TETRA

ABSTRACT In this paper we will talk about ENC and TETRA system Overviews.

Author : By reyad Mohamed alfeturi EE 526

TETRA ENC Field Trip

2O14 - 2O15

1

2

Contents 1. Introduction •

Etisalat Naweaa Company (ENC)

•

NTN Project

•

Professional Mobile Radio (PMR)

2. TETRA •

TETRA Services

•

TETRA Air Interface

•

TETRA Modes of Operation (Sub-Standards)

•

TETRA System Architecture

•

TETRA Main System Components

•

TETRA security

•

TETRA Main System Components

•

Tracing a Basic Call

3. Before Testing 4. Summary 5. Appendix 6. Reference

3

Introduction This chapter introduce to Etisalat Naweaa Company (ENC) and

Professional Mobile Radio (PMR)

4

1. Introduction 1. 1Etisalat Naweaa Company (ENC) Is a public national company owned and regulated by the ministry of telecommunication & information technology.

The company was established in 2009. And it specializes in the implementation, management and operation of mission critical telecommunication systems required to fulfil the needs of all of the government sectors across the Libyan soils.

1.1.1 The Company's Dependency: ENC is a national company under the supervision of the Ministry of Communications. ENC company independent company, which is responsible for the supply and operation of public safety equipment, such as TETRA.

Fig 1: Company's Dependency

5

1.1.2 Partners & Consultants Companies is Contracting with ENC who are partners or consultants.

And the company MOTOROLA is the leader in manufacturing TETRA equipment, SYSTEL is subcontractor Official for MOTOROLA in the Middle East.

1.2

National TETRA Network Project

ENC signed a contract with MOTOROLA Solutions Inc. to implement the first national mission critical wireless network of its kind across the Libyan soil in 31/10/3013.

The project involves the supply, installation and operation of the modern digital TETRA wireless network systems in order to provide a wide area of wireless coverage across the Libyan soil, which includes providing

6

coverage for the main cities, villages, coastal lines, main road networks, border check points & outlets and Territorial waters with 30 km depth Inside the sea.

1.2.1 NTN Project Scope The project aims to build a secure, reliable and efficient telecommunication infrastructure that provides mission critical stationary and mobile services (Voice + Data) for the professional community in Libya.

1.2.2 Targeted Customers The project specifically targets the professional community in Libya. Both in the private and the public sectors. Which includes: •

Gas & Oil Sector.

•

Electricity & Energy Supply Sector

•

Telecommunication & Information Technology Sector.

•

Military Sector, Border Guards, Coastguards.

•

Public Safety Sector.

•

Ambulance & Rescue Agencies

•

Railways.

•

Water supply and sanitation sector

•

Utilities

•

Private Sector (Future Plans)

7

1.2.3 Targeted Coverage Main cities, villages for coverage (blue color and green color), Coastal lines, main road networks (light blue color) Border check points & outlets and Territorial.

Fig 2: Main cities, villages, coastal lines, main road networks, border check points & outlets and Territorial.

1.2.4 Core Network Main Switches linked with high-speed redundant fiber optics links for Tripoli, Benghazi, Sabah, almantakah alwosta.

Fig 3: Main Switches linked with high-speed redundant fiber optics links.

8

1.2.5 Used Topology & Redundancy Each one of the main 4 Switches is backed up by a redundant switch which is separated from the main switch by distance of 60-80km taking into consideration natural\man-made disasters.

Fig 4: Used Topology & Redundancy

The topology used is ring topology and in any hope has a router the advantage in these topology when a filer happened between hopes can be transmitted data in other direction, the loop will be invers direction and will not disconnect a service.

1.2.6 Current Status of the Project Stations distribution in this time for operating and services in Libya.

Fig 5: Current Status of the Project

9

1.3. Professional Mobile Radio (PMR) 1.3.1What is PMR? • Private Mobile Radio (PMR) - sometimes called Professional Mobile Radio is a radio communication system developed for professional users who needed to keep in contact over relatively short distances with a central base station / dispatcher. Usually these systems were private and belonged to the organizations that required their services.

• From their early designs, conventional PMR systems have developed into 'trunked' systems. Which allowed the emergence of Public Access Mobile Radio (PAMR) and pushed the development of new features and services for these systems.

• Operation of PMR radio equipment is based on such standards as MPT1327, TETRA, APCO 25, and DMR. 1.3.2 Some of PMR Standards APCOP25 : P25 or APCO-25 is a suite of standards for digital radio communications for use by federal, state/province and local public safety agencies in North America to enable them to communicate with other agencies and mutual aid response teams in emergencies. In this regard, P25 fills the same role as the European Terrestrial Trunked Radio (TETRA) protocol, but the two are not interoperable.

MPT: (DMR) is an open digital radio standard for professional mobile radio (PMR) users specified in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 parts 1-4[1] and used in products sold in all regions of the world. The applicable ETSI emissions compliance standards are EN 300 113 and EN 300 390. The standard was first published in 2005 and has been widely adopted by radio manufacturers and users.[2] Products built to the DMR standard also comply with the U.S. Federal Communications Commission (FCC) mandates in the United States for the use and certification of 12.5 kHz and 6.25 kHz narrowband technology for systems covered by Part 90 regulations. Designed as a low cost entry level radio system for commercial

10

use, DMR is not classed as a mission critical or critical communications platform, a situation further compounded by vendors introducing proprietary standards over and above the limited ETSI DMR standards list and nulling interoperability between different vendor offerings.

