In case you're like me and have always wanted to know what the 'modules' on the top of modern street lights were; today I discovered the answer.

Due to an unfortunate series of events involving a vehicle and a lamp post, I came into temporary possession of one of said 'modules' and managed to find a make and model number on it.

A brief Interwebs search uncovered the following user manual:
https://fccid.io/NTAN3G/User-Manual/Users-Manual-4518810.pdf

TLDR: It's a Wireless Light Control Unit.

Features include:

• Light sensor - Operates as a photocell with the integrated microcontroller and is used as a backup light control in the event of microcontroller failure.
• Energy meter - Continuous measurement collection and aggregation.
• Integrated RF antenna.
• Real Time Clock (only when connected to the system or when unit received its time zone from the system and operates with GPS)
• Network data is protected by AES 128 encryption.
• Relay Control for LED driver/ballast power.
• Uses licensed frequency.
• Built in GPS receiver for auto-commissioning

But the really interesting thing is that they all work together to form a AES 128 encrypted mesh network operating in the 450-470MHz band (licensed) to distribute the control signals.

It's low speed (4.8kbps), but I guess there's not a lot of data in a 'switch on/off' signal.

It also monitors various operating parameters such as:

• Current
• Voltage
• Lamp energy (kWh)
• Metered/Active power (Watt)
• Power Factor
• Lamp Burning hours
• LED Driver Temperature (depend on LED driver characteristics)

Bonus fun fact: The unit allows the lights to be dimmed!

Anyway, I thought that was pretty interesting.