In Brief:Full TETRA service at Schiphol AirportKPN Royal Dutch Telecom has replaced the existing MPT 1327network and radio equipment at Schiphol Airport by astate-of-the-art TETRA infrastructure based on Rohill’sTetraNode. The joint approach of KPN and Rohill has proven tobe very fruitful. This page

Seville Metro speeds up and announcesopening date by Spring 2008After some delay due to Civil Works problems, DominionTecnologías will start implementing the TetraNode Network forSeville Metro in 2007. This page

First TETRA System of IstanbulUskom Komunikasyon Sistemleri A.S. from Turkey has beenawarded several contracts for the delivery of communicationsand SCADA systems for the Istanbul Tram Lines. The contractsinclude the deployment of a multi-site TETRA network based onTetraNode. This page

Rohill launches new websiteThe Rohill website has been re-designed. Take a look atwww.Rohill.com. When doing so, register to receive the digitalversion of the next Tetra Notes and receive a complementary gift.

This page

Seamless WiMAX integrationRohill will introduce the TetraNode AdvancedTCA platformwith integrated WiMAX at TETRA World Congress 2007.This platform offers two optimised solutions for voice and datacommunications on a single system. Page 2

Line Dispatch Station Chameleon: Total FlexibilityTETRA World Congress 2007 marks the introduction of anothernovelty: the Line Dispatch Station Chameleon from Rohill.Chameleon combines powerful group-oriented dispatch facilitieswith unprecedented configuration flexibility. Page 2

TetraNode adds new dimension to telephony integrationIntegration of telephony has been a strong point of TetraNodeever since its introduction. With the introduction of the VoIPgateway server, TetraNode adds another dimension to telephonyintegration. Page 2

Line or radio dispatch station; what do you need?There are two types of dispatch stations: the radio dispatchstation and the line dispatch station. This article looks at thetypical dispatch solutions provided by each of them. Page 2

TetraNode Now Offers Seamless andSecure Connectivity to GSMRohill has partnered Tripleton to start a joint developmentto provide seamless and secure connectivity between TETRAand GSM networks, thus extending the coverage of its TetraNodenetwork out to the globally available GSM network. Page 2

Superior FCAPS capabilitiesThe recent introductions of NodeWatch, SubscriberWatchand CoverageWatch have significantly improved the FCAPScapabilities of TetraNode. Page 2

TetraNode offers a unique additional security benefitThis article explains what makes Rohill’s TetraNode uniquein terms of security features, compared with other TETRAinfrastructures. Page 3

TETRA versus APCO Project 25This article compares the benefits, features and functionality ofthe two open standards TETRA and Project25. Page 3

Recording solutions: luxury of essential?This article explains how voice and data monitoring andrecording can improve operations and, consequently, save livesin a mission-critical environment. Page 3

The ‘five nines’ and MontaVista Carrier Grade LinuxKlaas van Gend, Field Application Engineer Europe, MontaVista,explains how Carrier Grade Linux can help users to achievesystem availability in the range of five to six nines. Page 3

An alien in HoogeveenTetra Notes talked to Alister Bailey to find out whatmotivated him to move from the UK to the Netherlands to joinRohill in 2005. Page 4

Live monitoring the TetraNodeinfrastructure with NodeWatchIn order to maintain the agreed service level with its customers,TETRA network ChuChubi Trunking in the Caribbean areaneeds to be able to access and monitor the system status anduse in real time. For that purpose, the NodeWatch clientapplication is used. Page 4

Telvent to supply TETRA communicationsequipment for La Coruña and Vigo AirportTelvent signed two contracts with Spain’s airport operator AENAfor the delivery of TETRA terminals. The terminal units will beused as part of the TETRA communications system of La Coruñaand Vigo airport in Spain. Page 4

Successful implementation of TetraNode Networkat Santiago de Compostela Airport Early this year, Dominion Tecnologías successfully implementeda TETRA network based on the TetraNode Entry Level Platformfor Santiago de Compostela Airport, the most important airportin Galicia, Spain. Page 4

TetraNode system for Sofia AirportRohill, through its distributor company Comtek 2000, has won atender for the delivery of a TetraNode system for the main airportin Bulgaria. Redundancy features and the PABX group-call facilitywere deciding factors for the contract award. Page 4

Upgrading a TETRA systemThe very first TETRA networks are now ready to be upgraded toinclude the latest technology. This article presents the reasonsfor upgrading a TETRA system and the criteria for selecting aTETRA system upgrade. Page 4

CREATING A SAFER, MORE SECURE WORLD WITH TETRACIRCULATION: 20,000 COPIES TWC 2007 EDITION

• 350MHz type approval China• Setar network in Aruba expanded• Alcon appointed as official Brazilian

TetraNode distributor• Saudi Ericsson signs long-term

cooperation agreement with Rohill• Isolux focuses on utility market in

Latin America and Italy • STA expands TetraNode system in

the mountains of Andorra• Networking networks project ChuChubi

Trunking at the Dutch Antilles expanded• ZS Botswana launches hybrid TETRA and

MPT 1327 TetraNode network• Additional TetraNode systems for AENA

Rohill announces the introduction of• Powerful dynamic group call propagation • Ambience listening• Secondary control channel• Traffic channel pooling• Multislot Packet Data• Seamless WiMAX integration • NodeWatch client• Line Dispatch Station Chameleon

Rohill launches new websiteRohill has officially launched its newre-designed website. With a new look andfeel it is more attractive, comprehensiveand user-friendly. If you have any questions, comments or concerns, please contact us.

Tetra Notes goes digitalIf you would like to receive a digital versionof the next Tetra Notes, please register onwww.rohill.com/tetranotes. After registration, you will receive a complementary gift.

News-flashes

Schiphol airport is probably one of the mostdemanding environments the world for thedaily exchange of critical information interms of volume and speed. The operationof commercial airlines and support servicesrequires swift and reliable mobile communi-cations for a quick and efficient response tothe dynamics of change. At the same time, theairport emergency services require reliableways of communication in their continuousfight against incidents, fire and the threat ofterrorist attacks.

KPN Royal Dutch Telecom has been providing thesevital means of mobile radio communications to thewide variety of Schiphol users for many years now.In the last eight years, the service provision of KPNhas been based on an analogue MPT 1327 network,containing over 70 radio channels to provideprofessional mobile communications to 3500 usersdaily. Due to changing user demands and the MPT1327 standard becoming obsolete by the increasingdeployment of digital TETRA systems, KPNproposed to replace the existing network and radioequipment by a state-of-the-art TETRA infrastructureand user radio equipment. In subsequent discussionswith the two key user organizations at Schiphol,being the airport authorities and the Dutch airline,the TETRA platform proved to be the ultimate,future-proof platform for a single network that iscapable of meeting the business requirements of allthe different teams and companies working togetherat Schiphol airport. By the end of the year 2005,KPN secured the contract to provide mobile radiocommunications at Schiphol airport for another sixyears, based on TETRA infrastructure and radioequipment.

The TETRA radio infrastructure is based on Rohill’sTetraNode, using the AdvancedTCA platform.AdvancedTCA is an open standards PC-based platformspecially designed for carrier-grade telecomapplications with excellent system performance andavailability. As the radio network at Schiphol iscrucial for the daily exchange of critical informationand is used day and night by thousands of users,the network has to be able to cope with a hightraffic load and has to be operational at all times.The AdvancedTCA platform meets these criticaldemands, offering true no-single-point-of-failurewith fast switch-over within a single chassis andsupplying a vast amount of processing power. Radiocoverage at Schiphol airport is provided for by onetrue single site, which is equipped with no less than16 TETRA carriers. This equals 62 channels speechand data communications, while the residing twochannels are used as main control channels forsignalling and short data messaging.

Since the majority of the end-users works outside aswell as indoors, the site does not only allow foroutdoor coverage, but is also connected to anextensive radiating cable network for indoorcoverage. To optimise the RF coverage, the basestation is based on the Rohill R?8060 series.The standard 3?way diversity is used to realiseoutdoor diversity and allows for separate connectionof the radiating cable network, whilst the improvedRF sensitivity leads to an overall increase ofRF coverage. Naturally, also the base station isconfigured fully redundantly, avoiding outage of thesystem by failure of a single component.

