Essential guide to two-way radio terms

Every field has its own terminology and acronyms that professionals use with casual ease, often forgetting that lay people might not know what they’re talking about. It’s a matter of convenience rather than an attempt to exclude anyone. After all, a single term can sum up concepts that would otherwise take many more words to explain. 

Use our glossary of radio terms to get acquainted with the world of two-way radios. You’ll uncover a few interesting technical details along the way. 

For convenience, we have divided the information into sections beginning with the devices and their accessories. Some of the terms will be very familiar, almost self-explanatory, but we have included them to clarify their meaning in context. 

Radio terms explained: devices and accessories (A-Z)

Analogue two-way radio: These are devices that use radio waves to transmit signals. They’re still used in some contexts due to their simplicity, reliability and lower cost. 

ATEX: ATEX stands for “Atmospheres Explosibles” and refers to the EU directive used to rate two-way radios that are suitable for use in explosive atmospheres. 

Battery pack: This is relatively self-explanatory. Some two-way radios have battery packs that clip onto the back of the radio. They can be removed for charging, allowing users to switch them for fully-charged battery packs. 

Charger: There are many types of chargers. They range from those using micro-USBs to single and multi-unit chargers (also known as a six bank charger) .

Digital two-way radio: Digital two-way radios are replacing analogue two-way radios in many contexts. Because they use digitised signals, they enable features like noise cancellation, GPS tracking, text messaging, job ticketing, and encryption. They also have greater range. 

Frequency: Frequency affects the range and performance of two-way radios. Ultra-high frequency (UHF) and very high frequency (VHF) radios are those most commonly used.

Full duplex: A full duplex radio has transmit and receive frequencies and the radio can perform both functions at once. This allows users to talk and listen much as they would when using a telephone. 

Headsets and microphones: There are different types of headsets, so although you broadly know what they are, this term is worth expanding on. Dual muff headsets offer hearing protection in noisy environments while allowing the user to hear their radio. There are also lightweight headsets that don’t offer hearing protection but allow the user to hear their radio easily. Both of these types can come with microphones activated by pushing a talk button. Throat microphones pick up vibrations and can be helpful when the user has to wear a facemask. Whilst remote speaker microphones can be attached to your lapel or clothing.

Half duplex: All parties using a half duplex radio can talk and listen, but they can’t talk while someone else is speaking. Most two-way radios fit into this category.

Intrinsically safe: An intrinsically safe radio is designed to operate without the risk of igniting explosions in areas where flammable gases or dust are present. 

IP ratings: An ingress protection (IP) rating indicates a two-way radio’s ability to withstand exposure to dust and liquids. It consists of two numbers, the first indicating resistance to dust, and the second its ability to withstand exposure to liquids. 

Land mobile radio system (LMRS): This term refers to radio systems consisting of stationary units or base stations, or installed in vehicles.  

LTE multimode device: This type of two-way radio is compatible with digital, analogue, and cell phone signals. It interconnects two technologies i.e. DMR or TETRA with 3/4G / WI FI to form a converged solution to allow users to enjoy the best of both worlds, making it a useful tool in mission critical situations.

Mixed mode operation: Mixed mode operation allows users to hear digital and analogue communications on the same channel.

Milliamp hours (mAh): When choosing two-way radios, mAh will be an important consideration. It indicates battery life. The higher the figure, the less often you will need to charge the device. 

OLED: This acronym stands for “organic light-emitting diode.” It indicates an LED screen capable of high-quality displays. 

POC: Push-to-talk over cellular (POC) devices use cell phone signals or WIFI to connect users. 

PMR446: Two-way radios with this rating do not require licensing. They are suitable for relatively short-range communication. 

PTT: The push to talk button (PTT) is a standard feature for two-way radios. Simply press the button and talk to transmit messages. 

Receiver sensitivity: This term refers to a two-way radio’s capacity to receive and process a weak signal.

Roger beep or courtesy beep: When using half duplex radios, only one person can talk at a time. A roger beep is a tone that indicates a user has stopped transmitting a message and is ready to receive. 

Transceiver: This is a synonym for “two-way radio.” It refers to the device itself. 

VOX: Voice activated transmission (VOX) is activated hands-free. In other words, users do not have to push to talk. 

Watts: We all know that wattage refers to power. In practical terms, wattage indicates the range of two-way radios. Higher-wattage radios have greater range. 

Transmission terms

Base station (also known as a repeater): A base station is a fixed radio installation that acts as a central hub for wireless communication, offering a longer range than handheld radios to create a wider coverage area and is used to coordinate two-way radio users, such as when a transport operator communicates with drivers or to expand coverage on a large site. 

Channel: When your team uses two-way radios, they must be able to communicate without interference from outsiders who are also using two-way radios. Your selected channel allows this to occur.

Continuous Tone Controlled Squelch System (CTCSS): This system allows radios to be set up so that users won’t hear all the messages broadcast on a channel. 

Ofcom: Ofcom licenses and regulates two-way radios used in the UK. Unless you have PMR446 devices, you will require an Ofcom license.

Repeater: Repeaters receive and retransmit two-way radio signals. This allows users to communicate over greater distances (also see base station). 

Rx: An abbreviation used when talking about the reception of a radio signal. For example, a user might test Rx and confirm whether or not the signal is good. 

Tx: Just as Rx refers to signal reception, Tx stands for signal transmission. 

Employee safety: two-way radio terms

Emergency mode: Two-way radio users experiencing an emergency can sound the alarm by pressing a single button, this is usually indicated by a different colour on the top of a radio.

Lone worker: A lone worker is an employee who works in locations where supervisors and colleagues can no longer see or hear them. Because this can place them at risk, two-way radios allow them to stay in touch, check in, or call for support when needed. 

Man down: A person who is injured or incapacitated may be in need of urgent help. Certain two-way radios offer man-down alerts. An alarm is automatically triggered if position or movement tracking indicates that the worker may be in need of assistance. 

Personal attack button: Security guards, healthcare workers, and even retail personnel may face personal attacks while they are at work. A personal attack button sends an alert indicating that a worker is being threatened or attacked. 

Two-way radio communication jargon

Two-way radio communication terms (jargon) enhance communication, limiting the need for repetition or clarification. You can find information on this terminology, and the reasons why it is used, in our guide to two-way radio etiquette. 

Enhance workplace communication with Radiocoms

Two-way radios and push-to-talk technologies like PoC are used across industries for the simple reason that they allow for instant communication. They’re especially important in business-critical or mission-critical scenarios where communication cannot be delayed and entire teams must be coordinated.

If you need help choosing appropriate devices for your context, Radiocoms offers you the support you need to set up and run communications systems. Our decades of experience have made us a supplier of choice for fire departments, manufacturing industries, transportation, construction, healthcare, and more. Contact us for advice from our experts, business-quality two-way radios, and ongoing technical support and assistance from Radiocoms.

Read more about two-way radios.