Comparison of SIM only plans - Part 2

[xiaofan]

Fun fact from Gomo thread.

actually SingTel 3G is still running healthy today!
both UARFCN 3088 (900MHz) and 10613 (2100MHz) are still running

There are still some credit card POS machines running on 3G that I've seen.
Plus, when there is no SIM card in a phone, in order to call emergency service, 3G is still required! Even if VoLTE is supported, that requires a SIM card. VoLTE for Emergency Service is another different techonology, and I believe this is the reason Singaproe still can't give up 3G

@gaoqikai also has doubts about pure 5G SA only without NSA.

As for a pure-SA NR network, I doubt it is doable.
SA roaming is very hard to do. NR uses a different encryption and authentication method than LTE. That's why when you travel and do a 5G roaming, you are mostly always on NSA.
Like China, in about 2022, the country was SA only. But more tourist came in 2023, 2024, and they couldn't connect to 5G roaming. So China re-opened NSA for those roaming use.

If Singapore turns to SA only, will be not so good for incoming travellers.

Of course @A7997A is much more optimistic about 5G SA with 4G fallback, without 5G NSA

It seems like M1 is already on 5G SA only, if I disable 5G SA, it drops down to 4G, not 5G NSA.
Not sure about starhub, but that could be a strategy that Singtel could use.

Also it is 3 years down the road, and many networks now have 5G SA so the situation will likely be quite different.

All in all, let's see if the phase-out of 5G NSA really happens in Jan 2026 for SingTel.

 

[gaoqikai]

still shows https://zym.sg/faq/roaming-calls-sms/

1.If I am currently out of Singapore, will I be charged for incoming and outgoing call?​

Yes, you will be charged for roaming incoming / outgoing calls when you are outside of Singapore.

You are strongly advised to use messaging apps like WhatsApp, Line, WeChat etc. when you are roaming outside of Singapore. These calls are free over Wi-Fi or data, so you will not be charged for them.

yes this apply to "answered" roaming calls. For "declined" ones, here's ZYM's previous FAQ:
https://en.ocworkbench.com/charges-...-while-roaming-overseas-with-singtel-and-zym/

now this line is removed. Hope it means declined calls no longer charged.

I believe it will be charged, probably because of Singtel.

I tend to think it will be charged for all Singtel based MVNOs. Not so sure about M1/Starhub based MVNOs.

https://www.singtel.com/personal/products-services/mobile/roaming/faqs

1. Roaming voice call is charged on a per minute basis. For USA and Canada, call charges will be incurred after 30 seconds of ringing even if incoming calls are unanswered.
2. Rerouted IDD Calls are incoming calls you received (including rejected calls) while you were overseas and have been rerouted from Singapore to the country you are in.
   You will be billed the Singtel IDD rate.

For my experience, I was on vivify from Apr to Nov 2024. During that time, sometimes in JB, I receive calls from SG but I declined or ignored many. Never got any charge! So on my experience vivifi did not have this issue

 

[gaoqikai]

Fun fact from Gomo thread.



@gaoqikai also has doubts about pure 5G SA only without NSA.



Of course @A7997A is much more optimistic about 5G SA with 4G fallback, without 5G NSA



All in all, let's see if the phase-out of 5G NSA really happens in Jan 2026 for SingTel.

yes if your phone allows you to force connect to 3G, you can take a try. Current iPhone's doesn't... If on Android, can try *#*#4636#*#*, might have the option for WCDMA only.

As for future 5G NSA, I think it mght be possible to switch all local SIM connections to SA only. If no SA coverage, fall back to LTE. But for international roamers, allow them to connect to NSA for roaming.

This is possible. Cell stations can emit both SA and NSA at the same time. So coverage is the same.

 

[xiaofan]

Some screenshots for NetMonitor app (free version) using my Poco X7 Pro, to show Singtel 5G SA and NSA in an industrial building in Jurong West

Singal from moderate to poor, then it will go from 5G SA to 5G NSA.

You can also see that for my Poco X7 Pro phone, 5G+ icon will correspond to 5G SA, 5G icon will correspond to 5G NSA.

In the very weak signal areas, we can also see 700 MHz band in action (N28). For 5G SA, I see N1 and N78 more often.

 

[JAYSCS]

Good point about the likely date of the article to be in 2020 or maybe 2021.

