Tetra Introduction [PDF]

Zitiervorschau

Standard by ETSI for Digital Mobile Radio Systems

Apr-10

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Table of contents

What is TETRA? Functionality and characteristics TETRA technology basics Technology comparison Some scenarios and applications User specific considerations The future of TETRA

Apr-10

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What is TETRA ?

Apr-10

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TETRA in short

> TETRA means TErrestrial Trunked RAdio > It is a standard specified by the ETSI during the ‘90s in response to the need of a common digital trunked standard for professional mobile radio (PMR) > TETRA has been specified by ETSI together with users and it is defined to meet the needs of the most demanding users > TETRA is an open standard

Apr-10

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The leading technology

> TETRA is a consolidated standard and has been fully accepted by the Administrations of all European countries and in many other countries in the rest of the world. > ETSI is currently working on TETRA release 2, that will further enhance the services of TETRA and will maintain the standard future-proof.

Apr-10

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ETSI - (1/2) (European Telecommunications Standards Institute)

What

Who

> Produce the telecommunication standards of the future > Promote the world-wide standardization process whenever possible

> Non-profit making organization > It unites approximately 800 members from 56 countries inside and outside Europe > It represents:

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•

Administrations,

•

Network operators

•

Users

•

Manufacturers

•

Service providers

•

Research bodies

ETSI - (2/2) (European Telecommunications Standards Institute)

How > Deep analysis of customer requirements > Exploitation of its long experience and of the rich set of skills of the members > Coordination with most important international standardization bodies (mainly the ITU-T and the ITU-R)

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Results Some references: GSM, DECT, TETRA, UMTS,...

TETRA MoU - (1/2)

The TETRA Memorandum of Understanding (MoU) was established in December 1994. Today it represents 100 organisations from 30 countries. Who

Apr-10

All TETRA stakeholders:  users  manufacturers (the entire European PMR industry, exclusive of EADS)  operators  test houses  telecom agencies

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TETRA MoU - (2/2)

What

Act on behalf of all interested parties in order to support TETRA adoption and evolution

Promote TETRA events and exhibitions collect users feedback support interoperability testing (IOP)

How

Results TETRA is the world-wide consolidated standard for PMR A large number of the deployed systems are multi-vendor solutions. TETRA actually is a real open standard. Apr-10

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Interoperability certification

> The Interoperability Certificate (IOP) assures that various manufacturers terminals can indistinctly operate on any TETRA network. > Tests are supervised from an independent accredited test house: initially was Teledanmark (Danish operator) now ISCTI (Italian Telecommunications Public Institute) > All functionality tested and approved are summarized in public tables

http://www.tetramou.com/facts/index.asp?pagereq=interoperability/interoperability.asp&setsub=2

Apr-10

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SCHENGEN position

> SCHENGEN Police Telecom Group (now replaced by Police Co-operation Working Group - PCWG) adopted TETRA for pan-European police communications. > ETSI confirmed that TETRA standard is compliant and supports the SCHENGEN operational and security requirements. > CEPT/ERC designated a 5 MHz spectrum in the frequency band 380÷400 MHz, for Police Forces usage of TETRA across Europe.

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TETRA references (December 2005 - source TETRA MoU)

> Total 788 contracts in 77 countries

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Functionalities and Characteristics

What are the PMR user needs? F

ull su pport s p u o to effi r g n cient e g twe n c i e o v n b o t rol ro and integr s m n t o i t u s ated oms nica ether b oup r u g m e g to om rg ow c working so for la s al user dently; on fast and reliable communications st Tru a n e e r ndep a wide a especially under critical conditions or n i and under emergency e Easy a icat re Termin nd fast n u m availab he hars als ab nforma m w o y i c r le to h en l ity of a tion (d e y l v l e a l a / v l wor t e a e job iron ) neede Id me k in i t m d to ca y r e e n rry out v ts e Trust on ons ti a c security li p p a d n ls a e o o a T of comm h g t a i nst host re and p u unicatio d e e i p l s e t to i ntercep n ed it u e s ns m t tion and l a n es io s s fe interrup improve pro tion t n e r e f if d s k n tas n betwee o i t c e n n ) rco s borders s o r Easy inte c a o ices ls a v ( r s n loit e io t organisa ed s t costs c n ong the inv a Adv lowes est est me te the

TETRA unique feature set

Users that take advantage of these technologies are spread over many sectors of both public services and private companies, that eed mobile communications to support their workforce

bile ephony

Full Duplex Voice

Air Interface Encryption

Mobile Security

End-to-End Encryption Status Messaging

Packet Mode

Mobile

Circuit Mode

DMO

Group Priority Emergency

Mobile

Main features (1/2)

> Real open standard in digital mobile radio tailored for professional users > Unlimited support to point-to multipoint (group) voice and data communications, with an extensive set of enhanced ancillary services > Focus on communications between radio terminals and control room/dispatcher operators > Direct mode of operation (DMO) in order to allow communications also in fringe or out of coverage areas and at times of capacity limitations

Main features (2/2)

> Multiple security schemes and algorithms > Voice and data capabilities with 4 TDMA channels in 25 kHz channel spacing: • • •

concurrent voice and data; full-duplex voice call using simplex radios; net data rates up to 28.8 Kbit/s.

