While it seems like just yesterday, it is now 21 years since the BACnet standard, ASHRAE 135, was approved and published. Since then, much has happened. We had a brief, but furious, industry debate over the need for open protocols, and battles over which protocol to use. Over the years, it has largely settled out: Essentially all HVAC controls suppliers offer systems that use BACnet and provide fairly strong support for other protocols such as LonWorks and Modbus, along with various uses of XML and other web standards. In many ways, it feels like this is an issue that has been resolved and no further work is needed.
This really could not be further from the truth. While it should be expected that robust open protocols like BACnet will continue to be widely used, readily supported, and continually enhanced, we should also expect that new protocols will be needed for markets, applications, and use cases that are not readily supported by a control protocol such as what was originally defined in BACnet. Here are some examples of what will need to be supported in future protocol implementations.