The Internet of Things (IoT) describes the network of physical objects that are all around us which are blessed with sensors, software, and other technology for the purpose of connecting and exchanging data with other devices and systems all over the Internet. And there is a lot of them with estimates of over 7 billion and they are only growing. Heaps of variety as well, I have even seen an IoT Toaster! The way a lot of these devices are connecting to the internet is by strapping themselves onto mobile networks. So how can you be sure that your IoT device can connect and work on the specific mobile networks around you? That is where I am here to help.
See below for contents.
- Mobile Network Overview
- Spectrum Management
- Devices that Use IoT Mobile Connectivity
- How to Determine Coverage
- Checking If an IoT Device Can Connect to a Network
- Resources
As always if you have any questions, queries or things to add please let us know your thoughts!
Mobile Network Overview
First lets lay some understanding. Mobile Networks are often referred to today as 3G or 4G or 5G. The G standing for 'generation'. A new generation of cellular standards has appeared approximately every tenth year since the 1G systems came to be in the early 1980s. Each generation is characterized by new frequency bands, higher data rates and non–backward-compatible transmission technology. So what exactly is 3G, 4G or 5G? Truthfully, they are marketing terms and not technical terms. One quick look at the Wiki page of mobile phone generations contents demonstrates this better than I could. You can see the section of that wiki page below.
There is a huge amount going on here, but I will keep it clear. So currently running in Australia (my current location) are 3G, 4G and in the cities 5G. The first commercial 3G networks were introduced in mid-2001 and it is worth knowing that they will cease to be used by 2024. When it comes to real-world, 3G is around 2 – 5 Mbps download speeds. 4G is around 20 Mbps and 50 Mbps (that is 10x faster). 5G you can reach 1200Mpbs if the stars are aligned correctly and you are the only one using the service but real-world usage is around 100-400Mbps.
When it comes to IoT they often run on Narrow Band Cellular Standards. This is a low power Wide area network radio technology started by an organisation called 3GPP group. Two main Narrow Band Cellular Standards that you will often see used are NB-IoT and LTE-M. Below is a table which shows these two standards categorised. Now Keep in mind that LTE (long term evolution) is for our purposes here effectively a 4G technology. Now Keep in mind that LTE (long term evolution) is for our purposes here effectively a 4G technology.
The full truth is much more complicated - read ahead at your own peril. For example, LTE CAT M1 is organised by 3GPP Long Term Evolution LTE. This is a pre-4G LTE technology organised by a group called 3GPP Long Term Evolution (LTE) which is often branded 4G – LTE. To add to the confusion the 3GPP Long Term Evolution (LTE) group (often shortened to 3GPP) organises 4G and 5G technologies as well which are not necessarily LTE. All the Narrowband Cellular Standards above in the chart can be simplified to 4G LTE technologies. Worth noting as well certain providers may offer 4G LTE but LTE CAT M1 is not actually supported.
Spectrum Management
So why all the confusing technicalities. It comes down to the history of the way the spectrum has been managed. The spectrum is a continuous range of electromagnetic radiation waves. This extends from the longest radio waves to the shortest like gamma rays radiation and X-rays. The radiofrequency spectrum, which is what IoT devices and mobile phones work with, sits in the lower part of the spectrum. Spectrum management is the process of regulating the use of radio frequencies with the intent to promote efficient use and improve society. You can see where this going. The term radio spectrum typically refers to the full frequency range from 3 kHz to 300 GHz (which is a large range) that may be used for wireless communication. Increasing demand for services such as mobile telephones and many others has required changes in the philosophy of spectrum management such as the now-massive demand for wireless broadband and the rapid expansion of wireless internet services. And each country has a different philosophy. Most countries consider RF spectrum as an exclusive property of the state. The RF spectrum is seen as a national resource, much like water, land, gas and minerals. RF is different however as it is reusable. The purpose nowadays is spectrum management is to mitigate radio spectrum pollution and maximize usable radio spectrum. Military, Scientific study, Space Missions, Consumers, Businesses, Airplanes everyone wants a slice of this radio frequency pi. So this landscape becomes very complicated. Just look at this info-graph on the Australian Radiofrequency Spectrum Allocations Chart that you can see below.
