlsruhe Institut für Telematik
Tele Services I Mobilkommunikation SS 1998 Telecommunication services that enable voice communication via mobile phones All these basic services have to obey cellular functions, security measurements etc. Offered services mobile telephony primary goal of GSM was to enable mobile telephony offering the traditional bandwidth of 3.1 kHz 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) Multinumbering several ISDN phone numbers per user possible Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

10 Universität Karlsruhe Institut für Telematik
Tele Services II Mobilkommunikation SS 1998 Additional services Non-Voice-Teleservices group 3 fax voice mailbox (implemented in the fixed network supporting the mobile terminals) electronic mail (MHS, Message Handling System, implemented in the fixed network) ... 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 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

11 Supplementary services
Universität Karlsruhe Institut für Telematik Supplementary services Mobilkommunikation SS 1998 Services in addition to the basic services, cannot be offered stand-alone Similar to ISDN services besides lower bandwidth due to the radio link May differ between different service providers, countries and protocol versions Important services 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) ... Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

12 Architecture of the GSM system
Universität Karlsruhe Institut für Telematik Architecture of the GSM system Mobilkommunikation SS 1998 GSM is a PLMN (Public Land Mobile Network) several providers setup mobile networks following the GSM standard within each country components MS (mobile station) BS (base station) MSC (mobile switching center) LR (location register) subsystems RSS (radio subsystem): covers all radio aspects NSS (network and switching subsystem): call forwarding, handover, switching OSS (operation subsystem): management of the network Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

13 Universität Karlsruhe Institut für Telematik
GSM: overview Mobilkommunikation SS 1998 OMC, EIR, AUC fixed network HLR GMSC NSS with OSS VLR MSC VLR MSC BSC BSC RSS Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

14 GSM: elements and interfaces
Universität Karlsruhe Institut für Telematik GSM: elements and interfaces Mobilkommunikation SS 1998 radio cell BSS MS MS Um radio cell MS RSS BTS BTS Abis BSC BSC A MSC MSC NSS VLR VLR signaling HLR ISDN, PSTN GMSC PDN IWF O OSS EIR AUC OMC Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

15 GSM: system architecture
Universität Karlsruhe Institut für Telematik GSM: system architecture Mobilkommunikation SS 1998 radio subsystem network and switching subsystem fixed partner networks MS MS ISDN PSTN Um MSC Abis BTS BSC EIR BTS SS7 HLR VLR BTS BSC ISDN PSTN BTS A MSC BSS IWF PSPDN CSPDN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

16 System architecture: radio subsystem
Universität Karlsruhe Institut für Telematik System architecture: radio subsystem Mobilkommunikation SS 1998 radio subsystem network and switching subsystem MS MS Components MS (Mobile Station) BSS (Base Station Subsystem): consisting of BTS (Base Transceiver Station): sender and receiver BSC (Base Station Controller): controlling several transceivers Interfaces Um : radio interface Abis : standardized, open interface with 16 kbit/s user channels A: standardized, open interface with 64 kbit/s user channels Um Abis BTS BSC MSC BTS A BTS MSC BSC BTS BSS Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

17 System architecture: network and switching subsystem
Universität Karlsruhe Institut für Telematik System architecture: network and switching subsystem Mobilkommunikation SS 1998 network subsystem fixed partner networks Components MSC (Mobile Services Switching Center): IWF (Interworking Functions) ISDN (Integrated Services Digital Network) PSTN (Public Switched Telephone Network) PSPDN (Packet Switched Public Data Net.) CSPDN (Circuit Switched Public Data Net.) Databases HLR (Home Location Register) VLR (Visitor Location Register) EIR (Equipment Identity Register) ISDN PSTN MSC EIR SS7 HLR VLR ISDN PSTN MSC IWF PSPDN CSPDN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

18 Universität Karlsruhe Institut für Telematik
Radio subsystem Mobilkommunikation SS 1998 The Radio Subsystem (RSS) comprises the cellular mobile network up to the switching centers Components 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 Base Station Controller (BSC): switching between BTSs, controlling BTSs, managing of network resources, mapping of radio channels (Um) onto terrestrial channels (A interface) BSS = BSC + sum(BTS) + interconnection Mobile Stations (MS) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

19 Universität Karlsruhe Institut für Telematik
GSM: cellular network Mobilkommunikation SS 1998 segmentation of the area into cells cell possible radio coverage of the cell 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 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

20 Example coverage of GSM networks (www.gsmworld.com)
Universität Karlsruhe Institut für Telematik Example coverage of GSM networks ( Mobilkommunikation SS 1998 T-Mobile (GSM-900/1800) Berlin Vodafone (GSM-900/1800) e-plus (GSM-1800) O2 (GSM-1800) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

21 Base Transceiver Station and Base Station Controller
Universität Karlsruhe Institut für Telematik Base Transceiver Station and Base Station Controller Mobilkommunikation SS 1998 Tasks of a BSS are distributed over BSC and BTS BTS comprises radio specific functions BSC is the switching center for radio channels Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