Fig 6: Some of PMR Standards

DMR : Digital mobile radio (DMR) is an open digital radio standard for professional mobile radio (PMR) users specified in the European Telecommunications Standards Institute (ETSI) Standard TS 102 361 parts 1-4[1] and used in products sold in all regions of the world. The applicable ETSI emissions compliance standards are EN 300 113 and EN 300 390. The standard was first published in 2005 and has been widely adopted by radio manufacturers and users.[2] Products built to the DMR standard also comply with the U.S. Federal Communications Commission (FCC) mandates in the United States for the use and certification of 12.5 kHz and 6.25 kHz narrowband technology for systems covered by Part 90 regulations. Designed as a low cost entry level radio system for commercial use, DMR is not classed as a mission critical or critical communications platform, a situation further compounded by vendors introducing proprietary standards over and above the limited ETSI DMR standards list and nulling interoperability between different vendor offerings

PMRdigital: dPMR or digital private mobile radio, is a Common Air Interface (CAI) for digital mobile communications. dPMR is an open, non-proprietary standard that was developed by the European Telecommunications Standards Institute (ETSI) and published under the reference ETSI TS 102 658.

A simplified version of the dPMR protocol intended for license-free applications was also published by ETSI under the reference TS 102 490. dPMR is very similar to NXDN protocol implementation by Kenwood and Icom; both now offer dual-standard equipment (July 2013).

11

OpenSky: is a registered trademark of Harris Corporation

[1]

and is the trade name for a

wireless communication system, invented by M/A-COM Inc. that is now a division of Harris RF Communications. OpenSky technology applies voice over IP transport to radio communications applications in a unique architecture.

In the mid-1990s Federal Express invited proposals for a data and voice network to the vehicular level. As the world's largest shipper, FedEx was a key opportunity, and major market players presented their existing product offerings over some time.

D-STAR: D-STAR (Digital Smart Technologies for Amateur Radio) is an FDMA and GMSK digital voice and data protocol specification developed in the late 1990s by the Japan Amateur Radio League for amateur radio. There are newer digital radio modes used by amateurs, D-STAR was the first packet-based standard designed and widely used specifically for amateur radio.

1.3.2 Some of PMR advantages over Commercial Cellular systems • Modern PMR systems utilizes varying levels of security from basic voice scrambling right up to complex military grade encryption algorithms depending upon the needs of the encryption.

• Very short call setup time down to the mille-second level (efficient signaling protocols).

• Sophisticated communications features such as push-to-talk group calls, direct mode calls, and emergency calls.

• Central operation with dispatchers control centers.

• Wide area of coverage (usage of low frequency bands, usually UHF/VHF).

• High level of reliability and Resilience (Durable terminal equipment, central equipment redundancy ... etc.)

• Low total cost of ownership (in the long term).

12

1.3.4 Private Access Mobile Radio (PAMR) A Private Access Mobile Radio (PAMR) network operator offers trunked system services to many different organizations. The operator administers a “trunk� of channels which are made available individually for the period of a call (individual or group call). This way, the frequency resources are shared much more efficiently. The PMR user groups mentioned above could share their networks thus becoming PAMR users. Typical examples of PAMR users include maintenance fleets, courier and delivery services, as well as construction and taxi companies.

13

TETRA This chapter introduce to TETRA stands for TErrestrial TRunked Radio.

14

2. TETRA What is TETRA? The acronym TETRA stands for TErrestrial TRunked RAdio. Which is a set of standards for modern digital trunked mobile radio developed by ETSI (European Telecommunications Standards Institute) to meet the needs of traditional Professional Mobile Radio (PMR) users and organizations.

TETRA architecture is scalable. This means that multiple levels of network deployments ranging from single site local area coverage to multiple site wide area national coverage can be achieved.

A little Bit of History: •

The project started life in 1989 as Mobile Digital Trunked Radio System (MDTRS).

•

In the early 90's the project name was changed to TRans European Trunked RAdio (TETRA).

•

However, in the mid 90's the meaning of the TETRA acronym was changed to TErrestrial TRunked RAdio after ETSI found a worldwide interest in the TETRA standards.

•

Later in 1995 ETSI introduced the first standard for the TETRA system (TETRA Air Interface Standard) which enabled

15

•

manufacturers to design their radio communications equipment to interoperate successfully.

The first contracts for deploying a TETRA network was signed back in 1996.

•

In 1999, multiple users and manufacturers within the Technical Committee (TC) TETRA and the TETRA association identified the need to enhance TETRA in several areas, which resulted in the standardization of what's considered to be the 2nd with a set of new features and enhancements. Release of TETRA At the end of 2005.

•

Field tests and trials of TETRA are still on-going by ETSI and its host of manufacturers and testers until this day.

TETRA Worldwide Acceptance At the TETRA World Congress in November 2004, it was reported by the TETRA MoU Association (Currently - TETRA + Critical Communications Association) that 622 contracts had been placed for TETRA spanning 70 countries world-wide (90% increase over those recorded in 2003).

•

In June 2008 the number of contracts increased up to 103 countries.

•

At the end of 2009 there were 114 countries using TETRA systems in Western Europe, Eastern Europe, Middle East, Africa, Asia Pacific, Caribbean and Latin America.

16

Information about The TETRA system owned by ENC which is targeted for expansion in the NTN project is implemented by MOTOROLA solutions Inc...

The solution's brand is DIMETRA IP which stands for Digital Motorola Enhanced Trunked Radio, an implementation for the TETRA open standard that is built around Motorola's IP (Internet Protocol) core technology.

