October 8, 2019
Multi-protocol hardware offers flexibility and interoperability for both device developers and consumers.
Multi-protocol hardware has emerged as a response to the recent popularization of multiple distinct communication protocols, including Bluetooth® Low Energy and Zigbee. While consistent standards are crucial for Internet of Things (IoT) functionality, these popular protocols aren’t always designed to “talk” to each other. This can frustrate consumers who expect their devices to be able to interface seamlessly or need to determine if a device they’re looking at buying will work with their existing setup. It’s also a significant headache for anyone tasked with designing, installing, or updating IoT devices.
Fortunately, multi-protocol hardware represents an effective solution — one that’s ready to use today. When a chip is designed to support and utilize multiple protocols, it opens up a range of use cases. It benefits developers looking for a unified, cost-effective solution that can be sent to various markets and easily upgraded to align with emerging requirements. And, for consumers, hardware featuring multiple built-in protocols means there’s a higher probability that a given device will be able to integrate with their existing network.
As IoT devices proliferate, device usability and integration will only become more important, and multi-protocol hardware provides a clear way forward. This hardware enables end users to take advantage of the strengths of different protocols while seamlessly transitioning between them. For instance, a consumer could use a smartphone or tablet with built-in Bluetooth functionality to access and manage Zigbee mesh network devices. This is much more convenient than using additional Zigbee devices for management tasks — plus, it retains the integrity of the Zigbee mesh network.
Currently, mesh wireless connectivity can be accomplished with a few different protocols, including Zigbee, Bluetooth Low Energy, and various proprietary standards. For developers, implementing two or more of these protocols can streamline product planning and create added manufacturing flexibility.
As long as their preferred system-on-a-chip and corresponding software development kit support it, developers can incorporate two or more standards from the hardware level up. Implementing a multi-protocol approach requires support at the chip level, but helps manufacturers avoid a more costly multi-chip architecture — and could even reduce the overall bill-of-materials (BOM) and design complexity.
Increasing a chip’s available protocols gives manufacturers maximum flexibility throughout the production process, even if the product is later limited to a single protocol. This flexibility creates the potential for penetrating multiple markets, or for upgrading products down the line if market pressures demand the use of a specific mesh protocol.
Depending on the specific use case, one of several multi-protocol design types may prove to be appropriate. One of these types is switched multi-protocol, where only one protocol is “active” at a time. The device is technically capable of using multiple protocols, but it requires rebooting or reprovisioning to switch between modes. Practically speaking, this multi-protocol functionality wouldn’t be used for any single use case, but it would make it possible to send the product to two different markets without a costly redesign.
A larger multi-radio, multi-protocol solution can utilize two radio frequencies and two radios, allowing different protocols to operate simultaneously on their own bandwidth. For instance, smart metering in England utilizes dual PHY Zigbee communications hubs that use both 2.4 GHz Zigbee devices and 868 MHz Zigbee devices. While it has its advantages, this type of design is not as streamlined as switched radio options, and carries a higher BOM cost. As such, multi-radio solutions are more commonly found in gateway devices, rather than in end node devices.
Typically, the best market solution is the design in which multiple protocols are concurrent, or active at the same time. In this approach, a fast-switching radio autonomously “slices” time between two or more protocols. These solutions are designed with hardware and software that allow multiple protocols to run simultaneously on the same chip. For instance, a device might ordinarily use Zigbee to maintain mesh network connectivity, but intermittently need Bluetooth LE to interface with a smartphone app (see the examples below).
Although designing a multi-protocol device can add some complexity and initial expense, this approach can often be well worth it, as multi-protocol designs offer critical benefits in certain cases.
For instance, when it comes to commercial applications, using multi-protocol mesh hardware for smart lighting systems adds flexibility. A commercial mesh lighting network is typically created using the IEEE 802.15.4 standard, which is also inherent to the Zigbee protocol. This approach helps manufacturers achieve maximum coverage and connectivity, as this protocol can support large (i.e. many-node), low-energy, secure mesh networks. At the same time, building in the Bluetooth LE protocol would improve a lighting system’s ease-of-use. Because Bluetooth is already built into many smartphones, service technicians or building managers would be able to control, configure, diagnose, and update their lights from the palm of their hand.
In this way — and a number of others — multi-protocol design gives manufacturers access to greater market potential. By giving consumers the option of buying a bulb that is concurrently multi-protocol right out-of-the-box, manufacturers needn’t worry about whether a given consumer has a Zigbee-based network or a Bluetooth LE Mesh-based network. This means manufacturers are able to let their devices scan and provision themselves with no intervention, and consumers don’t have to specify their network type pre-purchase (meaning they will face fewer barriers when choosing and purchasing a product).
In addition to smart lighting systems, interoperable remote controls are another clear consumer-facing use case for multi-protocol mesh hardware. Many cable boxes utilize the Zigbee RF4CE protocol stack, but Bluetooth LE is the standard protocol for many other consumer electronics, including televisions. As such, it makes sense for manufacturers to design multi-protocol remote controls that function seamlessly with both RF4CE and Bluetooth LE instead of requiring consumers to purchase separate remotes to control each of their devices.
As IoT devices (and protocol standards) continue to proliferate, even more use cases for multi-protocol mesh hardware will emerge. In light of this reality, smart device manufacturers should start experimenting with ways to integrate a multi-protocol approach into their product designs. After all, at the end of the day, multi-protocol devices can help device manufacturers achieve their foremost goal: enabling consumers to enjoy the Internet of Things without thinking twice about all the complex technology that makes it work.