Paging is a long-established means of alerting professionals, and a number of technology companies have been working hard to bring TETRA’s benefits to this market, as Richard Martin discovers
Paging is a widely used technology for sending simple alerts and messages to wide variety of remote users, such as medical staff, taxi drivers and repair crews. Traditional paging has been one-way and this is still the case with today’s paging systems.
Pagers needing a link back to a despatcher to acknowledge a call use other technologies such as GSM or LPWA. With TETRA the two-way communication capability is built in, and encryption is available if needed. The TETRA link will also pass location back to the control centre using LIP (Location Information Protocol) if a GPS receiver is installed in the device. TETRA has group call capability and user devices frequently feature an emergency button.
Phil Kidner, CEO of the TETRA and Critical Communications Association (TCCA), says that the drive for a TETRA pager came from operators, particularly in Norway and Germany, who wanted to use their TETRA networks for critical responders, taking advantage of the resilience and security they offered.
Several manufacturers have now introduced TETRA pagers, including Airbus Defence and Space, Oelmann and TPL Systèmes. Users already include hospital staff utilities, fire officers and police. It should be noted that TETRA paging is still in its early stages of market development; it is attractive to operators with an existing TETRA network or who need a secure system, or both.
Derek Banner, chairman of the Critical Messaging Association – Europe, helps to set paging in context. Throughout the world, modern paging networks generally use either POCSAG or FLEX codes over a variety of licensed frequencies. POCSAG is an open standard that any paging manufacturer or operator can freely use; FLEX is a standard developed by Motorola. POCSAG supports paging services at up to 2,400 bps, and Flex at 6,400 bps. The higher speeds enable the channel to handle more traffic as well as supporting richer messages. Originally paging was a one way “beeping” service, but over the years it has been developed to support numeric, alphanumeric and fully encoded messaging.
Banner says: “A return path can be added using GSM networks, allowing the user to acknowledge or respond to received messages and, with the aid of an in-built GPS receiver, the despatcher can be informed of their current location and ability to deal with a situation. Emergency service despatchers can identify the closest and best-qualified person to deal with an incident, and the same would be true for a delivery van, sales person or taxi responding to a call. The group calling facility in every paging network is used to narrowcast information to any amount of targeted users within a group with only one transmission.”
He highlights that “localised or on-site paging systems are sometimes linked to fire alarms, particularly useful for the hard of hearing who can then be alerted to a fire with vibration or light alerts on the pager. In hospitals, pagers are widely used and repeaters or additional transmitters can be added to ensure coverage in all areas.”
Banner adds: “The challenges posed for utilities and emergency services by major power outages can be severe. Traditional communications systems can break down during these crucial times, either due to congestion or power failure. However, paging base
stations only transmit when
there is a message to send, so back-up batteries or generators last a long time. A network can remain in service for a long period until power is restored. Swissphone has a complete system for such an eventuality which allows for two-way messaging throughout an elongated
power outage.”
Some years ago the UK Royal National Lifeboat Institution (RNLI) installed its private paging network. This consists of about 300 base stations around the coastline of the UK and Ireland. The RNLI relies of volunteers to operate the lifeboats at short notice for emergencies in coastal waters, and only paging has the cost effectiveness and coverage
to suffice.
Banner commented on the Belgian and Dutch emergency services’ recent selection of a paging system to complement their TETRA radios. In Belgium about 220 transmitters cover the whole country, even in basements. Because paging networks use a “simulcast” transmission system there is an overlap in coverage so that, in the unlikely event of a base station failure, pagers still receive coverage from the neighbouring base stations, and thus still receive messages. The Critical Messaging Association recommends the use of multiple, separate technologies for emergency services to ensure continuity in the event of a major failure of any one communications system.
Traditional pagers are robust and reliable. They are also sensitive and therefore have extremely good reception and service within buildings. They are small, easy to use, have a long battery life and are inexpensive. Any competing technology will have to match all of these benefits. Banner notes that “a paging receiver is small, has an internal antenna and has a low-power battery source. This tends to limit receiver sensitivity and hence the coverage network. TETRA networks are designed to operate with large devices with external antennae so coverage and overall cost should be taken into consideration. Traditional paging networks take all these things into consideration and hence provide excellent, cost-effective coverage which is second to none.”
The UK ESN network is an interesting case where, as in Belgium and the Netherlands, a separate paging network (or the use of PageOne’s existing public network) should be considered. As the ESN will use a commercial network, this would be a cost-effective addition to ensure continuity of service in the event of technical or traffic congestion problems with the LTE network.
Banner says “a conventional paging system would be an inexpensive and sound way to provide extra capacity and message redundancy for an LTE-based ESN”.
Airbus Defence and Space's P8GR TETRA pager is being used in Germany to alert fire-fighters. Credit: Airbus Defence and Space
TETRA pagers: Who, what, where
Airbus Defence and Space
The TETRA pager P8GR from Airbus Defence and Space was introduced to the market in 2015 with excellent performance (more than 48 hours’ battery autonomy with standard battery) and optimised radio features within a very compact TETRA device. It weighs 145 grams and has an internal antenna. In contrast with standard analogue paging devices, the P8GR enables secure two-way communication between the control centre and the operational units.
