What is the difference between LTE and Wi-Fi?
The key difference between LTE and WiFi is coverage. LTE coverage has been widely expanded in recent years, so there’s likely to be mobile coverage where you need it. Wi-Fi on the other hand, even if it is a public Wi-Fi network will have a limited footprint, when compared to LTE.
Let’s look in more detail how LTE and WiFi compare.
Smartphones have allowed us to do things that once needed laptops or a handheld, truly portable devices. Being “always-on” and with better battery life smartphones have become the most widespread internet access device.
But cutting the wires to enable you to do what you want, where you want means you also need a network. It also opens up the opportunity for more widespread use of IoT to benefit your business. LTE (or 4G) and Wi-Fi can be used for this, and the terms are often used interchangeably.
But what is the difference between LTE and Wi-Fi? These can be critical, so which is best for my IoT or data solution ? Let’s start with a basic look at both.
What is WiFi?
WiFi is a radio technology specifically for data. It is also a trademark of The Wi-Fi Alliance, a body that drives global adoption and is made up of device and service providers. To ensure that everything works together the devices used have to meet the 802.11 IEEE standards, and over time those standards have developed.
Due to the constant development of the standards the speed and coverage Wi-Fi can provide has increased significantly. For example, the initial speeds for Wi-Fi were 10Mbps, but with the current standard (Wi-Fi 6) speeds are now hitting 1Gbps.
How Does WiFi Work?
WiFi depends on a critical central hub, or “access point” that propagates the WiFi network. This hub controls which WiFi devices can connect to the WiFi coverage it creates. The device authenticates with the hub then uses the Wi-Fi connection (or session as it is sometimes called) to send data to the hub. In turn the hub will be connected to a wired network that will allow data to reach a local server, or the internet.
Extending a WiFi network’s coverage area can be done by adding further hubs. These can be linked together using either wired /ethernet connections, or WiFi itself. The capabilities of WiFi are constantly evolving, here's a good summary of what WiFi can do and how that has developed over time. .
What is LTE?
LTE (Long Term Evolution) is often described by the generic term 4G. Essentially, they are interchangeable terms describing the public mobile networking technology that succeeded 3G.
Firstly, LTE provides far more bandwidth to a device than was available for 3G. What this means is that larger volume data transfers can be done than was possible under 3G.
It also means that new applications can be enabled – for example quality two-way video conferencing, or HD video streaming. A further benefit is the increased capacity that can be offered – either per device, or to increase the number of devices that can be supported. In the context of increased use of mobile data in high density areas, such as city centres, this is important.
How Does LTE Work?
A mobile operator's phone masts generate the wireless network and allow LTE enabled devices to connect to it. The ability to connect depends on a SIM card on the device that initially “shakes hands” with the network and validates that it is allowed to connect.
Once connected, LTE provides the device with the ability to wirelessly connect to the internet. Unlike Wi-Fi, LTE enables mobility and will keep your data session alive as you move between the cells on the operator’s network. With standard Wi-Fi you authenticate to the hub, not the network. That means you need to re-authenticate if you move between hubs, even if they are on the same physical network. However, a new generation of Wi-Fi - Mesh Wi-Fi - allows some session handover.
What are the differences between LTE and WiFi?
LTE has a major benefit in that you do not need to worry about managing the network. All you will need is your IoT device and a SIM. The mobile operator owns and manages the physical network needed to provide you with the connection to your device.
Unless you are using a public Wi-Fi network you will need to build and operate the network yourself. If you already have the network for other reasons that may be fine. However, the cost and time of using your own Wi-Fi network needs to be factored into your decision making.
The security of both your data and the devices you use should be a major concern when deploying your IoT solution. The security built into LTE networks, from user authentication to encryption of all traffic, is considered significant. It is constantly being evaluated and updated by cybersecurity experts. It should be remembered that to some extent the operators’ reputation depends on it. Protecting personal data as well as supporting secure transfer of sensitive data - such as banking transactions - is something LTE has been designed to deliver.
By contrast, with WiFi, the security is outsourced to the user. There are many popular tools/protocols to deliver security on WiFi networks. Many are included in the operating system that comes with a WiFi hub. However, they depend on the user to implement and manage them to deliver the promised benefits. One of the challenges is the constant attack these security measures face, and the consequent need to implement fixes when vulnerabilities are found. Hub manufacturers are highly skilled at producing timely fixes for these vulnerabilities.
You can read more about the risks and issues associated with WiFi networking (private and public).
Unless you are prepared to spend time setting up and managing the security you need to manage your data and devices LTE is a clear winner in this area.
WiFi will have a limited footprint, even if it is a public WiFi network when compared to LTE. The mobile operators have had a major drive to extend coverage in recent years to meet smartphone user demand. In some countries, such as the UK there is a coverage obligation that helps drive that as well. This means it is highly likely mobile coverage will be available where you need it. In addition, if your solution will be mobile, tracking a delivery vehicle, the breadth of coverage a LTE network offers will be key and so probably the best choice.
WiFi may well be suitable for a static solution, for example tracking temperature in a storeroom. If the storeroom is on-site, within the same WiFi network footprint as you, then it will be a good option. This assumes you have already covered the security requirements as a part of the original installation.
Even if the static solution is at a remote location the number of sensors you need to deploy may well determine the decision. It isn't just about the WiFi, you also need to think about the broadband speed and whether it can cope with the additional traffic.
Where your IoT solution is static, in a remote location with no existing network connections, LTE could still be the best solution.
LTE and WiFi in an ever changing world
Mobile Operators are now focusing on LTE as the replacement for 2G services that they are now retiring at an increasing rate. Since this article was first written 2 of the 4 operators in the UK have announced they will be shutting their 2G networks down in 2025. This allows them to re-use the spectrum to provide much needed capacity for LTE services. LTE network architecture is also seen as the building block for the future of mobile as it is future proofed, being based on IP, and was designed to be fully multimedia.
WiFi is also evolving to provide higher throughput and better security management. Next generation hubs are becoming widely available and the increased management capability means the gap between LTE and WiFi is closing fast. This means we are heading towards an environment where LTE and WiFi can work together seamlessly in the public networking arena to provide the user with continuous connectivity removing any fear of missing out on that critical social media posting!