22 Universität Karlsruhe Institut für Telematik
Mobile station Mobilkommunikation SS 1998 Terminal for the use of GSM services A mobile station (MS) comprises several functional groups MT (Mobile Terminal): offers common functions used by all services the MS offers corresponds to the network termination (NT) of an ISDN access end-point of the radio interface (Um) TA (Terminal Adapter): terminal adaptation, hides radio specific characteristics TE (Terminal Equipment): peripheral device of the MS, offers services to a user does not contain GSM specific functions SIM (Subscriber Identity Module): personalization of the mobile terminal, stores user parameters R S Um TE TA MT Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

23 Network and switching subsystem
Universität Karlsruhe Institut für Telematik Network and switching subsystem Mobilkommunikation SS 1998 NSS is the main component of the public mobile network GSM 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 Databases (important: scalability, high capacity, low delay) 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) Visitor Location Register (VLR) local database for a subset of user data, including data about all user currently in the domain of the VLR Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

24 Mobile Services Switching Center
Universität Karlsruhe Institut für Telematik Mobile Services Switching Center Mobilkommunikation SS 1998 The MSC (mobile switching center) plays a central role in GSM 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 specific functions for paging and call forwarding termination of SS7 (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 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

25 Universität Karlsruhe Institut für Telematik
Operation subsystem Mobilkommunikation SS 1998 The OSS (Operation Subsystem) enables centralized operation, management, and maintenance of all GSM subsystems Components Authentication Center (AUC) generates user specific authentication parameters on request of a VLR authentication parameters used for authentication of mobile terminals and encryption of user data on the air interface within the GSM system Equipment Identity Register (EIR) registers GSM mobile stations and user rights stolen or malfunctioning mobile stations can be locked and sometimes even localized Operation and Maintenance Center (OMC) different control capabilities for the radio subsystem and the network subsystem Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

26 Universität Karlsruhe Institut für Telematik
GSM - TDMA/FDMA Mobilkommunikation SS 1998 MHz 124 channels (200 kHz) downlink frequency MHz 124 channels (200 kHz) 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 guard space tail user data S Training S user data tail 3 bits 57 bits 1 26 bits 1 57 bits 3 546.5 µs 577 µs Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

27 Universität Karlsruhe Institut für Telematik
GSM - TDMA/FDMA Mobilkommunikation SS 1998 GSM time-slot (normal burst) Tail are all set to 0 and can be used to enhance the receiver performance. The training sequence is used to adapt the parameters and select the strongest signal. A flag S indicates whether the data field contains user or network control data. GSM bursts A normal burst for data transmission A frequency correction burst allows the MS to correct the local oscillator to avoid interference A synchronization burst with an extended training sequence synchronizes the MS with BTS in time. An access burst is used for the initial connection setup. A dummy burst is used if no data is available for a slot. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

28 GSM – Logical channels and frame hierarchy
Universität Karlsruhe Institut für Telematik GSM – Logical channels and frame hierarchy Mobilkommunikation SS 1998 GSM specifies two basic groups of logical channels: Traffic channels (TCH): GSM uses a TCH to transmit user data. Control channels (CCH): CCHs are used to control medium access, allocation of traffic channels or mobility management. Broadcast control channel (BCCH):A BTS uses this channel to signal information such as the cell identifier, options, and frequencies to all MSs within a cell. Common control channel (CCCH): All information regarding connection setup between MS and BS is exchanged via the CCCH. Dedicated control channel (DCCH): Before a MS established a TCH with the BTS, it uses DCCH for signaling. Logical frame hierarchy 26 frame  multi-frame  26 multi-frames + 51 frames or 51 multi-frames + 26 frames  2048 superframe  hyperframe Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

29 GSM hierarchy of frames
Universität Karlsruhe Institut für Telematik GSM hierarchy of frames Mobilkommunikation SS 1998 hyperframe 1 2 ... 2045 2046 2047 3 h 28 min s superframe 1 2 ... 48 49 50 6.12 s 1 ... 24 25 multiframe 1 ... 24 25 120 ms 1 2 ... 48 49 50 235.4 ms frame 1 ... 6 7 4.615 ms slot burst 577 µs Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

30 GSM protocol layers for signaling
Universität Karlsruhe Institut für Telematik GSM protocol layers for signaling Mobilkommunikation SS 1998 Um Abis A MS BTS BSC MSC CM CM MM MM RR’ BTSM BSSAP RR BSSAP RR’ BTSM SS7 SS7 LAPDm LAPDm LAPD LAPD radio radio PCM PCM PCM PCM 16/64 kbit/s 64 kbit/s / 2.048 Mbit/s Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

31 Mobile Terminated Call (Wired phone call)
Universität Karlsruhe Institut für Telematik Mobile Terminated Call (Wired phone call) Mobilkommunikation SS 1998 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 4 HLR VLR 5 8 9 3 6 14 15 PSTN 7 calling station GMSC MSC 1 2 10 13 10 10 16 BSS BSS BSS 11 11 11 11 12 17 MS Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

32 Mobile Originated Call
Universität Karlsruhe Institut für Telematik Mobile Originated Call Mobilkommunikation SS 1998 1, 2: connection request 3, 4: security check 5-8: check resources (free circuit) 9-10: set up call VLR 3 4 PSTN 6 5 GMSC MSC 7 8 2 9 1 MS BSS 10 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

