Wireless carriers and equipment makers are keen to talk about 5G cellular. At this stage, it is still mainly talk. They can’t agree on what 5G is yet. They haven’t even decided how much spectrum it needs or which bands to use.

There are areas where everyone agrees, however. Every definition of 5G includes a promise of faster wireless speeds and shorter response times. Most say it will be capable of downloads of up to 10 gigabits per second. Some say these speeds will be symmetric.

Almost every 5G plan includes a response time, or latency, of less than 1 millisecond. This is vital. One of the proposed applications for 5G is controlling driverless cars. Too much lag in the network could prove fatal. Today’s 4G networks are just not up to the job. Nor can they respond fast enough for data-heavy applications like simultaneous language translation, which allows speakers of different tongues to chat on their phones.

Huawei, the world’s largest telecommunications equipment maker, believes its 5G network will be able to handle one million connections in a square kilometre. That’s one connection per square metre, about 1000 times the density of connections that today’s 4G networks can manage.

Carriers and equipment companies all say words to the effect that the 5G network will give users the impression of infinite speed and infinite capacity. It’s marketing talk, but effective.

They all talk about connecting billions of devices as part of the so-called Internet-of-Things (IoT). In addition to controlling driverless cars, the 5G network will be able to pilot drones and connect kitchen fridges to supermarkets. It will also be able to control robots and track remote sensors, measuring anything you can put a number on.

Some industry insiders say 5G will be able to stream 4k, and, before much longer, 8k video to portable devices. At the Mobile World Congress 2016, in Barcelona, one exhibitor talked about enabling surgeons to perform remote life-saving operations.

The next generation

As the name suggests, 5G is the fifth generation of cellular wireless technology.

A new generation turns up roughly every 10 years, that’s just about frequent enough to keep telcos’ spending on a continual investment hamster wheel. In many parts of the world 4G networks are only just being rolled out now. Here in New Zealand there are still areas where cellular coverage is only 3G.

When mobile phone technology was still shiny and new, nobody thought about network generations. 

The first wave of cellular networks was strictly analogue and needed brick-sized phones. In the early 1990s the first digital cellular technologies appeared. In hindsight, this was labelled as the second generation.

Mobile data didn’t take off until a decade later when the first 3G network appeared in the first decade of the new century.

This generation swapped circuit-switching for packet-switching. 3G meant we could access any information from anywhere that was in broadcast reach of a cellular tower. It made clunky video transmissions possible. Looking back, a more important change was that it became practical to send high-resolution images. You can blame 3G for selfies. The technology also suited social media.

From around 2010, carriers began moving to 4G networks. These made greater use of IP (internet protocol) which made mobile broadband practical.

Each succeeding phone generation has meant higher data speeds. The emphasis on data over voice has increased with every upgrade. Each upgrade has also brought new frequency bands to the mobile party.

The future is here:

The Mercedes-Benz F 015 Luxury in Motion research car and its immersive user experience is an innovative perspective into the future of mobility and will rely heavily on the latency of 5G technology.

Another half-promise made of 5G is that it will be a truly global network. That is, you’ll be able to use the same handsets and SIM cards — assuming we still use SIM cards — in every country you visit.

To get there you can expect plenty of haggling and lobbying as equipment makers, governments and telcos work through their competing ideas. Some want to take a giant leap towards an entirely fresh technology, others prefer an evolution of existing technologies. Phone-makers like Apple and Samsung won’t want to commit to building devices until there is an agreed standard.

All of this will take time. In the meantime, the engineers are busy at work. Not only are they preparing the next generation, but they are also tweaking today’s cellular technologies in a bid to deliver some 5G advantages ahead of time.

You may hear talk of 4.5G. This is an interim technology delivering some of 5G’s benefits ahead of a new standard. In part, the idea is to get some 5G benefits to market early, but there is another motivation. Switching to a new standard is expensive for carriers, and mobile network margins are wafer thin at the best of times. The proposed 4.5G technologies are little more than software updates — perhaps a card swap — on existing networks. It means carriers can go on making them pay for longer.

“In addition to controlling driverless cars, the 5G network will be able to pilot drones and connect kitchen fridges to supermarkets.”

One reason why carriers will be prepared to pay for the expense of network upgrades is that existing 4G networks in some parts of the world are becoming congested. Carriers can add more towers and build smaller sites, but only up to a point. Eventually this kind of expansion sees diminishing returns.

Today’s 4G networks mainly use frequency bands below 3 gigahertz. This is running out. As the adage goes: “They aren’t making any more of it”. Moving to a new generation network means tapping into higher frequencies. Although there are issues with higher frequency spectrum bands’ characteristics, they can be useful in densely populated areas. One problem is that thin obstacles can block high frequency signals. In some cases, even people moving around can interfere with data streams.

There are other forces, pulling from different directions, at the 5G plans. For the most part, companies planning to use 5G for the Internet-of-Things don’t need high bandwidth. The IoT is tipped to be lucrative over the coming decade, so these companies’ money carries influence with carriers. Typically, hardware sips tiny amounts of data, but device makers want their products to run for years on a single battery. So, they want 5G to deliver less bandwidth but to be light on power consumption.

Media companies pull in the opposite direction. They want carriers to deliver high bandwidth so they can stream high-resolution movies, sports and other video. They’re not worried about power. And financial traders want networks to minimise latency, so market trades happen instantly. Gamers also want less latency.

Another challenge for 5G is that phone owners increasingly use wi-fi connections for calls and data. So many homes, offices buildings and workplaces have ubiquitous wi-fi connections via fibre networks. They are common in cafes and high-traffic public places. Many phone owners choose to use these networks, often at no charge. For these people there’s not much need for a fancy new mobile data network, especially if it comes with a hefty price tag.