Lecture 10


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Lecture 10

  1. 1. TETRA – Terrestrial Trunk Radio Service <ul><li>Trunked radio systems </li></ul><ul><ul><li>many different radio carriers </li></ul></ul><ul><ul><li>assign single carrier for a short period to one user/group of users </li></ul></ul><ul><ul><li>taxi service, fleet management, rescue teams </li></ul></ul><ul><ul><li>interfaces to public networks, voice and data services </li></ul></ul><ul><ul><li>very reliable, fast call setup, local operation </li></ul></ul><ul><li>TETRA - ETSI standard </li></ul><ul><ul><li>formerly: Trans European Trunked Radio </li></ul></ul><ul><ul><li>point-to-point and point-to-multipoint </li></ul></ul><ul><ul><li>encryption (end-to-end, air interface), authentication of devices, users and networks </li></ul></ul><ul><ul><li>group call, broadcast, sub-second group-call setup </li></ul></ul><ul><ul><li>ad-hoc (“direct mode”), relay and infrastructure networks </li></ul></ul><ul><ul><li>call queuing with pre-emptive priorities </li></ul></ul>
  2. 2. TETRA – Contracts by Sector (percentage) TETRA – Contracts by Sector (percentage) Used in over 70 countries, more than 20 device manufacturers
  3. 3. TETRA – Network Architecture TETRA infrastructure BS BS switch switch switch NMS BS other TETRA networks PSTN, ISDN, Internet, PDN DMO ISI PEI AI AI: Air Interface BS: Base Station DMO: Direct Mode Operation ISI: Inter-System Interface NMS: Network Management System PEI: Peripheral Equipment Interface
  4. 4. TETRA – Direct Mode I <ul><li>Direct Mode enables ad-hoc operation and is one of the most important differences to pure infrastructure-based networks such as GSM, cdma2000 or UMTS. </li></ul>Individual Call Group Call “ Dual Watch” – alternating participation in Infrastructure and ad-hoc network Managed Direct Mode network Authorizing mobile station
  5. 5. TETRA – Direct Mode II <ul><li>An additional repeater may increase the transmission range (e.g. police car) </li></ul>Direct Mode with Gateway network Direct Mode with Repeater Direct Mode with Repeater/Gateway network Managed Repeater/Gateway network Authorizing Repeater
  6. 6. TETRA – Technology <ul><li>Services </li></ul><ul><ul><li>Voice+Data (V+D) and Packet Data Optimized (PDO) </li></ul></ul><ul><ul><li>Short data service (SDS) </li></ul></ul><ul><li>Frequencies </li></ul><ul><ul><li>Duplex: FDD, Modulation: DQPSK </li></ul></ul><ul><ul><li>Europe (in MHz, not all available yet) </li></ul></ul><ul><ul><ul><li>380-390 UL / 390-400 DL; 410-420 UL / 420-430 DL, 450-460 UL / 460-470 DL; 870-876 UL / 915-921 DL </li></ul></ul></ul><ul><ul><li>Other countries </li></ul></ul><ul><ul><ul><li>380-390 UL / 390-400 DL; 410-420 UL / 420-430 DL, 806-821 UL / 851-866 DL </li></ul></ul></ul>
  7. 7. TDMA structure of the voice+data system 0 1 2 57 58 59 ... hyperframe 0 1 2 15 16 17 ... multiframe 0 1 2 3 0 slot 509 frame 14.17 ms 56.67 ms 1.02 s 61.2 s CF Control Frame
  8. 8. TETRA – Data Rates hyperframe <ul><li>Infrastructure mode, V+D in kbit/s </li></ul><ul><li>No. of time slots 1 2 3 4 </li></ul><ul><li>No protection 7.2 14.4 21.6 28.8 </li></ul><ul><li>Low protection 4.8 9.6 14.4 19.2 </li></ul><ul><li>High protection 2.4 4.8 7.2 9.6 </li></ul><ul><li>TETRA Release 2 – Supporting higher data rates </li></ul><ul><ul><li>TEDS (TETRA Enhanced Data Service) </li></ul></ul><ul><ul><li>up to 100 kbit/s </li></ul></ul><ul><ul><li>backward compatibility </li></ul></ul>
