Wireless communications in industrial plants have grown so prevalent that they are generally taken for granted. However, with quick advancements in technology and capabilities, it’s a good idea to assess radio systems on a regular basis.
Much of today’s radio equipment is built to be upgraded in the future. Both analog and digital systems are supported by portable radios. Trunked systems can be transformed from traditional systems. Small, single-site systems can also be scaled up to cover huge regions, if not entire countries. Before investing in new or improved industrial radio communication systems, it’s important to understand and examine some of the fundamentals.
Frequencies
In general, very high frequency (VHF) channels are ideal for long ranges with minimum physical interference, such as rural locations. UHF channels have a limited range, but they perform better in and around buildings, as well as in urban settings. All radio communications in the industrial sector will be narrowband in a few years. As a result of this change, plant engineers purchasing radio equipment should ensure that it can function on both 12.5-Hz and 25-Hz centers.
Simplex
This is the most basic sort of radio system, operating on a single frequency and only permitting one-way transmission. It’s also known as a one-way operation. The definition is frequently broadened to include transmission in two directions, but only in one at a time.
Half-duplex or a semi-duplex
This type uses two frequencies to allow transmission in both directions alternately. One frequency is used for transmission and another for the reception. In most cases, mobile or portable units can only communicate with the “base” unit.
Full-duplex or duplex
Both directions of transmission are possible with these circuits. The full-duplex transmission allows both directions to be transmitted at the same time.
Repeaters
Repeater systems receive and retransmit signals from mobile and portable equipment, extending the effective range or coverage area.
Analog
Analog radio systems are the most common and oldest types of radio systems. The voice and signals are “unaltered” in analog. Communications are received in the same order as they were delivered.
Digital
The voice is changed from an analog to a digital signal, sent, and then reconverted to analog so that our ears can hear it in digital radio systems. Because signals can be reduced and other information can be conveyed together with the voice message, digital systems have a variety of technological advantages.
Voice and data communications can be carried out on the same radio using integrated voice and data systems. Now, systems are being developed that combine two-way voice radio, wireless data communications, and a cellular telephone into a single device.
Radio systems that are tethered
Trunking allows a large number of users to share a small number of communication channels or trunks. A number of users can connect with each other without having to wait for channels to clear or talks to end by employing a computerized central controller to make decisions about frequency utilization and routing.
