Our cellular networks have become heavily reliant on customers using WiFi. According to Cisco’s latest Virtual Network Index about 60% of the data generated from cellphones is carried over WiFi and landline broadband connections. Most of us have our cellphones set to grab WiFi networks that we are comfortable with, particularly in the home and office.

The move to use WiFi for data was pushed by the cellular companies. As recently as just a few years ago they were experiencing major congestion at cell sites. This congestion was due to a combination of cell sites using older versions of 4G technology and of inadequate backhaul data pipes feeding many cell sites. The cellular carriers and manufacturers made it easy to switch back and forth between cellular and WiFi and most people quickly got adept at minimizing data usage on the cellular network.

Many people have also started using WiFi calling. This is particularly valuable to those who live or work in a building with poor indoor cellular coverage, and WiFi calling allows a phone to process voice through the WiFi connection. But this has always been a sketchy technology and WiFi calling is often susceptible to poor voice quality and unexpected call droppage due to WiFi fluctuations. WiFi calling also doesn’t roam, so anybody walking out of the range of their WiFi router automatically drops the call.

However, recently we’ve seen possibly the start of a trend of more broadband traffic staying on the cellular network. In a recent blog I cited evidence that unlimited cellular customers are using less WiFi and are instead staying on their cellular data network even when WiFi is available. Since most people use WiFi to preserve usage on their cellular data plans, as more people feel comfortable about not hitting a data caps we ought to see many people sticking more to cellular.

5G ought to make it even easier to keep traffic on the cellular network. The new standard will make it easier to make and hold a connection to a cell site due to a big increase in the number of possible simultaneous connections available at each cell site. This should finally eliminate not being able to make a cellular connection in crowded locations.

The 5G improvements are also going to increase the available bandwidth to cellphones through the use of multiple antennas and frequencies. The expectations are that cellphone download speeds will creep up with each incremental improvement in the coming 5G networks and that speeds will slowly improve over the next decade.

Unfortunately this improved performance might not make that big of a difference within buildings with poor cellular coverage today, because for the most part the frequencies used for 5G cellular will be the same ones used today. We keep reading about the coming use of millimeter waves, but the characteristics of those frequencies, such as the short distances covered are going to best fit urban areas and it’s likely to be a long while until we see these frequencies being used everywhere in the cellular networks. Even where used, those higher frequencies will have an even harder time penetrating buildings than today’s lower frequencies.

Overall, the improvements of 5G ought to mean that cellular customers ought to be able to stay more easily with cellular networks and not need WiFi to the same extent as today. A transition to less use of WiFi will be accelerated if the cellular marketing plans continue to push unlimited or large data-cap plans.

This all has big implications on network planning. Today’s cellular networks would be instantly swamped if people stopped using WiFi. The use of cellular data is also growing at a much faster pace than the use of landline data. Those two factors together portends a blazingly fast growth in the backhaul needed for cell sites. We are likely to see geometric rates of growth, making it expensive and difficult for the cellular carriers to keep up with data demand. It’s sounding to me like being a cellular network planner might be one of the hardest jobs in the industry right now.