  9. 9. UMTS and IMT-2000 <ul><li>ITU Floats an Idea of a Universal Mobile Telecommunications Systems(UMTS) that caters to: </li></ul><ul><ul><li>Large Bandwidth requirements for voice and data transfer </li></ul></ul><ul><ul><li>Worldwide Operation </li></ul></ul><ul><ul><li>Addresses User Mobility and Terminal(Device) Mobility </li></ul></ul><ul><ul><li>Formerly, this idea was termed Future Public Land Mobile Telecommunications Systems (FLTMS). </li></ul></ul><ul><ul><li>Recommendations for FLTMTS: </li></ul></ul><ul><ul><li>Network Architecture(M.817) </li></ul></ul><ul><ul><li>Radio Interface Requirements (M.1034) </li></ul></ul><ul><ul><li>Framework for Services offered(M.816) </li></ul></ul>
  10. 10. UMTS and IMT-2000 <ul><ul><li>Thus emerged the Standard International Mobile Telecommunications (IMT 2000). </li></ul></ul><ul><ul><li>2000 Refers to the year of emergence and also the MZ frequency Range. </li></ul></ul><ul><ul><li>IMT 2000 Frequency Bands (Suggested Initial Allocation): </li></ul></ul><ul><ul><ul><li>1885 – 2025 MHz </li></ul></ul></ul><ul><ul><ul><li>2110 – 2200MHz </li></ul></ul></ul><ul><ul><li>The European Proposal for IMT-2000 was UMTS. </li></ul></ul>
  11. 11. UMTS and IMT-2000 <ul><li>Proposals for IMT-2000 (International Mobile Telecommunications) </li></ul><ul><ul><li>UWC-136, cdma2000, WP-CDMA </li></ul></ul><ul><ul><li>UMTS (Universal Mobile Telecommunications System) from ETSI </li></ul></ul><ul><li>UMTS </li></ul><ul><ul><li>UTRA (was: UMTS, now: Universal Terrestrial Radio Access) </li></ul></ul><ul><ul><li>enhancements of GSM </li></ul></ul><ul><ul><ul><li>EDGE (Enhanced Data rates for GSM Evolution): GSM up to 384 kbit/s </li></ul></ul></ul><ul><ul><ul><li>CAMEL (Customized Application for Mobile Enhanced Logic) – Intelligent network support ex., creation of VHE (virtual Home Environment) for visiting subscribers </li></ul></ul></ul><ul><ul><li>fits into GMM (Global Multimedia Mobility) initiative from ETSI(European Telecommunications Standards Institute) </li></ul></ul><ul><ul><li>requirements </li></ul></ul><ul><ul><ul><li>min. 144 kbit/s rural (goal: 384 kbit/s) </li></ul></ul></ul><ul><ul><ul><li>min. 384 kbit/s suburban (goal: 512 kbit/s) </li></ul></ul></ul><ul><ul><ul><li>up to 2 Mbit/s urban </li></ul></ul></ul>
  12. 13. IMT-2000 family 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 GSM (MAP) ANSI-41 (IS-634) IP-Network IMT-2000 Core Network ITU-T IMT-2000 Radio Access ITU-R Interface for Internetworking Initial UMTS (R99 w/ FDD) Universal Terrestrial Radio Access 3G-Partnership Project Flexible assignment of Core Network and Radio Access
  13. 14. GSM and UMTS Releases 1992 3.x.y Ph1 - Phase 1 1995 4.x.y Ph2 - Phase 2 early 1997 5.x.y R96 - Phase 2+ Release 1996 early 1998 6.x.y R97 - Phase 2+ Release 1997 early 1999 7.x.y R98 - Phase 2+ Release 1998 8.x.y - Phase 2+ Release 1999 March 2000 3.x.y R99 Release 1999 - 9.x.y - Phase 2+ Release 2000 Renaming… 4.x.y R00 Release 2000 - March 2001 4.x.y Rel-4 Release 4 Phase 2+ Release 4 March - June 2002 5.x.y Rel-5 Release 5 Phase 2+ Release 5 December 2004 - March 2005 6.x.y Rel-6 Release 6 Phase 2+ Release 6 Freeze date (indicative only) Spec version number Abbreviated name 3G Release GSM/EDGE Release