2.1 TETRA Services Basic Services Voice Services (Encrypted \ Clear): • Point-To-Point call: two way full-duplex call.

• Group call: point-to-multipoint call. Not all parties are required to be present while the call is initiated.

• Acknowledged group call: point-to-multipoint call. All parties are required to be present while the call is initiated.

• Broadcast call: this type of call is usually used by dispatcher units which represents a central communication points in PMR systems in order to contact a wide base of users at the same time.

Data Services (Encrypted\Clear): • Short data service (SDS): which offers user defined and pre-defined reception and transmission for individual messages and group messages.

• Circuit mode data: which offers multiple data rates starting from 2.4 kbps up to 28.8 kbps using different levels of protection ranging from unprotected

17

data transmission to highly protected data transmission.

• Packed data service (PDS): which offers either connection oriented or connectionless packet data transmission.

Supplementary Services PMR type supplementary services: • Access priority, pre-emptive priority, priority call.

• Include call, transfer of control, late entry.

• Call authorized by despatcher, ambience listening, discreet listening.

• Area selection.

• Short number addressing • Talking party identification • Dynamic group number assignment

Telephone type supplementary services: • List search call.

• Call forwarding - unconditional/busy/no reply/not reachable.

• Call barring - incoming/outgoing calls.

• Call report.

• Call waiting.

• Call hold.

• Calling/connected line identity presentation.

• Calling/connected line identity restriction.

• Call completion to busy subscriber/on no reply.

• Advice of charge.

• Call retention

18

Remember That Manufacturers are not constrained to provide the features and services presented in the standard only. They can add and tailor the features set provided by their systems according to market trends and user needs taking into account that the standard services must be available in any TETRA system marketed by any manufacturer.

MOTOROLA's DIMETRA IP v8.2 TETRA system which is the base system used in the NTN project is reported to have over 400 features. Some of these features are system related and some of them are user related.

2.2 TETRA Air Interface Frequency Allocation Original design: 380-390 paired with 390-400 MHz for public safety use.

410-420 paired with 420-430 MHz for other uses CEPT Recommendation: 450-460 paired with 460-470 MHz • 870-876 paired with 915-921 MHz Duplex spacing: 45 MHz for the 900 MHz band 10 MHz for all of the other bands

Fig 7: Frequency Allocation

19

Multiplexing Techniques • TETRA uses TDMA\FDMA multiplexing.

• 25 KHz RF carrier spacing.

• 10 MHz Duplex Spacing (45 MHz in 900 MHz band).

• Each carrier is divided\multiplexed into 4 time-slots using TDMA. • Each BTS can hold up to 8 RF carriers. With the utilization of TDMA\FDMA multiplexing, a maximum of 32 channels can be provided.

Fig 8: Multiplexing Techniques

TDMA Frame Structure TETRA is a TDMA standard. This means several users share one frequency, speech and data are transmitted in digital format and multiplexed into time slots. All of the four different TETRA time slots on one carrier bear different channels, so there can be as many as four different calls on one 25 kHz wide carrier frequency. There are (at least) two advantages of this method:

20

• Several time slots can be used to transmit voice and data at the same time or time slots (channels) can be combined to transfer data at higher rates. • The four channels are transmitted and received by the same equipment in the base station, which can reduce the infrastructure cost.

Fig 9: TDMA Frame Structure

One time frame consists of four time slots. Data is compressed and sent in one of the available time slots. On a traffic channel, every 18th frame is used to exchange additional control information between the radio terminal and

21

The base station as shown below:

Several radio terminals may use the same carrier. So that they do not interfere with each other’s communication, each terminal is assigned its own time slot for the duration of the call. The terminal sends its data in a burst, i.e. the radio power is turned on for a short period and turned off again before another terminal transmits in the next time slot.

Fig 10: Bursts and Time Slots

Bursts and Time Slots A radio terminal transmits its data in so-called “bursts�. The transmitter emits RF power for a defined period of time (usually a time slot). The RF carrier is modulated with the bits that make up the call or control information. During a call, one burst is transmitted per

22

TDMA frame. Although a base station usually sends a continuous bit stream, this stream of data is also divided into time slots often called bursts (although the power remains on). A burst can carry one or several logical channels, e.g. in the downlink (from base station to terminals). Most bursts consist of a long bit sequence for one channel and a shorter bit sequence to broadcast how and when this physical channel is used. Each time slot consists of a number of bits, grouped into bit fields with their respective meaning. The TETRA base station uses the following types of bursts: • Normal (continuous or discontinuous) Downlink Burst NDB, used for most transmissions from the base station to the terminal • Synchronization (continuous or discontinuous) downlink Burst SB, carrying a longer training sequence, used to support the terminal when it synchronizes to the base station The TETRA terminal uses a different set of bursts: • Control uplink Burst CB, a half-slot burst used by the terminal for initial network access • Linearization uplink Burst LB, a burst sent only to allow the terminal to adjust its own transmitter • Normal uplink Burst NUB, the burst type used in any other transmissions Modulation & Voice Compression The modulation format of TETRA is ð/4 DQPSK (differential quaternary phase shift keying). This modulation method shifts the phase of the RF carrier in steps of ±ð/4 or ±3ð/4 depending on the data transmitted.

23

Fig 11: Modulation format of TETR

With each phase change, one symbol containing two bits is transmitted. In a vector diagram of the modulation signal shown below, the ideal positions of the eight possible signal vector states lie on a circle.

