2 Way Radio Communications Guide

HUMAN FACTORS IN TWO - WAY RADIO COMMUNICATIONS

The Human factors database of worldly experience has proven to us all time and again, that the:

· inherent limitations of human memory,

· effects of stress and fatigue,

· risks associated with distractions and interruptions,

· limited ability to multitask

ensure that even the most skilled professionals are ultimately exposed to making errors and mistakes.

One way to limit this occurrence is to adopt effective Two-Way Communication methods that create a well-understood environment, reduce the chances of error and, consequently, support an accomplished Safety Management System (SMS).

When analysing Two-Way Communication in general, the following factors are highlighted namely:

· The receiver will feedback the information as passed to the sender, which forms what can be defined as a `Closed Feedback Loop`.

· By making any relevant corrections during this conversational period, the sender and receiver can be said to be working together in order to achieve the same outcome.

· This `Closed Feedback Loop` ultimately prevents any misunderstanding that could occur by the receiver, should they have erroneously misinterpreted any part of the original message.

When applying these factors in Two Way Communications on frequency, there are several Human Factor considerations that become apparent: (NOTE: the list that follows is non-exhaustive)

Ø The overpowering thought that when you speak on frequency, that there may be others listening out that are more proficient than yourself, according to you

Ø `Stage Fright` - attempting to speak on frequency, but being overcome by an emotion that exposes doubt, resulting the proverbial `Uhm` as an outcome.

Ø An accurate understanding of English which may not necessarily be your first language

Ø A good understanding of Radio Terminology, (RT), and how to apply it effectively

Ø The possibility of your transmission being corrected by someone else on frequency

Ø The concept of being `Live` on frequency as soon as you select the Push To Talk, (PTT) switch

Ø The likelihood that others may know you by identifying your name on frequency, which could lead to an expectation according to you

Ø The possibility of being challenged on frequency and not knowing how to manage, or respond to the situation

Ø Being exposed to an unplanned emergency, that requires your urgent response to others on frequency.

Ø The amplification processes that need to be considered when making a transmission on frequency.

When reviewing each of these 10 points that have been highlighted in this list above, it is apparent that FEAR is one of the key determining factors in the concluding outcome of Two-Way Communications on frequency. This phenomenon is unfortunately a variable that cannot readily be avoided; however, it can be prevented through:

Pro-active training and guidance

by those qualified personnel who, through prior exposure, have learnt the art of managing two-way communications on frequency with a determined, and balanced approach.

In a world where the Push to Talk. (PTT) switch appears to be mightier than the sword, experienced individuals involved in all aspects of personnel training, need to consider not only teaching what needs to be said during two way frequency communications, but they also need to focus on support solutions and mechanisms geared towards overcoming the Human Factor element pertaining to this subject.

For further information on this thought-provoking subject keep a lookout for our related technical book, due to be released soon.

When making use of a VHF Radio, the user must select the PTT (Push to Talk) feature which is normally located on the left side of the handheld radio, or on the outer rim of a fixed radio`s microphone switch, in order to transmit a message to the receiving party. Push-to-talk (PTT) buttons make wireless communication easy. Simply press the visible PTT button to send a communication to your recipient. There is generally a slight delay at the start, so wait for a second or two before talking.

Operators within the Aviation and Marine disciplines for example, make use of a VHF Radio to assist them as a voice tool within their daily duties and responsibilities. This utilisation is not however limited to these mentioned disciplines, and extends into other fields such as firefighting, security, surveillance, search and rescue, defence, etc. First time users of any HF, VHF or UHF Radio generally have an unassuming hidden fear to press the PTT and transmit their message. This fear stems from the fact that the user knows that when they select this switch, it automatically progresses to the next stage which is `Push to Talk`, and not `Push to Think`!

Everything else becomes a distant blur once the PTT has been selected, and the user is completely focused on their speech as they recite the transmission, at times for all those `newbies` on frequency, with a hesitant anticipation of what to say next. Interesting enough though, the same cannot be said when this same mentioned operator relays similar information over a cellphone. Is it because, unbeknown to them, that they feel more comfortable speaking on a cellphone knowing that only the person on the receiving side is hearing them talk, as opposed to speaking on a radio where there are a number of users on this same frequency at any given stage.

Now as a feature of two-way radios, PTT offers the following advantages over devices such as cell phones:

Security is improved because open cell phone networks, which can be vulnerable to security risks, are avoided when two-way radio frequencies are used;

• Clarity is improved because both the technology itself and PTT protocol require communicators to take turns and communicate clearly;

  
  

• Instant connectivity is at the press of a button, whereas cell phone features are designed more for versatility and convenience;

  
  

• Devices with PTT, as part of their physical design, are built to withstand the stresses of hazardous and demanding situations.

Firstly, the squelch feature of a two-way radio keeps the speaker quiet when no signal is present. The squelch setting adjusts the threshold at which signals will open i.e. (un-mute),the audio channel. The squelch feature is designed to suppress the audio output of the receiver in the absence of a sufficiently strong desired input signal.

NOTE: This is not an automated function, and it is up to the Operator to accurately make this selection.

With the squelch level correctly set, you will only hear sound when you are actually receiving a signal. Backing off the squelch control, (i.e. deselecting this feature), will result in the operator hearing white noise, (also referred to as clutter), if there is no signal present.

