TETRA is now seen as a stable, mature technology, with a diverse range of uses, and a progression path for future upgrades
Final preparations are under way for the meeting of the international TETRA community at the TETRA World Congress from 26 – 29 May at the ICM international congress centre in Munich.
After the success of the 2008 Congress in Hong Kong – which attracted more than 2000 visitors from over 60 different countries – the event returns to Europe for what is expected to be the largest Congress to date. Over 2500 representatives of the public safety and security services, transport companies, oil and gas, military, manufacturing, utilities and other users of critical communications are expected to join the TETRA Association and senior industry figures to discuss the latest developments and future requirements of TETRA.
It should be regarded as a success story for the suppliers and developers of a technology that looked to many to have a limited shelf life.
Once TETRA had won contracts for public safety networks, went the thinking, it could then be safely ignored by the rest of the wireless industry, which would scoop up further deals by highlighting their vastly higher data rates, range and abundance of terminals, and breadth of coverage.
But it hasn't quite worked like that. Instead, as we will see from some of the examples in this article, TETRA has been adopted for use in a wide range of circumstances. It also continues to expand its geogrpahic reach, and make advances technically, refreshing the technology to meet modern needs and issues.
One of these issues will be the way in which TETRA services are designed in the new cost-efficient environment.
Athough organisations employing TETRA?networks are unlikely to be able to compromise the quality of service, suppliers know they are competing in a changed world, and need to help their customers and users work in as cost-efficient manner as possible.
One way of doing this is making sure that the planning of the network makes full use of the RF?resources employed.
Dimitris Kanakidis from Net Technologies wrote in the TETRA Association's last newsletter that new TETRA network deployments need to consider two main factors: the cost of deployment, and network efficiency.
"Effective RF planning can help to achieve the optimum trade-off between these two factors," he writes. "RF planning is a tool that can assist the decision making process, eliminating the possibility of unwanted cost or performance modifications through the network deployment phase and providing valuable information such as:
– An estimation of the number of Base Stations required
– Definition of site locations, which will initiate the site acquisition procedure
– Specification of network characteristics by emulating different deployment scenarios, leading to appropriate equipment selection and planning inputs
– Estimation of frequency allocation plan in order to avoid major interference cases
– Estimation of capacity efficiency based upon specific traffic requirements
Based on this RF planning output, an equipment cost prediction can be made. This can lead to an efficient cost control of a network deployment project and help to reduce cost by avoiding unpredicted overheads."
Another aspect that can help increase the flexibility of radio resources is Software Defined Radio, which enables reconfigurable system architectures for wireless communications. Traditional hardware-based radio devices limit cross-functionality and can only be modified through physical intervention, but the current communications ecosystem means that modifying radio devices easily and cost-effectively is business-critical. SDR enables new wireless features and capabilities to be added to existing radio systems through software upgrades rather than requiring new hardware.
Axell Wireless, whose CEO Ian Brown is featured in this issue (p16) is one company taking up the SDT?mantle, by launching the first digital TETRA repeaters onto the market.
There is also a focus on the industry on outsourced networks. Just as cellular operators and other service prividers are seeing the value in outsourcing the management of their networks, TETRA network users are following the trend.
By outsourcing the procurement, installation and management of networks to a company such as Motorola, for instance, network owners can reduce their costs, and it's a trend that many expect to see become increasingly popular.
Another driver in reducing costs is to seek partnership between interested parties in building out a network.
For instance, Cardiff's city centre partnership RadioNet, a retail management and security radio, is the first deployment of a municipal TETRA network in the UK.
RadioNet is a municipal partnership which provides communications services linking retail, local government, entertainment and leisure business with the Police and CCTV control rooms. The new digital scheme adopted by RadioNet enables seamless and uninterrupted multi-agency communication by providing separate talk groups for different disciplines within the retail, police, city centre and local authority teams.
These teams of radio users need to liaise at different times, most often to resolve issues related to security. In addition, each user needs to be clearly recognised and identified when speaking and audio must be of the necessary high quality when communicating in a busy and noisy city centre. This partnership contract was secured by PMR Products PMR Products implemented RadioNet's migration from analogue to digital technology with the deployment of a TETRA network supplied by the Danish infrastructure supplier Damm. Sepura's hand-held radios were selected for their compact size and weight, which makes them easily carried by shop-workers and wardens.