On the other hand, my test results shows that it is difficult for Singtel to be ready for full 5G SA on 1 January 2026.

Singtel 4G fallback does not work for me in some weak signal areas, it is usually 5G SA to 5G NSA to no signal during transition, not seeing 4G LTE at all. That is why my impression is that SingTel 4G coverage is deteriorating very badly while 5G SA/NSA coverage greatly improved this year.

But my impression may not be exactly correct, it could be Singtel 4G LTE coverage is as good as 5G NSA. So when I lose 5G NSA, I also lose 4G LTE.

In that case, when 5G NSA really shuts down, I will get 5G SA to 4G LTE fallback. But that is a downgrade of user experiences, right?

But let's see what will happen in Jan 2026.

If 5G SA falls back to 5G NSA during weak signal, it simply means 5G network is bad but 4G network is good there. The reason it is not falling straight to 4G because your 5G NSA (and many other users' 5G NSA) is active. So when 5G NSA shut down, one may not get a outage but better constant network connection as there is no 5G NSA users to hijack 4G users, leaving more spectrum (5G NSA sucks up too much data) to more users instead. 5G NSA in fact is the main cause of present 4G problem.

 

[xiaofan]

If 5G SA falls back to 5G NSA during weak signal, it simply means 5G network is bad but 4G network is good there. The reason it is not falling straight to 4G because your 5G NSA (and many other users' 5G NSA) is active. So when 5G NSA shut down, one may not get a outage but better constant network connection as there is no 5G NSA users to hijack 4G users, leaving more spectrum (5G NSA sucks up too much data) to more users instead. 5G NSA in fact is the main cause of present 4G problem.

Not so sure how you can conclude the 4G network is good in this case.

To me the SingTel network is not good in quite some parts of this building, even though it has improved compared to last time (no signal at all in the same weak signal area).

BTW, even in Funan, I found quite a few places with weak signal.

In any case, you may want to think from the user experience/psychology side. when the 5G NSA network shuts down, in the same area, the user may see no more 5G icon on the phone but see a 4G LTE icon, what will they think? They will think this is a downgrade, right?

 

[JAYSCS]

Not so sure how you can conclude the 4G network is good in this case.

To me the SingTel network is not be good in quite some parts of this building, even though it has improved compared to last time (no signal at all in the same weak signal area).

BTW, even in Funan, I found quite a few places with weak signal.

In any case, you may want to think from the user experience/psychology side. when the 5G NSA network shuts down, in the same area, the user may see no more 5G icon on the phone but see a 4G LTE icon, what will they think? They will think this is a downgrade, right?

5G or 4G is just a number game, at the end of the day it is about seamless connection (even ultra speed is not important comparatively). If the users deems 5G looks nicer on screen, then they will port out to those telcos that always show 5G I suppose.

 

[xiaofan]

5G or 4G is just a number game, at the end of the day it is about seamless connection (even ultra speed is not important comparatively). If the users deems 5G looks nicer on screen, then they will port out to those telcos that always show 5G I suppose.

LOL.

But to Singtel and more so for M1, both ISPs may want to get users to 5G as much as possible, as 4G coverage is not that great.

Before 5G access is fully free for Singtel 20.37 per month SIM Only plan (and now S$15.28 per month), I got only three month free 5G access. At that time I compared the 4G coverage versus 4G+5G coverage, there was a big difference in the Boon Lay and Taman Jurong area. With only 4G, I got disconnected on the bus. With 4G+5G, things were much better.

Now 4G+5G coverage is even better with the new 700 MHz 5G coverage. And I actually think Singtel 4G coverage does not improve at all but rather deteriorate over the years.

So in this case, I think 5G SA with 4G fall back is associated with seamless connection. 4G alone will be associated with frequent disconnection.

I am also trying to argue that 5G SA with 5G NSA + 4G fallback (current situation) is better than 5G SA with only 4G fallback (after 5G NSA shutdown). But I guess if 5G SA becomes really good, then this is a moot point. Unfortunately 5G SA is not that good now for quite some places, no matter SingTel/StarHub/M1.
back

 

[JAYSCS]

LOL.

But to Singtel and more so for M1, both ISPs may want to get users to 5G as much as possible, as 4G coverage is not that great.