33 Universität Karlsruhe Institut für Telematik
MTC/MOC Mobilkommunikation SS 1998 BTS MS paging request channel request immediate assignment paging response authentication request authentication response ciphering command ciphering complete setup call confirmed assignment command assignment complete alerting connect connect acknowledge data/speech exchange service request MTC MOC Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

34 Universität Karlsruhe Institut für Telematik
4 types of handover Mobilkommunikation SS 1998 GSM handover: Intra-cell: A new frequency needs to be arranged by BSC because of interference. Inter-cell, intra-BSC handover: The mobile station moves from one cell to another. The BSC performs a handover. Inter-BSC, intra-MSC handover: The handover is controlled by the MSC. Inter MSC handover: Both MSCs perform the handover together. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

35 Universität Karlsruhe Institut für Telematik
4 types of handover Mobilkommunikation SS 1998 1 2 3 4 MS MS MS MS BTS BTS BTS BTS BSC BSC BSC MSC MSC Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

36 Universität Karlsruhe Institut für Telematik
Handover decision Mobilkommunikation SS 1998 receive level BTSold receive level BTSold HO_MARGIN MS MS BTSold BTSnew Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

37 Universität Karlsruhe Institut für Telematik
Handover procedure Mobilkommunikation SS 1998 MS BTSold BSCold MSC BSCnew BTSnew measurement report measurement result HO decision HO required HO request resource allocation ch. activation ch. activation ack HO request ack HO command HO command HO command HO access Link establishment HO complete HO complete clear command clear command clear complete clear complete Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

38 Universität Karlsruhe Institut für Telematik
Security in GSM Mobilkommunikation SS 1998 Security services access control/authentication user  SIM (Subscriber Identity Module): secret PIN (personal identification number) SIM  network: challenge response method confidentiality voice and signaling encrypted on the wireless link (after successful authentication) anonymity temporary identity TMSI (Temporary Mobile Subscriber Identity) newly assigned at each new location update (LUP) encrypted transmission 3 algorithms specified in GSM A3 for authentication (“secret”, open interface) A5 for encryption (standardized) A8 for key generation (“secret”, open interface) “secret”: A3 and A8 available via the Internet network providers can use stronger mechanisms Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

39 Universität Karlsruhe Institut für Telematik
GSM - authentication Mobilkommunikation SS 1998 SIM mobile network RAND Ki RAND RAND Ki 128 bit 128 bit 128 bit 128 bit AC A3 A3 SIM SRES* 32 bit SRES bit SRES* =? SRES SRES MSC SRES 32 bit Ki: individual subscriber authentication key SRES: signed response Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

40 GSM - key generation and encryption
Universität Karlsruhe Institut für Telematik GSM - key generation and encryption Mobilkommunikation SS 1998 mobile network (BTS) MS with SIM RAND Ki RAND RAND Ki AC SIM 128 bit 128 bit 128 bit 128 bit A8 A8 cipher key Kc 64 bit Kc 64 bit data encrypted data SRES data BSS MS A5 A5 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

41 Universität Karlsruhe Institut für Telematik
Data services in GSM I Mobilkommunikation SS 1998 Data transmission standardized with only 9.6 kbit/s advanced coding allows 14,4 kbit/s not enough for Internet and multimedia applications HSCSD (High-Speed Circuit Switched Data) mainly software update on MS and MSC to split a traffic stream into several streams. bundling of several time-slots to get higher AIUR (Air Interface User Rate) (e.g., 57.6 kbit/s using 4 slots, 14.4 each) advantage: ready to use, constant quality, simple disadvantage: channels blocked for voice transmission Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

42 Universität Karlsruhe Institut für Telematik
Data services in GSM II Mobilkommunikation SS 1998 GPRS (General Packet Radio Service) packet switching using free slots only if data packets ready to send (e.g., 50 kbit/s using 4 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 GGSN (Gateway GSN) interworking unit between GPRS and PDN (Packet Data Network) SGSN (Serving GSN) supports the MS (location, billing, security) GR (GPRS Register) user addresses Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

43 GPRS user data rates in kbit/s
Coding scheme 1 slot 2 slots 3 slots 4 slots 5 slots 6 slots 7 slots 8 slots CS-1 9.05 18.2 27.15 36.2 45.25 54.3 63.35 72.4 CS-2 13.4 26.8 40.2 53.6 67 80.4 93.8 107.2 CS-3 15.6 31.2 46.8 62.4 78 93.6 109.2 124.8 CS-4 21.4 42.8 64.2 85.6 107 128.4 149.8 171.2

44 Examples for GPRS device classes
Receiving slots Sending slots Maximum number of slots 1 2 3 5 4 8 10 12

45 GPRS quality of service
Universität Karlsruhe Institut für Telematik GPRS quality of service Mobilkommunikation SS 1998 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

46 GPRS architecture and interfaces
Universität Karlsruhe Institut für Telematik GPRS architecture and interfaces Mobilkommunikation SS 1998 MS BSS GGSN SGSN MSC Um EIR HLR/ GR VLR PDN Gb Gn Gi Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

