Connecting devices to the Internet of Things

Over the past six to eight years, according to IoT Institute, well-known players like Cisco, Intel, Google, and Qualcomm have invested heavily in IoT companies as they work to build out their ecosystems. Given those statistics, it’s only rational (and, frankly, essential) to see household device manufacturers continue to design new IoT-enabled products.

However, determining where to start can be a daunting task for start-ups and small businesses. There is currently no regulatory agency to set standards for the IoT, and the variety of communication protocols resembles the American Wild West of the late 1800s.

The good news is that there are certain protocols that seem to be very promising in the IoT marketplace. Some of them are well-known, but others are relatively obscured from the mainstream consciousness. The following is a list of requirements identified by Cisco IoT experts as important for start-ups and small businesses to know when looking to design for the IoT.

Determining your needs

There are four important requirements you’ll need to establish prior to starting your design:

1. Range
2. Radio Frequency Bands
3. Power Consumption
4. Topology

Range

To get yourself started, ask and answer two questions:

1. What is your desired area of coverage?
2. Do indoor and outdoor deployments need to be differentiated?

Depending on your needs, the most promising communication technologies are as follows:

• Short Range = Less than 100m distance between two devices
• Medium Range = Between 100m and less than one mile
• Long Range = Distances greater than one mile

Radio frequency bands

Should you opt for your device to connect wirelessly, you’ll need to decide whether to use licensed or unlicensed radio frequency bands. Some of the key differences between licensed and unlicensed bands are detailed in the table below:

Organisations such as the International Telecommunication Union (ITU) and Federal Communications Commission (FCC) define and set the regulations and transmission requirements for the licensed radio frequency bands, so the guarantees and protections come from reputable agencies.

It’s important to note that the unlicensed bands are regulated, but they do not afford the protections (and thus, better service guarantees) of licensed bands.

Power consumption

Identifying a device’s power consumption needs is equally important.

For battery-powered devices, an important concept to determine is how often a battery would need to be changed. If it’s too frequently, the device won’t succeed in the market. Conversely, if the battery puts out too little power, the device may not have the functionality to succeed in the market.

With utility costs becoming a greater focus for product commercialisation, power consumption is important to consider for plug-in devices as well. If a new device or set of devices requires a high amount of power to run properly, that extra power cost could turn away cost-conscious consumers and hurt a product’s chance of succeeding in the marketplace.

Topology

Finally, you’ll need to decide the best scheme for your devices to connect with others. At this point, three main topology schemes lead the current IoT landscape: star, peer-to-peer and mesh topologies.

Star topology

In a star topology, every node or client connects to a central network device. A common example of this is an in-home entertainment system (see image). In that system, the speakers and the TV (the nodes or clients) all connect to the receiver (the central network device). Our cellular infrastructure also operates on a star topology, whereas our cell phones (clients) all connect to cell towers and a central station (central network device).

Peer-to-peer topology

Peer-to-peer topology is when each device is interconnected with others and each device may have its own clients linked to itself. In this topology, no central network device is needed.

The most common example is a personal PC connecting over the internet. In this example, files can be shared directly between systems on the network without the need of a central server, with each computer becoming a file server as well as a client.

Mesh topology

A mesh topology is an advanced form of peer-to-peer topology. Properly constructed and optimised, it allows devices to communicate and cooperate with each other for maximum data efficiency and battery usage.

One innovative example of a mesh topology is FabFi. Funded by a grant from the National Science Foundation, FabFi is a small-scale, open-source wireless network being developed to transmit wireless Ethernet signals using common building materials and off-the-shelf electronics.

However, there are significant hurdles one must overcome to optimise a mesh topology and implement devices so that they function properly; otherwise, the battery lifetimes can be greatly shortened. One such hurdle is a properly optimised implementation for battery-powered nodes. If not done properly, the battery lifetime is greatly shortened, putting the node at risk for failing in the market.