When developing IoT products, there are lots of important decisions to consider — including the type of connectivity. Wi-Fi and mobile network connectivity are two of the most popular. Here we explore the advantages and disadvantages of each.
Until recently, there were not many cases where the choice between Wi-Fi and mobile network connectivity was hard to make. Wi-Fi was the best choice for high-speed local needs, and using the mobile network was perfect for global connectivity – especially for moving objects. But, with the advancement of mobile network connectivity over the past few years, the choice between which to use is far less clear.
The main areas to consider when setting up an IoT system really depend on how it is going to be used.
With this in mind, the question of mobile networks vs. Wi-Fi for IoT can be broken down into five key considerations:
Before 4G/LTE networks this was an easy comparison to make – Wi-Fi networks were significantly faster than mobile. But with the advent of 4G and now 5G, the speed gap between the two is rapidly closing. While 4G mobile networks are technically the same speed as many Wi-Fi connections with a top speed of around 1000 Mbps, factors like technological infrastructure, interference, and the number of devices on the network needs to be considered.
The technological infrastructure is the hardware that makes up the local network, and it applies to both mobile connectivity and Wi-Fi, but in different ways. For a Wi-Fi connection, speed is capped by the local broadband internet top speed as well as the router’s top speed. For a mobile network, speed is dictated by the capabilities of the towers and transmitters in the local area. As an IoT example, suppose a factory uses IoT monitoring of supply chains. If the factory is in a remote location but has a nearby mobile tower, then 4G or 5G would be much faster. But if it is in a city with a higher internet speed, then Wi-Fi might be a good option. In urban areas, cellular networks are typically more developed and have more infrastructure in place than in rural areas, this includes more cell towers, which allows for fast internet speeds. In contrast, Wi-Fi networks rely on a single access point, typically provided by a home or business, and its coverage is limited to the proximity of that access point.
At first, interference from other signals might seem like a tight comparison between the mobile and Wi-Fi. Ultimately, mobile pulls ahead because of the strength of mobile signals. A Wi-Fi signal is often stopped by walls, doors, or devices like microwaves that emit higher frequencies. But mobile networks are designed to work indoors and outdoors, and from much greater distances. In short, this means that there often needs to be an unobstructed route between a device and a Wi-Fi router to enjoy the high speeds connected to Wi-Fi. With mobile however, interference plays less of a role.
While a typical home Wi-Fi network can technically support around 250 devices, using more than three or four at once starts to impact connection speed. Mobile network connectivity, on the other hand, is designed to support large numbers of devices without hurting the speed since they are using a wider system provided by a network of transmitter towers.
The level of security needed depends largely on what uses are planned for the IoT devices. While no one wants to be interfered with by a hacker, some types of IoT users are much more sensitive than others. Medical technologies, banking, and transportation are all areas in which interference from hostile parties could have a devastating impact. Both Wi-Fi and mobile networks have built-in security measures, but the technology in mobile connectivity goes much deeper than a simple password or two factor authentications.
All signals that are transmitted through a mobile network are encrypted. Upon receiving data input, the IoT device encrypts the data before transmission, which the receiving device then decrypts. So, if a signal is intercepted from a mobile network by a hostile third party, it would be indecipherable to anyone without the ability to decrypt it. Hackers generally tend to follow the path of least resistance, so the need for decryption technology is a massive deterrent.
While Wi-Fi is often protected by passwords and even two-factor authentication systems, the data itself is rarely encrypted. In fact, if someone were able to get past the firewalls protecting a Wi-Fi network they would have access to all of the data and functionality of the system. This is why it’s not unusual to hear about a university or a healthcare system being infiltrated by hackers since these institutions often have private Wi-Fi networks used for larger file transfers.
Another key consideration in security is that mobile network subscriptions come with trained security personnel at the connectivity provider. These experts are able to find the sources of any network intrusions and deal with them quickly. In a Wi-Fi network, it is up to the individual to either hire experts in cybersecurity to deal with a threat or do it themselves.
While Wi-Fi often has an advantage in speed and data throughput in limited spaces, mobile networks has a clear advantage in the coverage area. This comes in part from the frequencies used by both technologies. Wi-Fi uses higher frequencies ranging from 2.5GHz all the way up to newer 6 GHz systems. This allows for large amounts of data to be sent through the network but over a relatively small geographical area. The maximum range for an average 2.5 GHz router is less than 100 m, and at a higher GHz level, it’s even smaller.
So, this works well for an IoT network contained within a single building but poses problems when dealing with global coverage. There are Wi-Fi extender networks that can push the distance a Wi-Fi signal could travel to nearly 20 km, but that involves high costs and installation on the part of the network owners.