47 GPRS protocol architecture
Universität Karlsruhe Institut für Telematik GPRS protocol architecture Mobilkommunikation SS 1998 MS BSS SGSN GGSN Um Gb Gn Gi apps. IP/X.25 IP/X.25 SNDCP SNDCP GTP GTP LLC LLC UDP/TCP UDP/TCP RLC RLC BSSGP BSSGP IP IP MAC MAC FR FR L1/L2 L1/L2 radio radio Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

48 Universität Karlsruhe Institut für Telematik
DECT Mobilkommunikation SS 1998 DECT (Digital European Cordless Telephone) standardized by ETSI (ETS x) for cordless telephones standard describes air interface between base-station and mobile phone DECT has been renamed for international marketing reasons into „Digital Enhanced Cordless Telecommunication“ Characteristics frequency: MHz channels: 120 full duplex duplex mechanism: TDD (Time Division Duplex) with 10 ms frame length multiplexing scheme: FDMA with 10 carrier frequencies, TDMA with 2x 12 slots modulation: digital, Gaußian Minimum Shift Key (GMSK) power: 10 mW average (max. 250 mW) range: approx. 50 m in buildings, 300 m open space Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

49 DECT system architecture reference model
Universität Karlsruhe Institut für Telematik DECT system architecture reference model Mobilkommunikation SS 1998 D4 D3 VDB D2 PA PT FT local network HDB PA PT D1 global network FT local network Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

50 Universität Karlsruhe Institut für Telematik
DECT layers I Mobilkommunikation SS 1998 Physical layer modulation/demodulation generation of the physical channel structure with a guaranteed throughput controlling of radio transmission channel assignment on request of the MAC layer detection of incoming signals sender/receiver synchronization collecting status information for the management plane MAC layer maintaining basic services, activating/deactivating physical channels multiplexing of logical channels e.g., C: signaling, I: user data, P: paging, Q: broadcast segmentation/reassembly error control/error correction Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

51 Universität Karlsruhe Institut für Telematik
DECT layers II Mobilkommunikation SS 1998 Data link control layer creation and keeping up reliable connections between the mobile terminal and basestation two DLC protocols for the control plane (C-Plane) connectionless broadcast service: paging functionality Lc+LAPC protocol: in-call signaling (similar to LAPD within ISDN), adapted to the underlying MAC service several services specified for the user plane (U-Plane) 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 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

52 Universität Karlsruhe Institut für Telematik
DECT layers III Mobilkommunikation SS 1998 Network layer similar to ISDN (Q.931) and GSM (04.08) offers services to request, check, reserve, control, and release resources at the basestation and mobile terminal resources necessary for a wireless connection necessary for the connection of the DECT system to the fixed network main tasks call control: setup, release, negotiation, control call independent services: call forwarding, accounting, call redirecting mobility management: identity management, authentication, management of the location register Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

53 Universität Karlsruhe Institut für Telematik
DECT reference model Mobilkommunikation SS 1998 C-Plane U-Plane close to the OSI reference model management plane over all layers several services in C(ontrol)- and U(ser)-plane signaling, interworking application processes network layer OSI layer 3 management data link control data link control OSI layer 2 medium access control physical layer OSI layer 1 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

54 DECT time multiplex frame
Universität Karlsruhe Institut für Telematik DECT time multiplex frame Mobilkommunikation SS 1998 1 frame = 10 ms 12 down slots 12 up slots slot guard 420 bit + 52 µs guard time („60 bit“) in ms 419 sync D field 31 387 A: network control B: user data X: transmission quality A field B field X field 63 319 3 protected mode DATA 64 C 16 DATA 64 C 16 DATA 64 C 16 DATA 64 C 16 25.6 kbit/s simplex bearer unprotected mode 32 kbit/s DATA Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

55 Enhancements of the standard
Universität Karlsruhe Institut für Telematik Enhancements of the standard Mobilkommunikation SS 1998 Several „DECT Application Profiles“ in addition to the DECT specification GAP (Generic Access Profile) standardized by ETSI in 1997 assures interoperability between DECT equipment of different manufacturers (minimal requirements for voice communication) enhanced management capabilities through the fixed network: Cordless Terminal Mobility (CTM) DECT/GSM Interworking Profile (GIP): connection to GSM ISDN Interworking Profiles (IAP, IIP): connection to ISDN Radio Local Loop Access Profile (RAP): public telephone service CTM Access Profile (CAP): support for user mobility DECT basestation GAP Common Air Interface Portable Part fixed network Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

56 TETRA - Terrestrial Trunked Radio
Universität Karlsruhe Institut für Telematik TETRA - Terrestrial Trunked Radio Mobilkommunikation SS 1998 Trunked radio systems 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 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: MHz, MHz FDD, DQPSK group call, broadcast, sub-second group-call setup Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

57 TDMA structure of the voice+data system
Universität Karlsruhe Institut für Telematik TDMA structure of the voice+data system Mobilkommunikation SS 1998 hyperframe 1 2 ... 57 58 59 61.2 s multiframe 1 2 ... 15 16 17 1.02 s CF frame Control Frame 1 2 3 56.67 ms slot 14.17 ms Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

