Smart Lighting: Hub or No Hub?
When considering adding smart lighting to your home there are obviously a number of considerations. These encompass various practical issues such as price tolerance to regional availability. Before that though, the question of whether you’ll tolerate a hub or not must be addressed. This would seem to some to be a no brainer, why have an extra piece of hardware if you can do it without? Certainly some brands would have you believe no hub is a clearly better choice, but we need to understand why these things exist in the first place.
What is a hub?
Firstly, when it comes to smart devices, ‘hub’ is really a misnomer which makes it sound as if the devices need some central connection point just to work. While this is part of the role, we’re really talking about a ‘bridge’. In network parlance, a bridge is a device that connects one network to another. In the context of smart devices this is generally required when the devices communicate using a different protocol than WiFi but need to be controllable by a smartphone, smart home controller, or over the internet. We see these for things like Garage Door openers, which need to bridge garage door RF communications with WiFi, or low powered battery devices like sensors and door locks, that need to bridge between Bluetooth LE and WiFi. When it comes to smart lights, typically we’re looking at the ZigBee protocol which is widely used for smart home devices.
Protocols like ZigBee and Z-Wave have been used for many years by bespoke home control platforms for their reliability, low power requirement, and responsiveness. As we move toward more connected homes, some device makers are choosing to use these protocols over WiFi for the same reasons. ZigBee in particular has a specific profile tailored for lighting systems control, ZigBee Light Link (ZLL).
To explore the differences between a bridged solution and WiFi for smart lighting, I’ll Use two well known brands which have taken each path, Philips Hue for the bridged solution, and LIFX for the WiFi solution. I’ve chosen these two as they both offer a comprehensive range of lighting options, are widely available internationally, and compete at similar price and quality points.
Why not just use WiFi?
LIFX in particular makes a big deal in it’s marketing about not requiring a hub, as if this is a great technical achievement that is obviously superior. Arguably, this is actually the opposite of true. WiFi controllers are a dime a dozen, and the software components to drive it are freely available. We see WiFi connectivity being added to everything from coffee machines to vacuum cleaners because it’s easy, and light bulbs are no exception.
WiFi is an obvious choice because it’s a widely deployed and accepted standard, and using it removes the risk of technical roadblocks for your customers. You can safely assume they have a working WiFi network, and using WiFi will allow you to talk to whatever you need to with minimal fuss. That’s great, but WiFi is essentially a wireless equivalent to wired Ethernet cables, intended for high speed, high bandwidth applications and with all the capabilities needed to communicate across large complex networks. To deliver all that capability requires high power requirements, and a lot of software and network overhead. This is why we only see WiFi in devices which are either mains powered, or have large capacity batteries like smart phones.
ZigBee, on the other hand, is a highly efficient control protocol specifically for managing connected devices in a local setting. It’s very efficient, and creates a self managing mesh network between all associated devices to ensure good connectivity and redundancy. It’s also very low power, so low in fact that some ZLL switch implementations don’t need a power source. They can generate enough energy from the physical button press to send the command signal, since that’s all they need to do.
Benefits of ZigBee Bridges
By centering control of a ZLL network on the bridge you get fully local control of the system (no internet connection required), and the ability to run automated actions across the network without needing to have an app running all the time. You also eliminate the need to manage potentially dozens of extra individual devices on your WiFi network, all of which can pose a security threat as they are fully internet aware and easily accessible if a vulnerability is found in that particular brand’s WiFi implementation.
What about integration with other apps and devices? A bridge solution has an advantage here as well. Integration compatibility typically needs some level of software support in the device, or it needs to be handled externally by a cloud service. This means a WiFi solution needs to have that software compatibility built into each light bulb, or it requires an internet connection and the inherent reliability and latency that comes with it. Using a bridge means all the integration support need only be built into the bridge, and it can then handle all the back and forth on behalf of the other devices it manages, and again, can do so with no internet connection required. This improves reliability and response time significantly.
