A. Communications equipment

Even though familiar communications equipment (such as the internet and cellular phones) is often available in the field, you will still be faced with slightly uncommon devices at times, ones that range from the rustic and old-fashioned to the high-tech and sophisticated. You may not be challenged into communicating by pigeon post, but some old-fashioned devices such as radios might be tricky for first-time users and therefore require basic technical know-how. The same applies to the more advanced SATCOM (satellite communications).

This chapter will highlight the main types of communications equipment that you might encounter while on mission and take you through the basic steps needed to familiarise yourself with these devices.

We will first introduce you to VHF (very high frequency) and HF (high frequency) radios, before moving on to SATCOM. Finally, we will look at mobile phones and the internet from a security point of view.

1. Radio 

VHF radio

Very high frequency (VHF) radio waves travel in straight lines. Just imagine for a moment that you are looking from your vehicle to your office in the distance through a set of binoculars. The radio waves from your set are following very much the same line of sight. If you can see your office, you will be able to communicate with it. If there is a forest or mountain in the way, you cannot see your office; likewise, the radio waves travelling in the line of sight cannot get through. Obstacles such as trees, forests, houses and pylons make it difficult for VHF radio waves to follow certain paths. Obstacles either absorb the waves completely or deflect them. If you want to improve communications, find your way to high ground and send your message from a point where there are no such obstacles in the way. Distance is naturally an important factor. As your VHF waves are broadcast outward from the antenna, they spread out like ripples of water on a pond after you drop a stone into it. The further away from you the signal travels, the weaker it becomes. Some sets are more powerful than others. You can experiment as you get to know your area and thereby understand the distance over which you can communicate.

HF radio 

High frequency (HF) radio is designed for longer-range communications and works by sending its signal skywards until it bounces off the electrically charged ionosphere and back to earth.

Unlike the VHF sets, from which you can obtain better results through correct use, the HF transmission and the clarity of your signal depend largely on a number of factors, most of which are usually out of your control.

For example, natural phenomena such as sunspots can have a marked effect on HF radio signals. The frequency assigned to you may work well at one time of the day and then be virtually useless at another. It may be better by day than by night, but again this is largely out of your control. Sometimes you will be told to use different frequencies at different times of the day to overcome these problems. If you have a mechanism on your HF set with which to tune your antenna, always do so. Ask how this should be done. When the antenna is not tuned, you cannot communicate, because the transmitter is disabled and reception is almost impossible.

How to use VHF and HF radio

The following is an overview of radio communications procedures that, when followed, will minimise radio time, make radio time more effective and reduce misinterpretation of radio messages.

Preparing your radio set for operation


  1. give the call sign of the station you are calling (this alerts the station that they are being called);
  2. then say “This is…”;
  3. then give your call sign;
  4. transmit your message;
  5. end your message with “over”; end the conversation with “out” (see also the Annex for radio procedures).

Even when you think that you speak English properly, your accent and choice of words, in combination with background noise, may make it very difficult for others to understand you. In order to facilitate understanding, a phonetic alphabet has been developed which helps the recipient of the message to quickly understand what you mean. Therefore, when asked to spell a word, use the phonetic alphabet, which can be found in the Annex along with a list of procedure words.

2. Mobile phones

Nowadays, with GSM (Global System for Mobile  Communications), you can not only obtain broad international coverage for your mobile, but also access your  email through your phone. Also, unlike communicating  over a VHF radio network (where all your colleagues  within range can hear what you are saying), using a  mobile phone normally gives you the luxury of having  a simple one-to-one conversation.

This might sound like the perfect communications deal. However, things are not always so bright and shiny in the field. Despite all its positive points, the use of mobile phones can present certain disadvantages:

In addition, there are a number of security-related aspects that you should take into account:

3. Satellite communications (SATCOM)

SATCOM devices are simple to use. They work by bouncing signals off a satellite and back down to a ground receiver or relay station, which can then retransmit. The area on the ground where you can obtain good communications from your SATCOM is known as the ‘footprint’. Remember, just because a particular brand of SATCOM operated wonderfully on your last mission does not mean it will be ideal in another part of the world. The ‘footprint’ may be completely different. Take the advice of your communications experts when they are issuing your equipment. They know what will work and what you require. The most important feature of SATCOM is guaranteed long-range communication.

In spite of the positive aspects of using SATCOM, you should keep the following in mind:

4. Internet/computers

These days we all use the internet and other computer networks to communicate with friends and colleagues. We all know the advantages of the system, but it is extremely important to highlight the following dangers: