Hot pursuit: TETRA for motorcycles
When chasing down criminals or rushing to provide emergency care, motorcycle users need the TETRA radios on their bikes to be safely and properly installed – as the potential consequences from a botched job can be severe, as Richard Martin discovers
There are some emergencies so time-critical that the car – the normal vehicle of choice for PPDR users – leaves much to be desired. At these times, motorcyclists’ ability to weave through traffic, access pedestrian areas and get through narrow gaps between buildings becomes invaluable.
While police have used motorcycles for many years, in recent times their use by paramedics has become more common. With time a critical factor in medical emergencies, the ability to get to the patient quickly is literally a life-saver.
Let’s look at the use of motorcycles by community police officers to patrol a challenging suburb in a major city. They will be expected to quickly react and get to minor but frequent incidents. Suspects may flee down footpaths and alleyways. The officers will need access to communications at all times – both on and off the motorcycle. They will patrol alone for much of the time and may occasionally be in danger.
An emergency button and other lone-worker features are desirable, and TETRA will provide officer location to the control room using GPS, enabling rapid back-up. The motorcycles will be clearly marked and can be fitted with panniers to store radio equipment. A radio will be fitted with connection to a helmet with integral headphones and microphones; a conventional antenna, giving good coverage; and handlebar controls, to control the radio while riding. When the officer is on foot, he will use a handheld radio.
In this example, conventional mounting options for the radio and antennas are used, but the design must still fully meet all operational needs.
The other equipment mounted on the bike also needs to be factored in – a motorway patrol bike may carry a very different range of equipment from the community officer. Were this to be a covert installation, there would be further design problems to solve. Above all, the safety of the rider needs to be maintained; even the most skilful motorcycle rider is vulnerable to errors from other road users and needs to have their full attention on the conditions around them. Fitting a TETRA or any other radio needs to be done in such a way as to have zero impact on their safety.
Why not simply carry a portable radio with connections to headset? A holder with power could be mounted on the bike to maintain charge over long periods, and connections to a bike-mounted antenna can be provided. There are several reasons for using a bike-mounted radio, such as range – a vehicle radio will work at higher power and maintain contact over extended ranges. The radio will provide communications for all riders of the bike, even if they would not normally carry a handheld radio. That said, most public safety officers will carry their own handheld TETRA radio.
Planning and design
The installation design begins with some basic questions. For example, is the vehicle branded as a public safety patrol such as a paramedic, or is it covert, as could be the case with an unmarked police motorcycle? The design will be different for these two applications. Marked bike installations are usually on new motorcycles, but in the case of covert fits, second-hand bikes are sometimes used.
Neil Barker, MD of Sonic Communications in Birmingham, talks about the importance of preparation.
Sonic has been installing TETRA radios on motorcycles for many years, as well as on other vehicles. It is active in bodies such as the Federation of Communication Services (FCS) to define standards and best practice for vehicle communications installations.
Barker highlights the need for EMC compatibility between the radio and the bike. With modern models being fitted with electronics to control many functions, the emissions from the radio could cause issues with the motorcycle’s engine management system, resulting in loss of power while transmitting – even speedometers showing false readings have been seen in the past. The Home Office will conduct EMC tests on a new motorcycle model before certifying it for public safety use and it will also make recommendations regarding installation design. The usual practice is that an installer will fit a TETRA or other radio onto a new model following Home Office testing and it will then return for further independent EMC testing. Once approved, the installer will then be able to supply fitted motorcycles to customers directly without further testing and carry out self-certification thereafter.
Barker notes that TETRA is less demanding regarding electromagnetic compatibility, in terms of radio emissions, compared with the much older 25W AM analogue radios used pre-Airwave; however, it is critical that radiation does not exceed safety levels in the rider’s body, so antenna type and position on the machine are still important.
He stresses the importance of maintaining rider safety, so for example, the balance of the bike needs to be maintained. The antenna should be positioned so that the rider can mount and dismount without catching it. The cabling routes need to be clear of the exhaust and fuel lines, and not restrict access to removable covers and panels or impede maintenance tasks.
The main radio unit can be installed in a pannier or top box or possibly in the front fairing of larger motorcycles, depending on the size of the equipment, with weatherproof control heads commonly being fitted in front of the rider above the handlebars, so that the rider can view the display without interfering with his view of the road. Barker says
most dedicated emergency service motorcycles will have a dedicated area behind the rider where the passenger would have sat on a standard machine, which creates space for the radio underneath a weatherproof cover. If fitted, a pannier may also be a location for the radio, but may be full with other items; for example, a paramedic will have medical equipment. Ideally the radio should not restrict storage of mission-essential equipment.
For the control head, the normal installation uses an all-weather IP67-rated head in front of the rider. This may be attached to the handlebar or to a fairing. The head must have a dimmer setting for riding in poor light or night time.
Motorcycles are not fitted with large batteries, typically 12Ahr. This means that a radio drawing even a few amps will start to drain a bike’s battery if it is stationary with the engine switched off for any period. In such cases the rider may elect to leave the engine running. For example, at a road traffic incident or a public festival, the radio will need to be active and perhaps the bike’s warning lights must be kept on. For such situations, Sonic has a solution called Run Lock, which prevents theft of the bike with the engine running. As well as providing sufficient power, the battery needs to provide a relatively smooth DC supply to the radio and its associated ancillary equipment, and it can be necessary to provide additional smoothing and filtering if the supply is “noisy”. Barker advises that these factors need to be assessed during the design and steps taken if necessary.