58 Universität Karlsruhe Institut für Telematik
UMTS and IMT-2000 Mobilkommunikation SS 1998 Proposals for IMT-2000 (International Mobile Telecommunications) UWC-136 (Universal Wireless Consortium (US)), cdma2000 (based on IS-95), WP-CDMA (Wideband packet-CDMA) UMTS (Universal Mobile Telecommunications System) from ETSI UMTS UTRA (was: UMTS, now: Universal Terrestrial Radio Access) enhancements of GSM EDGE (Enhanced Data rates for GSM Evolution): GSM up to 384 kbit/s CAMEL (Customized Application for Mobile Enhanced Logic) – intelligent network support VHE (virtual Home Environment) fits into GMM (Global Multimedia Mobility) initiative from ETSI GMM provides an architecture to integrate mobile and fixed terminals, different access networks, and several core transport networks. requirements for UMTS and UTRA min. 144 kbit/s rural (goal: 384 kbit/s) min. 384 kbit/s suburban (goal: 512 kbit/s) up to 2 Mbit/s urban Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

59 Universität Karlsruhe Institut für Telematik
Frequencies for IMT-2000 Mobilkommunikation SS 1998 1850 1900 1950 2000 2050 2100 2150 2200 MHz ITU allocation (WRC 1992) IMT-2000 MSS IMT-2000 MSS GSM 1800 DE CT T D UTRA FDD  MSS T D UTRA FDD  MSS Europe GSM 1800 IMT-2000 MSS IMT-2000 MSS China PHS cdma2000 W-CDMA MSS cdma2000 W-CDMA MSS Japan PCS MSS rsv. MSS North America 1850 1900 1950 2000 2050 2100 2150 2200 MHz Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

60 Universität Karlsruhe Institut für Telematik
UMTS and IMT-2000 Mobilkommunikation SS 1998 IMT-2000 family IMT-DS: The direct spread technology comprises wideband CDMA (W-CDMA) systems. It consists of UTRA-FDD in Europe and FOMA (Freedom of Mobile Multimedia Access in Japan developed by 3GPP (3rd Generation Partnership Project). IMT-TC: The time code technology uses time-division CDMA (TD-CDMA). It consists of UTRA-TDD in Europe and TD-synchronous CDMA (TD-SCDMA) in China developed by 3GPP. IMT-MC: The multi-carrier technology comprises cdma2000 developed by 3GPP2. IMT-SC: The single carrier technology comprises the enhancement of the US TDMA, UWC-136. It applies EDGE (Enhanced Data Rates for Global Evolution) developed by 3GPP/UWCC. IMT-FT: The frequency time technology comprises an enhanced version of DECT developed by ETSI. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

61 Universität Karlsruhe Institut für Telematik
IMT-2000 family Mobilkommunikation SS 1998 Interface for Internetworking IMT-2000 Core Network ITU-T (Telecomm.) GSM (MAP) ANSI-41 (IS-634) IP-Network Flexible assignment of Core Network and Radio Access Initial UMTS (R99 w/ FDD) IMT-DS (Direct Spread) UTRA FDD (W-CDMA) 3GPP IMT-TC (Time Code) UTRA TDD (TD-CDMA); TD-SCDMA 3GPP IMT-MC (Multi Carrier) cdma2000 3GPP2 IMT-SC (Single Carrier) UWC-136 (EDGE) UWCC/3GPP IMT-FT (Freq. Time) DECT ETSI IMT-2000 Radio Access ITU-R (Radiocomm.) The main driving forces are 3GPP (European and Japanese) and 3GPP2 (Qualcomm and CDMA). Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

62 Licensing Example: UMTS in Germany, 18. August 2000
Universität Karlsruhe Institut für Telematik Licensing Example: UMTS in Germany, 18. August 2000 Mobilkommunikation SS 1998 UTRA-FDD: Uplink MHz Downlink MHz duplex spacing 190 MHz 12 channels, each 5 MHz UTRA-TDD: MHz, MHz; 5 MHz channels Coverage: 25% of the population until 12/2003, 50% until 12/2005 Sum: billion € Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

63 UMTS releases and standardization
Universität Karlsruhe Institut für Telematik UMTS releases and standardization Mobilkommunikation SS 1998 UMTS releases and standardization Release 99: It describes the new radio access technologies UTRA-FDD and UTRA-TDD, and standardizes the use of a GSM/GPRS network as core. This enables a cost effective migration from GSM to UMTS. It is currently deployed. Release 4: It introduces quality of service in the fixed network plus several execution environment. Release 5: It specifies a different core network. The GSM/GPRS based network will be replaced by an almost all-IP-core. Release 6: 3GPP is currently working on release 6 (release 7). Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

64 UMTS architecture (Release 99 used here!)
Universität Karlsruhe Institut für Telematik UMTS architecture (Release 99 used here!) Mobilkommunikation SS 1998 UTRAN (UTRA Network) Cell level mobility Radio Network Subsystem (RNS) Encapsulation of all radio specific tasks UE (User Equipment) CN (Core Network) Inter system handover Location management if there is no dedicated connection between UE and UTRAN Uu Iu UE UTRAN CN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

