TETRA TERRESTRIAL TRUNKED RADIO 123 seminarsonly com WHAT

TETRA (TERRESTRIAL TRUNKED RADIO) 123 seminarsonly. com

WHAT IS TETRA • * Advanced Digital Radio Communications Public Safety Services, Utilities, Government, Military Transport, Local • * Operational throughout Europe, Asia-Pacific, South America and Middle East • * Standard promoted by ETSI • System for * Multi-vendor supply / interoperation 123 seminarsonly. com Africa,

FREQUENCY RANGE • 1. 400 MHz • 380 - 400 MHz for public safety systems • 410 - 430 MHz for commercial applications • 2. 800 MHz for commercial applications • standard based on TDMA technology with 4 timeslot and 25 k. Hz band 123 seminarsonly. com

TETRA is superior PMR technology • Individual and group communications • Direct mode communication between radios • Packet data and fast data transfer services • Over-the-air programming of radios • Frequency economy • Fast call set-up time • Security features 123 seminarsonly. com

To ensure an open multivendor market, TETRA specifies the following essential interfaces: • Air Interface ensure the interoperability of terminal equipment from different manufacturers. • Terminal Equipment Interface (TEI) facilitates the independent development of mobile data applications. • Inter-System Interface (ISI) allows the interconnection of TETRA Networks from different manufacturers. • Direct Mode Operation (DMO) guarantees communication between terminals also beyond network coverage. 123 seminarsonly. com

TECHNOLOGY OF TETRA FDMA 123 seminarsonly. com TDMA

TETRA TDMA • 4: 1 TDMA (Time Division Multiple Access) 25 k. Hz carrier spacing • Digital modulation, /4 DQPSK at 36 kbits/s • Speech calls use one channel • Data calls can use up to 4 channels ( Data transfer rates up to 7. 2 kbit/ s per channel) Four user channels interleaved into one 25 k. Hz carrier 123 seminarsonly. com

Air Interface - TDMA Illustrated Hyperframe (61. 2 s) 1 2 3 4 5 60 Multiframe (1. 02 s) 1 2 3 4 17 18 control frame TDMA frame (56. 67 ms) 1 2 3 4 Time slot (14. 167 ms) = 510 modulating bits 1 2 3 4 5 123 seminarsonly. com 508 509 510

PHASE SHIFT KEYING PROCESS 010 011 001 45 100 101 000 111 123 seminarsonly. com 110

WIRELESS CHANNEL AT TRANSMITTER END PROPAGATION CHANNEL ENCODER MODULATOR 123 seminarsonly. com RF/IF STAGES

WIRELESS CHANNEL AT RECIEVER END PROPAGATIO N CHANNEL RF/IF STAGES DEMODULATOR 123 seminarsonly. com DECODER

7 CELLULAR CONCEPT 4 ARFCN IN ONE CELL 4*7=28 ARFCN 123 seminarsonly. com

HANDOVER PROCESS 123 seminarsonly. com

TETRA Traffic case - simplex calls • Simplex Calls – Mobile is either transmitting or receiving – Requires operation of PTT switch (Push To Talk) – Talk time is usually limited, typically 1 minute maximum – Group calls are always simplex 123 seminarsonly. com

TETRA Traffic case - duplex calls • Duplex Calls – Mobile is transmitting and receiving (like GSM phone call) – Does not require holding PTT to continue transmission – Recommended for making measurements - no talk timer – Phone calls are usually but not always duplex 123 seminarsonly. com

TETRA Traffic case - Group call • Group call – A call between more than 2 parties – Call is always simplex, direct set-up – Only possible if one or more groups have been attached 123 seminarsonly. com

TETRA is the Cost - Effective Technology Four-channel TDMA gives excellent spectrum economy - 4 channels in one 25 k. Hz carrier TDMA makes costeffective Base Stations 123 seminarsonly. com Trunking technology supports controlled use of shared networks

Exrtremly urgent Highly important INFORMATION IMPORTANCE TETRA INFORMATION TETRA GSM DECT routine TIME CRITICALLY OF CALL SET UP Non urgent Urgent <1 min 123 seminarsonly. com <10 sec Immediate <1 s

Difference between GSM and TETRA System GSM System TETRA System Designed for public cellular telephony. Designed for professional mobile radio applications. Based on Duplex & point to point communication. Based on simplex, semi duplex, fill duplex also point to point & multi point to point communication. Not suitable for emergency services Suitable for emergency services due (Call set up time ~ a few seconds). to very fast call set up time (300 ms) Do not maintain privacy and mutual security. Direct Mode Operation(DMO) is not possible. Maintain privacy and mutual security. Direct Mode Operation(DMO) is possible, which supports voice and data transmission without a Base Station between Radio Terminals. 123 seminarsonly. com

WORLD USAGE 123 seminarsonly. com

Thank you 123 seminarsonly. com