Fig 12: DQPSK (differential

quaternary phase shift keying)

TETRA uses error-tolerant modulation and coding formats. The information to be transmitted is coded, adding some redundant information in the CRC. This information can be used to identify reception errors and to reconstruct the correct bit stream with a highly sophisticated bit error correction algorithm. But if the correction function is operating at its limits (e.g. because transmitter and receiver are far from each other so that the signal quality is very low with many errors), speech quality could suddenly turn

24

from good to bad. Therefore, correctly adjusted demodulators and modulators are necessary.

A-CELP (Algebraic Code-Excited Linear Predictive) Codec The TETRA speech codec is the base on the code excited linear predictive (CELP) coding model. This is to a parametric code using linear predictive coding with a bit rate of about 4.5Kbps. This technique is used transmit information about the exciting sequence and the filter coefficients. The TETRA code use an excitation generated based on a codebook of algebraic code (ACELP) and content many excitation sequence of pulse with different amplitude.

Fig 13: A-CELP Codec

25

Types of Communication Channels 1- Control Channel The Control channel allows the controller within the system to communicate with all radios in the system to receive call requests and send channel assignments to the radios in the field.

A radio uses a control channel to send in call requests or to receive call assignments. A radio always tunes to the control channel except when it is assigned to a call on a traffic channel. When a call is completed, the radios involved in the call switch back to the active control channel.

2- Traffic Channel When one of the members of a group requests voice or data services, the group (or individual - depending on the call type) is assigned its own traffic channel for the duration of the call. A group that is assigned to a particular traffic channel cannot be heard by members of a talk group assigned to another traffic channel.

2.3TETRA Modes of Operation (Sub-Standards) Trunked Mode Operation Which is the default mode of operation of the system that utilizes the whole system infrastructure, enabling the use of the complete set of features and services provided by the system.

26

Voice + Data (V+D): V+D is the standard most commonly referenced. It allows switching between Speech and data transmission instantaneously; both can even be transmitted “at the same time� (in different time slots on the same channel). The radio protocol has been optimized to allow fast call set-up, both semi- and full duplex and high spectrum efficiency in a trunked mode environment, i.e. using base stations to relay information.

Direct Mode Operation (DMO) (DMO) being used when there is no infrastructure (base station) available.

In this case, only one party can speak at a time (simplex). Receive and transmit frequencies are identical (no duplex spacing).

27

Dual Watch (DMO Gateway) This type of operation allows DMO terminals to use one another as repeaters in case of being out of trunked network coverage. Also, a Radio terminal can be used as a gateway to link another terminal to the trunked network by providing a coverage extension. In order to do that, the gateway terminal must be capable of Dual Watch operation.

Packet Data Optimized (PDO) For applications requiring occasional data transmissions, the PDO standard has been created. This can be a highly efficient method for dataonly transmissions to save costs. There are much higher data rate requirements foreseen in the future and to cater for these new demands, an ETSI project group (DAWS) has been set up to define a faster system built on the TETRA PDO core.

Extra Mode of Operation As an example of the TETRA proprietary features added by manufacturers above the standard feature suit, another TETRA mode of operation is mentioned in this section that is incorporated within

28

MOTOROLA's DIMETRA IP system which is the "Local Site Trunking" mode of operation.

This function allows communication (locally) on disconnected sites of a TETRA network to continue without loss of features and performance. The affected site operates as a single site trunked system providing services to radios registered with the site.

Simplex, Semi-Duplex, Full Duplex In trunked mode operation, there is always a base station and network to switch information between one or several users.

Any type of communication can be: • Full duplex (both users can speak and listen at the same time) • Semi-duplex, where only one party can speak at a time, usually a Press-ToTalk button is used and the end of speech is announced by “Over”

29

• Simplex, which can be a broadcast message In order to avoid interference, base station and mobile station use different Frequencies with a fixed duplex offset, e.g. 10 MHz

There is also a direct mode operation (DMO) being used when there is no base station available. In this case, only one party can speak at a time (simplex). Receive and transmit frequencies are identical (no duplex spacing).

30

Connectivity Connectivity between networks of different type is becoming increasingly important. This has been taken into account in the development of TETRA technology. TETRA networks facilitate a tide range of connections to external networks. A TETRA network can be connected to, for example, public and private telephone networks, different types of data networks as well as large command and control systems. All these networks can he accessed from the mobile terminal.

Fig 14: Connectivity

Connectivity combined with bandwidth-on-demand makes TETRA a superior platform for data application development.

TETRA is Complementary to GSM TETRA is not intended to compete with GSM or any cellular technologies they are clearly made for different purposes. TETRA is designed for professional mobile radio applications and GSM is designed for public cellular telephony. Although these applications may occasionally overlap, there is a fundamental difference in the requirements.

31

There have been proposals to add PMR-type functionality in the GSM standards to expand the GSM market towards professional radio users especially for railway applications. It is likely, that GSM will someday contain some professional user oriented features. but those will be far from the PMR needs. It will not be possible to implement direct mode operation, fast call set-up or proper semi-duplex group communications features into today's GSM networks.

The modification of the GSM standards and systems to a PMR-like product has been studied by many manufacturers. The result was clearly that this son of modifications deep in the core of the current GSM architecture would be too expensive, line-consuming and risky to implement. TETRA is clearly a superior platform for digital professional mobile radio applications.

