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Comment by whatevermang | Hacker News Reader

Okay. 3G is pretty good. No doubt about it. But from a security perspective (which I suspect is what's driving this), I think 4/5G are better. Like many instances in security, supporting legacy devices is not a desirable outcome for the security of the network as a whole.

That said, for telcos/the government to unilaterally decide that people's handsets are no longer working (with little to no notice and no financial compensation) is a bit on the nose.

The correct thing would be to let customers come into store with an existing plan and handset, and give them a new phone and bill that back to the government so there's no interruption to services for them.

RIP 3G, you were pretty good.

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It isn't about security, it's about spectrum.

3G wasn't designed to be forward-compatible. It expects to have a dedicated frequency band it can operate on. But spectrum is limited, and telcos really don't want to reserve something like 25% of what little spectrum they have to support a handful of legacy devices.

4G/5G support Dynamic Spectrum Sharing. This means a single frequency can be used to carry both technologies, with the ratio between them adjustable as demand varies. With DSS a 5G base station reserving a tiny fraction of transmission time for legacy 4G emergency calls would be absolutely trivial, which makes future hard shutdowns unnecessary from a technical POV.

Feel like you need to read the article. Many of the devices affected do not fit any reasonable interpretation of the term “legacy”. It turns out 3G is in many ways superior to 4G and 5G.

3G is a legacy protocol. The handsets themselves are irrelevant. They're shutting down a legacy protocol and (for somewhat misguided reasons) blocking handsets because they can't access 000 anymore. Despite it having advantages over 4/5G, I do think it's progress (at least in terms of security).

A load of older IoT devices and POS terminals are likely not working anymore though. That's a harder problem to solve.

> blocking handsets because they can't access 000 anymore

As the article explains, many handsets which can access 000 are being blocked.

My iPhone XR can't make calls anymore, for example.

- Australian carriers are blocking 4G phones based on whitelists, citing government mandate/ruling/whatever. Consequently many 4G phones are getting stuck in No Service state.

- Previously, phones that weren't whitelisted could connect to 4G for Internet, and disconnect & fall back to 3G for calls.

- Voice calling on 4G is finicky, and carriers don't like supporting random customer bought contraptions trying to do it.

- (you can whine all day about how calling is the sole defining feature for an object to be a "phone", doesn't change the fact that calling on 4G is a carrier-grade ever-beta duct tape hack).

dc: iiuc

Did you read the article? No one disputes that 3G is no legacy network as of now. But it’s needed because the devices that are in widespread use are not able to do specific things on 4G/5G which includes emergency calls.

And while progress may be good, risking people’s lifes for it isn’t. You can be mad on the device vendors for not implementing the technology, the standard inventors for not defining the VoLTE standard well enough, the government for not having any foresight at all, the operators for being profit driven. But you cannot just ignore it and turn off 3G and risk people’s lifes. Apart from that it’s just pure idiotism to also ignore the half million people that are losing any mobile network.

Plan it better, or punish operators or vendors more, but not ignore their and your incompetence completely and just continue shutting down integral mobile network services.

>Many of the devices affected do not fit any reasonable interpretation of the term “legacy”.

I'm really just going on a tangent rant, but I don't like that the word "legacy" has been associated with negative connotations in the tech world.

In the rest of the Anglosphere, a "legacy" is something to be admired and respected. Being old with stories to tell is a sign that someone or something weathered and survived the tests of time above all others.

Only in the tech world do I see legacies shunned in favour of the next new shiny at speeds that make progressives blush in embarrassment.

> The correct thing would be to let customers come into store with an existing plan and handset, and give them a new phone and bill that back to the government so there's no interruption to services for them.

I’m not sure I agree. Why is that the right thing? It’s a politically popular approach but not clear there’s a right/wrong here. For example, people might buy second-hand 3G headsets to get brand new ones on the government’s dime.

The exchange could be limited to only existing, paid plans. New plans would require a device compatible with the new specification. I don't think it's too hard since American phone carriers were able to offer free LTE devices to users with activated 3g devices.

Correct. You need an existing plan, and clearly the carrier can see what handset you are/were using. It's also the right thing to do because they are imposing a financial burden on people. People with older handsets are (I assume) likely the ones that can't afford newer ones.

does 4G and 5G not affected by SS7 attack???

SS7 is used in all kinds of operator messaging, so unless a network disables all 3G and lower (including when roaming), it'll stick around.

With 4G, a lot of SS7 functionality has been moved to a different protocol that's more resilient and less (obviously) designed to be used to spy on foreign assets. There's still a level of firewalling necessary for any operator that cares about security, but it's not nearly as bad as on SS7.

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