The mesh capabilities of ZLL are a huge boon when it comes to an extensive lighting deployment inside and outside the home. As each light (or other device) needs only to be in range of another device on the network to have good signal, it makes it very easy to roll out lights anywhere without connectivity issues. WiFi devices must all have good signal back to the nearest WiFi access point, which is typically the home router. Indeed, LIFX users report the most issues arising from connectivity problems, either with cheap WiFi routers, interference, or distance to the light. Obviously having a newer mesh router solution will help with this, but even then it’s easy to find some lighting locations (particular outdoors) won’t be well served.
I mentioned other devices, and this is another important point. A solid lighting solution needs to provide the means to control then lights intuitively as well as automation and smart phone control. Voice assistants can help, but aren’t always the most convenient means to turn on a light. ZLL supports other very light weight accessories that can enhance the lighting solution such as switch and motion sensors. The very low power requirement allows these devices to be powered by small batteries for very long periods, and placed anywhere in the ZLL network. Doing this with WiFi lights is more problematic. You either need powered solutions like wired smart light switches, or Bluetooth devices, which required a bridge solution of there own to be able to control the lights.
So…Why use WiFi?
You might be asking if I would rate the benefits of a ZLL bridge solution so high that you should never choose WiFi for your lighting. That’s not really true. As with all things in life, and especially smart home, some compromise is almost always required. A key point of difference between Philips Hue and LIFX is their general approach to lighting. Philips has focused on lighting for daily living and ambience. Their lights tend to do well with stylish fittings, accent lighting, and handle a wide range of soft tones and warm colors. LIFX preferences bright lighting and strong colors for flashy feature lighting, often outperforming Hue when it comes to full saturation.
Philips leverages Zigbee’s responsiveness to enable things like Hue Sync, which allows for color changes up to 25 times a second in order to provide accent lighting to enhance the activity on a screen for things like games and video. LIFX offers products like the Tile and Beam which have multi-zone LED arrays to allow for animated effects, and the LIFX+ range which can provide infra-red lighting for security cameras when not being used for normal lighting.
Suffice to say, there are definite reasons to choose one over the other, or indeed mix and match. Looking beyond these two leading brands, there is also the factor of price point, but even there you can find offerings from both camps. Many lower cost LED bulbs are WiFi, due to the ease of implementation, but GE and Ikea offer ZigBee products and their own bridge solutions to match. To handy thing with these alternatives is that ZigBee is also an international standard, and these products can be used with Philips Hue bridge as well.
You may well want to choose a brand to go with and stick to it for the simple reason of having one app to manage all your lights. With WiFi offerings in particular, each brand will require the device makers app to configure and control, so that can present a significant inconvenience. Choosing brands that have common compatibility with a smart home platform like HomeKit, Smart Things or Wink can ease this pain, as you can then use the platform app to manage and controls the offerings across brands, but without that investment you’ll be better off sticking with one provider.
ZigBee is a little better in this regard, as you can pair compatible lights (and other accessories) with a single bridge and manage them through the one app regardless of brand. So long as they correctly support the ZLL standard, it should work as expected. You can get some peace of mind by looking for the ZigBee certified logo on the packaging.
While there are many more brand offerings in the WiFi camp with truly innovative and interesting lighting products, there are some inherent limitations and liabilities with using WiFi for a distributed solution with high reliability requirements like lighting. Potential performance and connectivity issues, security and manageability being key considerations.
Going for a ZLL bridge solution has distinct advantages in terms of setup, reliability, responsiveness, and the ease at which you can build a truly comprehensive lighting solution including switches, sensors and even blind controls that all work together without needing to be on the internet at all. Obviously these solution offer remote connectivity for out-of-home management as an options, so you’re not losing out in that regard. Philips Hue in particular also offers outstanding integration support with a huge range of partners, including pretty much every major smart home platform and controller.
If you are looking for eye catching feature lighting for select rooms, then WiFi is a good option with products like LIFX and Nanoleaf, but for a full home roll out of smart lighting, using a good ZigBee bridge provider is going to give you a better experience where it counts, day to day living.