It is a common misunderstanding, that GSM professional radios would be cheaper than for example TETRA professional radios, just because GSM cellular phones are cheaper. This wishful thinking is not based on any hard

32

facts. Both the manufacturing and operator communities are lacking interest to seriously develop professional mobile radio features into GSM. The expected market volume is far too small for the big cellular phone manufacturers, whose production capacity could manufacture the total cumulative five-year European volume within a few days.

The expected infrastructure market volumes for example on tile railway sector are likewise too small compared with the main stream GSM market volumes. The successful GSM infrastructure vendors are not interested in implementing professional mobile radio features.

It can as well be assumed that the interest of current GSM operators in the implementation of these features will significantly decrease, when the risks and costs involved in implementing these features in the existing networks is revealed.

33

2.4 TETRA System Architecture Standard System Architecture

Fig 15: Standard System Architecture

Interfaces The interfaces in a TETRA network are [2]: I1 = Radio air interface I2 = Line station interface I3 = Inter-system interface. This interface allows interconnection of TETRA networks from different manufacturers I4 = Terminal equipment interface for a mobile station I4 = Terminal equipment interface for a line station I5 = Network management interface I6 = Direct mode interface

34

Network Components Functional structure of a TETRA network includes

Mobile Station (MS) comprises subscriber’s physical equipment, a Subscriber Identity Module (SIM) and a TETRA Equipment Identity (TEI) specified to each device. TEI is input by the operator which means a stolen device can be disabled immediately.

Line Station (LS) has similar structure as a mobile station but with the switching and management infrastructure connected over ISDN. It provides the same function and services as a mobile station.

Switching and Management Infrastructure (SwMI) contains base stations that establish and maintain communication between mobile stations and line stations over ISDN. It allocates channels, switches calls and contains databases with subscriber's information.

Network Management Unit provides local and remote management functionality.

Gateways interconnect a TETRA network with a non-TETRA Network such as PSTN, ISDN and PDN. Translation or conversion of information formats and communication protocols might be necessary.

Fig 16: Simplified System Architecture

35

2.5 TETRA security Security Requirements A secure communication network should provide Confidentiality, Integrity, Authentication, Nonrepudiation and Reliability Confidentiality Only authorized users should have access to the information being exchanged.

Integrity Only authorized users should be able to modify the information being exchanged.

Authentication The identity of the sender can be verified by the receiver.

Nonrepudiation The sender cannot deny the message he sent.

Reliability The service and resources are available and not denied to authorized users.

Classes of Security

The TETRA system provides three different security classes: Class 1: No encryption Class 2: The Static Cipher Key encryption Class 3: The Dynamic Cipher Key encryption Air Interface Encryption Since anyone could listen to air channels during the communication of MS and BS, it is important to encrypt information transmitted over the air.

Encryption is a method to make sure the intercepted information is not intelligible to anyone other than intended receiver.

Air interface encryption handled in the upper part of the MAC layer, and the MAC headers left unencrypted.

36

Air Encryption Process Air interface encryption realized using an encryption algorithm implemented in a Key Stream Generator (KGS). As shown in figure: 17, the KGS has two inputs, an Initial Value (IV) and a cipher key and one output as a Key Stream Segment (KSS). The cipher text obtained by modulo-2 addition (XORed) the KSS bits with plaintext.

Fig 17: Speech and control information encryption

The Initial Value (IV) is 29-bit data with composition of slot number (2 bits), frame number (5 bits), multiframe number (6 bits), hyper-frames (15 bits) and a final bit indicates downlink transmission (0) or uplink transmission.

As shown in figure: 18 the Encryption Cipher Key (ECK) is derived from a selected Cipher Key (CK) which could be one of SCK, DCK, MGCK or CCK. The CK will be modified by the Carrier Number (CN), LA-id, and Colour Code (CC) using the algorithm TB5.

37

Fig 18: Generation of [ECK]

End-to-End Encryption Air interface encryption described above protects the communication between mobile stations and the base station. The end-to-end encryption also protects the transmission of the information through networks (BS to MSC, MSC to MSC and links within the TETRA infrastructure). Information encrypted by the sender and only be decrypted by the receiver. End-to-end encryption and key management are not specified in.

Air Encryption Algorithm The TETRA encryption algorithm (TEA) is used on the air interface. The TETRA MoU recommends a number of possible algorithms [18, 19, 20, 21] for different commercial requirements. TEA2 and TEA3 are restricted export algorithms that primarily designed for public safety organizations, while TEA1 and TEA4 are readily exportable algorithms The algorithm specifications can be obtained under a 'Non-disclosure and restricted usage licence' from ETSI.

38

Fig 19: Encryption

Mutual Authentication The TETRA system supports mutual authentication between the MS and the infrastructure. The mutual authentication will start as an one way authentication and the challenged party will decide whether to made the authentication mutual. The second authentication will only perform when the first authentication is successful.

Fig 20: Mutual Authentication

39

Highest level of network security Features: • FIPS 140-2 Level 3-oriented tamper-proof end-to-end encryption modules available in every system gateway.

• Each encryption module supports up to eight algorithms including AES 256 and OTAK functionality.