65 UMTS domains and interfaces
Universität Karlsruhe Institut für Telematik UMTS domains and interfaces Mobilkommunikation SS 1998 User Equipment Domain Assigned to a single user in order to access UMTS services Infrastructure Domain Shared among all users Offers UMTS services to all accepted users Home Network Domain Zu Cu Uu Iu Yu USIM Domain Mobile Equipment Domain Access Network Domain Serving Network Domain Transit Network Domain Core Network Domain User Equipment Domain Infrastructure Domain Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

66 UMTS domains and interfaces
Universität Karlsruhe Institut für Telematik UMTS domains and interfaces Mobilkommunikation SS 1998 Universal Subscriber Identity Module (USIM) Functions for encryption and authentication of users Located on a SIM inserted into a mobile device Mobile Equipment Domain Functions for radio transmission User interface for establishing/maintaining end-to-end connections Access Network Domain Access network dependent functions Core Network Domain Access network independent functions Serving Network Domain Network currently responsible for communication Home Network Domain Location and access network independent functions Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

67 UMTS radio interface - Spreading and scrambling of user data
Universität Karlsruhe Institut für Telematik UMTS radio interface - Spreading and scrambling of user data Mobilkommunikation SS 1998 Constant chipping rate of 3.84 Mchip/s Different user data rates supported via different spreading factors (# of chips/bit) higher data rate: less chips per bit and vice versa User separation via unique, quasi orthogonal (their cross-correlation should be almost zero) scrambling codes users are not separated via orthogonal spreading codes much simpler management of codes: each station can use the same orthogonal spreading codes precise synchronization not necessary as the scrambling codes stay quasi-orthogonal data1 data2 data3 data4 data5 spr. code1 spr. code2 spr. code3 spr. code1 spr. code4 scrambling code1 scrambling code2 sender1 sender2 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

68 OVSF (Orthogonal Variable Spreading Factor) coding
1,1,1,1,1,1,1,1 1,1,1,1 ... 1,1,1,1,-1,-1,-1,-1 1,1 1,1,-1,-1,1,1,-1,-1 ... 1,1,-1,-1 X,X 1,1,-1,-1,-1,-1,1,1 1 X 1,-1,1,-1,1,-1,1,-1 X,-X ... 1,-1,1,-1 1,-1,1,-1,-1,1,-1,1 1,-1 SF=n SF=2n 1,-1,-1,1,1,-1,-1,1 ... 1,-1,-1,1 1,-1,-1,1,-1,1,1,-1 SF=1 SF=2 SF=4 SF=8

69 Universität Karlsruhe Institut für Telematik
UTRA-FDD (W-CDMA) Mobilkommunikation SS 1998 UTRA-FDD (W-CDMA) The FDD mode for UTRA uses wideband CDMA (W-CDMA) with direct sequence spreading. Uplink and downlink use different frequencies. Uplink (1920 ~ 1980 MHz) and downlink (2110 – 2170 MHz). Time slots are not used for user separation but to support periodic functions. Each time slot is 38,400 chips/s x 10 ms x 1/15 = 2560 chips (≈2/3 ms). The occupied bandwidth per W-CDMA channel is 4.4 to 5 MHz. In Germany, the FDD spectrum was sold over 50 billion Euros. The provide higher data rates, the infrastructure should be improved: Twice as many base stations as GSM (500 m cell diameters) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

70 Typical UTRA-FDD uplink data rates
Dedicated physical data channel (DPDCH) conveys user or signaling data Dedicated physical control channel (DPCCH) Conveys control data for the physical layer and uses the constant spreading factor 256. Dedicated physical channel (DPCH) The downlink time multiplexes control and user data. Physical random access channel (PRACH) Used for coordinating medium access on the uplink. User data rate [kbit/s] 12.2 (voice) 64 144 384 DPDCH [kbit/s] 60 240 480 960 DPCCH [kbit/s] 15 Spreading 16 8 4

71 UMTS FDD frame structure
Universität Karlsruhe Institut für Telematik UMTS FDD frame structure Mobilkommunikation SS 1998 W-CDMA MHz uplink MHz downlink chipping rate: Mchip/s soft handover QPSK complex power control (1500 power control cycles/s) spreading factors: Uplink: 4-256; Downlink:4-512 Radio frame 10 ms 1 2 ... 12 13 14 Time slot 666.7 µs Pilot TFCI FBI TPC uplink DPCCH 2560 chips, 10 bits 666.7 µs Data uplink DPDCH 2560 chips, 10*2k bits (k = 0...6) 666.7 µs Data1 TPC TFCI Data2 Pilot downlink DPCH 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 DPDCH DPCCH DPDCH DPCCH 2560 chips, 10*2k bits (k = 0...7) Slot structure NOT for user separation but synchronisation for periodic functions! Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

