Communicating in the Wildland Urban Interface

Communicating during emergency operations is a constant challenge for those in the fire service. Nowhere does that become more evident than during a wildland urban interface (WUI) incident.

Communicating during emergency operations is a constant challenge for those in the fire service. Nowhere does that become more evident than during a wildland urban interface (WUI) incident. Structural firefighters who find themselves participating in these incidents for either the first time or very infrequently will likely find the communications environment challenging (for example quite different from what they are used to.) The good news is there are some basic concepts, terminologies and hardware that can be utilized, thus allowing communications in the WUI to become more effective.

The following topics will be discussed in this article

  • Frequency bands
  • Hardware
  • Frequency use
  • Topography and distance

Frequency Bands

When multiple agencies come together for an incident, regardless of the nature, one challenge is ensuring that everyone is operating on the same frequency band. On a typical structure fire, the agency with jurisdictional authority typically makes this decision. With the WUI and the associated topographical obstacles often found in that environment, the VHF frequency band is generally considered the best choice. VHF frequencies are a wider radio wave which offers an advantage when traveling over and around topographical features. It is for this reason that most federal and state agencies, chose to remain on this frequency band.

According to Mark Hall with First Responder Communications, many changes are on the horizon, but VHF is likely to be around for some time. One recent change in VHF is the narrow banding of frequencies which creates more channels. Be aware, however, that older radios need to be upgraded or reprogrammed to be able to utilize these frequencies. Narrow banding, along with the advent of digital VHF radios, are some of the ways that technicians can increase the effectiveness and efficiency of this popular radio band. If your agency is apt to respond to fires in the wildland environment and those responses are often on state or federal lands, you will be well served to invest in radios with VHF capabilities.


Since we still have our "tech" hats on, let's dive a little deeper into this discussion of VHF and which hardware will serve you best. Portable radios come in every style and configuration imaginable, with the Bendix King (BK) still the most commonly found radio on wildland incidents. According to Hall, the newer models have a vast amount of untapped technology held within which will allow them to work with future system upgrades.

One reason for the Bendix King's popularity is the fact that these radios are field-programmable, which means that a channel/frequency can be entered directly into the radio by hand. Better yet, a group of channels can be transferred from one radio to another via a method called cloning. This cloning process requires a cloning cable which connects the two radios together and allows the channels to be transferred. Both portable and mobile radios have the ability to hold hundreds of channels which are arranged into groups. Most agencies leave Group 15 blank, thus allowing incident frequency groups to be entered without overwriting a pre-set group.

Another reason to become familiar with the BK radio is that most federal, state and local radio caches consist of BK radios. If you arrive at a larger fire and need a VHF radio, you'll likely be handed a Bendix King.

A few basic skills you will need to know are:

  • Change the radio from one channel group to another
  • Enter and delete scan channels
  • Set the priority channel
  • Click the "Worksheet Below"

Frequency Use

The simple fact is that although you may have all the high-tech radio gadgetry in the palm of your hand, a communication error chain can begin from a misunderstanding of the limitations of the channel/frequency you are on. Radios transmit in two modes: direct and repeated. A direct channel transmits from radio "A" directly to radio "B" and is commonly used as a tactical channel within divisions and in air operations. A repeated channel transmits from radio "A" through a repeater unit to radio "B," which allows for a long distance transmission, and is often used as an incident "command" channel when the direct channels are incapable of clear transmission.

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