Mobile networks on the other hand use both high and low frequencies, with the low frequencies able to reach much further. However, this comes at the cost of data throughput which has traditionally been significantly lower than Wi-Fi networks. But with 4G and 5G networks, speeds are beginning to increase.
In looking at actual distances, the average range of a cell/mobile phone tower is approximately 21 km in a non-urban environment. However, unlike Wi-Fi networks, it is not up to the individual to provide the infrastructure for area coverage. Mobile towers are already common in most places where an IoT device would be needed.
In looking at the issue of complexity in mobile versus Wi-Fi, it at first may seem to be a toss-up. Mobile plans can sometimes have complicated regulations and agreements, but Wi-Fi setups require many more cables, devices, and hardware on site.
In a small use case such as an individual’s home, Wi-Fi would likely be far less complicated given that it’s a simple matter of plugging in a router and signing in a few devices. But, as soon as you are dealing with more than ten or fifteen devices, the amount of hardware and setup effort needed to establish a stable Wi-Fi network becomes cumbersome.
With mobile networks, simply turning on the device is all the work that is needed. The infrastructure that supports the network is all housed off-site through the mobile provider’s servers. This dramatically reduces the complexity when an IoT network has hundreds of individual devices.
Having a nonlocalized mobile network is imperative in managing the complexity of a global industry because it allows for seamless communication and data transfer across borders. Imagine trying to deal with hardware issues in Japan while the company is based in Norway and the specific individual who could solve the problem is living in the United States. With mobile networks, however, the infrastructure for global support is already established and most of the times included in the subscription. The experts needed are present in whatever country the coverage is offered – thereby avoiding a whole lot of logistical complexity.
Mobile subscription support services such as IoT Connect from Telenor IoT also cover areas ranging from security to running troubleshooting call centers. These factors make mobile network connectivity the clear frontrunner in this category.
The cost of IoT solutions is often hard to pin down because so much depends on what features are needed in each case. The number of devices, speed needed, and customer facing technology all play into the cost.
That said, a mobile network subscription is often more expensive up front, but cheaper in the long run. Mobile subscription services for IoT generally cost more than the hardware needed for a Wi-Fi setup, but after the system is running it incurs less maintenance costs than Wi-Fi.
Relying on Wi-Fi for IoT involves hiring IT workers to install the hardware and manage the system, cybersecurity experts to ensure the network is not open to hacking, and setting up call centers to deal with customer service issues. All of these needs come at a cost to the IoT company.
But with mobile connectivity, all of these services are provided as part of the subscription fee. So, on a small IoT scale such as a private residence, Wi-Fi would be the most cost effective since the homeowner could likely set it up and run it. But as soon as business is involved mobile network connectivity becomes far more cost effective.
Taking a look at a few use cases can help to highlight the pros and cons of each system.
A national power company wanting to install smart meters in homes across the country would be able to use mobile networks much more effectively than using Wi-Fi. With mobile connectivity, the devices could be set up on a single network. Attempting to connect each individual meter to the homeowner’s personal Wi-Fi network would be an overly complicated and costly project.
From a manufacturing perspective, the meters could be set up to work on a particular mobile network rather than needing to adapt to multiple types of Wi-Fi. Homeowners may not even have Wi-Fi which would render the meters useless.
For international transportation and fleet management companies, IoT is effectively used to track cargo as well as to maximize fleet management efficiency.
In directly comparing mobile to Wi-Fi, the range of mobile puts it ahead. For mobile, the coverage area comes down to the placement of towers. For Wi-Fi, it tops out at a few hundred meters from a Wi-Fi transmitter.
Solar power companies around the world have started using IoT to monitor power consumption and production at a local level. The solar panels installed on someone’s roof could be run through a Wi-Fi network or through a mobile network.
Running the system through Wi-Fi might at first seem the most obvious because there is a good chance the person has a working Wi-Fi setup. However, problems with weather, incorrect installation, and security issues often come up and it is the responsibility of the homeowner to correct them rather than the IoT solar company. This can lead to high numbers of calls to solar companies from homeowners trying to figure out how to gain access to the company online portal and get the IoT network up and running.
Using a mobile network presents a much simpler option because the solar company is not dependent on the homeowner to get the IoT network up and running. The solar company simply installs the panels and the rest of the network setup is outsourced to the IoT mobile provider. The connectivity, the security setup, and the monitoring are all done off-site so the homeowner is not responsible for that aspect of things. Because of that, the amount of work the solar IoT company has to do to troubleshoot problems on-site drops dramatically.
As mobile networks continue to grow in speed and stability, the places they can be used in IoT will continue to increase as well. Wi-Fi has many effective uses, and will likely continue to be a staple for larger businesses that have the technology already installed and works in a confined geographical area. But as industries adapt and become more nimble, mobile network connectivity presents many more exciting options.
In summary, mobile networks are, in general, considered better than Wi-Fi for several reasons: