LONDON - After months of uncertainty, the UK appears set to allow Huawei’s telecoms equipment to be part of the country’s 5G networks - with some limitations. The move would put the UK at odds with the US, which has been pressing other nations to ban use of the Chinese firm’s kit on security grounds. It could also cause tensions with Australia, which last year blocked its networks from using Huawei’s 5G gear. While Theresa May is reportedly willing to give Huawei the green light, this would not mean the prime minister’s cyber-advisers have disregarded the threat of a future Chinese cyber-attack. That concern still preoccupies many security officials’ minds, since much of our critical infrastructure - from power stations to automated transport - is likely to be dependent on the next-generation communications technology. Rather, there is a belief that restricting Huawei’s equipment to certain parts of the UK’s network means that the risk can be managed. At the heart of the matter, there seems to be a critical disagreement: Canberra and Washington believe that there are fundamental differences between 5G and 4G, which mean an outright ban is the wiser choice.

What is 5G and what will it mean for you?

To make sense of all this, it is worth exploring first why Australia came to its conclusion.

Telecom networks are preparing to spend huge sums to install 5G equipment

But it is worth saying up front that, for its part, Huawei has denied it would ever compromise a client’s network because it had been ordered to do so by Beijing.

It has said that it has been “targeted by a sustained campaign of ill-informed accusations that its involvement in 5G infrastructure somehow poses a threat”.

Why did Australia ban Huawei?

Australia concluded in August that it was impossible to “mitigate” the national security risks involved in allowing Huawei to form any part of its 5G network, because next-generation networks would operate in a different way to their predecessors.

The reason for this, it added, was that the relationship between two distinct bits of the network would change.

The first part - “the core” - it said was where the “most sensitive functions occur”, including device authentication, voice and data-routing and billing.

The second - “the edge” - referred to equipment including antennae and base stations that is used to capture the radio signals emitted by wireless devices and send them into the core.

The key phrase in a ministerial statement then explained: “The distinction between the core and the edge will disappear over time.”

One of the country’s spy chiefs, Mike Burgess, later expanded on this, saying that as 5G technologies matured, the expectation was that the distinction between the edge and core “collapses” because “sensitive functions” would begin to move outside of the protected part.

Part of the reason for this, he explained, would be to take advantage of the lower latencies 5G offers - the lag between issuing a command and getting a response. This, for example, could help make it safe to direct surgical robots or remote-controlled vehicles from afar.

Mike Burgess has confirmed Australia’s restrictions amount to a 5G ban on Huawei

But, Mr Burgess added, the consequences could be dire if the 5G kit was then compromised and used to mount an attack.

“Elements of the power grid may not work, water supply [and] sewage pumps may not work - it has the potential to impact our country greatly,” explained the director general of the Australian Signals Directorate.

And Huawei was considered a company that could be “subject to extrajudicial directions from a foreign government that conflict with Australian law”.

In other words, the fear was that it could be compelled to facilitate a Beijing-mounted cyber-attack.