Understanding RF Modems And Their Uses

Radio frequency modems, also called “RF modems” and “wireless data modems”, power an impressive array of industrial functions.

RF wireless systems enable mining companies to work in remote areas. RF modems perform critical tasks for water supply and sewerage systems. They monitor gas pipelines, track fleet vehicles, control farm irrigation, and monitor bushfire zones – among many other uses.

But unless you work directly with RF modems or RF system design, it’s unlikely you have dedicated much time to thinking about this mission-critical technology.

Keep reading for a rundown of RF modems, including:

  • How they work
  • Where they’re used
  • Considerations for RF wireless system design

What are RF modems?

RF modems transfer data wirelessly over long distances, providing reliable real-time communication independent of satellite or telecommunication networks.

Let’s break that definition down.

Long-distance data transfer

High-quality RF systems can comfortably span tens of kilometres.

Reliable

Most RF systems use licenced bandwidths to avoid interference. Unlicenced RF data transmitters, like our RF Innovations Piccolo low-cost unit, use frequency-hopping technology to prevent jamming.

Real-time data communication

RF systems send data packets at blistering speeds over UHF or VHF bandwidths. Powerful data modems like our RF-9256 900MHz high-speed unit can transmit data at 115,200 bits per second (bps) with a 30km line of sight. Piccolo, a “low power” unit by comparison, still transmits up to 38,400bps.

For reference, your modem at home probably maxes out at 28,800bps and is more likely to transmit at speeds under 15,000bps.

Independent

One significant advantage of RF systems is they operate independently, enabling remote telemetry systems beyond the boundaries of telecommunications coverage.

Where are RF modems used?

RF modems have a wide variety of uses in mining, agriculture, utilities and transport, where reliable data transfer is critical. The most common applications include:

  • Fleet tracking: RF modems have differential GPS capabilities that provide more accurate location tracking than traditional satellite GPS
  • Remote I/O control: Controlling pumps, motors, fans, gates, and other I/O applications
  • SCADA systems: Creating a data transfer network to collect data and monitor processes remotely
  • Automated meter reading: Collecting data from environmental monitoring equipment, for example, in bushfire alert systems or gas pipelines

From fleet management to remote telemetry, RF systems provide a more stable solution for an almost endless range of industrial applications.

Factors affecting RF system design

Point-to-point or point-to-multipoint

RF modems enable direct communication between a base station and remote assets, or distributed networks using repeaters

UHF or VHF

Whether it’s better to use short, powerful UHF bandwidths or longer, narrower VHF waves depends on the application, environment and scale of the system

RF modem power and sensitivity

Our RF modems have maximum ranges from 5km to 30km, with increasing power demands as the range increases

Licensed or licence-free

Licenced networks are typically better for large-area applications, whereas licence-free RF systems suit smaller telemetry applications

Expert advice from Australia’s RF modem specialists

STI Engineering designs and manufactures the industry-leading RF Innovations range of RF modems. Our team also provides consultation services for RF wireless system design.

With almost three decades of experience and the best equipment in the business, we’re fully equipped to design and develop RF systems at any scale. Get in touch with our team here.