Furthermore, one additional small remote site isincluded to provide RF coverage for a remotelylocated runway and a standby system is included forultimate system back-up. The standby system is tobe used for contingency purposes only. In casethe main system can no longer be used due to aphysical calamity, for instance a fire in the technicalroom, the back-up system shall be used. The standbysystem is hot standby and is installed at a remotelocation to provide or restore the vital radiocommunications in such cases. In the meantime,steps can be taken to restore the main systemwithout disrupting or blocking the operationalactivities of the end-users.

As indicated earlier, one of the challenging issuesKPN faced at Schiphol is how to enjoy the benefits ofone single radio network and, at the same time,having to comply with the business requirements ofall the different teams and companies using thesystem. The solution has been found in an excellentco-operation between Rohill and KPN. KPN, with its

long history as a system integrator, identified andtranslated the functional demands of the users intoglobal technical solutions with clear requirements.Rohill, as a leading technology provider, providesnot only the extremely flexible third-generationTetraNode platform, but also additional functionalityfor the proposed solutions. Combined with the veryshort time Rohill needed to develop the agreedsolutions, this joint approach has proven to be veryfruitful and enabled KPN to offer Schiphol airportan optimal solution, tailored to the individual userneeds, without compromising system manageabilityor system functionality.

Obviously, the new network provides all thefunctionality and more which the users enjoyedfrom the existing radio service. This includes theability to communicate fast within groups and/orbetween individual radios, the use of priorities inthe network for emergency calls and the possibilityto contact radio subscribers outside the ownorganization (also called interfleet communications).Apart from these rather ‘standard’ requirements forprofessional communications, the advanced keyfunctionalities of the new TETRA system lie amongother things in the enhanced data capabilities,the increased integration with the telephony andIT domain, sophisticated security features forday-to-day operations and mission-critical use and,last but not least, extensive network managementfeatures.

The enhanced data capabilities include the oppor-tunity to use IP packet data and the possibility toimplement and use location-based services, basedon the built-in GPS receiver of the TETRA radio.

The latter enables, for instance, a fuelling company tofind out where the fuelling trucks are on the airportand thus contributes to a more efficient assignment oftasks. The increased integration of the telephony andIT domain translates into various functions, rangingfrom a telephone user being able to use Direct-Dial-Into reach a radio user to the possibility to implementflight-oriented dialling. Flight-oriented dialling meansthat a user can not only be reached from a telephoneor radio based on his unique radio or telephonenumber but he can also be reached based on theassigned task or duty he currently fulfils using a dyna-mically assigned flight or functional number.

The trend towards flight-oriented communications,seamlessly crossing borders between differentcommunications systems, is well established andalready in operation at several locations in the world.

The security aspects of the Schiphol TETRAsystem are various. Within the network, inter-fleetcommunications is regulated and within companies,communications within secure teams or groups canbe shielded from non-authorised users. The TETRAtechnology is inherently secured against threatsfrom outside the network. Unlike conventionalanalogue communications systems, anyonescanning TETRA channels will not get any intelligibleinformation. To prevent unauthorised access to thenetwork, authentication is used. Should even moreextensive protection be required, the networkallows for standard cost-effective TETRA end-to-endencryption as well.

Although not directly offered to the end-user, thenetwork management features of a complex mis-sion-critical system such as the Schiphol TETRAsystem are of the utmost importance. KPN providesthe end-user with a full service, including the userradio equipment and access to the radio networkand all its features at a fixed monthly fee.Service levels are in place to ensure the quality andavailability of the service and are reported back tothe key users by KPN each month. It is clear that inthis mission-critical environment, faults have to beidentified as soon as possible, or if possible, evenbefore they occur. Advanced network managementis therefore available, consisting of a customer unitthat handles the subscriber data, a centralisednetwork management centre that monitors andmaintains the network on a 24 hour basis and alocal repair shop to which users can turn to if theirradios need to be repaired or have to be replaced. Ifa fault is detected in the network, it is automatically andimmediately reported to the network management centre,where immediate remote analysis can be performedand subsequent counter actions can be defined.

At this moment, the TETRA network at Schiphol isalready in use by several hundreds of end-users.Further migration of users is currently in full swing.Due to the dynamics at the airport, however, about1500 users will enter the TETRA system after the peakof the summer holidays and will then also experiencethe benefits of the new system like the current users.To realise a ‘clean’ migration, it has been decided tomake a switch-over to the new TETRA system first,without changing the communications processes.After a successful migration, the new functionalitiesand methods of working will be introduced on a caseby case basis, exploiting the new opportunities of thesystem to the maximum.

The achievements realised so far show that in thecomplex environment of Schiphol with its largenumber of different teams and companies, its broadspectrum of individual business requirements andits high traffic load concentrated on a geographicallysmall area, it is still possible to offer a full serviceon one shared single TETRA network and meet theindividual requirements as well.

Realising that this concept does not only fit functio-nally, but can also be considered the most efficientsolution in terms of costs, radio spectrum and future-proof flexibility, we can all look forward to enjoyingthe benefits of TETRA for many years to come.

Tetra Notes thanks Meint Joustra,Senior Consultant Professional Mobile Radio,KPN Royal Dutch Telecom, for providingthis article.

Dominion Tecnologías will finally startimplementing the TetraNode Network forSeville Metro in 2007. The 2004 contracthas been delayed due to Civil Worksproblems, but recently Seville MetroAuthorities have confirmed the openingdate by Spring 2008.

Dominion Tecnologías, one of Rohill’s partners, iscurrently deploying the TETRA infrastructure forSeville Metro. This is a turnkey project for line 1 ofthe city metro.

Line 1 is about 19 km long and runs from Mairenade Aljarafe to Montequinto. In total 23 stations areplanned to be built, of which 11 underground.The line serves around 14 million passengers peryear. Coverage inside the tunnels is achievedthrough more than 14 km of 1-1/4” radiating cable,which together with the extremely high sensitivityof the carriers will allow for inside traincoverage (hand-portables) on the whole line.Optical and RF-RF repeaters will complete thecoverage to include all the premises at thestations, the emergency exits and the control room.

Sixteen sites equipped with R-8060 basestation transceivers with direct IP interfacehave been supplied. This allows directcommunication with the TNX through a dedicatedIP network. Interfacing with the company PABXwill be through E1 with QSIG. As undergroundbase stations do not have access to GPS,synchronisation is provided by ultra stable clocksources.

Seville Metro believes in total integration ofapplications as a basis of their daily operations.That is why the TetraNode IP-centric concept offersreal advantages to the metro company.

• Custom-made dispatcher: Seville Metro isdeveloping its own integrated dispatcherapplication using TetraNode’s XML interface.This will enable complete management of traintraffic, train-to-ground communications andPABX calls through the same console.

• Train Console: Trains will use the most advancedand newly integrated console, developed byDominion Tecnologías itself. The console is basedon a central processor which controls the on-boardTETRA radio and interfaces to the train’s maincomputer and intercom system. In this way, thedriver will have a complete communication suiteusing a rugged touch screen as user interface.Packet data capabilities of TetraNode areplanned to be used in the near future.

Tetra Notes thanks Carlos Fernández Alonso,TETRA Networks Manager, Dominion TecnologíasS.L.U., for providing this article.

Seville Metro speeds upand announces openingdate by Spring 2008

Istanbul Municipality awarded UskomKomunikasyon Sistemleri A.S. from Ankara,Turkey, various contracts for the supply ofcommunications and SCADA systems for theIstanbul Tram Lines.

These contracts include the deployment of amulti-site TETRA network for Istanbul City, coveringthe vital communications requirements of PublicTram Transportation.

The TETRA infrastructure is based onRohill’s TetraNode. It is composed of a TetraNodeeXchange and three TETRA base station sites.TetraNode was specifically chosen because of itsseamless expansion capabilities and its leadingIP technology, providing robust, yet simple

interfaces for all application requirements oftransportation and utility companies.

Uskom is a system integrator in the field ofcommunications and control systems with contractsin Turkey, UAE, Saudi Arabia, Nigeria, Iraq,Turkmenistan, Bulgaria and Kosova. Uskom is theRohill partner in Turkey.

Uskom strongly believes that TetraNode capabilitieswill help Turkey to develop robust and future-proofTETRA system infrastructures for many years tocome.

Tetra Notes thanks Murat Arslan, GeneralManager, Uskom Komunikasyon Sistemleri A.S,for providing this article.