Two-way radios usually have several levels for squelch adjustment. You ideally want to select a level at which the background noise is just eliminated when no signal is present.

The Volume Control is exactly what its name implies, however what is important to note is that this feature works independently from the Squelch feature. A common error made by the Operator when faced with white noise, is to turn the volume control switch down to a point from which this clutter sound has disappeared. The problem however with this action is that it also removes what audible sound you previously had before you adjusted the setting, resulting in your radio strength being unnecessarily weaker than what it should be. Remember you ideally want your radios transmission strength to have a minimum scoring of a Level 4 when measured against the Radio Strength Table. The Operator needs to be well aware of the functions for both these switches when setting their radio for operational purposes. 

When planning to speak on the frequency during two way radio communications, there are a number of considerations that you have to be aware of both prior, during and once the transmission has been completed. (This is in addition to you conducting a radio strength check prior to commencing with operational two-way radio transmissions).

Prior to making a Transmission

• Listen out on the intended operational frequency to make sure that no one else is currently transmitting

• Make sure that you have selected the correct frequency / channel

NOTE:

1.  A channel is a range of frequencies allocated for transmission. So, when we say Channel 6 for example, this corresponds to a specific range of frequencies allocated to transmit in that channel.

2. A frequency itself is a value based on the number of cycles per unit of time.

During the actual Transmission

• If you start to falter at any stage while making a transmission rather: a) STOP talking, b) PAUSE to think what you actually wanted to say initially and c) BREATHE and start making your original transmission, but this time speak with uninterrupted confidence.

After the Transmission is completed

• Take your finger off the PTT the second that your transmission is complete, in order to release the `hold` that you had on that specific frequency while you were transmitting.

NOTE:

Only one person can speak on a designated frequency/channel at any stage. Should you try to `talk over` a person who is already transmitting, there is a good chance that, due to what is termed `double transmission`, no one would have heard a thing except for lots of background noise caused by frequency interference. This would result in the operator who had made the original transmission having to repeat it on frequency. During emergency, or busy operational periods, this could definitely affect the outcome of that particular situation in a negative manner.

It is important to note that the content of your transmission determines the actions that will be followed by you, as well as the understanding of others on frequency as to what you intend to do next. An ambiguous transmission can easily be misunderstood by other parties on frequency, which can ultimately lead to an unsafe environment.

Understanding the recipient on frequency needs leads in turn to the anticipation of potential feedback. Having a grasp on the content of your message in advance of having to make the transmission itself, ensures that you are always in control of your actions on frequency.

In this section we will be guiding and promoting the steps for you to follow in ensuring your message content can be clearly understood by all parties on frequency at the time.

The categories of radio management for a two-way radio license, used in either the Aviation, Maritime or Ground Based disciplines, is measured within the following 2 specifications, namely:

a) The actual Radio, (+ allotted frequencies / channels), as an approved communication device;

b) The approval for an Operator to use this Radio for communication purposes within a particular discipline.

So, in simplified terms, the radio that you going to be utilising for two way communications needs to have firstly been approved by the Communications Authority for your area of intended use, and the Operator in turn needs to be in possession of the appropriate radio license, as issued by the Regulatory Authority, that entitles them to speak on this radio for the purposes of two-way communications within that required radio management category.

So why does the radio`s frequency bands technical parameters that it has been allotted, have to be approved?

The International Telecommunication Union defines frequency allocation as being of "a given frequency band for the purpose of its use by one or more terrestrial or space radiocommunication services or the radio astronomy service under specified conditions". Each radio is licensed to only operate on frequencies that have been assigned for a very specific purpose with respect to radio communications. As an example, it would not make any sense for an Operator to try and communicate with Marine vessels using a radio that has been approved to transmit on frequency bands associated for aeronautical operations only.

The frequency band allocation has a lot to do with the fitted antenna that is mounted on the radio (portable), or within the vicinity of the radio (when we referring to a Fixed Station). If you hypothetically had to tweak the radio to far out of its allocated bandwidth, it`s antenna would stop operating. Even if you carried on your person, or had multiple fixed antenna`s (for all occasions so to speak), this continual `resort to an adapting approach`, would ultimately damage that radio when used in this unapproved manner.

So, when one wishes to acquire a radio for two-way communication purposes, make sure that the radio has been certified by an appropriate authority invested to manage the various radio frequencies, for all the specified two-way radio disciplines. There will normally be a certified logo for that Communications Authority, permanently displayed in the vicinity of the radios battery as fitted.

It is also very important to note that each discipline requires a different radio license to be issued for the operator, and that you can not use your operator radio license interchangeably within the field of two-way radio communications. In order to use multiple radios for two-way communications within various disciplines, the operator needs to hold the relevant radio licensing for each.

iI is most certainly a requirement for all operators of two-way radio equipment to be trained, qualified and hold the relevant radio proficiency certification for that specific discipline. This is of course prior to being authorised to commence with the specific two-way communications.

P.S. – Pease take note of the licensing expiry in all instances, (the physical radio license for a radio with allotted frequencies, plus the Operators radio license for two way radio communication purposes), and where renewals are required, ensure that they are complied with in advance of that expiration date for insurance, and safe operation purposes.