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Terrestrial Trunked Radio for Professional Cellular Systems

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Terrestrial Trunked Radio for Professional Cellular Systems TETRA Terrestrial Trunked Radio for Professional Cellular Systems TETRA, the European standard for The European Institute for Telecommu- ports the packet oriented transmission Trunked Radio Systems, is primarily nications Standards (ETSI) has devel- of data via the radio channel (TETRA intended for users in the public secu- oped this standard in co-operation with PDO = “Packet Data Optimized”). rity sphere, transport, utilities and op- the leading manufacturers, system Thus the system platform is able to erators of public Trunked Radio net- operators and users. combine the two radio services, mobile works. TETRA has been conceived for high data transmission and paging, which As fully digital radio system, TETRA is frequency economy, reliable voice and were up to now only offered by sepa- hallmarked by improved transmission data transmission and versatile oper- rate infrastructures. This improves the quality and higher frequency economy. ating features. In addition to the cen- flexibility and economic viability of the The comprehensive functionality addi- tral standard for speech and data ystem for the network operator, service tionally ensures high flexibility in pro- (TETRA “Voice and Data”) there is also providers, and not least for the end fessional mobile communications. a special variant which optimally sup- user. New Features The proven advantages of analogue gether with a considerable improve- quencies, in synchronism with the al- Trunked Radio Systems + fast call set- ment in speech transmission quality. located time slots. In this way complex up (“Push-to-talk”-mode), group ori- Compared to GSM networks, which filter systems, which would be neces- ented communication and the utilisation currently offer 8 communication chan- sary for simultaneous transmission and of control stations + have been ex- nels in 200 kHz channel spacing TETRA- reception, can be avoided. tended through the addition of further systems offer a quadrupling of the fre- features, like encryption, “Late Entry“, quency utilisation. TETRA Packet Data Optimized economic duplex option, etc. The transmission rate on the TETRA TETRA allows the adjustment of the Digitisation reduces the costs for opera- carrier frequencies is 36kBit/s. In ad- transmission rate and the reliability tors and users, and offers access to the dition to the message content to be functions to the specific application. The modern telecommunications world transmitted the data includes the pro- data rate can be varied between 2.4 (ISDN, DECT, GSM), with all the per- tocol-information and codes necessary kBit/s, for extremely high security re- formance features of a state-of-the-art for the securing of the radio link be- quirements, using one time slot, and private exchange, for example caller tween subscriber radio and radio base 28.8kBit/s if the data protection pro- identification, call diversion, short-di- station. The maximum user data rate tocol is disabled, and four time slots are aling, call waiting and call-holding. per communication channel is 7.2kBit/ used. s (per time slot). The TETRA CODEC TDMA Access Method digitises and compresses the speech so Direct-Mode TETRA is defined as a time multiplexed that a continuous two-way conversation Important measures for increasing the system (TDMA = “Time Division Mul- is possible, using two corresponding flexibility for TETRA users are embed- tiple Access”) with four independent time slots. The CODEC output delivers ded in the Direct Mode. The Direct transmission channels per carrier. The 4.8kBit/s, which is transmitted within in Mode enables communication between spacing between the individual carri- a time slot of 7.2kBit, including the subscriber radios independent of the ers is 25kHz. This provides, in compari- securing code. radio-network. Thus TETRA subscriber son to analogue Trunked Radio System, The duplex offset is 10 MHz in “Time radios can be used as ”walkie-talkies” which operate with 12.5 kHz spacing Division Duplex” mode. This means within and without the network. It is also according to the MPT standard, a dou- that the user terminal constantly switches possible to operate a subscriber radio bling of the frequency utilisation to- between the transmit and receive fre- as a repeater for another radio, in Mikrophone