• Repeater sites do not require GPS timing for synchronization. and the Benefits Reduce network vulnerability to vandal attacks and facilitate indoor installation

2.6 TETRA Main System Components Radio Terminal (Mobile Station) Subscribers get services from the network by using the Radio terminal (MS). When the Radio terminal is switched on, cell selection and reselection processes allow it to be camped on the cell with the highest received power level . Different types of Radio terminals are available depending of the scope of the use and nominal output: • Handheld radio terminal • Vehicular radio terminal • Motorcycle radio terminal • Aircraft radio terminal • Desktop radio terminal

40

Complete Digital TETRA Infrastructure System Power Trunk-T BSR The Base Station/Repeater is a modular unit that is easy to deploy and maintain. Each plug-and play module contains different functional blocks and provides specific alarms to minimize in-field repair time. Provides outstanding RF performance via 75 W output power, triple diversity option and highest sensitivity levels that boost your TETRA network coverage.

Power Trunk-T CNC The Central Node Controller provides the intelligence and processing capability for the trunking system. It manages call processing, users’ configurations, and real-time locations inside the network. These features ensure fast call setup, seamless roaming, and automatic switchover to a Redundant unit in case of failure. The hardware is an industrial-grade, highperformance computer using a real-time operating system.

41

Power Trunk-T NMS The Network Management System is based on a client/server networking architecture. Data collection and management are distributed across multiple client workstations through standard IP protocols. Designed according to the FCAPS model, the Power Trunk-T NMS can be configured for different access privileges to permit separate technical and operational management.

The NMS allows multiple agencies to share the network, yet isolates each agency’s subscriber management.

PowerTrunk-T LSC The Local Site Controller maintains communication with the Central Node Controller and manages the repeater units in case the link with the CNC is lost. Should that happen, the LSC provides a powerful fallback operation by maintaining all trunking functionality as a single site.

Power Trunk-T Connect The Connect Module provides an interface for interoperability with other systems such as mutual-aid channels, analog systems, or legacy trunking

42

systems. It is also the VoIP gateway for the CAD system: one module supports up to 10 dispatch consoles and 20 radio interfaces. Additional modules can be interconnected to increase capacity.

Fig 21: power trunk-t system node

EADS TETRA infrastructure This section describes all the relevant parts of the TETRA Switching and Management Infrastructure (SwMI) and provided interfaces that are the basic components of the LS implementation. The shown SwMI implementation is designed and manufactured by EADS Secure Networks

43

according to the ETSI TETRA standard. Since this thesis focuses on specific applications and features developed on top of the EADS TETRA infrastructure it would be beneficial to limit the main infrastructural definitions only to those influenced by the concept of location system solution. The network parts from mobile stations to SwMI involved with the TETRA LS is shown in Figure 22

Fig 22: The TETRA Switching and Management Infrastructure (SwMI)

Figure 3.2 shows the EADS TETRA SwMI involved with the TETRA LS solution. The included elements, with the exception of DWS and NMS, handle the location update data delivery between MSs and TCS. The TCS is the network element which provides TETRA system connectivity interface for the LS subsystem. For the LS, the DWS element takes part in subscriber management as NMS deals with network management and supervision tasks. (EADS 2009a; EADS 2009b.)

44

MS . Mobile Station MS equipment represents the users' tools for wireless voice and data communication via a TETRA network. TETRA mobile stations can be categorized in terms of equipment portability as hand-portable or vehiclemounted models which both fulfill the same basic functions. For the TETRA LS a MS is a user equipment that acquires the geographical coordinates via the Global Positioning System (GPS) and transmits these through the TETRA AI. TBS. TETRA Base Station TETRA Base Stations provide a wireless interface for TETRA networks utilizing the TETRA AI. Being a cellular system, TETRA networks' geographical coverage is provided by TBSs as cells. The TBS transmission functions are supervision, parameterization, control and air interface signaling.

DXT. Digital Exchange for TETRA The DXT is an access-layer switch which is the center of all communications supporting fast call set-up and high traffic throughput. It is a switching element handling all switching and management tasks required for connectivity to all other TETRA network elements. There can be multiple DXS switches implemented in one network providing and ensuring sufficient network performance.

CDD. Configuration and Data Distribution server In the EADS TETRA system configuration, an element called the Configuration and Data Distribution (CDD) server provides a range of data distribution services. It is a mandatory network element in all multi-DXT EADS TETRA network configurations. It provides access to all data in a network and also various services for monitoring subscribers.

45

TCS. TETRA Connectivity Server The TETRA Connectivity Server (TCS) offers for authorized TCS client applications an interface to the EADS TETRA system. To enable this it provides a secure and efficient Application Programming Interface (API) for the client applications to access the services provided by the TETRA system.

Such client applications include control room applications and a vast amount of 3rd party applications which are needed to extend the TETRA system feature portfolio for end-user specific needs. One of the TCS client applications is a network element called the location server which is described in more detail DWS. Dispatcher Workstation Dispatching workstations are used to run PMR operations in public safety and security organizations with an effective system of fleet management and filed unit dispatching. It can also be used as a centralized location to handle subscriber and workstation user management functions.

ENC Currently Provides

Fig 23: MTP850s Handheld, MTM5400 Vehicular + Desktop

46

Base Transceiver Station (BTS) Which is a part of the Switching & Management Infrastructure (SwiMI), the standard does not specify BTS functionality nor structure. In the following are the BTS functions based on the functionality of the BTS equipment used in the NTN project: • Radio link formatting, coding, timing, framing and error control.

• Timing control supervision to radios (Timing Advance).

• Radio link quality measurements (Signal Quality Estimate).

• Site to site frame synchronization.

• Interface translation: radio link to network equipment.

• Switching functions between multiple base transceivers (radio carriers).

• Air Interface Encryption.

• Local Site Trunking.