Steve Clarke, managing Director for PMR Products comments, "The installation was completed in a record time of less than 10 days and the actual changeover from analogue to digital occurred over a single weekend. The penetration of the radio signals around Cardiff city centre is vastly superior to that of the previous equipment and the audio quality is noticeably higher. In particular, remote access to the system for diagnostic purposes proved to be invaluable when a complete power failure across the city knocked all the systems out".
As well as a focus on reducing costs, TETRA has seen expansion into different geographies and areas of use.
EADS Defence & Security recently announced, in collaboration with Beijing Satellite Science & Technology Co Ltd, the first TETRA project in China's oil and gas fields – providing a complete TETRA radio communication system for the Puguang Gas Field of the Sinopec Zhongyuan Oilfield Company. The system that will be delivered includes one DXTip switch, six TB3 base stations and a Network Management and Dispatching System; it operates on the 800-MHz frequency band.
The radio network will provide coverage over the Puguang Gas Field and neighbouring production operation areas. It is scheduled to be in full use by the end of June 2009 for managing and dispatching the production crews as well as for broadcasting important messages such as evacuation orders in case of an emergency.
"This is the first digital trunking network for Chinese oil and gas field industry, and our TETRA system meets the very special needs of the crews on the field: it is very flexible, reliable, and scalable, and above all, it can provide better safety. We are ready to build this network as a model for the whole industry," said François Bégaud, head of Security and Communication Solutions for the Asia Pacific Region.?DS is a world leading provider of mission-critical communication and Command & Control solutions through its integrated activity Defence and Communications Systems (DCS).?
Another recent Petrochem win has come from Rohde & Schwarz's Professional Mobile Radio division. It has signed a €5.7 million contract for the delivery of a TETRA radio system to the Kuwait National Petroleum Company. Setup of the network, is scheduled to be completed by April 2010.
With an ACCESSNET-T TETRA network featuring latest-generation base stations (DIB-R4) and redundant exchanges (DMX-R2), the order also includes explosion-proof terminals for 1650 users. All of these contracts were announced in the past couple of months, and there have been many more that show the extended reach of TETRA.
And as well as geographical reach, TETRA?users are promised a faster future, thanks to TEDS (Tetra Enhanced Data Service). TEDS.
TEDS is part of TETRA standards Release 2, an evolution of TETRA release 1 to which it is backwards compatible. It is intended to provide a change in the data rates available over TETRA, thereby meeting the need for higher speed services.
Based on a 50KHz channel bandwidth and a 64 QAM modulation scheme (themaximum allowable) it is theoretically possible to achieve a net IP data rate of157kb/s, but this gives low protection from errors on the air interface. Instead,a high protection mechanism is typically used to ensure the resilience of thedata transmission, giving an effective data rate of up to 80kbps, available toapplications, once overheads are considered.
TEDS progress has been slow to date, due to spectrum issues, as well as manufacturers' own production schedules.
The spectrum requirement for a nationwide TEDS network is at least 2 x 1 MHz, a 50 KHz TEDS Channel and TEDS reuse factor of 20. This means that countires need to update their spectrum regulations to include 50 KHz, 100 KHz and 150 KHz channels. It also means that for site engineering and planning considerations, it is ideal to have TEDS and TETRA1 in the same, or in adjacent bands for new networks, although that dopes require more planning effort. Operators and users have had to negotiate with regulators for spectrum.
The European Post and Telecommunication Committee CEPT has started a study to investigate the needs of emergency services for the availability of frequency bands for the introduction of Wide Band Digital Mobile PMR/PAMR in the 400 MHz and 800/900 MHz band.
But 2009 is being earmarked as the year we will see the first deployments of this technology. Motorola is providing TEDS to Nodnett, Norway's public safety network, fulfiling a contract awarded back in 2007.
So, 15 years after the Tetra Association first formed, whether one addresses the new economic climate, or the regulatory and spectrum challenges, there is still plenty of interest to discuss and look forward to within the TETRA?community.