ST Engineering Telematics Wireless

Licensed vs. Unlicensed Frequency in Streetlighting – Does it Matter? (Part 3)

Licensed vs. Unlicensed Frequency in Streetlighting – Does it Matter? (Part 3)

Part 3: Licensed vs. Unlicensed Frequency in Streetlighting – The Importance of Licensed Frequencies

In this 3-part blog series, I’ve explored the critical safety aspects of smart streetlighting (Part 1), and examined unlicensed RF frequencies, their typical usage and some of the drawbacks of unlicensed for smart streetlighting (Part 2).

Now, I’ll look more in-depth at licensed frequencies and why companies like ours see real value in them for critical streetlighting applications:


Obtaining a license to operate a wireless network for narrow-band applications on FCC licensed frequencies is as simple as filling out a form, paying a fee, and waiting several weeks for approval. Once approved by the FCC, the critical application, such as streetlighting, operates on a unique pair of frequencies which (in most cases) no other wireless networks may use, by law. 

When the streetlight control network is operating independently on a clean set of licensed frequencies, there is little or no electromagnetic interference from other wireless networks or systems.  If, for any reason,  interference does exist it is up to the FCC to clean up the airwaves or provide alternative clean frequencies.

Additionally, the rules for wireless communication on FCC licensed frequencies are significantly more beneficial for wireless communication since that is what the frequencies are designated for.  As an  example, rather  than being able to transmit data just a few hundred feet, a networked streetlight controller operating on FCC licensed frequencies can transmit data more than 15 miles. That means two streetlights which are 30 miles apart can send their data directly to the same gateway, without having to employ any of the tricks used by controllers operating on unlicensed frequencies, such as hopping through other networked streetlight controllers or installing many gateways to cover the area. 

The practical implication of operating technologies such as streetlights using licensed frequencies is that most municipalities could control all their streetlights with just a single gateway. It’s analogous to a user being able to stay connected to his or her home WI-FI network if they are within a 15-mile radius of the home. If that were the case, most people would not need a cellular provider which, by the way, also operates on licensed frequencies.

Even in instances where achieving  a 15-mile coverage radius around the gateway is not possible due to the topography, in most cases deploying a networked solution on an FCC licensed frequency is still more robust. 

The comparative chart below highlights the strengths and weakness of deploying a star networked streetlight control system on FCC licensed frequencies compared to the most deployed wide area mesh or star networks on unlicensed frequencies.

For questions about this topic or smart streetlighting in general, we’re here to help. Reach out to us at

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