Communication systems play a crucial role in today’s world, in just about any area. These systems are made up of various devices that can be either wireless or wired, plus a range of equipment including portable and mobile radios, base or fixed station radios, repeaters, and even more accessories, such as carrying cases, speaker microphones and battery eliminators. If you’re looking to implement a communications system into your business, you’ll need to consider a couple of important factors. The technologies that the system is made up of will play a crucial role in your choice, for instance. However, there’s more to it, so let’s delve in.
As briefly aforementioned, communication systems can be either wired or wireless. Wired communication systems are also known as hard-line systems and they are basically localised, private telephone systems that need wires to operate in a limited space. Wireless systems, on the other hand, use radio frequencies to connect multiple users and are capable of operating over a larger space. I’ll focus on wireless systems, as they’ve largely overtaken wired communication systems not in popularity due to their convenience, versatility, capability and functionality.
The major advantages of wireless communication systems over wired communications systems are their ability to provide communications through obstacles to an unlimited number of users. The range of the signal, however, depends on the receiver and transmitter. That being said, if you’re considering a wireless system, make sure you get a high-quality and capable receiver and transmitter, from a manufacturer like Elsema, for example.
Elsema transmitter and receiver products are designed to connect right to a mains supply. They use a 32-bit digital encrypted code for security, so they can be used in sensitive applications. Furthermore, the receiver can store an unlimited number of transmitters. It’s important for the amplitude of the signal received to be lower than the amplitude of the background. Why? Well, think of walkie-talkies, and how you can hear the background and static noise. This also means that over a longer range, all you’ll end up hearing is static. However, the range of the signal can be impacted by atmospheric disturbances, like high-power radio frequency sources, electrical storms, and so on. Keep in mind that radio frequency signals aren’t capable of passing through water.
Additionally, shared communication systems are subjected to saturation by users. What this means is that they have a maximum capacity of users they can “withstand”, and going over that capacity will reduce the quality of the signal and the amount of information that can be transferred through the system.
Wireless systems transmit data using a specific radio frequency. The band ranges anywhere between 0.05MHz to 900MHz. Most public safety communication systems use frequencies between 30 and 900MHz. Cell phones and other systems like positioning receivers, irrigation systems and electronic signs transmit in the frequency band between 1GHz and 20GHz.
Types of Equipment
Portable vs Base Radios
Portable radios are smaller, lighter, handheld devices that feature a transmitter and receiver, an attached power supply, microphone and speaker, and an antenna. The receivers they feature are typically low-powered, and they need to have their batteries frequently recharged or replaced. The good thing is that they can be combined with other portable and base station radio systems.
Base radio stations also contain a receiver and transmitter, but they’re powered by an external electrical system (generally 220-240V), and they’re connected to an antenna that’s up to a few hundred metres away, generally located on top of a tower or building. Since base station radios use external electrical systems, they have the most powerful transmitters and the most sensitive receivers. The microphone can be a desktop or handheld type, and the speaker can be internal or external to the radio.
Interoperability refers to the process of connecting different types of equipment and communication technologies so that they can communicate with one another without the need for relay personnel or dispatchers. It basically describes the situation where different systems that are incompatible with one another can work together without needing extra manpower. For example, a police radio system can exchange information directly through voice or data with the Australia Federation Guard or a municipality’s public service department. Some systems can even enable interoperability between different talk groups and third party dispatch systems.
Communication security is becoming more and more important. Nowadays, you can buy a radio receiver that will let you monitor most public safety communications. That being said, security may be hard to achieve unless proper measures are incorporated into the planning of the overall communication system. Having a receiver with an encrypted code, like the Elsema one mentioned above can be very helpful. Other features that can come in handy for security are voice inversion, digitising voice and data, use of PCS phone circuits and use of digital cellular. You can also use spread-of-spectrum techniques to boost security.