> Standard interfaces for data terminal connections (PEI) and for TETRA networks interconnection (ISI) > Wide set of telephony and PMR supplementary services > Call Set Up Time: about 300 ms

TETRA services (1/4)

> Voice and data capabilities • • • • •

4 traffic channels in one 25 kHz radio channel point-to-point and point-to-multi point concurrent voice and data full-duplex call using simplex radios fast call set-up

> Fully digital trunked (TMO) and direct (DMO) modes of operation: • Dual watch • Repeater • Gateway

TETRA Direct Mode - Available terminals

4

4 3

3 2

Control Center

1) Basic 2) Repeater 3) Dual Watch 4) Gateway

3

1 2

4

TETRA services (2/4)

Multiple security schemes & algorithms > Authentication: • of User / Terminal • of the Infrastructure

> Encryption: • Air Interface Encryption • End-to-End Encryption

> Security Management > Disabling of stolen radios

Security

??????xyz

Switching

Authentication

Dispatcher

portables Handportables

Radio Base Station

Radio Base Station

END-to-END Encryption

AIR Interf. Encryption Voice/data encryption

TETRA services (3/4)

> Data rates up to 28.8 Kbit/s > Data communications • Circuit Mode Data • Status/Short Data Service (SDS) real time • Packet Data

> Data rate suitable to support applications such as: • mobile localisation • file/image transfer • slow video

TETRA services (4/4) STD. Interfaces > > > > > >

Air I/F ISI PEI PABX (Digital/Analogue) PSTN (Digital Analogue) PDN (Industrial Standards)

PMR Supplementary Services Access Priority Priority call (incl. Pre-emptive) Include call Late Entry Call authorised by Dispatcher Area selection Dynamic Group Number assignment  Discreet and Ambience Listening  Short Number Addressing       

Network Interfaces

Internet

PDN

LAN/WAN

ISI PSTN PEI

ISDN PABX

Virtual Private Networks (VPN)

> Possibility of sharing the same physical network among different organizations. Advantages are: • •

reduced costs for infrastructure; reduced cost for running the network.

> Each virtual network guarantees the complete independence to

Technology basics

System characteristics

OPERATIVE FREQUENCY:

Band and duplex spacing (Tx/Rx):

380÷400 410÷430 450÷470 806÷870 870÷921

Carrier spacing:

25 kHz

MHz MHz MHz MHz MHz

MODULATION: Gross bite rate per carrier:

P/4-DQPSK 36 Kbit/s

Max data rate per carrier:

28,8 Kbit/s

Type:

(10 (10 (10 (45 (45

MHz) MHz) MHz) MHz) MHz)

Radio Access: Conventional Vs. Trunked

Conventional

Trunked

> Channels are dedicated to specific services > Uneven load distribution among channels > Waste of spectrum resources

> Channels are dynamically assigned to user requests > Traffic load distributed among channels > Optimal use of spectrum resources

Advantages of digital systems

> Constant voice quality

> High speed data transmission

> Subscribers and network authentication

> High security ciphering

Who are you ?

Digital Radio System

MICRO

FILTER

SAMPLE

COD.

COMPR. M U X

CODEC (TX)

MOD.

Transmission channel

(RF on air) SPEAKER

FILTER and PROCESSING

DECOD.

CODEC (RX)

DECOMP. M U X

DEMOD.

Bitrate on demand: TDMA and FDMA

Spectrum kHz

25 Carrier 1

CH 1

12.5 Carrier 2

CH 2

C H

C H

C H

C H

1

2

3

4

To

To

FDMA

TDMA

Carrier 1

Time

Advantages of TDMA systems

> Bitrate on demand > Higher data rates > Simultaneous voice and data > Simplex terminals for duplex communications > One TRX to manage four traffic channels

Time Division Multiple Access (TDMA) 1 hyperframe = 60 multiframes ( = 61.2 s )

1

2

3

4

5

60

1 multiframe = 18 TDMA frames ( = 1.02 s )

1

2

3

4

5

18

control frame 1 TDMA frame = 4 timeslots ( ~ 56.67 ms )