Another key factor in rider safety is the provision of easy-to-use radio controls that ideally do not require the rider to look down or take his hand off the handlebar.
While every country has its own regulations governing the use of radio controls while riding a motorcycle, generally it should be possible to answer and close a call without taking the hands off the handlebars or the eyes off the road ahead. Simple-to-use handlebar controls can meet this need. The job of the officer can also be made easier by setting up talk groups to eliminate the need to change talk group while riding. All controls should be easily used when wearing gloves. Push-to-talk (PTT) is the most frequently used control when riding, but Barker says that volume, home or talk group controls need to be easy to access and use.
Selecting and mounting the antenna should be done with care to maximise radio performance without compromising the mission. For covert cycles in particular there have been recent antenna improvements such as pad antennas to mount under a mud guard or inside a fairing. Also, Panorama Antennas has a TETRA/LTE combined “shark-fin” antenna available, and this may be useful as LTE becomes more commonly used alongside TETRA.
Continuing the importance of safety, Barker advises that the final part of any motorcycle installation inspection will involve the machine being ridden on public roads by an experienced motorcyclist, to check all functions of the machine and make sure the radio communications quality meets expectations.
The rider must be provided with a microphone and speakers. This is a demanding environment – with ambient noise levels exceeding 100dB, riders often wear earplugs giving 20dB+ of attenuation. The headset needs to be able to compensate for this, but also consider the risk of hearing damage due to over-exposure to high volume levels. The most recent headsets can be worn inside any helmet, combining hearing protection from noise with communications. The connection between the communications headset and the bike must separate easily in the event of the rider falling or being thrown from the bike to ensure the rider suffers no unnecessary additional injuries. In many cases when off the motorcycle they will remove the helmet, for example to take a statement. Their handheld radio becomes their communications lifeline at these times.
A wireless connection to the helmet would improve safety and flexibility, and such systems using Bluetooth or similar are available, but the batteries would need to be charged and sufficient to run for a full shift.
Fitting cameras on the motorcycle enable an automated number plate recognition system to alert the rider to a vehicle of interest. A small computer fitted on the motorcycle can store all the numbers of interest, and then be updated either over the radio data link or Wi-Fi when in the depot/station. Alerts can also be sent over the radio’s data connection to the despatch centre, which can then advise on the action to be taken; as some officers usually work alone, this could be vital for their safety. In the future, it may be possible to deploy helmet-mounted displays for critical information, but such technology is not currently cost-effective for general use.
Following best practice
John Thomson, technical sales and support manager at Panorama Antennas, also heads the FCS Installers Group, and he highlights its installation code of practice, FCS1362:2016.
This is not a mandatory document but it provides detailed guidelines for radio installations. It is written mainly for four-wheeled vehicles, but many of the guidelines can be applied to motorcycles. It covers significant aspects applicable to motorcycles including power, cabling and antenna installation. FCS1362:2016 also recommends a process of customer consultation during the planning process, as well as thorough testing before entering service. Thomson recommends that this work should always be carried out by companies with a good record of motorcycle communications installations, as this is a specialised task requiring the right experience and skills.
Motorcycles are a cost-effective and highly flexible means of mobilising officers. As an example, a motorcycle paramedic in a city centre can quickly attend incidents in shopping centres and congested traffic. Communications are vital for such officers to respond to events, transmit updates, and receive additional information. The radio system must operate at all times and all locations; a good design of the installation will maximise this. The installation must also maintain the safety of the officer when riding and when working alone in difficult situations. We look forward to other technical developments such as wireless helmets, faster data links and helmet-mounted displays, which will further improve effectiveness and safety.
Leonardo motorcycle installation kit for VS3000 TETRA terminal
Leonardo can supply a motorcycle installation kit for the VS3000 TETRA terminal. The motorcycle installation is designed to support use in extreme operating conditions.
Typically, the radio is positioned on the rear of the motorcycle inside a waterproof box that maintains all the functions in all environmental conditions. All the transmission functions (voice and data) are accessed through a control head installed on the motorcycle handlebar. Controls for placing calls and PTT are installed on the handlebar, with an external loudspeaker (water resistant).
Main features and components:
- Control panel with integrated support for audio accessories.
- Microphone or telephone-style handset to be used when stationary.
- Auxiliary connector for motorcycle helmet with audio accessories.
- Internal microphone, directed towards the rider, to be used if the motorcycle helmet with audio accessories is not available.
- Remote loudspeaker.
- Remote PTT and volume controls on the handlebar.
The kit allows for the following modes of conversation:
- Using the microphone/handset.
- Using the fixed microphone (located inside the control panel).
- Using a helmet with audio accessories (advisable for better audio quality).
A typical installation on a Honda Deauville NT700 with a Motorola Solutions MTM800E TETRA Radio
The following photograph (below) – courtesy of Sonic Communications) shows the installation of the radio control head and handlebar controls, such as a PTT button and volume controls. The PTT button can be seen in red and is easy to reach without taking the hand off the handlebar.
The pictures below show the installation of the radio transceiver behind the rider in a waterproof box (top) and the antenna mounting (below).