• Operation, maintenance and administration agent

ENC Currently Uses Some of MTS4 Specs.

• Supported Frequency bands: 350 - 430 MHz, 380- 470 MHz 851 to 870 (TX), 806 to 825 (Rx) MHz • Supports up to 8 Radio Carriers (Base Radios) with expansion.

• Transmitted Power: 25W, 40W. • Receiver sensitivity:

47

 

-120 dBm typical (static at 4% BER) -113.5 dBm typical (Mobile at 4% BER) at UHF band.

-119.5 dBm typical (static at 4% BER) -113.5 dBm typical (faded at 4% BER) at 800 MHz

Fig 24: MTS4

Control Sites Control sites are the locations where the users of the system (dispatchers and network managers) access the dispatch consoles (line station depending on the transmission media) and/or the network management terminals (NMTs - also called NMUs). A control site can include a variety of equipment to serve its particular purpose in the system. It may have just dispatch consoles or NMTs or it may have both depending on the requirements.

Fig 25: dispatchers and network managers, line station - depending on the transmission media

48

Digital switching infrastructure The digital switching infrastructure of IP based TETRA networks manly consist of computer servers, routers, switches and firewalls in addition to the required software for its operation. The most important functions of the digital switch are the: 

Call control functions.



Subscriber management.



Mobility management.



Management of the radio channel & Signaling.



Management of the TETRA base station.



Management of the dispatcher workstation.

49

2.8 Tracing a Basic Call 1st Stage: When a radio user initiates a call, the radio signals to the system via the control channel and requests a traffic channel. In the figure below, Radio 1 is requesting a call, and Radio 2 and Radio 3 in Talkgroup B are listening on the control channel and detect the request for a call. The radios in Talkgroup A are also monitoring the control channel but ignore the call request because they are in different talkgroup. nd

2 Stage: The system validates the call request, assigns a traffic channel and signals a traffic channel grant to all radios of that group. The members of Talkgroup B respond by monitoring the temporarily assigned traffic channel. Radios in Talkgroup A continue to monitor the control channel as before. In the figure below, Radio 1 is transmitting on a traffic channel, and Radio 2 and Radio 3 are listening to the call. rd

3 Stage: When the call is finished, all radios in Talkgroup B return to monitoring the control channel. The traffic channel becomes available for other radios.

(c)

(b) Fig 26: (a) 1st stage, (b) 2nd stage (c) 3rd stage .

(a)

50

3. Before Testing Carry out the following instructions before testing: • Check that you have a fully charged battery (Not required when using Battery Eliminator WALN4097).

• Connect an RF cable to the N-type RF Connector of the IFR • Connect the other side of the RF cable to the antenna adapter assembly (Motorola Part Number FLN9659). Connect the RF cable to the other side of The antenna assembly connector

Fig 27: Typical Test Setup

51

PROGRAMMING THE RADIO Before Using the Customer Programming Software (CPS) Before you begin programming, ensure the following: • That your radio battery is fully charged.

• That you have connected the Data cable (FKN4897), according to Figure 28.

• That the Customer Programming Software (CPS) is installed in your computer.

Fig 28: Setup for Radio Programming.

52

Programming the Radio 1. Verify that the radio is turned off.

2. Run the Customer Programming Software (CPS) on your computer.

3. Press the “1” and “9” keys together and then the On/Off key for about 3 seconds. Verify that no display appears on the LCD screen.

4. Click the Toolbar “Read Phone” icon. Refer to the CPS Application Window Screen in the CPS User Guide, Publication No. 68P02956C20. The setup enters an initialization process that takes about 20 seconds. After that, a reading process starts.

Note: While reading is in progress, the radio screen displays the following data:

Figure 29: radio screen displays

A progress bar appear on the computer screen. After the reading process is finished, the radio Code plug screen appears.

53

CodePlug Programming 1. On the menu bar, click “File” “Open”.

2. Browse for the required Codeplug file and open the file.

3. The Codeplug window appears on the screen.

4. Click the Toolbar “Tools” and select “Write Entire Codeplug”.

5. Press “Yes” icon.Note: The Codeplug is now being written into the radio. A progress bar is displayed on the computer screen showing the writing status. After a successful writing, the message “The Operation Was Successful” appears on the computer screen.

6. Press the OK button.

Application Programming 1. On the menu bar click “Tools”, “Write Software”.

2. Press “Continue” icon.

1. Note: The Codeplug reads data from the radio. A progress bar is displayed on the computer screen showing the writing status. After a successful reading, the “Write Software to Phone” appears on the computer screen.

2. Choose the Customized Choice” option.

3. Browse for the required application file and select it.

4. Press the “Write” button.

5. Note: The Codeplug is now being written into the radio. A progress bar is displayed on the computer screen showing the writing status.

6. After a successful writing, the message “The Operation Was Successful” appears on the computer screen.

7. Press the “Cancel” button.

8. Click the Toolbar “R” (Reset) icon.

54

LCD Display Test 1. Press any key consecutively. The display shows horizontal lines that becomes thicker with every key press, until it becomes fully dark.

2. Press any key again, the following appears at the top of the display:

3. Press any key consecutively. The display shows vertical lines that becomes thicker with every key press, until it becomes fully dark.

4. Press any key again. The display shows a map of Europe.

5. Press any key again. The display shows “Vibrator On”, verify that the radio is vibrating.

6. Press any key again. The display shows “Red Led on” and the Red LED at the top of the radio is lit.

7. Press any key again. The display shows “Green Led on” and the Green LED at the top of the radio is lit.

8. Press any key, the LED located on the top of the radio (near the antenna),Turns ON, and the two halves of this LED starts blinking with RED and Green lights.

