2. Summer school Jukka Heikkilä Professor, vice dean The faculty of Information Technology University of Jyväskylä P.O. Box 35 FIN-40351 JYVÄSKYLÄ FINLAND tel:+358 50 581 8361 email: jups@cc.jyu.fi

3. Alternative techs TETRA

4. 3 Stg in between n Quick connection –to a limited number of users vs. broadcast? vs. pont-to-point? n High security (3 levels) –from authentication to end-to-end encryption n Open std for application developers (cost) n Access to other systems via gateways –voice + data n DMO (direct mode operation) –outside the radio coverage of BTS –have mechanisms for roaming control

5. Individual Centred Communication Increasing User Base OrganisationCentredCommunicationManagementTool IncreasingInformationImportance Market Position of Technologies (Toikkanen, 1999) Fixed Telephony Cellular - GSM PMR TETRA

6. 5 Intro

7. 6 What makes TETRA unique (Toikkanen, 1999) n Unique group communication package in total n Fast call set-up time n Direct Mode (DMO) n Queuing of channel resources n Signalling during voice call n Pre-emptive priorities, ambience listening n Multiple security schemes & algorithms –authentication of radios (& networks) –air interface & end-to-end encryption –disabling of stolen radios n Brings harmonised PMR spectrum to Europe

8. 7 Device manufactures are committed to the standard set TETRA interoperability demonstration at TETRA World Congress, 16-18.11.1999, Amsterdam:

9. 8 TETRA TDMA (Blomberg, 1999) n 4:1 TDMA (Time Division Multiple Access) n 4 logical channels n 25 kHz carrier spacing n Voice calls use one channel n Data calls can use up to 4 channels (multi-slot data) n Voice and Data can be transmitted simultaneously in different timeslots Four user channels multiplexed into one 25 kHz carrier

10. 9 Tetra bands n Availability of infrastructure and terminals with frequency bands: –380 ÷ 400 MHz (Emergency) –410 ÷ 430 MHz (Civil/autohorities) –450 ÷ 470 MHz (Planned) –806 ÷ 921 MHz

11. 10 Core TETRA Standards (Toikkanen, 1999) n Voice plus data (V+D) n Packet Data Optimised (PDO) n Direct Mode Operation (DMO) n Conformance Testing n TETRA Speech Codec AI ISI PEI DMO LS Air Interface (AI) Inter-System Interface (ISI) Peripheral Equipment Interface (PEI) Line Station (LS)

12. 11 Data Communication Services (Toikkanen, 1999) n Status service –efficient, real time n Short Data service, SDS –text messaging + application vehicle n IP Packet Data –opens the world of Internet connectivity n Circuit Mode Data –for specialised applications like video surveillance 36kbits/s gross bit rate 28.8kbits/s user bit rate 7.2kbits/s 1 2 34

13. 12 Direct Mode Operation (DMO) (Lovett, 2000) n Direct Mode (DM) is direct communication between two TETRA DM terminals….. …or several TETRA DM terminals or mobile stations without the use of a trunking network infrastructure.

14. 13 ‘Back-to-Back’ DMO (Lovett, 2000) DMO Master DMO Slave 1234 Slot Structure Speech Slot Pre-emption 1234 DMO Air Interface ‘Frequency Efficient’ mode can use these timeslots for another call

15. 14 Standard API and Applications (Nouri, 1999) SDS WAP IP Packet Data TETRA TETRANETWORK Applications Standard API Bearer Service AVLTelemetry Circuit Mode Data Internet Access Proprietary TETRA ADAPTATION LAYER SDS

16. 15 TETRA interface standards (Toikkanen, 2000) a) available b) in drafting phase n n Air interface n n PSTN, ISDN gateways n n Data network gateway n n Intersystem interface (general, Indiv Call, Group Call, Mob Mgmt) n n Peripheral Equipment Interface (PEI) n n Direct mode air interface n n Direct mode repeater and gateway n n Lawful interception (phase 1) n n Test specifications for interfaces n n Intersystem interface (SDS) n n Lawful interception (phase 2) ? n n Line Station

17. Gardermoen (OSL) PMR users (Ludvigsen, 2001) PMR System Flight handling Passanger handling Deice Fire & Rescue dept. Fuelling Catering Tech. Maintenance Car Parking

18. 17 Gardermoen (OSL) terminals (Ludvigsen, 2001) n Total of 770 terminals –OSL: 250 terminals –Airlines:300 terminals –Other:220 terminals n Dispatchers –De-icing (1) –SAS (1) –Fire brigade/rescue team (2) –IT - department (1) –Technical - department (1)

19. 18 Operational experiences at OSL (Ludvigsen, 2001)  First TETRA system in operation May 98, limited number of terminal types and accessories with reduced functionality  The system proved to be in stable operation from July 99. Both HW- and SW-upgrades on central equipment and portables. Facing a new comprehensive upgrade this summer.  For critical communications (Tower-to-Ground) the audio quality on portable terminals is unacceptable to the users  Complains on size and weight on terminals Operational with high availability for 800 users in non-critical functions

20. 19 Milestones in the TETRA standard (Godfrey, 2000) n 1990:standardisation start n 1991:standard based on TDMA technology with 4 timeslot and 25 kHz band n 1995:standard first phase completed n 1996:frequency armonisation in Europe (CEPT/NATO) n 1997:standard second phase completed n 1998:first systems installation n 2000:presence of 32 TETRA network in 21 countries