Full TETRA service at Schiphol Airport

First TETRA systemof Istanbul

Page: 2 - Tetra Notes

Ever since TETRA has been an establishedstandard in the market for mission-criticalcommunications, there has also often been apush from the market for higher data speeds.Some 10 years ago, the request for ahigh-speed data layer in TETRA was stronglypromoted by the TETRA PAMR networkoperator Dolphin. This strategy was of courselargely based on their wish to position TETRAas a quasi-cellular standard.

Today, the high-speed data issue is still consideredimportant for TETRA, especially in view of therequirements of throughput demanding applications.End-users often compare TETRA networks withthe current GSM, 3G and UMTS networks and theirperformance.

Although the TETRA release 2 standards includehigh-speed data service TEDS (TETRA EnhancedData Service) in addition to multi-slot packetdata and other data transmission servicesalready implemented in TETRA release 1, it is veryimportant to have an unbiased look at high speeddata services.

A Swiss knife can serve as a corkscrew.Nevertheless, a waiter in a restaurant will alwaysuse a real corkscrew, even if he had a Swiss knife inhis pocket. Integrated solutions, like a Swiss knife,become difficult to operate, impractical to use andcompromise all functions they represent.

For TETRA, the same may be true. TETRA has beendesigned as a mission-critical voice communicationssolution with data transmission capabilitiesspecifically designed for those user groups forwhich reliability, availability, ease of operation, fastaccess and group call facilities are essential.The TETRA user market is a specialist user group,requiring a dedicated tool like a waiter.

The data transmission ability of TETRA is suitablefor a wide range of applications but requires carefulconsideration of bandwidth availability. Althoughtransparent IP connectivity is offered through packetdata, the service is not designed for random surfingof the Internet where bandwidth constraints arehardly considered. Still, dedicated and optimisedmission-critical client server applications can benefitfrom the TETRA release 1 data capabilities.

Laws of physics relate bandwidth to data speedand coverage. Higher data rates require morebandwidth and provide less coverage. Everybodywill understand that less coverage will immediatelyincrease the costs of the infrastructure and createsan unbalanced situation, as more base station siteswill be required to cover the same area. Therefore,high-speed data solutions on TETRA are basicallyonly interesting for dedicated area use at highdensity, small coverage locations, such as airports,city centres and at events.

For the vast majority of TETRA users, TETRA release1 data services in the same coverage area as that ofvoice communications are sufficient, especiallyif optimised applications for data transfer areconsidered. For those areas where high-speed datais required, TETRA networks should provide forseamless interworking with those network solutionswhich have been designed for this purpose, insteadof adding another tool to a Swiss knife.

Considering all this, Rohill will introduce the TetraNodeAdvancedTCA platform with integrated WiMAX at TWC2007. This platform offers two optimised solutions forvoice and data communications on a single system.

Nevertheless, Rohill remains committed to theTETRA standard and will also introduce TEDS fordedicated users for whom the seamless integrationof TetraNode with WiMAX is not a suitable option.

Integration of telephony has been a strongpoint of TetraNode ever since its introduction.Whatever the size of the network, TetraNodecan be equipped with the appropriate numberand types of telephony interfaces. These canrange from a single 2-wire telephone line oran ISDN Basic Rate line up to a large quantityof trunked E&M interfaces as well as E1 tele-phony based on ISDN Primary Rate and QSIG.The flexibility in terms of telephony trunks,which are accessible by the user or by configu-ration of the system, is unmatched. A uniqueTetraNode function is group call from atelephone set. A group call can be initiatedeither by dialling a specific Direct Dial In(DDI) number per group number, or by post-dialling the group number, whereby intelligenttransmission control within the TetraNodesystem allows for comfortable operationwithout the need for a PTT button. In addition,the MS-ISDN capability of TetraNode adds extraflexibility for integration of differentnumbering schemes in order to reach radiosand talk-groups from the telephone networkusing DDI.

The TetraNode VoIP gateway server adds anotherdimension to telephony integration. Virtuallyall PABXs supplied today use VoIP for connectingtelphone sets and even trunks to the PSTN.The TetraNode VoIP gateway server runs on Linux,the same mission-critical operating system as usedfor TetraNode systems. The TetraNode VoIP gatewayserver provides VoIP trunks to existing PABXs,but can also operate as a PABX in order toserve VoIP telephone sets. This allows forseamless integration with the Cisco CallManagersolution for IP telephony, but also with anyother SIP compatible service from a public orprivate network. The TetraNode VoIP gatewayserver enables direct connectivity with a widerange of SIP-based telephone sets from companieslike Alcatel, Cisco, Linksys, Siemens and manyothers.

The TetraNode VoIP gateway server is based onopen standards and products, which are configuredto meet the specific requirements of mission-criticalcommunications. Together with TetraNode, it is theperfect match for any modern communicationssystem.

TETRA World Congress 2007 marks theintroduction of Rohill’s new Line DispatchStation Chameleon. This new product is notjust a remake of the existing Line Dispatchersolution. Chameleon combines powerfulgroup-oriented dispatch facilities withunprecedented configuration flexibility,yet remains easy to operate.

Chameleon is designed for mission-criticalapplications for which maximum control andconfidence in operation are essential requirements.Public safety users will appreciate the support ofgroup-oriented communication; up to 16 talk-groups may be selected for simultaneous monitoring.The user interface can be made familiar to users ofexisting analogue and trunked radio systems byprecise emulation of existing (legacy) dispatchersolutions from other leading brands in this industry.However, a refreshing look using modern graphicalelements is just as easy to achieve. This is why theproduct is referred to as the Chameleon, the animalthat can perfectly mimic its environment.

Following the simplicity of the powerful soft-switching architecture of TetraNode, Chameleonoperates as a command and control workstationwithin a pure IP networking environment usingQuality-of-Service (QoS) mechanisms on the basisof open industry standards. No proprietary compo-nents are needed to interconnect control rooms tothe TetraNode system, or to create control roomswith a large number of workstations.

Options for secure VPNs are available which areessential for multi-agency and operator-basedTetraNode networks. Centralised configurationmanagement allows the screen layout and userauthorisations to be updated dynamically on thebasis of a personalised profile selected on login.This also enables customised configurations fordifferent work shifts. Interoperability betweendifferent agencies can be achieved by extendingaccess to multiple fleets or security groups,enabling patches between the applicable talk-groups, individuals and telephone users.

Another truly unique feature of Chameleon is theability to mix or supplement line connections withradio connections. System security may also beenhanced as a side-effect while no IP traffic is nee-ded towards the system. Mixing TETRA mobiles withline connections also offers an effective solution forfallback operation should a fixed-link failure occur.

Depending on user authorisations, other powerfulfeatures of Chameleon include:• End-to-End Encryption (E2EE) on the basis of

the open TETRA MoU SFPG recommendations.• Pre-configured and ad-hoc Dynamic Group

Number Assignment (DGNA) schemes.• Short Data Service and status messages may

be sent, received and processed according toapplicable workflow requirements.

• PTT priority and efficient emergencycall handling.

• Multi-dispatcher incoming-call handling.• Discreet Listening.• Ambience Listening.• Remote enable/disable of TETRA terminals.• Spacial acoustic arrangement of monitored

talk-groups.

The impressive capabilities and flexibility ofChameleon are enabled by open standards - as arethe revolutionary TetraNode concepts. This sets thesolution truly apart from competitive solutions,which are based on proprietary hardware andsoftware to enable vendor lock-in. TetraNode isan open solution, enabling easy applicationdevelopment and seamless growth due to smoothsystem scalability.

SeamlessWiMAXintegrationRohill introduces

TetraNode

AdvancedTCA

platform with

integrated WiMAX at TWC 2007

Line Dispatch Station Chameleon:

TotalFlexibility

TetraNode adds newdimension to telephonyintegrationSeamless telephony integration withTetraNode VoIP gateway server

Superior FCAPScapabilitiesXML-over-IP based concept enhancesnetwork management tasks of TetraNode

The field of activity of a dispatch stationoperator is typically to direct and guidea mobile workforce using wireless communi-cations. The dispatch station operator(or ‘dispatcher’ for short) usually collectsor receives information from varioussources. It helps the dispatcher to direct,co-ordinate and monitor - like a moviedirector - the tasks performed in the field.Typical dispatch-oriented communicationsare found in public safety, transport andutility networks.

Members of the mobile workforce equipped withmobile and hand-portable radios communicatewith the dispatcher and with one another using theair interface of the radio network.

Basically, there are two types of dispatch stations:

• the radio dispatch station uses the air interfaceto communicate with other subscribers throughthe radio network;

• the line dispatch station uses a dedicated lineconnection with the radio network infrastructureto communicate with other subscribers.