Before 5G access is fully free for Singtel 20.37 per month SIM Only plan (and now S$15.28 per month), I got only three month free 5G access. At that time I compared the 4G coverage versus 4G+5G coverage, there was a big difference in the Boon Lay and Taman Jurong area. With only 4G, I got disconnected on the bus. With 4G+5G, things were much better.

Now 4G+5G coverage is even better with the new 700 MHz 5G coverage. And I actually think Singtel 4G coverage does not improve at all but rather deteriorate over the years.

So in this case, I think 5G SA with 4G fall back is associated with seamless connection. 4G alone will be associated with frequent disconnection.

I am also trying to argue that 5G SA with 5G NSA + 4G fallback (current situation) is better than 5G SA with only 4G fallback (after 5G NSA shutdown). But I guess if 5G SA becomes really good, then this is a moot point. Unfortunately 5G SA is not that good now for quite some places, no matter SingTel/StarHub/M1.
back

But 5G network will improve over time with more stations deployment. The intention to shut down 5G NSA by ImDA is also to encourage better 5G network, instead of having 5G NSA dragging 5G SA progress and hijacking 4G network.

 

[xiaofan]

But 5G network will improve over time with more stations deployment. The intention to shut down 5G NSA by ImDA is also to encourage better 5G network, instead of having 5G NSA dragging 5G SA progress and hijacking 4G network.

Yes, eventurally 5G SA network will be good enough, just not on 31 Dec 2025.

Anyway, Singtel (as well as some other ISPs) often has a way to work around IMDA rules. Let's see.

Example: IPv6 adoption in Singapore
https://forums.hardwarezone.com.sg/threads/ipv6-discussions.6976522/page-27#post-157646136

 

[JAYSCS]

Yes, eventurally 5G SA network will be good enough, just not on 31 Dec 2025.

Anyway, Singtel (as well as some other ISPs) often has a way to work around IMDA rules. Let's see.

Example: IPv6 adoption in Singapore
https://forums.hardwarezone.com.sg/threads/ipv6-discussions.6976522/page-27#post-157646136

Hmm, well see. But the trend is irreversible, just like the demise of 2G and 3G, analogue TV (thankfully analogue radio remains) whereby those who owns many such devices have to move forward despite heart breaking news. In Singapore, nothing is turning back, no looking back, only what is ahead awaiting. Embrace the new era, the only unchanged is change.

 

[xiaofan]

Hmm, well see. But the trend is irreversible, just like the demise of 2G and 3G, analogue TV (thankfully analogue radio remains) whereby those who owns many such devices have to move forward despite heart breaking news. In Singapore, nothing is turning back, no looking back, only what is ahead awaiting. Embrace the new era, the only unchanged is change.

No argument here.

5G SA is the way to go and eventually it will be there.

6G is also on the horizon.

Qualcomm thinks 6G devices will start appearing as early as 2028
https://www.hardwarezone.com.sg/mob...ks-6g-devices-will-start-appearing-early-2028

 

[A7997A]

LOL.

But to Singtel and more so for M1, both ISPs may want to get users to 5G as much as possible, as 4G coverage is not that great.

Before 5G access is fully free for Singtel 20.37 per month SIM Only plan (and now S$15.28 per month), I got only three month free 5G access. At that time I compared the 4G coverage versus 4G+5G coverage, there was a big difference in the Boon Lay and Taman Jurong area. With only 4G, I got disconnected on the bus. With 4G+5G, things were much better.

Now 4G+5G coverage is even better with the new 700 MHz 5G coverage. And I actually think Singtel 4G coverage does not improve at all but rather deteriorate over the years.

So in this case, I think 5G SA with 4G fall back is associated with seamless connection. 4G alone will be associated with frequent disconnection.

I am also trying to argue that 5G SA with 5G NSA + 4G fallback (current situation) is better than 5G SA with only 4G fallback (after 5G NSA shutdown). But I guess if 5G SA becomes really good, then this is a moot point. Unfortunately 5G SA is not that good now for quite some places, no matter SingTel/StarHub/M1.
back

Bear in mind that 5G NSA is technically using 4G core, it is a matter of allocation of resource between 4G and 5G NSA. The reason why 5G NSA appears to be better is due to resource being allocated to that instead of 4G.

So if 5G NSA shutdown results in rellocation to 4G. Then what you observe at that point will be quite different.