  14. 15. UMTS architecture (Release 99 used here!) <ul><li>UTRAN (UTRA Network) </li></ul><ul><ul><li>Cell level mobility </li></ul></ul><ul><ul><li>Contains several Radio Network Subsystems (RNS) </li></ul></ul><ul><ul><li>Encapsulation of all radio specific tasks </li></ul></ul><ul><li>UE (User Equipment) </li></ul><ul><li>CN (Core Network) </li></ul><ul><ul><li>Inter system handover </li></ul></ul><ul><ul><li>Location management if there is no dedicated connection between UE and UTRAN </li></ul></ul>UTRAN UE CN I u U u
  15. 16. Further Break-up of Architecture : UMTS domains and interfaces I USIM Domain Mobile Equipment Domain Access Network Domain Serving Network Domain Transit Network Domain Home Network Domain C u U u I u User Equipment Domain Z u Y u Core Network Domain Infrastructure Domain <ul><li>User Equipment Domain </li></ul><ul><ul><li>Assigned to a single user in order to access UMTS services </li></ul></ul><ul><li>Infrastructure Domain </li></ul><ul><ul><li>Shared among all users </li></ul></ul><ul><ul><li>Offers UMTS services to all accepted users </li></ul></ul>
  16. 17. UMTS domains and interfaces II <ul><li>Universal Subscriber Identity Module (USIM) </li></ul><ul><ul><li>Functions for encryption and authentication of users </li></ul></ul><ul><ul><li>Located on a SIM inserted into a mobile device </li></ul></ul><ul><li>Mobile Equipment Domain </li></ul><ul><ul><li>Functions for radio transmission </li></ul></ul><ul><ul><li>User interface for establishing/maintaining end-to-end connections </li></ul></ul><ul><li>Access Network Domain </li></ul><ul><ul><li>Access network dependent functions </li></ul></ul><ul><li>Core Network Domain </li></ul><ul><ul><li>Access network independent functions </li></ul></ul><ul><ul><li>Serving Network Domain </li></ul></ul><ul><ul><ul><li>Network currently responsible for communication </li></ul></ul></ul><ul><ul><li>Home Network Domain </li></ul></ul><ul><ul><ul><li>Location and access network independent functions </li></ul></ul></ul>
  17. 18. Spreading and scrambling of user data <ul><li>Constant chipping rate of 3.84 Mchip/s </li></ul><ul><li>Different user data rates supported via different spreading factors (no. of chips/bit) </li></ul><ul><ul><li>higher data rate: less chips per bit and vice versa </li></ul></ul><ul><li>User separation via unique, quasi orthogonal (cross correlation should be zero nearly )scrambling codes </li></ul><ul><ul><li>users are not separated via orthogonal spreading codes </li></ul></ul><ul><ul><li>much simpler management of codes: each station can use the same orthogonal spreading codes </li></ul></ul><ul><ul><li>precise synchronisation not necessary as the scrambling codes stay quasi-orthogonal </li></ul></ul>data 1 data 2 data 3 scrambling code 1 spr. code 3 spr. code 2 spr. code 1 data 4 data 5 scrambling code 2 spr. code 4 spr. code 1 sender 1 sender 2
  18. 19. OSVF coding (Orthogonal Variable Spreading Factor) 1 1,1 1,-1 1,1,1,1 1,1,-1,-1 X X,X X,-X 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,-1,1,-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,-1,-1,-1,-1 SF=1 SF=2 SF=4 SF=8 SF=n SF=2n ... ... ... ...