The P8GR is dedicated to callout, text messaging (only receiving) and status messaging. It is also supported by a wide range of accessories designed to enhance its performance. For example, two-battery versions are available and the pager can be charged from any standard USB socket (mains adaptor or in-car), using only the USB cable. The Smart Home Station for P8GR ensures that the pager is being charged when the user is at work or home. Furthermore, the connectivity for additional alarming peripherals allows the messages to reach their recipients without delay.
Large-scale terminal deployments for organisations with varying requirements are possible thanks to the versatile configuration options with Airbus Defence and Space’s TaqtoTM terminal management solution. The integrated micro-USB port also allows the terminal user to program the pager and perform firmware updates effectively. The P8GR is entering service in Germany for the fire service, which has a large number of professional and volunteer fire officers. There are some projects in Finland, where it is also being adopted for alerts in hospitals but also for staff at home or away from the hospital on stand-by. This system will work even if the commercial mobile networks are congested or unavailable, because the P8GR operates within the secure and mission-critical radio networks.
TPL Systèmes
TPL Systèmes is a French telco with 10 years’ history in paging. Its Birdy TETRA pager enables transmitting and receiving messages via both private TETRA systems as well as commercial cellular networks. By supporting both ways of communicating, the Birdy TETRA can ensure connection between the user and control room.
The Birdy TETRA also has GPS built in for positioning, as well as a colour display and a Windows-based programming tool. It has lone worker protection capabilities – it can issue an alert in response to no movement for a period of time, has a tilt sensor, and will alert in response to the user pressing the device’s emergency button.
TPL Systèmes is having success with this device among industrial and utility customers who want to use their TETRA network for paging. The South African Police in Cape Town have put this unit into service. More conventional pagers have to use GSM to send messages back to a controller and this can add cost; using the TETRA network eliminates this. Using TETRA also allows the use of over-the-air encryption, which is of particular importance for utility customers who must protect their infrastructure and communications against malicious attack. For users who roam outside of a TETRA network, a GPRS (GSM) option is available. An indoor location system using fixed beacons is also supported.
TPL Systèmes' TETRA pagers are being used by the South African Police and have colour displays
The Birdy TETRA unit has a colour display to show
icons and longer messages, and has received good feedback from users. The unit can be linked to a call-out application in the control room so that despatchers can immediately see who is available to attend an incident as they receive acknowledgements back from the end-users over the
TETRA network.
TPL Systèmes sees the TETRA pager market as a specialised area for its business, but is pleased to see growth in industrial and selected emergency services usage.
Oelmann
Oelmann Elektronik GmbH, based in Germany, released its Viper TETRA pager in 2010 for secure alerting and messaging. Since then the number of these devices in operation has grown to several thousand around the world, including many small and average fleets of users, together with those on a nationwide network such as Airwave (UK), Nødnett (Norway) and Rakel (Sweden).
The device is based on a proven modular basis from the Oelmann’s Viper family, which already includes POCSAG, WLAN and GSM pagers. The Viper TETRA pager is a two-way standard TETRA portable device with a GPS receiver able to not only receive alerts and messages but to also send back acknowledgements, messages and statuses, so that the dispatcher knows who is registered, active and able to attend the call. TEA encryption is included for high security, or the unit can also run in non-encrypted clear mode. Enhanced RF SA mode/TxI functionality is important in areas where the transmission is impossible or difficult, at hospitals or events where radio silence is required. A man-down sensor will send an alert to a despatcher or controller if the user fails to meet pre-programmed movement or posture limits. The Viper is small and light, weighing 160g and measuring 92/57/24 mm. It is IP54-rated and operates from -20 to 55°C. ATEX-certified devices are also available, and the device can be supplied with standard or high-capacity batteries.
Oelmann's new generation of VIPER TETRA pagers are fully backwards compatible
Igor Alexeev, Oelmann’s sales director, points to the future use of this unit in professional networks, including in the US, and highlights the advantages of having a secure two-way communications solution, which TETRA gives, as well as comprehensive group alerting and messaging capability.
At the present time, Oelmann has developed the second generation of this device, which it claims surpasses its predecessor in all technical respects, including some previously non-standard frequency bands and slim-factor modems for IoT-like purposes. To increase their appeal to longstanding customers, the latest Viper TETRA pagers are backwards compatible with all accessories and software for previous versions.
Summary
Those manufacturers that have introduced TETRA pagers have created a new market, which is still under development. Industrial or small TETRA networks are the current sweet spot for TETRA pagers, eliminating the need for building a paging system or renting time on an existing system and paying for a GSM service if paging alerts need an uplink for acknowledgement. These TETRA units should really be considered to be messaging devices with advanced capabilities well beyond the simple pagers of a decade ago. Two-way communications, emergency button, lone worker safety alerts, encryption and navigation are included in several of them, and operators need to consider these capabilities when making comparisons with other paging technologies and pagers.
Top image: Airbus Defence and Space