What makes a dispatch station special is thefit-for-purpose man-machine interface (MMI)

to perform the dispatch tasks in a fast andeasy-to-operate way. The dedicated MMIs in today’ssolutions are based on desktop PCs with monitor,headset/desktop microphone and loudspeakers.Operation takes place through (touch) screen,keyboard, mouse and/or foot bars.

Depending on the network size and the numberof mobile stations, the dispatch functions areperformed from a single or from multiple operatorpositions. Which functionality is supported by thedispatch stations depends on the type of connectionbetween the dispatch station and the network.It is obvious that an air interface can onlycarry information using the services the air interfaceprovides, whereas the line dispatch station candirectly receive supplementary information fromthe network itself. The line dispatch station couldperform multiple talk-group monitoring moreeasily than a radio dispatch station. Functions suchas network loading and subscriber monitoring areimpossible for a radio dispatch station to carry out.

Rohill offers Chameleon to build dispatchsolutions to be used as a radio dispatchstation, as a line dispatch station and even as acombination of both. Chameleon is part ofthe TetraNode product range. For more informationon Chameleon, see the product introductionarticle on this page.

LLiinnee oorr RRaaddiioo DDiissppaattcchhssttaattiioonn;; wwhhaatt ddoo yyoouu nneeeedd??

FCAPS is the ISO model and framework for network management. FCAPS is an acronym for Fault,Configuration, Accounting, Performance and Security management. These are the managementcategories which the ISO model uses to define the various different network management tasks.

The recent introduction of NodeWatch, SubscriberWatch and CoverageWatch have significantly improved theFCAPS capabilities of TetraNode. TetraNode now offers superior FCAPS capabilities in comparison with anyother competitive solution.

TetraNode applications according to the FCAPS model

The new FCAPS capabilities are enabled by truly open and standards-based concepts, offering a future-proofgrowth path for additional third-party and Rohill applications and solutions. The mentioned tools can be usedby the different agencies or technical teams in order to effectively manage their own fleets or regions.Examples of management tasks include:

• Checking the status (on/off) and location (site) of a subscriber using SubscriberWatch.• Finding the cause of individual user complaints, such as registration failures and

wrong group attachments using SubscriberWatch.• Analysing call performance and the call success rate using Call Detail Records.• Finding troubled mobiles or hand-portables by determining the coverage in comparison

with the average coverage using CoverageWatch.• Optimising coverage and performance by pro-active analysis of trends in coverage

and control channel load (NodeWatch and CoverageWatch).• Monitoring the whole network on a single graphical map using NodeWatch.

Real-time data and reports are filtered for the subscriber or management group to which the authorisednetwork management user belongs. Helpdesk responsibilities can thus be delegated to agencies, allowingmore flexibility and a more secured operation of the network. By narrowing the dataflow to the absoluteminimum required for remote operation of the service, secure access is made possible through the Internetor private WAN.

Centralised management of all connected client applications is another feature of the application suite, whichreduces operating costs by eliminating the need to manage each of the connected workstations. Helpdesk per-sonnel and technicians are now able to oversee the whole network, not just the activity in a single switch orzone. These impressive and often unique capabilities of the TetraNode system management applications putthe operator and agencies back in control.

Rohill has partnered Tripleton UK to start a jointdevelopment to provide seamless and secureconnectivity between TETRA and GSM networks,thus extending the coverage of its TetraNodenetwork out to the globally available GSM net-work. By offering secure connectivity, the securi-ty and mission-critical status of TetraNode willbe crucially preserved.

Using currently available products from Tripleton andsome integration work in TetraNode, Rohill is able tooffer secure connectivity from GSM to TETRA, as shownin figure 1. In keeping with its philosophy of providingstate-of-the-art solutions, Rohill will work withTripleton to develop optimised solutions to offer thequickest possible call setup, optimum speech qualityand true end-to-end encryption connectivity. In addi-tion, Rohill can uniquely offer enhanced line dispatcherfeatures such as end-to-end monitoring and conferen-cing. The Enigma GSM handset is to be upgraded toincorporate the security recommendations of TETRAend-to-end calls to permit interoperability with similar-ly supported TETRA terminals.

Offering secure connectivity into TETRA from the GSMnetwork is not a trivial task. GSM is the father of TETRAconceived some 20 years ago and while its goals aredifferent to TETRA (to offer global connectivity and roa-ming), the security model developed has some glaringweaknesses that allow it to be exploited readily. Not amonth goes by without some top government official ordepartment is reported to be the victim of GSM eaves-dropping. When TETRA was developed, the securitymodel took into account and remedied the flaws ofGSM. Tripleton responded to the demand for makingcommunications over GSM secure in a similar way upto the highest levels and developed the Enigma T301B.Operating Enigma with TetraNode gives the user thefreedom to move in and out of the coverage of TETRAand still stay in touch with his key TETRA and GSM per-sonnel using a single handset.

TETRA - GSM: current solution features• Full duplex secure voice communications

from GSM into TetraNode network.• Excellent speech quality.• Two-sided authentication for secure

access into TetraNode.• Enigma/Linecrypt plug-and-play technology.• Enigma/Linecrypt operate integrated

hardware/software tailor-made security modulethat has been formally evaluated by ITSEC.

• Enigma supports up to five hours talktime and 350 hours standby time.

• Local management and exclusivecommunications groups.

Figure 1

TETRA – GSM: optimised seamless solution• GSM handset compliant to TETRA E2E

Encryption standard (TETRA MoU SFPG Rec. 02).• Real end-to-end encryption to a TETRA

handset compliant to SFPG Rec. 02.• Seamless operation.• Full duplex communication.• Optimised call setup times and speech delays

in keeping with TETRA standard.• TetraNode incorporates TETRA MoU SFPG Rec.

02 for secure call monitoring and conferencing.

Figure 2

TetraNode Now Offers Seamless and Secure Connectivity to GSM

F - Fault Simple Network Management Device alarms

Protocol (SNMP) Link failures

IP equipment failures

Network Management System (NMS) System, node, site and device status

Link status

Node Watch Client (NWC) History and current device alarms

History and current link failures

Subscriber Watch Client (SWC) Find terminal programming failures

Coverage Watch Client (CWC) Find problems with coverage caused

by defective site equipment, cables or

antennas

Find problems with terminal installation

causing poor coverage for a specific terminal

C - Configuration Network Management System (NMS) Configuration of nodes, sites and devices

Subscriber management

A - Accounting Call Log Streaming (CLS) Detailed information for billing systems

Call Detail Records (CDR) Detailed information on call performance

RADIUS Logging of user sessions

P - Performance Node Watch Client (NWC) Queuing statistics

Control channel load statistics

View activity on individual channels (timeslots)

Availability Reports Downtime reporting per node, device and link

Call Detail Records (CDR) Daily statistics on call performance

Coverage Watch Client (CWC) Determine and optimise system coverage

S - Security Network Management System (NMS) Configure Virtual Private Networking

Configure security profiles

User authorisations

Authentication Key Client (AKC) Import/export and manage authentication keys

Manage encryption keys

Tetra Notes thanks Charles Vilner, Executive Director, Security Division, Tripleton Ltd. for providing this article.

TETRA-GSM: current solution

TETRA-GSM: optimised seamless solution

Tetra Notes - Page: 3

The TETRA standard incorporates severalsecurity features to meet the security needsof TETRA users. These features includeAuthentication, Air interface encryption andEnd-to-end encryption.

AuthenticationAuthentication is the first level of protection of aTETRA network. Without authentication, TETRAterminals with the same Mobile Country Code(MCC) and Mobile Network Code (MNC) as that ofthe infrastructure and with a valid Individual TETRASubscriber Identity (ITSI) can register to theinfrastructure. TETRA infrastructures that supportauthentication, like TetraNode, only allow TETRAterminals with a valid authentication key to registerto the network. In case of mutual authentication,TETRA terminals can also authenticate the network,preventing registration on potentially fakebase stations.

Air interface encryptionThe radio link between base station and terminal isconsidered more vulnerable than the fixed networklinks. Air interface encryption applies to all signal-ling and identities as well as the voice and datapayload across the radio link. The registrationof TETRA terminals is also encrypted, as is theidentity of individual subscribers and groups, sotraffic cannot be analysed. Air interface encryptioncan use Static Cipher Keys (SCK), individual DerivedCipher Keys (DCK), Common Cipher Keys (CCK)and Group Cipher Keys (GCK). Air interfaceencryption can be combined with authentication.