  19. 20. UMTS FDD frame structure <ul><li>W-CDMA </li></ul><ul><li>1920-1980 MHz uplink </li></ul><ul><li>2110-2170 MHz downlink </li></ul><ul><li>chipping rate: 3.840 Mchip/s </li></ul><ul><li>soft handover </li></ul><ul><li>QPSK </li></ul><ul><li>complex power control (1500 power control cycles/s) </li></ul><ul><li>spreading: UL: 4-256; DL:4-512 </li></ul>0 1 2 1 2 1 3 1 4 ... Radio frame Pilot FBI TPC Time slot 6 66.7 µs 10 ms Data Data 1 uplink DPDCH uplink DPCCH downlink DPCH TPC TF C I Pilot 6 66.7 µs 6 66.7 µs DPCCH DPDCH 2560 chips, 10 bits 2560 chips, 10*2 k bits (k = 0...6) TFCI 2560 chips, 10*2 k bits (k = 0...7) Data 2 DPDCH DPCCH FBI: Feedback Information TPC: Transmit Power Control TF C I: Transport Format Combination Indicator DPCCH: Dedicated Physical Control Channel DPDCH: Dedicated Physical Data Channel DPCH: Dedicated Physical Channel Slot structure NOT for user separation but synchronisation for periodic functions! 38400 chips
  20. 21. Channels <ul><li>DPDCH: Dedicated Physical Data Channel </li></ul><ul><li>Conveys user or signaling data </li></ul><ul><li>Spreading factor : 4 to 256 </li></ul><ul><li>Data Rates 960kbps(spreading factor 4, 640 bits/slot , 15 slots/frame , 100 frames/sec). </li></ul><ul><li>Based on the increasing spreading factors, data rates come down . </li></ul>
  21. 22. Channels <ul><li>DPCCH: Dedicated Physical Control Channel </li></ul><ul><li>Conveys control data to physical layer </li></ul><ul><li>Spreading factor : constant 256. </li></ul><ul><li>Pilot Used for Channel Estimation </li></ul><ul><li>Transport Format Combination Identifier (TFCI) : specifies the channels transported within the DPDCHs. </li></ul><ul><li>Feedback Information Field (FBI) : Supports signaling for a soft handover. </li></ul><ul><li>Transmit Power Control(TPC) : used to control the transmission power of a sender (Automatic Power control algorithms). </li></ul>
  22. 23. Channels <ul><li>DPCH: Dedicated Physical Channel </li></ul><ul><li>The downlink time multiplexes control and user data </li></ul><ul><li>Spreading factors 4 to 512 </li></ul><ul><li>Available Data Rates for data channels within a DPCH: </li></ul><ul><li>6 kbps(for SF=512) , 24, 51, ………1872 kbps(SF=4) </li></ul>
  23. 24. Typical UTRA-FDD uplink data rates 4 8 16 64 Spreading 15 15 15 15 DPCCH [kbit/s] 960 480 240 60 DPDCH [kbit/s] 384 144 64 12.2 (voice) User data rate [kbit/s]
  24. 25. UMTS TDD frame structure (burst type 2) <ul><li>TD-CDMA </li></ul><ul><li>Chipping Rate : 3.84 Mchips/sec </li></ul><ul><li>2560 chips per slot </li></ul><ul><li>spreading: 1-16 </li></ul><ul><li>symmetric or asymmetric slot assignment to UL/DL (min. 1 per direction) </li></ul><ul><li>tight synchronisation needed </li></ul><ul><li>simpler power control (100-800 power control cycles/s) </li></ul>0 1 2 1 2 1 3 1 4 ... Radio frame Data 1104 chips Midample 256 chips Data 1104 chips Time slot 6 66.7 µs 10 ms Traffic burst GP GP: guard period 96 chips 2560 chips
  25. 26. UMTS TDD frame structure (burst type 2) <ul><li>If the users have different data rates, the TDD frames can be symmetrical/Unsymmetrical (frame can have same no. of uplink/downlink slots or a different combination) </li></ul><ul><li>The system has the capacity to change the up-link/downlink spreading factor as a function of data rates. </li></ul><ul><li>Guard space can loosen the synchronization needs a bit. </li></ul>Radio frame
  26. 27. Handover <ul><li>In Line with GSM </li></ul><ul><li>PLEASE REFER TO THE TEXT </li></ul>