Mobile vs Wi-Fi: An IoT Comparison

Speed

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.

Security

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.

Coverage

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.