As the Internet of Things (IoT) continues to grow, new information on emerging best practices, technical specifications, and design considerations continues to flood the market. It’s often difficult to be sure of which of these can be compared to others. New ideas and protocols are rapidly becoming available and some companies are pushing technologies that aren’t yet ready for prime time. This makes it even more confusing.
One of the most important decisions companies may be facing is which communication protocols to choose. This decision affects the hardware and what devices and functions are available. Communication protocols need to be grouped together, and, like puzzle pieces, only certain protocols will “connect” with each other.
Here’s a list of the most important protocols you should be keeping an eye on. This list is based on multiple factors from our research, including performance, latency, and interoperability, as well as current industry adoption levels.
If this list looks daunting, that’s all right. That’s the problem: It’s just a list. The protocols need to be organized in a way that allows a high-level understanding of the benefits and drawbacks of each.
The next section tries to make sense of all of these. So if you want to skip to the next paragraph, feel free.
With the critical protocols defined, the next step is to create an effective and efficient way of evaluating and comparing them. One way is to organize them into “protocol stacks.” A protocol stack shows which protocols can build on top of other protocols. Like puzzle pieces, only certain protocols “connect” to (sit on top of) other protocols.
A protocol stack must be used as a whole, so stacks must be compared to each other, rather than comparing separate parts of different stacks. This should eliminate much of the confusion around the IoT, which comes from not understanding what can be compared and which protocols can (and must) be paired together. Each stack consists of a three-layer model, as defined below:
Physical Layer: This layer describes how messages are physically exchanged. It describes what physical medium (cable, wireless) is used, what frequency (for wireless), and the message encoding scheme. This is how physical, measured events get translated into bits.
Routing Layer: Devices now have a way to exchange messages, but there also needs to be a set of rules governing how to get a message from one device to another when two devices aren’t close to each other. This layer explains how devices find each other and work together to get messages to devices not within range of the initiating device. The content of the message is unimportant for this layer. This layer focuses on delivery from point A to point B.
Application Layer: This layer explains the content of the messages. How do the bits translate into an action for a device? This layer describes what a “turn the light ON” or “DIM the light to 50%” message looks like. This lets devices work together to take action and communicate.
The table shows protocols from the list above organized into protocol stacks.
Now that the protocols are organized this way, you can evaluate each stack’s strengths and weakness and compare them based on project or product requirements.
Matt Smith, Head Engineer