CODEC Protocol Transmitter 4 Timeslots with a total of 36 kBit/s, 28.8 kBit/s useful rate A P D Frequency 1 analogue Signal Digital signal Digital signal 1 2 3 4 4.8 kBit/s protocol 7.2 kBit/s T TETRA-Infrastructure Speaker CODEC Protocol Receiver 1 2 3 4 A D P Frequency 1+10 MHz 2 TETRA PABX LAN PDN ISDN PSTN order to temporarily improve, or ex- DECT tend, the network coverage. For ex- e.g. Ethernet X.25 PCM 30/G703 analogue PCM 30/G703 ample, a watchman can, on leaving his vehicle, switch his vehicle radio to Direct Mode and then use the extended cov- erage thus provided by means of a other intersystem-interface TETRA- link-lines: hand-held radio, e.g. during his round networks PCM 30 or ISDN MSC leased-/dial-up within a factory building or grounds. microwave In addition ”Dual-Watch” operation is also offered, which in Direct Mode ensures the accessibility of a subscriber through the network. ring-structure line-structure hierachical structure, intermeshed R&S BICK Mobilfunk: ACCESSNET ®-T Your power partner Trunked Radio System As the Centre of Competence for mo- bile communication, within the Rohde &Schwarz group of companies, R&S BICK Mobilfunk has for many years been a trend-setter for professional analogue and digital networks. Right from the start R&S BICK Mobilfunk has played a competent role in the The decision to co-operate within the creation of the TETRA standard, through Memorandum of Understanding for working together with ETSI, and has TETRA (TETRA MoU) was a logical step considerably influenced the implemen- forward. The TETRA MoU group is an tation of user friendly and state-of-the- European meeting of interests for the Abbreviations art solutions. Market leader in Ger- promotion and rapid implementation many for public MPT-1327 trunked of TETRA. Trial systems are in opera- CODEC Coder-Decoder radio systems, thanks to the acceptance tion, common information events are DECT Digital European Cordless of our ACCESSNET® product, we have being presented, and technical discus- Telecommunication also achieved a commanding position sions about interoperability are being ETSI European Telecommunica- in the world market for special networks organised. tions Standard Institute for public transport companies and R&S BICK Mobilfunk offers particular GSM Global System for Mobile despatcher networks. advantages: the already implemented Communication MPT-1327 technology of our product ISDN Integrated Services Digital ACCESSNET ® was conceived with inter- Network operability in mind. Thus it will be LAN Local Area Network possible, within a single network, to MSC Mobile Switching Centre provide both MPT and TETRA channels. PABX Private Automatic Branch Within mixed fleets an MPT subscriber Exchange can communicate with TETRA subscrib- PDN Public Data Network ers directly. The Soft-Migration from PDO Packed Data Optimized ACCESSNET ®, the analogue Trunked PSTN Public Switched Telephone Radio System to the digital MPT-1327 Network System ACCESSNET ®-D, and ultimately TDMA Time Division Multiple Ac- to the TETRA Trunked Radio System cess ACCESSNET ®-T is our commitment. TETRA Terrestrial Trunked Radio TETRA 3 TETRA Services TETRA Basic Services Single call Group call Speech Transmission (encrypted) Group call with acknowledgment Broadcast call Plain data transmission, up to 28.8 kBit/s Reliable data transmission, up to 19.2 kBit/s Data Transmission (encrypted) Line switching Packet switching TETRA Extra Services Authorisation through dispatcher Call request via dispatcher Area selection The geographic operating area can be defined for each subscriber Improves access to the network for authorised subscribers at times of high Access priority network load Priority call Call connection with waiting list priority Late entry Automatic including of belated subscribers into calls Emergency call Call with highest priority Monitoring function Allows authorised subscribers monitoring Ambience listening Enables in special cases monitoring by the dispatcher Dynamic groups Enables the variable definition of groups Enables to transfer the responsibility for the call to another subscriber, without Transfer of group responsibility interruption ...mobility for professionals! Subject to change · Printed in Germany · 0598 (WA-hh) Printed in Germany · Subject to change · R&S BICK Mobilfunk GmbH · Im Landerfeld 7 · D-31848 Bad Münder · Germany Telefon (+49) 5042 998-0 · Telefax (+49) 5042 998-105 · http://www.rsbick.de.
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