Recently, the use of wireless networks for lighting control management has been rapidly expanding because the technology does more and costs less than ever. Wireless networks make lighting control flexible, letting users control lighting while offsite and enabling daylight harvesting, which adjusts light levels based on natural light. In a typical lighting system, the devices on the network are lights or groups of lights, switches, dimmer controls, occupancy sensors, or other types of sensors.
Devices in a network can be connected using two main architectures: star and mesh. A star network is configured like a computer’s local area network. It includes end point devices like lights and switches and special router nodes that only relay traffic around the network. Messages start at a device, travel through one or more routers, and end at another device. Typically, the routes from one device to another are defined when the network is set up. If a router or a link between two routers is unavailable, parts of the network may be unable to communicate with each other. This means routers must be carefully placed when designing the system so all the devices that need to link to it are within range.
On the other hand, in a mesh network, each node is both a device and a router, which enables a simplified strategy called “flood routing.” Each device repeats the messages it receives exactly once, which are then received in turn by every device within range. This means each device can hear the message from multiple relaying devices. Because redundancy is built into the system, a fault in a particular device or link won’t cause the entire network to break down since other links will still relay messages. Mesh networks are useful for lighting networks since there are usually a lot of devices in a building or room – and the more devices there are, the greater the degree of redundancy.
Mesh networking also simplifies network setup. No planning is required to locate routers, since each device repeats messages. Networks can operate independently, even without internet connection or control nodes within the network. New devices can be added simply by giving them with a network key, which means users don’t have to worry about associating them with a particular router.
Mesh networks and flood routing are not usually used for general purpose networking because the repeated messages use bandwidth. In lighting networks, however, the bandwidth requirement is low, minimizing this issue.
Mesh networking is an ideal choice for lighting networks. It’s easy to set up, offers flexibility and network resilience through redundancy, and, most importantly, it’s easy to use.