1

2

3

1

2

4

5

3

4 509 510

1 time slot = 510 modulation bits durations ( ~ 14.167 ms ) 1 2 3 4

509 510

1 subslot = 255 modulation bits durations ( ~ 7.08 ms ) 1

2

3

4

1

255

1

2 3

4

2

255

Radio channel usage: conventional analogue

1 channel in 25 kHz

1 channel in 25 kHz

CASE 1: conventional analogue systems

Radio channel usage: FDMA

1 channel in 12,5 kHz

1 channel in 12,5 kHz

1 channel 12,5 kHz

1 channel 12,5 kHz

CASE 2: FDMA analogue and digital systems

Radio channel usage: TDMA

1 ch

25 k n i l anne

Hz

1 ch anne l in 2 5 kH z

CASE 3: TETRA digital systems

Technology comparison

Why TETRA instead of proprietary PMR technologies

TSI STANDARD

   

> Interoperability > User requirements fulfillment > Future-proof technology

Trunked Digital TDMA based Richest set of services

PEN STANDARD

STATE-OF-THE-ART STANDARD

 Competitive prices  Competitive quality  Innovation

Real competition

> Currently there are: • Approximately 12 independent TETRA infrastructure manufacturers • Approximately 8 independent TETRA terminal manufacturers • A huge number of independent application developers

These figures are constantly increasing

TETRA in comparison to other PMR systems TETRA

MPT1327

TETRAPOL

SmartZone

EDACS

ETSI / EC

DTI

Forum TETRAPOL

MOTOROLA

ERICSSON

Open/Proprietary

Open

Open

Proprietary

Proprietary

Proprietary

Independent manufacturers

15÷20

roughly 15

1

1

1

Digital/Analogue

Digital

Analogue

Digital

Analogue/ Digital

Analogue/ Digital

Access

TDMA

FDMA

25

12,5

4

2 7,5

9,6

Defined by

Radio channel bandwidth (kHz) Traffic channels within 25 kHz Maximum data tx rate (kbit/s) Simultaneous voice and data Call set-up time

28,8

2,4

YES 300ms.

7,2 NO

1 sec.

300 ms.

Why TETRA instead of public cellular networks GROUP COMMUNICATIONS  Unlimited extension and number of members  Very powerful set of supplementary services DISPATCHING ORIENTED  Focus on communications between radio terminals and control room operators  Very powerful set of supplementary services

SECURE COMMUNICATIONS Widest set of services:  authentication  encryption  radio disabling  ... TRUNKED AND DIRECT MODE  Basic  Dual watch  Repeater  Gateway

TETRA in comparison to other public cellular networks Features Group/Broadcast Call

TETRA

GSM / GSM-R / GPRS

UMTS

9

9 GSM-R

-

with limitations Dynamic Group Number Assignment Call authorized by dispatcher Ambience and Discreet listening Authentication of the Infrastructure End-to-end encryption OTAR Physical disabling of stolen radios Direct Mode DMO Gateway/Repeater Fast Call Set-up Emergency calls (preemptive) Short Data Service Packet Mode Data Circuit Mode Data Concurrent Voice & Data

9 9 9 9 9 9 9 9 9 9 9 9 (real time) 9 9 9 9

9 GSM-R 9 9 GPRS 9 9 9 GPRS

9 ? 9 9 9 9 9

How do speeds compare?

0

100

200

Indoor Terminal

2 Mb/s

UMTS Handset

384 kb/s

EDGE Handset

384 kb/s

UMTS Vehicular

144 kb/s

GPRS

115 kb/s TETRA (Rel. 1) 28.8 kb/s

300

400

2000 kb/s

Some scenarios and applications

Some data transmission applications (1/2)

Automatic terminal localization > Using GPS receivers connected to TETRA terminals the determination of the mobile position is carried out and transferred to the control room. File transfer > Using the circuit or packet mode data transfer, it is possible to transfer data from/to radio terminal (suitable equipped) to/from proprietary database even external to the TETRA network.

Some data transmission applications (2/2)

Fax > This functionality is obtained through data transfer and specialized gateways. Image transmission / Slow video > The transmission of fixed (mugshot, building maps, ...) or slowly changing images is possible using particular compression algorithms that allow the optimization of transmitted data amount and therefore channel load.