Most TETRA infrastructures encrypt/decryptcommunications in the base station as a result of

which communications travels in clear mode overthe fixed network links to the Switching andManagement Infrastructure (SwMI). Although fixedlinks are less vulnerable, they do represent a potentialsecurity gap. That is why Rohill’s TetraNodeencrypts/decrypts the air interface already at theTetraNode eXchange (TNX or node). As a result,communications over the fixed network links isfully encrypted, providing an additional securitylevel compared with other TETRA infrastructures.

End-to-End encryptionTETRA offers standardised support for end-to-endencryption as defined in ETSI EN302109. Thisallows for a standard alternative to proprietaryofferings and technologies and ensurescompatibility between infrastructures andterminals. Normally, TETRA terminals with anidentical end-to-end encryption implementationcan communicate with one another over aTETRA infrastructure that supports end-to-endencryption. End-to-end encryption only encryptsthe payload (voice and data). The signalling andidentities are transmitted in clear mode over the airinterface as well as fixed network links.Combined with air interface encryption andauthentication, end-to-end encryption makes thesecurity level very high.

As mentioned earlier, most TETRA infrastructures donot apply air interface encryption to the fixed networklinks. Although they may offer both authentication aswell as air interface encryption and end-to-endencryption, the signalling and identities are notencrypted on the fixed network links. This leavesRohill’s TetraNode as the only TETRA infrastructurewith this unique additional security benefit.

Radio communications has become anessential part of many operational processes.Over the years, the use of communicationssystems has increased and no one will argueagainst further growth. At the same time,the reliability of products and technologieshas improved in such a way that communica-tions systems really can be identified asmission-critical communications systems.Today, these systems meet the highestdemands for getting voice or data from A to Bfast and in a reliable way. In the professionalmobile radio market, TETRA is the standardfor these communications needs.

In general, TETRA systems provide safe and reliablecommunications to large groups of users and arecapable of offering an end-to-end service.For better understanding, we can compare thesending of a message from one user to anotherto travelling from one city to another city byairplane. Aviation offers a fast, safe andreliable means of transportation through theair. Everyone is used to this way of transportationand never considers the individual stepswhich need to be taken to go from A to B.But what happens if something goes wrong?This question has often been answered through thecockpit voice and flight data recorder. Each time anaircraft crashes and the emergency and rescueteams have done their job, the next step is findingthe cockpit voice and flight data recorder.The black box enables the authorities toreconstruct the incident in more detail andhelps them in their quest to understand and to learnmore about making a journey safer. Can this beapplied to mission-critical TETRA networks too?

An operational TETRA network handles loadsof voice and data traffic simultaneously. Inmany ways, TETRA networks are optimised forpredictable and fast call setup and not forreconstructing incidents. What can be learnedfrom the aviation sector, though, is that

improvement can be achieved only with highlyintegrated voice and data recording facilitieslocated at the core of operations where all data isavailable.

But event reconstruction is more than onlyreplaying voice. It is necessary to have allinformation available with regard to the succession ofcalls and the times those calls were made. The RohillTetraNode infrastructure was the first TETRA systemwith an integrated voice and data recording solutionsimilar to the black box in airplanes. Based on adigital platform, Rohill’s Voice-data Logging Server(VLS) not only monitors speech and all data calls, butalso includes precise timestamps and call-relateddata. It is a highly flexible recording solution, found atthe core of the network, with external backupfacilities on CD, DVD or other storage media.

Within TetraNode, the voice conversations arestored on the Voice-data Logging Server asnative TETRA coded ACELP speech. This highlycompressed speech requires a minimum amountof hard disk space without compromisingspeech quality in any way. The Voice-dataLogging Server offers a complete, intuitive andscalable solution, which addresses any call-recording need within a TETRA network and,at the same time, provides total resilience andoperational benefits.

Especially in a mission-critical environment,voice and data monitoring and recordingmay improve operations and, consequently,save lives by learning from past incidents,and should therefore be an integral part of anycommunications network.

Every user wants 100% uptime for his vitalnetwork equipment. This, however, remainsa dream for now – hardware failures andsoftware bugs prevent systems fromachieving 100% uptime. The nearer a systemcomes to 100%, the less downtime it isallowed to have in a year. How does CarrierGrade Linux help?

What does ’the five nines‘ mean?Measuring reliability today is done using a multitudeof nines. An availability of four-times-nine meansthat a system should be up 99.99% in a year’stime - this means that downtime is 0.01% or 53minutes per year. In case of a five-times-nine availa-bility (99.999%), downtime may not exceed 5.26minutes per year. For a six-times-nine availability(99.9999%), downtimes longer than 31 secondsper year are not allowed. Because today’s systemshave a boot time of several minutes, five-times-nineavailability is a challenge if a system crashes andreboots (watchdog!) once a year. And this does noteven include hardware defects.

Why is Carrier Grade Linux more reliable?Over the years, Linux has gained a reputation as ahighly reliable operating system. The open sourcecommunity process guarantees that many peoplescrutinize every piece of code before it enters thekernel. Even so, the current size of the kernel is anindication of the difficulty to keep out bugs; there isno such thing as bug-free software.

That is why the operating system has to be mosttolerant to problems and not crash at the firstencounter of trouble. Vanilla Linux, as obtainedfrom kernel.org, is not so tolerant. After all, it is aLinux development. Stabilisation is left to thedistribution vendors, like MontaVista, Red Hatand Novell. One of the jobs of these vendors isto take a kernel version and ‘back port’ any fixesthat are incorporated in later versions in the opensource community. In this way, a vendor maintainsa stable branch of the kernel. Usually, the nextkernel version will contain a few dozen stabilityand security fixes - significant effort is involved inthis process!

Apart from back porting fixes to a stable baseline,vendors also improve stability by adding code thatalters system behaviour under failure. If akernel module (driver) performs a null pointerdereference, it will be halted and unloaded.This does not prevent the system from properlyfunctioning - and the module is probablyimmediately loaded again. Functioning of thesystem is therefore only impaired for just a fewseconds, compared to a reboot.

Standards, standards, standards...The kernel is not the only part of a running Linuxserver. There is also hardware that needs to bemonitored for imminent failures; a switch-over to astandby machine might prevent downtime. To makesure that Linux remains interoperable, severalstandardisation bodies each took a piece tostandardisation. The resulting systems are known asCarrier Grade Linux or CGL.

The most important standard is the CGL standarditself. CGL used to be defined by a standardisationcommittee of the Open Source Development Labs(OSDL), a non-profit organisation stimulatingLinux development. Due to the recent mergerof OSDL into the Linux Foundation, CGL is nowfostered by the Linux Foundation.

For several topics, CGL refers to other standards.Among them are the Linux Standards Base (LSB)and the File Hierarchy Standard (FHS), both ofwhich were already governed by the LinuxFoundation and POSIX. All of them deal withinteroperability. Standardisation body PICMGhandles hardware interoperability, for examplefor ATCA devices.

Another important standardisation body whichis part of the Carrier Grade Linux movement isthe Service Availability Forum (SAF). The SAFdefines several libraries, procedures and interfacesthat have direct impact on system serviceabilityand/or high availability. For example, the IPMIand HPI standards define how to extractinformation from the hardware, like temperatures,locations in the chassis, error conditions of

the hardware and such. The SAF AIS standarddefines how systems can implement highavailability through failover and redundancy. In thesimplest case, there is a running system (hot) and abackup system (the standby). The standby systemcontinuously monitors the hot system. If itdetects a failure, it will kick out the hot systemand take over. This requires complex monitoringmechanisms, check-pointing (to make surethat hot and standby systems show similar, reprodu-cible behaviour) and failover mechanisms.There are many open source and commercialpackages available to implement the AIS standard.Of course, Linux also supports network bonding,which uses multiple network interfaces as oneto improve throughput and to reduce single pointof failure.

MontaVista Carrier Grade Linux adheres to all ofthe above specifications - and will be happy toprovide conformance reports upon request.

Operation in the fieldRule number one: the system may not go down.An extensive event logging mechanism allowsfor system events to be logged and acted on.The Field Safe Application Debugger enablesdebugging and setting trace points withoutthe application halting or going down. TheRuntime Application Patcher makes patches ofapplications without interrupting operation.Crash dump tools allow for sending memory imagesto disk or to remote machines in case of acrash and with kexec the Linux system can berestarted without a reboot, saving valuable seconds.

