Chapter 2. IoT Devices and Networking Protocols

You have started your analysis and found that your IoT data is not always complete. You also suspect it is not always accurate. But you have no idea why that would be the case. You get several hundred records a day on average from each device.

The IoT devices your company makes are attached to freight trailers and track location, and sometimes even temperature. The temperature is monitored when the trailer is a refrigerated unit, called a reefer in the industry. The inside temperature of a reefer must be kept in a certain range depending on what is being transported.

Your device is located on the outside of the trailer with a lead line into the trailer to read temperature if the option is enabled. The trailer is pulled around by big rig trucks over roads all over the country.

You have been so focused on finding value in the data, you never thought about how it was captured and communicated to your company's servers. Now that you are thinking about...

IoT devices

There is a wide variety of IoT devices in use today. The range of designs and ingenuity in function is expanding at a furious pace. The scope of what is being measured, monitored, and tracked would be an entire book in itself. And it is, as you can find several through the publisher of this book.

The wild world of IoT devices

For analytics purposes, it is helpful to understand the variety of devices and how they are being used. Ideas from one industry can cross-pollinate into another and create unexpected value. The combination of devices and use cases can also present very different analytics opportunities and challenges.

Healthcare

Patients in acute care are having their vital signs monitored by low-power wireless sensors where the data can be analyzed remotely. There are several startups, such as Proteus Digital Health, that are developing pill-sized ingestible sensors. Proteus makes a digestible sensor pill that, in combination with a sensor patch worn on skin, monitors when...

Networking basics

Here is an oversimplified view of the networking protocol stack. There is much more going on here than we will cover in this chapter, but to help in understanding the discussion, it is useful to reduce it to a simple diagram:

 

Network communications operates in layers with the bottom layers not needing to know about the layers above it. It can get confusing talking about all the options available at each layer of the stack. The diagram shows the key layers that we are concerned with for IoT analytics, but know that there is more to the story.

The diagram is based on the simplified OSI model, which divides communication into five fundamental layers. There is a Physical layer at bottom that has more to do with device electrical engineering. We will leave that out to simplify things since we are focusing on analytics.

Connectivity will refer to options primarily in the Link layer of the stack. Data communication or messaging will be referring mainly to the Application layer....

IoT networking connectivity protocols

Connectivity is all about solving the main problem - establishing a method to communicate. The strategies used are affected by the constraints on the network devices. Power availability often is the most significant one.

Connectivity protocols (when the available power is limited)

The following protocols are specifically designed to address low power constraints. They are usually associated with lower complexity and bit transfer rates in the supported IoT devices.

Bluetooth Low Energy (also called Bluetooth Smart)

Named after a tenth-century Danish king who unified several fractious tribes, Bluetooth is a familiar technology to most consumers. The specification is maintained by an organization called the Bluetooth Special Interest Group (SIG) made up of 25,000 companies. Bluetooth Low Energy (BLE) is a newer implementation that is not directly compatible with Bluetooth classic (of mobile phone headset fame). It was designed for low power needs and a less...

IoT networking data messaging protocols

There are many strategies that IoT networked devices use to transfer data messages. Although connectivity and data messaging can sometimes blend together, we will discuss them separately for simplicity.

Not that it is really all that simple, but we will cover the most commonly used protocols. We will spend more time with the more frequently used ones.

Message Queue Telemetry Transport (MQTT)

MQTT is the most common data messaging protocol associated with IoT. It is supported by all the major cloud infrastructure providers (AWS, Microsoft, and Google). And it is most likely the protocol that is being used to deliver your data. It was designed for minimal power loss and minimal bandwidth requirements. It originated to support remote oil and gas use cases over satellite communication networks. It translated well into the broader IoT world as it developed in recent years.

 

At its heart, it is similar in concept to a messaging queue architecture but, despite...

Analyzing data to infer protocol and device characteristics

Back to the number-one rule in IoT analytics:

Never trust data you don't know

.

You need to get to know your data. Just like that new guy you just met, you Google him, ask around about him, and do a criminal background check (we know you do) before agreeing to go to dinner with him.

Here is a step-by-step strategy to start to understand the source of the data:

1. Draw a picture of the device: Sketch it out or use blueprints if you have them. This is where you make friends with the design engineer and ask her some questions. Draw the key sensors in the place they are located and note the sensor type and any limitations. Ask about any environmental conditions that affect accuracy and note it.
2. Find out how the device connects to a network: Note the connectivity type on your sketch.
3. Determine what data messaging protocol the device uses to communicate: Note this on your sketch. A simple example follows:

4. If you can visit an actual site where the...

Summary

This chapter reviewed in more depth the variety of IoT devices and networking protocols. You learned the scope of devices and some example use cases. The variety of networking protocols were discussed along with the business need they are trying to solve.

We reviewed how to understand the what and the why of the major categories of devices and networking protocol strategies. We also discussed some techniques to identify the characteristics of the device and the network protocol by analyzing the data.