And this is one country! There is a huge amount that factors that further go into deciding these allocations such as, the distance the radio wave it can travel, whether it can penetrate through trees or into buildings, the cost of equipment, which generally increases as the frequency increases. Also, different services need frequencies with different characteristics. Longer wavelengths need larger antennas but can travel longer distances than short wavelengths. So the idea of these organisation like the Australian Communications and Media Authority is to match the needs of service with the right characteristics. This makes the best use of spectrum. The result is that some bands are more valuable and in much higher demand than others.
Devices that Use IoT Mobile Connectivity
To give you an idea of the range of some of the IoT devices that have both mobile connectivity and really cool features I have linked a number of them below. The image to the right is of a Pycom GPy, check out the guide All Pycom Boards and Expansion Boards Compared for more on this IoT capable device.
- Sparkfun LTE CAT M1 IOT Shield
How to Determine Coverage
Let us get back to the Internet of thing devices and Coverage. Every country is different here is a good way to figure out if you have connectivity ergo network coverage in your local area no matter where you are in the globe. Jump onto a website called CellMapper. CellMapper is a global crowd-sourced cellular tower and coverage mapping service that absolutely rules. So if you see a dots on the page you can know with certainty that someone with a device connected to the network. Thus if you see a dot with of your Provider, Network and Band of your device desired you can know with a hundred per cent certainty that your particular device could connect to Mobile Network around the same place. People spend a lot of time driving to and fro places so a majority of this information comes from data of people in their cars on the roads. An example of using this can be seen below.
So based here in Australia our main providers are Optus, Telstra and Vodaphone. Our main network is 4G LTE and the Bands that we have in much of our Country are B7 and B28. Interesting facts in Australia, we use this band 28 (which is 700MHz) for a lot of regional coverage. This is because the lower energy RF travels further without degrading. Just like how AM radio works everywhere, partly because it bounces off the ionosphere, while FM radio has a much shorter range). So Plugging in Optus 5052, 4G LTE and B7 Band you can see by the red dots below that there is this spectrum available around the regional area of Newcastle that we are based.
Another good way of finding out whether you will have coverage for your IoT device is by jumping onto your provider's particular website and sussing out their coverage maps. Below is an example pulled from Telstra (who is Australias largest mobile network.) At the bottom of this page is the resources section will be a link to this coverage map and that of Vodafone and Optus. Also linked are Cellmapper and another 3rd Party Global Coverage checker called NPerf. Data demonstrated here end up as bubble maps and will not be 100% accurate however it is pretty reliable.
Checking if an IoT device Can Connect to a Mobile Network
Lets demonstrate this process with the PyCom GPy that I have right here and find out if I can connect it to a Mobile Network that is around me right now. Also, check out the guide All Pycom Boards and Expansion Boards Compared if this amazing piece of tech is new to you and you want to hit the ground running. So Jump into our Core Electronics website we find the website page for Pycom GPy we can then scroll down to the GPY Features and TX/RX Frequencies Headings. These headings including the information inside them can be seen below in the image, it has been annotated with red underlines for the important information.
Another great website to pull this kind of data from is GSMarena From this, we can pull the information that Low-Band 28 is supported and LTE-M CAT M1 is desired and only Vodaphone and Telstra are the available carriers for this LTE. So, jumping to the CellMapper website and typing those details, see below for an image of just this.
Keep in mind that LTE (long term evolution) is effectively 4G technology. We can see that around the Newcastle area there is a connection available for this as this band has been accessed. So from this information, we can determine that this device would work perfectly in this location with this network provider.
Resources
Below is a whole bunch of amazing websites and tools to get you right up to speed with this world.
Global Cellmapper Coverage Checker using Real Life Data
Australian Coverage Maps
https://www.vodafone.com.au/network/coverage-checker
https://www.telstra.com.au/coverage-networks/our-coverage
https://www.optus.com.au/about/network/coverage
Worldwide Coverage Maps (Third Party)
Some Spectrum Regulators around the World (each country has its own)
https://www.acma.gov.au/
https://www.caa.co.uk/
Great Website for IOT and Mobile Phone Datasheets