ConclusionBy extending the Linux kernel with patchesfor stabilisation and packages to implementserviceability and high-availability standards,MontaVista Carrier Grade Linux can achievea much higher reliability. System availabilityin the range of five to six nines can be achieved.

Tetra Notes thanks Klaas van Gend,Field Application Engineer Europe,MontaVista, for providing this article.

Potential users of new digital land mobileradio communications systems may findthemselves faced with a technology choice,i.e. a choice between TETRA and the Apco1

Project 25 standard. This article comparesthe benefits, features and functionality ofthese two open standards. Potential buyersmay use this information to their own benefit,although it is recommended to check allinformation with the manufacturers andStandards organisations before doing so.

The comparison focuses on the following aspects:• Target user groups• Target market places• Interoperability• Channel access• Functionality• Network architecture• Interoperability• Products and cost

Target user groupsThe TETRA project was started to create a standardfor Public Access Mobile Radio (PAMR) systems.However, it quickly became apparent that there wasa similar need for a standard covering the needs ofPublic Safety and other users of private systems.Therefore, the requirements were broadened tocover all of these needs. Today, Public Safety andSecurity are major users of TETRA systems, butTransport and many other sectors have alsoadopted the technology. Interestingly, Public AccessSystems have not been the success that waspredicted at the start. The early TETRA systemstended to be aimed at the larger requirements.However, since a number of manufacturers haveproduced infrastructures based on much smallerbuilding blocks, smaller facilities such as airportsand railways are now also seeing the use of TETRAtechnology.

The Project 25 standardisation was initiatedspecifically for the needs of the Public Safety user.The relatively simple needs of the many small tomedium-sized Public Safety agencies in the UnitedStates resulted in a technology which was optimisedfor non-trunked operation. A trunking protocol forlarger more complex systems was created as anoption. Large State-Wide systems based on Project25 technology are usually a mixture of trunked andnon-trunked operation.

Target market placesThe TETRA standard was initially aimed at satisfyingthe European user community. Due to the efforts ofthe TETRA Association and the increasing numberof manufacturers supporting the technology, TETRAhas become a global standard. Meanwhile, close to1100 TETRA contracts have been placed in around90 countries around the world.

Although some systems have been sold outside ofNorth America, the majority of Project 25 basedsystems have been for home grown consumption.The exception is in Australia where the vast ruralareas with low population density are similar to thatof the USA.

InteroperabilityFrom the start, interoperability has been of majorimportance to the TETRA community to make surethat a true competitive multi-vendor market couldbe created. Therefore, the Association built aninteroperability certification process and contractedan independent test house to witness interoperabilitytesting between manufacturers. A highly competitivemarket has resulted, leading to greater choice andlower prices for buyers of TETRA equipment.

The Project 25 standards contain several testspecifications. The task to create interoperability orconformance testing facility has been given to theU.S. Government laboratories in Boulder, Colorado.There also has been an attempt to produce‘P25 Interoperability Profile/PIP’ documents withinthe standardisation process, but signs of progressaround this are not very visible so far.

Channel accessTETRA standards chose the Time Division MultipleAccess (TDMA) method from the beginning. TETRAimplements four time slots, i.e. communicationchannels, within the same 25 kHz radio channel.This is equivalent to 6.25 kHz per channel.Thus, TETRA can provide 16 communicationchannels in 100 kHz spectrum.

Current Project 25 standards and systems use theFrequency Division Multiple Access (FDMA)method. Project 25 uses one 12.5 kHz radiochannel for each communication channel.Thus, Project 25 systems offer eight channels per100 kHz, so half the number of channels comparedto TETRA.

The common perception is that TDMA systems aremore cost-efficient in high capacity systems,whereas FDMA systems can provide longer range.Low user density or low population density areoften stated as reasons for choosing anFDMA system. This has indeed happened in the U.S.and in parts of Australia but is not universallyaccepted. In Scandinavia for example (a region withcomparable population density), the nation-widePublic Safety communities have adoptedTETRA TDMA technology.

Recent developments in TETRA base stationreceiver technology seem to be bringing TETRA onpar with FDMA technologies in terms of cell sizewhen terminal transmitting powers are in thetypical handset range. There are also a few other

technical issues that can have impact on thetechnology selection. TDMA by nature allows easierand more cost-efficient implementation of fullduplex radios. Concurrent use of voice and dataservices, as well the possibility for multi-slot datatransmission for higher bit rates, are also makingTDMA more attractive to adopt.

FunctionalityThe whole of the original TETRA standard iscomplete and issued. This includes voice services,short data services and both circuit and packetmode data services. The Peripheral EquipmentInterface (PEI) has also been defined. In October2005, a number of enhancements includingadditional codecs, range extension and a highspeed data capability were added to the Release 1standard. The TETRA standard addresses fullsecurity. This includes radio authentication, airinterface encryption and the option for end-to-endsignalling by use of nationally agreed algorithms.To compensate bit errors by retransmissions, it iscrucial to have a quick return path for retransmissionrequests that is available all the time. A readilyavailable return path requires a duplex channel andin this the TDMA technologies like TETRA have anadvantage.

The non-trunked elements of the Project 25standard have been complete for some time andequipment is available and in use. A trunkingprotocol standard was created later. The latestimplemented trunked Project 25 networks are saidto be compliant to this trunking standard. A Phase2 initiative is currently underway to create a 2 slot12.5 kHz TDMA technology that will be backwardcompatible. When complete, this will result in aspectrum efficiency of 6.25 kHz equivalent. Alongwith the Phase 2 TDMA development, there is workgoing on to complete the first phase of the Project25 Inter-Subsystem Interface (ISSI) standards.There has been little news in public concerningadoption of IP packet data in the P25 networks.Only recently has air interface encryption enteredthe discussion phase in the standardisation bodies.The authentication standard for Project 25 is nowbeing produced.

Network architectureTETRA was always intended to provide infrastructuresuitable for national and international networks.Therefore, the TETRA standard included appropriatearchitectural definitions as well as internationalnumbering and mobile country codes to facilitatethe implementation of cross-border roaming andinter-agency working. Large-scale networks withnationwide roaming are in operation and fast callsetup has been maintained even over long distances.The TETRA ISI was specified to support cross-border cooperation and the interconnection ofnetworks from different manufacturers. The TETRA

ISI requirement is becoming increasingly importantas networks are rolled out and work is now in handto provide this functionality.

Project 25 introduced a work item known as theInter Sub System Interface (ISSI), which due to anew mandate from the P25 Steering Committeewas revitalised as a work in progress item with themanufacturing community.

Interoperability To ensure problem-free technical interoperabilityin the field and to give the users visible means toevaluate the interoperability capabilities of eachindividual product, the TETRA InteroperabilityCertification process was set up by the TETRA MoUAssociation. The process produces detailed andpublicly available Interoperability Certificates thatare issued by a neutral professional test laboratoryfollowing detailed and auditable testing. So far,interoperability certificates have been issued toproducts from seven infrastructure suppliers andnine radio terminal suppliers.

Within the Project 25 community, thelaboratories working in conjunction with theNational Telecommunications and InformationAdministration (NTIA) are preparing a radiointeroperability and/or conformance testingprogramme for Project 25 products.

Products and cost TETRA handsets are shipped today containing featuressuch as built-in GPS receiver, 65,000-colourdisplay, built-in web and WAP browsers, etc.Authentication and encryption are standard featuresin practically every TETRA handset delivered today.All this is available in a TETRA handset that costs1,000 USD or less.

The sales price of equivalent Project 25 handsets(i.e. containing encryption and display) seems to bein the 3,000 to 5,000 USD range.

A similar tendency can also be seen in the publishedsystem contract data from manufacturers’ pressreleases. While it is common to find announcedProject 25 contracts with the total system price ofapproximately 1,000,000 USD per radio site, thecorresponding costs in the announced TETRAcontracts are typically several times lower.

This article is based on information provided bythe TETRA MoU Association.

1) APCO is the Association of Public SafetyCommunications Officials. This is a US-basedorganisation with international membersand affiliates dedicated to supporting thetelecommunications needs of the public safetycommunity.

TETRA versus APCO Project 25

‘‘TThhee ffiivvee nniinneess’’ aannddMMoonnttaaVViissttaa CCaarrrriieerr GGrraaddee LLiinnuuxx

Recording solutions:luxury or essential?

