James Miller, managing director of Brentwood Communications, explains how digital technology is allowing two way radio to be deployed across bigger sites than ever before, providing critical communications and safety support for facilities management teams.
Long before anyone had dreamt up mobile phones, we had walkie talkies. Handheld two way radios have been used in business and industry for decades because, quite frankly, there was nothing else that could be trusted to do the same job.
If you wanted a reliable, mobile, wireless communications device that could keep teams in contact as they worked across large sites, two way radios were your go to tool (and, as we shall discuss, still are).
However, two way radio has always had one key problem. It works by creating a localised radio network between units – and by localised, we mean limited. Each handset (or base unit, or vehicle radio) acts as both a transmitter and a receiver for radio signals. There are no enormous powerful antennas as we get for public broadcast radio. The strength of the signal, and therefore the distance it can transmit over, is limited by the output power of the radio unit.
For an analogue handheld radio, that output power is not very great. Neither, therefore, is the network range it can cover.
This has always posed a problem for deployment over big sites. In facilities management, for example, you might have teams working across large properties with several buildings and extensive grounds, or in multistorey high rise structures. The greater the distance, and the more obstacles there are in the form of walls, floors and ceilings, the more analogue handsets would struggle to give comprehensive coverage.
Versus Mobiles
At this point, it is usual to ask – what about mobile phones? As well all know, mobile phones are designed to provide coverage everywhere except the top of mountains and in railway tunnels. Moreover, the microwave frequencies they use are not daunted by passing through a few walls.
Mobile phones have revolutionised wireless communications. Yet two way radio remains by far the preferred option for business and industrial uses, for the following reasons amongst others:
- Audio quality: Mobile phones might work in most cases, but with a kind of lowest common denominator quality. Local radio networks suffer much less signal interference and deliver much clearer audio signals, an important factor for mission critical communications.
- Durability: Drop a mobile phone from height or into water, and that is probably that. Most business class two way radios are built to exacting IP standards for water, gas and dust ingress, and for withstanding shock and vibration.
- Ease of Use: One touch or even voice activation modes mean two way radios are simple and straightforward to use even when you have your hands full on the job – no having to scroll through long contact lists to make a call.
- Security features: Built for industry, most two way radio models come with in built safety features such as emergency alarm buttons, lone worker monitoring and man down alerts.
- Deployment anywhere: Let’s face it, mobile phone coverage may be pretty good most of the time, but it is far from absolutely reliable. If you are working underground or out in the countryside, there is not much you can do to get a better signal from the nearest antenna. Two way radios, on the other hand, can be used anywhere, and will create strong signals within range of each other wherever they are used.
New Horizons
The only advantage mobile phones have over legacy analogue radios is coverage. However, with the advent of digital two way radio, that has all changed. Digital transmissions are much more efficient that analogue, they travel over longer distances and, crucially, the signal does not deteriorate as you reach the limits of coverage.
A standard digital model such as the Hytera PD405, for example, can achieve ten times the output power of an equivalent analogue model.* It has an effective coverage range of 3km, plenty for most sites.
However, the real advantages in digital technology come in the wide range of specialised features that can be added to two way radios. The Motorola DP4800 is a premium class digital model packed full of the sort of features you would usually expect from a smartphone. It supports text messaging, private calling, work order ticketing and dispatching, all making it easier to communicate and coordinate operations in the work place.
In addition, thanks to support for data as well as voice connections, models like the Motorola DP4800 are no longer restricted to radio channels. Integrated Bluetooth, GPS, IP and telephony support means two way radio handsets can be linked into other data and communication channels, unlocking them from local area restrictions entirely.
Case Studies – Two Way Radios in FM
Nothing is ever achieved by staying in one place in facilities management, and when you have teams working on different tasks in different places across often large sites, it is essential that you have a convenient, reliable mode of communication. Brentwood has a long history supplying two way radio to FM professionals, and over the years we’ve leant a few tricks for guaranteeing always available coverage whatever the size and nature of the site.
We were recently commissioned by award-winning pharmaceutical company Bristol Laboratories to provide a two way radio network for the management of its production facilities. Because of health and safety requirements, the site has to be organised very specifically – working laboratories are heavily insulated and separated from office and administration facilities over several floors. The main challenge was to ensure these well protected labs could get adequate signal.
In this instance, we supplied powerful Motorola DP4800 handsets supported by a repeater and antenna system. Repeater units act like an amplifier for two way radio signals by separating out the transmission and reception channels. This additional boost, along with a fixed antenna on site, was enough to give excellent coverage even through the thick insulation of the lab walls.
An example of the difference in possibilities between analogue and digital two way radio technology was demonstrated by another recent client of ours. Rackspace, a global leader in cloud IT, was still using analogue handsets for maintenance and security at its UK headquarters in Hayes, west London – a site comprising five multistorey buildings plus underground car parks.
Coverage from analogue handsets was not surprisingly far from adequate, so Rackspace’s FM team contacted us. After carrying out a site inspection, we realised it was large enough to test even the most powerful digital models.
Our solution was to use something called a digital base station, in this case a Motorola DM4600. This allowed us to make use of a property of digital two way radios their analogue cousins do not have – they can be programmed to operate on more than one network at once. Using software built into the base station, we set up four different networks, more than enough to cover the whole site. Whichever network area a handset is operating in – and it picks up the different signal paths automatically – it is always in range of the central base station. As the base station controls all four networks, every handset can communicate with all the others, regardless of which area they are in – a perfect example of how digital technology is allowing two way radio to be used effectively on ever bigger, more complex sites.
*As compared to the Kenwood TK3501.