Scenario Control room operator can simultaneously communicate with and localise the vehicles Multiple channels allow multiple separated communications at the same time

ency Vehicles

sen din g

n tio a iz al c lo

Vo ice an dd ata

Vo ic e

an d

da ta

se nd in g

Base Station Voi ce

and d

Car 1 for an accident at High Road… old man with broken leg ...

ata loc sen din ali g za Vo tio ice n an dd ata sen din g

Control Room

Scenario > Patient’s medical data sending in electronic format, directly from the ambulance while going to the hospital > Possibility of communicating with fixed telephony network or cellular network, for instance to put in touch ambulance operators with specialist doctors reachable at cellular phone

Control Room Medical data

EVENT

Ambulance

Scenario > Suspect person is identified by means of personal data in his/her documents or with electronic fingerprint. Data are sent through radios for remote database research; if research is successful, complete data of suspect person (e.g. including mugshot) are sent back in real time to officers on the field.

Officer identifying suspect person

Fingerprint or Name INFO DATA BASE

Complete personal data including mugshot

Scenario

> Possibility of communicating with fixed telephony network or cellular network, for instance Integrated Command and Control centre managing an operation can put officers in touch with calling citizen in order to allow direct information exchange when needed

Control Room

Officer (e.g. looking for the place where the intervention

Citizen

Scenario

Separate communications, simultaneous and independent, among different teams operating on the same intervention and/or in the same area Co-ordinator can communicate with one team but he can be at any time alerted by another team and then change group communication

…OK team 1, …increase the flow!... report situation...

ention please!!!

am 1

Group Team call 1 requiring switch to urgent communication! team 1

Communication with team 2

Scenario

At any given time, if the two teams need to work together, the two group communications can be merged in one thanks to groups patching Dispatching station

…Team 2, this is team 1 calling...

…OK team 1!!

am 1 Coordinator

Scenario > Communications are fully confidential, avoiding the risk of improper use of information by any unauthorised people (criminals, terrorists, hackers, hostile government agencies, press, …) …immediate intervention required at Blue Mountain.. Protection by en

…OK, we are moving ..

Interception failed!!

cryption

Control Centre

Scenario When network coverage is not available (underground parking, tunnels, …), basic TETRA communication services are granted thanks to Direct Mode Operation Also under those conditions it is possible for Control Centre or other users under the network coverage to communicate with users outside of the coverage thanks to special equipment called DM-Gateway

Network

Un de r

gr ou nd

Scenario > Multiple organisations can share the network and set-up integrated communications only when needed > It is always supported the possibility to manage emergency scenarios with emergency calls, using pre-emption and granting call set-up within very short time (300ms)

…Urgent communication! Redirect the convoy…..

PROTECTED CONVOY

300 ms

Ambulance

Scenario Data transmission is supported at bitrate up to 28.8Kbps, supporting a wide range of applications including image and video transmission

ontrol Room

Dat a

tran smi s

sion

Onboard camera

User-specific considerations

Special issues for Public Safety (1/4)

> Some specific requirements must be carefully considered when TETRA networks are going to be deployed for mission-critical use: • • • • •

Reliable and Flexible network topology BS Fallback capability End-to-End encryption Direct Mode Gateway Data transmission (best bearer for service)

Special issues for Public Safety (2/4)

> Availability of radio communications for mission critical application must be granted at the largest extent > In addition to redundant elements, networks must offer the highest level of flexibility in order to streamline the network design to offer the required reliability in any customer-specific condition > Examples of these implementations are • Self healing rings to connect Radio Base Stations • Full network links redundancy • Disaster recovery mechanisms for Switching Nodes and Network Management System

Special issues for Public Safety (3/4) Additional mechanisms are crucial to support as far as possible the availability of communication services > Base Station Fallback operation: •

grants local communications under the BS coverage also when the Switching Node is not available (due to backbone interruption or Switching Node failure)

•

is required to provide complete set of services (individual and group voice&data transmission, security features, …) and, if possible, connection to other alternative fixed networks

> Direct Mode Gateway terminals: •

provide a valuable improvement to the possibility of communicating as they allow users to get in touch with the headquarter also when outside the network coverage

Special issues for Public Safety (4/4)

> Experiences world-wide confirm that Public Safety services efficiency is more and more dependent on the capability to manage data remotely, while moving. > One of the most valuable benefits brought by TETRA is the capability to efficiently exchange INFORMATION (e.g. localisation, database interrogation, images and video, …) between officers on the field and headquarter. > TETRA offers multiple mechanisms for data transmission and stateof-the-art performance (i.e. bitrate) in order to provide the best bearer for each application. > It is crucial hence to rely on the largest set of data transmission features provided by TETRA.

The future

TETRA Release 2: some major objectives

> New 3G applications availability obtained thanks to • Increased data transmission bandwidth

> Backward compatibility obtained thanks to • Same frequency bands as TETRA • Backward compatible air interface protocol

> Efficient interworking with 3G public networks obtained thanks to • SIM and CODEC integration with UMTS

TETRA is future proof Long Range TETRA

TETRA SIM Evolution

3G Interworking

Air IF Enhancement

High speed data

End presentation