72 UE in UTRA-FDD (W-CDMA)
Universität Karlsruhe Institut für Telematik UE in UTRA-FDD (W-CDMA) Mobilkommunikation SS 1998 A UE has to perform the following steps during the search for a cell after power on: Primary synchronization: A UE has to synchronize with the help of a 256 chip primary synchronization code. Secondary synchronization: This defines the group of scrambling codes. Identification of the scrambling code: the UE tries all scrambling codes within the group of codes to find the right code with the help of a correlator. After these three steps the UE can receive all further data over a broadcast channel. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

73 Universität Karlsruhe Institut für Telematik
UTRA-TDD (TD-CDMA) Mobilkommunikation SS 1998 UTRA-TDD (TD-CDMA) Separates up and downlink in time using a frame structure similar to FDD. 15 slots with 2560 chips per slot for a radio frame with a duration of 10 ms. The chipping rate is 3.84 Mchips/s. TDD frame can be symmetrical or asymmetrical. The switching points is used to indicate the switching between up and downlink. At least one slot must be allocated for the uplink and downlink respectively. UTRA TDD occupies 5 MHz bandwidth per channel. Germany paid less than 300 million Euros. It is unclear to what extend this system will be deployed. The coverage per cell is less than using UTRA-FDD. UEs must not move too fast (like WLANs). Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

74 UMTS TDD frame structure (burst type 2)
Universität Karlsruhe Institut für Telematik UMTS TDD frame structure (burst type 2) Mobilkommunikation SS 1998 Radio frame 10 ms 1 2 ... 12 13 14 Time slot 666.7 µs Data 1104 chips Midample 256 chips Data 1104 chips GP Traffic burst GP: guard period 96 chips 2560 chips Midample is used for tranning and channel estimation. TD-CDMA 2560 chips per slot spreading: 1-16 symmetric or asymmetric slot assignment to UpLink/DownLink (min. 1 per direction) tight synchronisation needed simpler power control ( power control cycles/s) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

75 Universität Karlsruhe Institut für Telematik
UTRA architecture Mobilkommunikation SS 1998 UTRA architecture Radio network subsystems (RNS) Radio network controller (RNC) controls several node Bs over the interface (Iub) and is connected with the core network (CN) over Iu. The interface Iur is the interface for connecting two RNCs. Each node B can control several antennas which make a radio cell. The mobile device, user equipment (UE), can be connected to one or more antennas. Core network The circuit switched domain (CSD) comprises the classical circuit switched services and connects to the RNS via the IuCS. The packet switched domain (PSD) uses the GPRS components SGSN and GGSN and connects to the RNS via the IuPS. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

76 Universität Karlsruhe Institut für Telematik
UTRAN architecture Mobilkommunikation SS 1998 RNS RNC: Radio Network Controller RNS: Radio Network Subsystem UE Node B Iub UTRAN comprises several RNSs Node B can support FDD or TDD or both RNC is responsible for handover decisions requiring signaling to the UE Cell offers FDD or TDD RNC Iu Node B Node B CN Iur Node B Iub Node B RNC Node B Node B RNS Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

77 Universität Karlsruhe Institut für Telematik
UTRAN RNC functions Mobilkommunikation SS 1998 Call admission control Congestion control Radio channel encryption/decryption ATM switching and multiplexing, protocol conversion - Radio network configuration Channel quality measurements Macro diversity Radio resource control Radio carrier control – bearer setup and release Data transmission over the radio interface Channel allocation (coding) Outer loop power control (FDD and TDD) Handover control and RNS relocation (moving) Management - System information including current load, current traffic, error states Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

78 Universität Karlsruhe Institut für Telematik
UTRAN Components Mobilkommunikation SS 1998 Node B The name node B was chosen during standardization until a new and better name was found. The main task is the inner loop power control to mitigate near-far effect. Measures connection qualities and signal strengths. Supports a special case of handover (soft-handover). User Equipment (UE) The UE performs signal quality measurements, inner loop power control, spreading and modulation, and rate matching. (counterpart of a node B). The UE has to cooperate during handover and cell selection, performs encryption and decryption. (RNC) The UE has to implement mobility management. (CN) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

79 Universität Karlsruhe Institut für Telematik
Core network Mobilkommunikation SS 1998 The Core Network (CN) and thus the Interface Iu, are separated into two logical domains: Circuit Switched Domain (CSD) Circuit switched service including signaling Resource reservation at connection setup GSM components (MSC, GMSC, VLR) IuCS Packet Switched Domain (PSD) GPRS components (SGSN, GGSN) IuPS Release 99 uses the GSM/GPRS network and adds a new radio access! Helps to save a lot of money … Much faster deployment Not as flexible as newer releases (5, 6) Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

80 Core network: architecture with 3G RNS and 2G BSS
Universität Karlsruhe Institut für Telematik Core network: architecture with 3G RNS and 2G BSS Mobilkommunikation SS 1998 VLR BSS BTS Abis Iu BSC MSC GMSC PSTN Node B BTS IuCS AuC EIR HLR GR Node B Iub Node B RNC SGSN GGSN Gi Gn Node B Node B IuPS CN RNS Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