9. Press any key again. The display shows “Backlight On” and the display backlight is on.

10.Press any key again. The display shows “Speaker Tone Test”, a tone is heard via the speaker.

55

11.Press any key again. The display shows “Earpiece Tone Test”, a tone is heard via the earpiece.

12.Press any key again. The display shows “Audio Loopback Test”, speak into the microphone, you should hear your voice via the earpiece.

13.Press any key again. The display shows “Chopper-Noise Test”, a low hum is heard via the earpiece.

14.Press any key again. The display shows all the radio keys.

15.Press every key, one by one. Each key you press causes its respective display to disappear.

16.Press Key. Every time you press causes the respective display to disappear.

17.After pressing all keys, the display is clear.

18.Turn the radio off.

56

4. Summary TETRA provides very fast call set-up time (300 ms), that is crucial for the TETRA mostly used by emergency and rescue service organizations, military, and as a general national safety communication network.

The system is then required to provide higher level of security than public mobile radio system. Guarantee confidential of communication, availability and reliability of the system is crucial. public safety and emergency services. Naturally, TETRA supports both semi-duplex operations for efficient group communication and duplex operation for telephony type individual calls. The advanced group and announcement call features included in TETRA meet the needs of the most critical user applications. Multiple call priority schemes ensure effective resource allocation to the most urgent traffic in the network.

Voice high quality when to compare with puplic mobile communication but in transfare data is not good with compare to puplic mobile communication .Voice However, analogue will provide high quality voice communication in high signal strength areas but this will gradually degrade down to poor voice quality in low RF signal strength areas.

TETRA have high relability because TETRA system have High level of redandent .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. Encryption keys of Multiple keys are supported in the TEA standards to allow different organizations use the same encryption algorithm but have their own unique key to prevent eavesdropping , Keys can be ‘static’ and/or ‘dynamic’ dependent on security needs and Using ACELP technique, TETRA Codec provides a nearly GSM quality at almost half bit rate Motorola Solutions is the leading supplier of TETRA to public safety customers. We have won the majority of recent nation-wide public safety TETRA contracts. In parallel Motorola Solutions is supplying TETRA systems to airports, Metro operators, Oil and gas companies and many other industrial organisations. The advantages of the centralised architecture together with other powerful features are available to all types of operator and end user.

57

PICTURES FROM ENC

MTS OF ENC CENTER

FEEDER FOR ANTENNA

Fig 30: MTS OF ENC CENTER AND FEEDER FOR ANTENNA MTS : you can see inside of MTS it have two card for two carrier Channels and from they have three ports for feeder antenna one feeder to transceiver and two for reciever and the maximum input cards carrier 4 . Can be transmitt over ethernet cable caste Category or normal connect coupled .

Test feeder for anttena used in ENC

SERVER OF ENC CENTER

UBS OF ENC CENTER

Fig 31: SERVER OF ENC CENTER AND UBS- OF ENC CENTER

From Picture you can see Server of ENC center Laptop inside S.box used this laptop for Management data and enter and edits.

UBS of ENC center this for reject the interruption of system and to increase reliability.

58

5. Appendix

Pictures

Practical Implementation

59

60

61

List of abbreviations AI

Air Interface

APCO

Association of Public Safety Organization Officials

API

Application Programming Interface

APL

Automatic Person Location

AVL

Automatic Vehicle Location

BL

Basic Link

CAD

Computer Aided Dispatching

CDD

Configuration and Data Distribution

CDF

Cumulative Distribution Function

CMCE

Circuit Mode Connection Entity

CP

Control Physical channels

DMO

Direct Mode Operation

DWS IF

Dispatcher Workstation Interface

EADS

European Aeronautic Defence and Space Company

ETSI

European Telecommunications Standards Institute

FCS

Frame Check Sequence

FDMA

Frequency Division Multiple Access

GIS

Geographic Information System

GPS

Global Positioning System

GSM

Global System for Mobile communications

GW IF

Gateway Interfaces

ISDN

Integrated Services Digital Network

ISI

Inter System Interface

ISSI

Inter Subsystem Interface

ISOOSI

International Standardization Organization – Open Systems Interconnection

LIP

Location Information Protocol

LLC

Logical Link Control

LMR

Land Mobile Radio

LS

Location System

LSI

Line Station Interface

62

6. Refrence [1] Lecture TETRA Students Training Material [2] TErrestrial Trunked RAdio - TETRA: A Global Security Tool [3] MOTOROLA DIMETRA TETRA SYSTEM CENTRALISED ARCHITECTURE ADVANTAGES WHITE PAP [4] Terrestrial Trunked Radio SCCOM [5] TETRA Introduction ACTERNA [6] Introduction TETRA Technology [7] Power Trunk TETRA and TETRA-Interoperable D-LMR [8] TETRA Portable Radio MTH500 [9] Interconnecting TETRA systems [10] TErrestrial Trunked RAdio - TETRA: A Global Security Tool [11] Digital Mobile Communications and the TETRA System [12] wikipedia.: http://en.wikipedia.org/

UNIVERSITY OF TRIPOLI

FACULTY OF ENGINEERING ELECTRICAL AND ELECTRONIC DEPARTMENT

Reyad Mohammed alfeturi 02108297 Supervision by: Dr- Tammam-Benmusa Fall 2014