The 5G we're using now is a hybrid of old and new mobile tech.
Nokia's chief technology officer for NZ, Dr Robert Joyce, explained the differences between NSA and SA saying with the former, your phone is connected to both 4G and 5G.
Signalling, which is the control mechanism for calls and data sessions, is done on 4G, Joyce said. Data meanwhile is transmitted both on 4G and 5G.
In SA mode, all of that happens on 5G.
5G SA probably won't be all that noticeable to regular smartphone users apart from apps being more responsive as one feature of the new tech is lower latency.
That's probably the most important feature for many users, followed by higher download and upload speeds and good coverage.
One interesting feature that Joyce mentioned is that 5G SA enabled phones can use low-band frequencies like 700, 850 and 950MHz. This is on top of the high frequency 3.5GHz carrier that 5G NSA uses.
Nokia has tested the band aggregation in Australia and got cell sizes as big as 75km, Joyce said.
That means improved coverage with fewer cell sites in other words, and low-band 5G also has better building penetration so you get better service indoors. Another benefit of low-band 5G that Joyce pointed to is that it can extend the coverage of the faster 3.5GHz band, as telcos can put the upload signal on lower frequencies with greater range.
Telcos can reuse the lower bands on which 2G and 3G ran before, but as Joyce says, it doesn't necessarily mean simpler network rollouts for them.
"... operators will still need to support NSA terminals [phones and devices] for years to come, and will need to run networks that can support NSA and SA simultaneously".
If Spark's example is anything to go by, telcos will also have to work with multiple technology partners for 5G SA rollouts: Spark got a cloud-native core solution for the trial from United States network builder Mavenir, and the whole thing runs on a suitcase-sized device from Amazon Web Services called Snowball Edge.
This is different from current mobile networks, which run in a centralised data centre. 5G SA will require data centres and mobile networks to be upgraded and deployed in the cloud.
For businesses, 5G SA brings features such as network slicing; this as the name implies lets telcos set up virtual networks from the same cell site, for different uses like Internet of Things and private connections.
Spark's also touting multi-access edge computing (MEC, oh yes, another acronym) for 5G SA.
MEC brings processing and storage closer to businesses, again for better performance and responsiveness. Running games on MEC boxes instead of on servers overseas might be coming as well.
There are gotchas for subscribers: 5G SA has to be supported not just by the mobile network, but also by the phones and devices connecting to it. Spark is using Oppo handsets which are built around newer Qualcomm chipsets, to get the end-to-end SA network connectivity.
Apple has had 5G SA modems since iPhone 12, although it requires an iOS update and the company's support site mentions the tech in conjunction with Mainland China.
Even if you do have a 5G SA phone and want to check out the new tech, cool your jets because Spark has only just started the laboratory trials on two sites, and has not committed to a launch date yet.
What's worth keeping a watching brief on is if Spark and other telcos manage to create new use-cases that customers are willing to pay for, like with network slicing and low-latency edge computing.
With physical mobile tower assets being sold off by their infrastructure investor owners, telcos should at least have the money to roll out the new tech, for fixed wireless broadband as well.
