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May 18, 2020
Smart home devices work best on mesh networks, but choosing the proper communication standard for your circumstances is critical to optimizing device performance.
As a growing number of consumers and enterprises have started to adopt smart home technologies and industrial IoT devices, it has become increasingly important for these devices to communicate with one another effectively.
Generally speaking, these devices perform best when integrated into mesh networks that facilitate interoperability to a greater degree than do traditional WiFi networks. However, building a mesh network capable of supporting the “many-to-many” network topologies necessitated by the ongoing proliferation of IoT devices can be a complex, challenging endeavor. As such, it’s important to understand the distinct benefits and drawbacks of each common mesh networking standard before attempting to create — or commission — a mesh network of your own.
Zigbee uses low-power radio signals to communicate over personal area networks, meaning Zigbee devices are incredibly energy-efficient. In this way, Zigbee can be an ideal specification for industrial IoT deployments, where there are often many battery-run products located in remote or hard-to-reach places.
Additionally, the standard can support a large number of network nodes (up to 65,000), making it incredibly easy to scale up a Zigbee mesh network as new devices are introduced. And because Zigbee devices are synced through smart hubs, they allow a great deal of network traffic to be diverted away from WiFi routers. This saves end users the hassle of purchasing additional routers, even when a large number of nodes are woven into a single network. This gives Zigbee a considerable cost advantage, and makes it an ideal standard for the consumer smart home market — especially for homes that feature many IoT devices.
That said, Zigbee does have a few shortcomings that end users need to take into account. For one, Zigbee mesh networks don’t offer the same out-of-the-box security features that certain other protocols do. Additionally, Zigbee doesn’t have a particularly high data rate — typically around 250 kbps, though sometimes as low as 40 or even 20 kbps. This makes it difficult to send complex information over Zigbee mesh networks, narrowing the range of IoT devices that are a good fit for such networks. Although many smart home products have relatively simple commands — think: turning lights on or off — devices designed to improve a home’s energy efficiency are one of the fastest growing segments of the smart home market. These devices record, organize, and transmit large volumes of data, meaning they are often too “active” for a Zigbee network to handle.
The Bluetooth® Low Energy specification is the most consumer-centric mesh networking option. The majority of smartphone, tablet, and personal computer manufacturers incorporate Bluetooth LE into their devices, and most major operating systems support the specification out of the box. In other words, Bluetooth LE is already part of practically every device consumers own. As such, many consumers are able to build Bluetooth LE mesh networks using exclusively products they have already purchased, enabling them to save money by not having to invest in additional routers or network gateways.
What’s more, Bluetooth LE can be used as the foundation of self-healing mesh networks, meaning individual devices on a network will be able to communicate with each other even if one node — or possibly even several nodes — runs out of power or becomes disconnected. Further, the specification’s data rates are incredibly high (1-2 Mbps), making it an ideal option for supporting more analytics-heavy smart home devices.
Bluetooth LE’s primary drawback is that its network protocol can create noise and cause latency issues. Unlike Zigbee, Bluetooth LE operates by using a managed flood mesh in which devices emit control signals that are pushed to multiple nodes. This requires a higher level of networking intelligence to be built into each device. It can also create noisy RF environments in which commands can be missed.
Aside from its ubiquity and familiarity, there aren’t many benefits to using WiFi as the foundation of a smart home environment. Granted, practically every smart device is compatible with WiFi, and one simply needs to purchase a router (which most people already own) to get started. And, because a WiFi mesh network will always be connected to the internet, consumers will have access to their devices from anywhere in the world.
Unfortunately, these benefits tend to be outweighed by the various drawbacks of building mesh networks using a WiFi standard. Most notably, WiFi requires constant energy to connect to a server, so devices that aren’t plugged in to an electrical socket will be forced to rely on strong batteries.
Additionally, WiFi routers are easily bogged down by too many devices connecting to them. This forces end users to perennially invest in updated routers if they want to maintain fast operating speeds as they add devices to their mesh networks. Needless to say, this can become very expensive very quickly. What’s more, costs in WiFi ecosystems may climb even higher when end users purchase individual devices at scale — a WiFi light bulb may offer the same functionality as a Bluetooth LE bulb, but will likely carry a considerably higher price tag.
At the end of the day, there’s no “right” choice when deciding which standard you should use to build a mesh network. Your decision will depend on how the benefits and drawbacks of each mesh networking standard align with the particulars of your unique circumstances. As mainstream adoption of smart home technologies continues to grow, it will be essential for tech experts to understand the nuances of the standards outlined above — and the many other mesh networking standards extant and speculative that will come to define the future of networking.
Telink’s compact, multimode SoCs support multiple protocols — including Zigbee and Bluetooth LE — improving interoperability while reducing lock-in risk. They also cost less than many single-protocol chips, making them a perfect option for manufacturers of smart home devices looking to minimize costs while giving consumers the secure, reliable, scalable connectivity they demand.