81 Core network: protocols with 3G RNS and 2G BSS
Universität Karlsruhe Institut für Telematik Core network: protocols with 3G RNS and 2G BSS Mobilkommunikation SS 1998 VLR PSTN/ ISDN MSC GMSC GSM-CS backbone RNS HLR RNS PDN (X.25), Internet (IP) SGSN GGSN Layer 3: IP GPRS backbone (IP) Layer 2: ATM SS 7 Layer 1: PDH, SDH, SONET UTRAN CN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

82 UMTS protocol stacks (user plane)
Universität Karlsruhe Institut für Telematik UMTS protocol stacks (user plane) Mobilkommunikation SS 1998 UE Uu UTRAN IuCS 3G MSC apps. & protocols Circuit switched RLC RLC SAR SAR MAC MAC AAL2 AAL2 radio radio ATM ATM UE Uu UTRAN IuPS 3G SGSN Gn 3G GGSN apps. & protocols IP, PPP, IP tunnel IP, PPP, Packet switched PDCP PDCP GTP GTP GTP GTP RLC RLC UDP/IP UDP/IP UDP/IP UDP/IP MAC MAC AAL5 AAL5 L2 L2 radio radio ATM ATM L1 L1 Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

83 Universität Karlsruhe Institut für Telematik
UMTS protocol stacks Mobilkommunikation SS 1998 Circuit Switched Domain (CSD) Radio link control (RLC) Segmentation and reassembly (SAR) ATM Adaptation Layer 2 (AAL2) Asynchronous Transfer Mode (ATM) Packet Switched Domain (PSD) Packet Data Convergence Protocol (PDCP) GPRS Tunneling Protocol (GTP) Handover Hard handover UTRA-TDD can only use this type. Switching between TDD cells is done between the slots of different frames at a certain point in time. Inter frequency handover (changing the carrier frequency) is a hard handover. All inter system handover are hard handovers in UMTS (to and from GSM or IMT-2000 systems). During a compressed mode which enables a UE to listen into GSM or other frequency bands, the spreading factor can be lowered or less data is sent before and after the break in transmission. Soft handover: In CDMA they use macro diversity. A UE receiving data from different antennas at the same time makes a handover soft. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

84 Support of mobility: macro diversity
Universität Karlsruhe Institut für Telematik Support of mobility: macro diversity Mobilkommunikation SS 1998 Multicasting of data via several physical channels Enables soft handover FDD mode only Downlink The RNC splits the data stream and forwards it to different nodes B. It allows simultaneous transmission of data via different cells. The UE combines the received data again. Different spreading codes in different cells Uplink The UE sends its data which is then received by several Node Bs. Reconstruction of data at Node B, SRNC (Serving RNC) or DRNC (Drift RNC) UE Node B Node B RNC CN Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

85 Support of mobility: handover
Universität Karlsruhe Institut für Telematik Support of mobility: handover Mobilkommunikation SS 1998 From and to other systems (e.g., UMTS to GSM) This is a must as UMTS coverage will be poor in the beginning RNC controlling the connection is called SRNC (Serving RNC) RNS offering additional resources (e.g., for soft handover) is called Drift RNC (DRNC) End-to-end connections between UE and CN only via Iu at the SRNS Change of SRNC requires change of Iu Initiated by the SRNC Controlled by the RNC and CN Node B SRNC CN Iub Iu UE Iur Node B DRNC Iub Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

86 Example handover types in UMTS/GSM
UE1 Node B1 RNC1 3G MSC1 Iu UE2 Node B2 Iub Iur UE3 Node B3 RNC2 3G MSC2 UE4 BTS BSC 2G MSC3 Abis A Intra-node B, intra-RNC – UE1 moves from one antenna, soft handover Inter-node B, intra-RNC – UE2 moves from node B1 to node B2, soft handover Inter-RNC – UE3 moves from node B2 to node B3, Intra-RNC – soft handover, Inter-RNC – hard handover. Inter-MSC – MSC2 takes over and perform a hard handover Inter-system – UE4moves from a 3G UMTS network into a 2G GSM network, hard handover.

87 Universität Karlsruhe Institut für Telematik
Handover Mobilkommunikation SS 1998 Intra-node B, intra-RNC UE1 moves from one antenna Inter-node B, intra-RNC UE2 moves from node B1 to node B2 Inter-RNC UE3 moves from node B2 to node B3 Inter-MSC MSC2 takes over and perform a handover Inter-system UE4moves from a 3G UMTS network into a 2G GSM network. Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller

88 UMTS services (originally)
Universität Karlsruhe Institut für Telematik UMTS services (originally) Mobilkommunikation SS 1998 Data transmission service profiles Virtual Home Environment (VHE) Enables access to personalized data independent of location, access network, and device Network operators may offer new services without changing the network Service providers may offer services based on components which allow the automatic adaptation to new networks and devices Integration of existing IN services Circuit switched 16 kbit/s Voice SMS successor, Packet switched 14.4 kbit/s Simple Messaging Switched Data asymmetrical, MM, downloads 384 kbit/s Medium MM Low coverage, max. 6 km/h 2 Mbit/s High MM Bidirectional, video telephone 128 kbit/s High Interactive MM Transport mode Bandwidth Service Profile Prof. Dr. Dr. h.c. G. Krüger E. Dorner / Dr. J. Schiller


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