 

[xiaofan]

Bear in mind that 5G NSA is technically using 4G core, it is a matter of allocation of resource between 4G and 5G NSA. The reason why 5G NSA appears to be better is due to resource being allocated to that instead of 4G.

So if 5G NSA shutdown results in rellocation to 4G. Then what you observe at that point will be quite different.

That is a big "if"...

Anyway, no argument about 5G SA being the future.

 

[xiaofan]

Other resources which I wish I had known about before I did my first ever porting. Hope these may be of help to those considering mobile providers.

https://www.opensignal.com/reports/2025/06/singapore/mobile-network-experience

"Detailed coverage maps for all major networks around the globe are available for free in the Opensignal app.
Download the Opensignal app, available on Android or iOS, to:

• Accurately measure the true mobile network experience you receive on your mobile network
• See 2G, 3G and 4G network availability, stats and speeds experienced on all networks worldwide
• Help contribute to the Singtel coverage map and contribute to future Singapore reports"

https://www.nperf.com/en/map/SG/-/-/signal
https://www.nperf.com/en/map/SG/-/-/download?ll=1.3355039025448037&lg=103.82449999999999&zoom=11

https://www.imda.gov.sg/about-imda/...s/telecom-service-providers-consumer-feedback

1. The above reference from OpenSignal is very good.
https://www.opensignal.com/reports/2025/06/singapore/mobile-network-experience

2. One more here from OpenSignal, on 5G SA.
https://www.opensignal.com/2025/06/...-at-the-city-states-5g-standalone-networks/dt

 

[gaoqikai]

Some screenshots for NetMonitor app (free version) using my Poco X7 Pro, to show Singtel 5G SA and NSA in an industrial building in Jurong West

Singal from moderate to poor, then it will go from 5G SA to 5G NSA.

You can also see that for my Poco X7 Pro phone, 5G+ icon will correspond to 5G SA, 5G icon will correspond to 5G NSA.

In the very weak signal areas, we can also see 700 MHz band in action (N28). For 5G SA, I see N1 and N78 more often.

this app looks good! Much better than that FB guy's Network Cell Info Lite

For me if I'm on Android, and for many people internationally,NSG (Network Signal Guru) is the most popular. Can show a lot of detailed info if phone is rooted. For example in my below screenshot, can see LTE CA, and even how much downlink speed each carrier provides.
https://imgur.com/gallery/nsg-mXlNe8j
even without root, it still show you much interesting info. Not only your connected cells, it also shows neighbor cells.

Another good app is Cellular-Pro

 

[xiaofan]

One finding today: using Singtel SIM Only Plus plan, Poco X7 Pro phone.

5G NSA only on Level 19 of NUH Medical Centre Zone B. Very strong signal, but no 5G SA.

Occasionally got 5G SA towards the lift lobby but with very weak signal and slower speed than 5G NSA.

 

[xiaofan]

Then for the train ride on Circle Line from Kent Ridge (CC24) to Buona Vista (CC22), all underground, no 5G SA either, only 5G NSA.

Conclusion based on recent testing: Singtel is not really ready for 5G SA in many places, main for underground areas, but also for some places above the ground.

 

[Jurong640]

Then for the train ride on Circle Line from Kent Ridge (CC24) to Buona Vista (CC22), all underground, no 5G SA either, only 5G NSA.

Conclusion based on recent testing: Singtel is not really ready for 5G SA in many places, main for underground areas, but also for some places above the ground.

It's mostly the same for M1. Maxx had 5G SA from Buona Vista to Harbourfront (circle line), but not the other lines. Some parts of the malls are using 5G NSA and some are using SA.

 

[RSKeisuke]

Some screenshots for NetMonitor app (free version) using my Poco X7 Pro, to show Singtel 5G SA and NSA in an industrial building in Jurong West

Singal from moderate to poor, then it will go from 5G SA to 5G NSA.

You can also see that for my Poco X7 Pro phone, 5G+ icon will correspond to 5G SA, 5G icon will correspond to 5G NSA.

In the very weak signal areas, we can also see 700 MHz band in action (N28). For 5G SA, I see N1 and N78 more often.

good app but take note that by default it is allowed to collect cellular parameters in the background.
it drains my batt 14% over a period of 10 plus hours while i'm out and about yesterday.

you can disable background activity under settings