Chapter 2: The "I" in IoT – IoT Connectivity

Connectivity plays an important role in the internet of things (IoT)—without connectivity, it would not be called IoT, being called something else.

In this chapter, we will cover different topics around IoT connectivity. There is a huge number of different IoT connectivity technologies available on the market, hence we thought that it would be difficult and boring to delve deep into each connectivity option available. We followed another approach to tackle this challenge—we will start by exploring some of the important concepts regarding networking and connectivity in general, such as network topologies, the Open Systems Interconnection (OSI) model, the Transmission Control Protocol/Internet Protocol (TCP/IP) model, radio, wired versus wireless networks, network performance metrics, and many other concepts that are required to understand different IoT connectivity options. We will also look at the different...

Connectivity concepts

Let's go through a list of different concepts that will help us explain the different IoT connectivity options that we will discuss in this chapter.

Basic network components

If you have two computing devices or nodes such as a computer, printer, or server and they need to talk to each other, you simply connect those devices directly, either by a wire/cable or wirelessly (through radio waves, as we will explain later in this chapter). Each device should have a network interface card (NIC) or a modem that will be responsible for sending data (in the case of a sender device) or receiving data (in the case of a receiver device). Before sending data that is in binary format (that is, 0s and 1s) via a transmission medium such as cables (such as twisted-pair cables, coaxial cables, and optical fiber cables) or through a wireless medium such as radio waves, you will need to encode or convert the data into a format that is understood by the transmission medium...

IoT connectivity selection criteria

There are several IoT connectivity options we could use in our IoT solution, and selecting which connectivity option to use is driven by the following criteria.

Amount of data

How much data needs to be transferred from the IoT endpoint device or IoT edge device or to the IoT cloud? Is it in bytes, KB, and so on?

Frequency of sending data

How frequently do you need to send data from the IoT endpoint device or IoT edge device to the IoT cloud? Is it every second, minute, day, and so on?

Communication range (distance)

What is the distance between the source of data (IoT endpoint device and/or IoT edge device) and the destination (IoT cloud)? Is it a few meters, miles, and so on?

Communication latency (speed)

What is the speed required in transferring the data? Is it in milliseconds, seconds, minutes, and so on?

Device types

Is the IoT device battery-based (low-power), in which case we should be careful about the selected...

IoT connectivity scenarios

There are many connectivity scenarios, but we will focus on two common scenarios that exist in any IoT solution.

Have a look at the following diagram:

Figure 2.12 – IoT connectivity scenarios

As per Figure 2.12, we could have the following scenarios.

Scenario #1

In this scenario, you have the following:

• IoT endpoint devices (device 1, device 2… device n): They are battery-based (low-power) IoT devices, they are fixed in their location, they have a radio communication module for wireless communication, they are low-cost devices, they require a low data-bits rate on the communication link, and their radio module is manufactured to operate on an unlicensed radio spectrum.
• IoT gateway device: You have one or more of these; they are plugged in or have a source of power through an electricity source or some other power technologies such as energy-harvesting technologies. The IoT gateway has internet connectivity...

IoT connectivity options

In the previous section, we covered lots of concepts about networking, wireless technologies, and different IoT connectivity needs, which were needed to understand the different IoT connectivity options we will mention in this section. We will not go into the low-level details of such technologies, but rather, will give a high-level overview of them.

We can classify connectivity broadly into two categories: wired and wireless connectivity. For wired connectivity, we have the options outlined next.

Classic Ethernet (IEEE 802.3)

The Ethernet protocol is a well-known and widely adapted internet protocol used in transmitting data at high speed on the LAN. This protocol covers the physical and data link layer of the OSI model. There are different kinds of Ethernet standards, and new standards provide data transfer at a rate of 10 Gbps.

The physical layer consists of cabling and devices; there are different Ethernet cables such as coaxial cables (a bit...

Summary

In this chapter, you learned about different IoT connectivity options, covering different aspects such as short-range versus long-range, low-power versus high-power, and licensed versus unlicensed radio spectrums. You also learned about the different connectivity protocols and standards that are used in different connectivity technologies. The protocols and standards explained in this chapter are mainly used in the physical and data link layer. IoT application layer protocols such as MQTT and CoAP will be covered in another chapter in this book.

Now, you will be able to identify what kind of connectivity option you should use and leverage for your IoT solution.

In the next chapter, we will continue to look at the anatomy of the word IoT. In this chapter, we covered the letter I. In the next chapter, we will cover the letter T which refers to things—in other words, IoT devices.