Brazilian air force personnel recover the Gol Transportes AéreosFlight 1907 black box in the Amazon rainforest.

TTeettrraaNNooddee ooffffeerrss aa uunniiqquueeaaddddiittiioonnaall sseeccuurriittyy bbeenneeffiitt

Page: 4 - Tetra Notes

Alister Bailey is an Englishman with over20 years of experience in the radio commu-nications industry. In 2005, he moved tothe Netherlands to join Rohill - a leadingmanufacturer of TETRA radio infrastructures.Tetra Notes talked to him to find out whatmotivated him to make this move and how hefeels about Rohill and the Netherlands.

Tetra Notes: Can you tell us a bit more about yourbackground?

AB: I have always had a strong interest in radiocommunications and computing, which is why I amnow in this industry. It started off as a hobby,building radios and being interested in electronicsin general. Later on, I graduated from the Universityof Manchester Institute of Science and Technology(UMIST) with an honours degree in Electronics.At the same time, I became involved with theuniversity radio club where I built my first radiorepeater.

Tetra Notes: What did you do after you graduated?

AB: After university, I joined Philips ResearchLaboratories in the UK in the Radio Systems group.I worked on many communication topics,from packet radio to radio propagation, systemsimulation, voice coders and communicationsprotocols. This gave me a very broad backgroundwhich was complemented with experiences fromthe politics of standardisation committees andpublic speaking. I also spent a couple of years at theResearch Labs in the Netherlands, which probablygave me a taste for the country, before I moved toCambridge to join the team working on the (new)TETRA standard.

Tetra Notes: What was your role in the earlyTETRA development?

AB: The Cambridge team was convinced that TETRAwas technically possible and would become thefuture replacement of PMR systems - we answeredthis challenge by demonstrating the first workingTETRA products at the ITU-1995 exhibition inGeneva. I ran the projects responsible for thevarious base station products used in this period.Eventually, Philips sold this division to the Simocoinvestors and the rest, as they say, is history.

Tetra Notes: How did you get to know Rohill andwhat made you want to come here?AB: I first met the Rohill team in 2003 when theywere delivering their first TETRA systems after20 years of making MPT and analogue products.Although I had been working on TETRA for tenyears by then, I was very impressed that Rohillhad really been successful with basing theirarchitecture on the Internet Protocol (IP) wheneveryone else had just been tinkering with itunsuccessfully in the lab. Then in 2005 I metRoland van der Boom again and he offered methe chance to come and join the team inHoogeveen, which - when I saw Rohill’s continuedprogress - I did with no hesitation.

Tetra Notes: And what is your role now at Rohill?

AB: As I have spent many years running variousdevelopment projects (and “got the T-shirt”) it wasagreed that I would have a dual role split roughly50/50 between commercial tasks including ProductManagement and working as Vice DevelopmentDirector where my responsibility is mainly RFrelated. This is good for Rohill and me as it createsa direct link between customer requirements andthe detail of the technology - a problem I have seenunsolved in other companies.

Tetra Notes: So what has been your involvementwith Rohill’s product development?

AB: Well, it must be fate – but just as I joined Rohill,it became necessary to accelerate the completionof the new R-8060 base station, so I becameheavily involved with the technical managementof this project for my first nine months. This hasbeen on the market for a year now and is sucha successful product that we are already having tore-engineer it to be able to build in higher volumes.

Tetra Notes: How does this base station comparewith others on the market?

AB: I am pleased to say that this product has one of thebest performances you can get - which basically givesbetter radio coverage to customers. Also, it is smallerthan most other equivalent units available andrequires lower power. All these points are critical forthe economics of big and small networks.

Tetra Notes: And, as a relative newcomer, whatstrikes you most about Rohill’s other products?

AB: I am still impressed by the way Rohillhas engineered such a flexible solution intosuch a ‘clean’ simple network architecture.Anyone looking at the technology cannot fail tobe impressed by the elegance of the solution.This means that you can simply plug it togetherand it works. As a consequence, it still surprisesme how little training is required for oursystems compared to some others on the market.

Tetra Notes: How has this been achieved, do youthink?

AB: It is no secret that Rohill’s support forand adoption of open standards has savedthem a huge amount of time and investment.It also means that everything is compatiblewith the wealth of products available from theworldwide computer industry. Although theothers in the market are slowly realising thisto be true, they have such a huge investmentin incompatible architectures and proprietarysystems that they are seriously hinderedfrom adopting the same approach with any degreeof commitment. Plus, they have a fair bit of catchingup to do!

Tetra Notes: What new products can we expectfrom Rohill in the future?

AB: Well, that would be telling! But I canreveal that Rohill is pressing ahead withnew developments all the time and visitors to ourstand at TETRA World Congress (Madrid) this yearwill see some of the highlights. Plus, behind thescenes we are busy managing the growth of oneof the most successful TETRA infrastructurecompanies in the world.

Tetra Notes: Finally, has your move to theNetherlands come up to your expectations and doyou think you will stay?

AB: Certainly! I enjoy the work, it is challengingand it is exciting to be part of a motivated andleading-edge team, so I plan to be here for sometime. My family is also happy here, and we enjoyliving next to some of the nicest countrysides in theNetherlands. Actually, I always get asked about myDutch - I use it socially and I know it will alwaysneed improvement, but to be honest it is not anobstacle as English is spoken so widely and Rohillis an international company using English as themain language.

AAnn aalliieenn iinn HHooooggeevveeeenn

Editor-in-Chief

Roelie Dröge-Bouwers

Tetra Notes would like to thank

Carlos Fernández Alonso, Diana Zabala,

Murat Arslan, Klaas van Gend,

Mariano Sopeña Quesada, Charles Vilner,

Meint Joustra and Víctor E. Martínez Zepeda

for their valuable contributions to this edition.

Main Sponsor

Rohill

Hoogeveen, The Netherlands

www.rohill.com

Graphic Design

Drukkerij Van Genne

Hoogeveen, The Netherlands

www.vangenne.nl

TetraNode is a registered trademark of Rohill.

© Copyright remains with the respective

author(s) of this publication.

Although the information in this publication has

been compiled with great care, the respective

author(s) of this publication accept(s) no

responsibility for any errors, omissions or other

inaccuracies in this information or for the

consequences thereof, nor shall the author(s) be

bound in any way by the contents of this publication.

Zenitel is a leading network serviceand solution provider in professionalradio communications. In the Caribbeanarea, Zenitel operates the ChuChubiTrunking network, a TETRA networkbased on TetraNode technology with close to6000 Revenue Generating Users (RGUs).In order to maintain the agreed servicelevel with its customers, ChuChubi Trunkingneeds to be able to access and monitorthe system status and use in real time.For that purpose, the NodeWatch clientapplication is used. NodeWatch gives agraphical view of the system status and use,while showing sites and links on ageographical map. The application comeswith a map-based top level overviewand a hierarchical display of systemcomponent details, functional states,occupancy and queues.

Within TetraNode, so-called ‘events’ are distributedthrough the network, to indicate system alarms, butalso call setup information down to site, carrier andeven time slot level. The NodeWatch application iscapable of receiving these events and of updatingthe displayed information. The application isfurther capable of showing the live control channelload of individual sites, the overall systemload, individual site load, actual call queue timesas well as queue lengths for individual sites. Alsocall-related data can be visualised, with detailedcall information for every time slot of all TETRA

carriers on the network, as well as the propagationof group calls, not only by site, but alsoby TETRA carrier and individual time slot.NodeWatch monitors and displays alarms fromany TetraNode network element and gives accessto the alarm history.

NodeWatch uses the latest Graphical User Interface(GUI) techniques to provide an intuitive, clear andreal-time view of the system. Different levels ofdetail can be shown or hidden to indicate the generalstatus of links, sites, nodes down and the occupancystatus of individual time slots on a specific carrier.The top level configuration of a system can be shownon top of a map. A range of alerts is configurable inorder to attract the operator’s attention to changesin the system status. Logging of data for generationof reports and traffic statistics is also possible.

NodeWatch runs on Windows XP and Windows Vistaand can be delivered with an optional touch screen.

Zenitel ChuChubi Trunking network on Curacao.

Live monitoring the TetraNodeinfrastructure with NodeWatch

Telvent GIT S.A. (Nasdaq: TLVT), the GlobalRealTime IT Company, has signed twocontracts with Aeropuertos Españolesy Navegación Aérea (AENA), Spain’s airportoperator, for the delivery of radiocommunications systems for La Coruña andVigo Airport in Spain.

