THOUGHT LEADERSHIP WHITE PAPER SERIES - IoT CoE Okol Group
Lutron's Clear Connect™ Technology: Say Hello to Reliability
released 4/08/2017 by Okol Group
When Lutron engineers invented Total Home Control solutions, such as RadioRA2, they faced one major challenge: develop a communication protocol so that lights, shades, thermostats, and many other devices communicate among themselves reliably and quickly. Open-source protocols such as Z-Wave, Bluetooth, and Wi-Fi all have limitations in range, latency, obsolescence, and performance. Clear Connect™ is Lutron's proprietary radio frequency technology that provides reliable and seemless communication between Lutron wireless components. Below are the major characteristics of Clear Connect™ technology:
Licensed Radio Frequency Band
Lutron realized that it needed a private radio channel in which all devices could communicate with no major external interferences and at a great distance. After careful analysis of the spectrum, Lutron decided to get a license for the 434 MHz radio frequency band, also known as UHF band. Basically, all Lutron devices that are Clear Connect™ enabled come with a miniature UHF transceiver that uses an exclusive frequency granted to Lutron. This means that Clear Connect™ devices can send and receive commands reliably and immediately since no one else is using the frequency. This is not the case with Z-Wave and Wi-Fi radios, which use unlicensed radio spectrum shared with a myriad of users and vendors (read more about "The Truth About Wi-Fi" here).
Lutron devices communicate with each other using Clear Connect™ UHF RF technology. © Okol Group Holdings, LLC
Group Commands - Yet Another Benefit
Unrelated to how the messages move around the system is the issue of the content of the message and how the system design reacts to that content. Lutron systems, including those with Clear Connect™, use “Group” or “Preset” commands. In this scheme, a button press sends out a generic command like “Preset 01.” The devices have distributed intelligence (e.g. devices have non-volatile memory and a database, and know how to react to this command). When a button is pressed, the system transmits “Preset 01” down the fixed network one time. All devices “hear” and respond simultaneously. These systems can be expanded with no degradation in performance. Most system designs do not have this mechanism and are unable to provide it. The reason is that it requires ownership, coordination, and hardware (memory) of all the devices in the network. In systems comprised of devices from a disparate group of manufacturers, commands must be issued to each device sequentially. These commands are called “directed commands.” To turn on 10 different devices requires 10 unique commands. This can create the “popcorn effect.” One light turns on; there is a pause, the next turns on, and so on. To see it in the application is a real letdown. Customers may be happy with the initial installation, add more devices, and become dissatisfied at a later date.
Minimal Air-time & Low RF emissions
Clear Connect™ only sends radio waves whenever an action is requested. It is not an "always-on" technology, which in turn keeps the radio spectrum fairly silent. Compared to other communication methods like Wi-Fi, where a beacon must be sent to check who is online, Clear Connect™ keeps a record of all devices associated to the controller and only sends a signal to perform a given action. In addition, the air-time is very short, in the order of seconds. The result is a low amount of RF emissions and maximum efficiency of the use of the spectrum.
Source:"Clear Connect™ RF Technology" by Rich Black, Lutron Electronics Co., Inc.