A two-way radio is a radio that can be used to transmit and receive radio waves. It is unlike other radios which only receives content. Two-way radios are a transceiver, a transmitter and a receiver in one entity.
A two-way radio can be used for person-to-person bidirectional communication with users who like radios. Two-way radios are generally called walkie-talkies, handy- talkies or hand-held. Two-way radios are most widely used in stationary or base stations, mobile stations like vehicles and hand-held portable models. MRS Communications are the UK’s leading providers of two-way radios and security radio systems.
It’s Usage
Groups of people who are geographically separated and need to have continuous verbal communication. Such as pilots and air traffic controllers, emergency services like firemen, policemen, delivery services will be best suited to use a two-way radio.
It is also very efficient for amateur radio operators who participate in two-way personal communications. But they must have been issued with an amateur radio license by a governmental regulatory authority after participating and passing a given test.
A single radio channel is used by the two-way radio system and will function in half-duplex mode. It works where only one user using the channel can transmit at a time. So users have to take turns to achieve efficient communication.
When a user wants to transmit, he/she just presses a “push to talk button”. Which will deactivate the receiver and turn on the transmitter. When the user releases the button, it will activate the receiver again. It is also able to separate different user groups who communicate in the same geographical area since multiple channels are provided. Thus, they can’t interfere with each other.
The radio systems can also be activated to operate in full-duplex mode in which two parties can be able to communicate simultaneously. A typical mobile phone is a good example of a full-duplex mode two-way radio. For a two-way radio to be in the full-duplex mode it requires two separate radio channel sharing methods to carry the two-directional conversations simultaneously.
The History and Evolution of Two-Way Radios
Receivers and Transmitters that were installed in the same fixed geographical location were first used to swap messages wirelessly. A two-way telegraph used to transmit communication across the Atlantic Ocean was used commercially.
Just before the onset of the first world war, military ships carried transmitters and receivers, allowing two-way communication. Senior Constable Fredrick William Downy of the Victorian Police developed the first two-way radio equipment.
As technology grew and radio equipment became easier, powerful and compact to use, small vehicles had two-way radio equipment installed. It also extended in the aircraft industry as radio equipment was installed on planes, hence observations were reported much more easily.
By the second world war, radio transmitters were used by both air and ground troops which allowed one user to transmit at a time. The use of transmitters and receivers that were tuned to different frequencies solved problems that were brought about by the introduction of the operation of a receiver to adjust to a transmitter.
In Today’s world, the use of two-way mobile radio equipment is just as simple as using any mobile phone, therefore it has made operations such as personal, commercial and military roles more efficient.
Types of Two-way Radios
They can be classified depending on their attributes:
Conventional
They operate on a fixed RF channel. They operate one channel at a time, In the case of radios with multiple channels. The user will choose the proper channel they would like to use.
In conventional types of radio systems, multi-channel systems are used for separate purposes, since channels are used for specific functions. Conventional types are referred to as Multisite operations since different channels can be used to do different tasks. They are also capable of automatic roaming since the radio switches channels on a vibrant basis.
Trunked
A trunked radio system will automatically pick any physical radiofrequency. If the trunked radio system is digitally trunked it can carry a simultaneous conversation on a channel. The system will also manage all time slots on any physical channel.
This function of simultaneously transmitting any communication over a single channel is termed multiplexing. Unlike conventional systems where radio systems require the user to switch channels manually when transmitting in a wide-area geographic conventional system, in most modern trunked systems roaming will be done automatically.
Simplex
This channel system will use a single channel to transmit and receive. Their legacy systems existed since the 1930’s hence it allows old radios to link and work with new radios by use of a single network.
Its biggest advantage is that it has a simple system configuration since two radios are only needed therefore reliability is increased.
The problem with this simplex configuration is that it offers communication over a short distance range.
Duplex
They transmit and receive on dissimilar and discrete channels. It cannot communicate without certain elements like repeater, base station or talk-through base. It has been configured to re-transmit the voice from any mobile units
These will make the users communicate from anywhere and with any reception range.
Two-way radios operate on different frequencies and these frequencies can be used in different geographical areas.