For both airports, Telvent will supply TetraNodebased TETRA networks, together with hand portable,mobile and stationary terminals. The equipmentwill interface with the current telephony systems aswell as the aeronautical band communicationssystems at the airports. Besides, it will allowcommunications with all ground staff and withvehicles circulating within the airport’s perimeter.This in turn will enable management to increase theefficiency of the airports’ daily operations andenable better coordination of emergency situations.“We are pleased to continue working closely withAENA on the technological upgrading of Spain’sairports”, stated Telvent’s chairman and chiefexecutive officer, Manuel Sánchez Ortega”.

Telvent’s solution is the only one on the market witha design based on non-proprietary devices, withmulti-protocol capacity and architecture based onsoftware instead of hardware, which simplifies andoptimises system operation. These features providethe user with a high degree of flexibility whenintegrating high-level applications such as vehicleand staff positioning systems, SCADA systems andemergency control centres.

La Coruña and Vigo airport will use the sameTetraNode TETRA communications technology asthat used at other Spanish airports, includingSeville, Menorca, Ibiza and Granada. Telvent has alongstanding relationship with AENA and otherinternational aviation bodies, for which it hasprovided weather observation technology for manyyears.

Telvent (Nasdaq: TLVT) specialises in highvalue-added systems and professional services inthe energy, transportation, environment and publicadministration industry segments. Its technologysolutions enable efficient and secure managementin real time of operational and business processesof leading companies worldwide. (www.telvent.com)

Tetra Notes thanks Víctor E. Martínez Zepeda,Commercial Director, TelecommunicationsDivision, Telvent Energía y Medio Ambiente S.A.,for providing this article.

Early in 2007, Dominion Tecnologíassuccessfully delivered and implementeda TETRA network based on the TetraNodeEntry Level Platform for Santiago deCompostela Airport. The project includedthe delivery of 60 Sepura terminals.A connection between the TETRA networkand the analogue air-to-ground system isalso provided.

Dominion Tecnologías managed to make theirfirst project for AENA a success due to fastdelivery and tuning of the system and terminals.Santiago the Compostela Airport is the mostimportant airport in Galicia (North-Western regionof Spain) with nearly two million passengers in 2006.

The TetraNode Entry Level Platform system allowsAENA personnel to communicate through a two-carrier site and will also connect TETRA users withusers of the airport’s PABX and with the incomingaeroplanes thanks to the air-to-ground interface.

Santiago de Compostela was declared a WorldHeritage City by UNESCO in 1985, in view of itsurban beauty and monumental integrity, as well asthe profound echoes of its spiritual significance asan apostolic sanctuary and the destination of theMiddle Ages' most important religious and culturalmovement: the Way of St. James pilgrimage.

Tetra Notes thanks Diana Zabala, RadioConsultant with Dominion Tecnologías S.L.U.,for providing this article.

Organisations can increase the functionalityand performance of their TETRA networksthrough intelligent upgrading, saving lots ofmoney.

Digital mission-critical TETRA technology has beenin commercial use for some ten years now.Considering the average lifetime of technology,it is clear that the very first TETRA networks arenow ready to be upgraded to include the lateststate-of-the-art technology. These new TETRAsystems could offer significant functional andcost-saving benefits for both network operators andend-users.

Below, serveral reasons for upgrading TETRAsystem are presented.

It is often the case that expansions cannot berealized and functionality cannot be addeddue to hardware limitations and the highcosts involved. This is even more true for the newRoHS (Restriction of Hazardous Substances)compliant generation of products.

After 10 years, many service and support contractsterminate and extending them may turn out to bevery expensive (usually a fixed percentage of theoriginal contract value). Prices of systems havedecreased substantially over the last few years withthe introduction of new technology platforms andCOTS (commercial off the shelf) products, thusreducing the total cost of ownership.

The latest TETRA systems meet much betterspecifications than the early ones. Not only in termsof sensitivity of the base station transceivers but alsoin terms of network performance. Radio coveragemay be increased with the same number of basestation sites.

The availability of application interfaces andgateways can further reduce the cost of ownershipand significantly increase efficiency in controllingand managing an organisation.

Last but surely not least, network redundancy andsystem reliability are important aspects to consider.For any mission-critical user, these characteristicsare of overriding importance and with the latestgeneration of TETRA technology, they are muchmore mature and readily available.

Risks of putting off the decision to upgradeIn addition to the above-mentioned arguments,there are situations which make it of the utmostimportance to take immediate action and notto postpone the decision to upgrade existingTETRA systems.

Some of the situations are addressed below.

Many TETRA technology platforms have alreadybeen discontinued. This means that manufactureshave stopped the production and commercialoffering of the system platform. If a networkis based on such a technology platform, upgradingthe network with the same technology is almostimpossible.

Some manufactures have not anticipated the rapidtechnological advances and still have non-IP basednetworks with dedicated, very complex hardware,using IP only as a buzz word. This technologicalapproach is outdated and should not be consideredfor new purchases for reasons of limitedperformance and functionality, complex hardwarestructure and non-distributed intelligence.

New infrastructure manufactures will emerge onthe market who, only recently, have introducedtheir TETRA systems. They do not have a solid baseof commercial reference projects. It will be verydifficult for these companies to catch up with theadvances in technology demanded by the market. Inaddition, interoperability (IOP) certificates are notpart of their portfolio at this point in time. Nobodywants to be a beta or pilot customer anymore.

The main criteria for selecting aTETRA system upgrade

• Technology used• Proven track record• Available service and support

Similar to the computer industry, only thosecompanies will be successful which design andmanufacture state-of-the-art technology witha commitment to continued development forfuture-proof investments without compromisingcustomer requirements. Depending on the lifetimeof an existing TETRA system, migration toTetraNode may mean increased networkperformance, additional features and extendedradio coverage due to highly sensitive base stationtransceivers.

Rohill’s proven track record speaks for itself. Thecompany offers current owners of a TETRA system theoppertunity to show them how upgrading a TETRAsystem to include TetraNode technology may savethem money and protect investments made in the past.

Rohill provides partner support from networkdesign to after-sales service with a 7x24 helpdesk;a service policy which is driven by a strongconviction that a trustful partnership and readilyavailable support is the basis for ongoing success.

Telvent tosupply TETRAcommunicationsequipment forLa Coruña andVigo Airport

Successfulimplementationof TetraNode Networkat Santiago deCompostela Airport

TetraNode systemfor Sofia AirportRedundancy features and PABX group callfacility deciding factors for contract awardSofia Airport, also known as Vrazhdebna(named after the village located tothe north) is the main airport in Bulgaria.The airport is a hub for Bulgarian airlines.It handled 2.2 million passengers in2006, a visitor number which is expectedto grow to 2.6 million in 2009.

Built in the 1930s on the outskirts of thethen relatively small capital city, Sofia Airport hasincreasingly been facing difficulties handling thegrowing number of passengers. After years ofstudying various locations, some as far as 70 kmaway from Sofia, it was agreed to expand theexisting airport. The airport's second terminalwas officially opened on 27th December 2006.

The new terminal has been equipped with thelatest technologies in order to offer the best serviceand facilities to match a first-class airport.The radio communications system was, of course,considered a vital tool for the coordinationand security of the airport and in December 2006it was decided to migrate from the existinganalogue radio system to a third-generation digitaltrunking system. In the past 16 years, Sofia airportauthorities have met their communications needsusing a Stornophone radio system and a DECTAlcatel system for communication between thevarious different staff members involved inoperations.

After a thorough analysis of their needs andconsidering the growth of traffic at Sofia airportas well as the new security issues involving airports,

TETRA was considered the technology to followand a public tender was issued.

Rohill participated in the tendering procedure andwon the tender through its distributor companyComtek 2000. The TetraNode system provedsuperior as it met all the technical requirementsand exceeded them even by offering a redundantswitch, which is considered essential in a mission-critical environment, like an international airport.The group call facility from and to a PABX was alsohighly appreciated by the customer. Comtek 2000proposed and delivered Sepura hand-portables andmobile radios for the first stage of the projectinvolving 200 users.

Plans are now being made to increase the numberof users and to implement applications which willoptimise communications, taking advantage of allthe possibilities TETRA and TetraNode offer to usersof mission-critical communications systems.

Tetra Notes thanks Comtek 2000 forproviding this article.

Upgrading aTETRA systemA step into the future