Cellular networks have changed dramatically over the years, to the extent that sunsetting is beginning on the ones we grew up with. Stuart Corner looks at what we lose to 3G and what we might gain from the already touted 6G.

Unless you have a very old cellphone, or an aged cellular-connected IoT device of some sort, this news may have escaped you: Telstra is closing its 3G cellular network in 2024.

It announced plans for the move back in October 2019, saying it could identify and track the 3G-only devices on its network and would be “proactively engaging with customers that have 3G-only devices from Q2 FY22.”

Optus and Vodafone have not yet announced any plans to close their 3G networks. So, except for people living in one of the rural areas where only Telstra has coverage, most people with 3G devices will be able to keep using them.

Telstra says 3G phones are typically more than six years old. Phones are easily replaced. There may be a few users of connected IoT devices for monitoring and control less easily replaced, but the possibility does not appear to concern the IoT Alliance Australia (IoTAA), which represents a broad spectrum of IoT interests.

In its response to the Government’s Regional Telecommunications Review in 2021 the IoTAA raised no concerns about the impact of Telstra’s 3G shutdown on IoT devices, saying only that, with the anticipated phase out of 3G mobile services it was “especially critical to support the regional voice footprint being at a minimum better than today.”

Cellular mobile technology has evolved rapidly since Telstra launched Australia’s first service in 1987: a new generation has entered service approximately every ten years. 3G is less than 20 years old. (Telstra announced in 2004 that it would close a network using a quite different technology known as CDMA and launch 3G under the brand name ‘Next G’).

Telstra launched 4G (also known as LTE) in 2011 and 5G in 2019. It was followed closely by Vodafone and Optus on both occasions. So, if that trend is to continue, we are due for another quantum leap in cellular mobile technology by the end of this decade.

6G in 2028

You may not have heard much about it, but development of 6G is already well underway: commercial networks are expected to be available in some countries as early as 2028.

Back in 2020 the South Korean Government was said to be planning to launch a pilot 6G network in 2026 and trial services in five key areas: digital healthcare, immersive content, self-driving cars, smart cities and smart factories. An April 2022 article in Business Korea suggests these plans are still on track.

In Australia, Telstra is already talking about 6G. At its 2021 investor day, it announced a new strategy, T25 “designed to transform every aspect of Telstra,” to run for three years from mid 2022.

In that announcement, Telstra said expansion of its 4G and 5G networks and the closure of 3G: “will set us up well for early planning on 6G, which will clearly be on the agenda by the end of T25.”

So, it’s timely to look at what 6G will bring and what it will mean for connected devices and their myriad applications.

For the academically inclined, a very comprehensive answer can be found in an August 2021 research paper 6G Internet of Things: A Comprehensive Survey, published in the IEEE Internet of Things Journal. The authors noted the “lack of a comprehensive survey on the use of 6G for IoT,” and sought to bridge this gap. They concluded that, even though research on 6G-IoT networks and applications is still in its infancy, “it is envisioned that 6G will transform the current IoT network infrastructures and bring new levels of service quality and user experience in … future applications.”

The hype that preceded the introduction of 5G touted its ability to support much higher data rates than 4G, many more connections per unit of area, and much lower latency – the time taken for a signal to get from a connected device to wherever in the network it needs to go, and back again.

However, some argue that the demands of new devices and applications will soon outstrip the capabilities even of 5G and therefore there are many potential applications just waiting for 6G for them to be implemented.

In another academic paper published by the IEEE, Enabling Massive IoT Toward 6G: A Comprehensive Survey, the authors say there is a mismatch between the demands of many emerging disruptive IoT applications such as augmented/virtual reality (AR/VR,) online games, autonomous driving and ‘smart everything’, and the capabilities even of 5G.

These devices and applications, they say, are “massive in number, data-intensive, computation-intensive, and delay-sensitive,” and they expect 6G to deliver the 1TB per second data rates, sub-millisecond latency and centimetre-level localisation needed to meet the demands of these applications.

Imagine how useful it would be in a factory, warehouse or other industrial facility to be able to locate every moveable object to within one centimetre.

A quantum leap from 5G

If 6G lives up to current predictions it will certainly do this. The capabilities of 6G are expected to exceed those of 5G by several orders of magnitude. The maximum throughput on a 5G network today is about 1GB per second. With 6G it is expected to be 1TB per second, one thousand times faster.

A 5G network will support about one million devices per square kilometre. With 6G that figure is expected to reach 10 million.

If such performance levels are achieved, 6G would enable communication and collaboration, at very high bandwidth and in real time, between devices at concentrations vastly greater than envisaged today.

The future autonomous car would not simply be an intelligent device that communicates with roadside infrastructure and with some central information and control sources, it would be one component of a giant synthetic ‘organism’ whose components included every other vehicle in the area, and much more. Traffic jams would likely be a thing of the past as vehicle flows would intersect with speed and safety unachievable by human drivers and enabled by reliable, instantaneous high bandwidth communication.

And we mortals would be part of this hyper-connected future reality: through brain implants that would replace smart phones and enable the implanted person to “interact with their environment and other people using discrete devices, some worn, some implanted, and some embedded in the world around them … to control their environments through gestures and communicate with loved ones through haptic messages,” according to the 2019 paper, A Vision of 6G Wireless Systems: Applications, Trends, Technologies, and Open Research Problems. It talks of a number of “important 6G use cases” including “emotion-driven devices [that] can match their functions to their user’s mood.”

One of the best sources of information on the potential impact and applications of 6G is the 6G Flagship, funded by the Government of Finland. Since 2020, it has published a series of white papers on multiple aspects and applications of 6G.

The European Union has created a 6G body, Hexa-X to bring together industry stakeholders and providers of future connectivity — network vendors, operators, verticals, and technology providers — with “the most prominent European research institutes and universities” to lead an integrated effort of research and development towards 6G.

Highly detailed digital twins

Hexa-X claims to have identified “a plethora of prospective 6G use cases.” One of the most intriguing is the potential for much more detailed digital twins —digital representations of machines, systems or environments — enabled by a massive increase in sensor density.

Hexa-X suggests: “Almost any aspect of an entire city could be digitally represented, allowing precise modelling, monitoring, and managing of almost any public or private service, such as utilities, public transportations, public health, or environmental and pollution monitoring for an immersive smart city.”

And while much of the attention around potential applications of 6G is focused on cutting edge applications that seem almost to be in the realms of science fiction, we come back to where we started: concerns for connectivity and all the benefits of communications in rural and remote areas.

A white paper from the 6G Flagship, 6G White Paper on Connectivity for Remote Areas, argues: “6G could be the first mobile radio generation that truly aims to close the digital divide.”

But the last word is perhaps best left to one of the leading manufacturers of mobile cellular technology, Chinese company Huawei, which claims to have been researching 6G since 2017.

6G, Huawei says, will have impacts far beyond communications. It will “serve as a distributed neural network that … fuse[s] the physical, cyber, and biological worlds, truly ushering in an era in which everything will be sensed, connected, and intelligent.”