Prepaid SIM card: How do credits for voice and data services relate to each other?

[Tercera_Edad]

This thread is probably only for those in a similar situation, not least because a meaningful exchange quite likely requires some degree of knowledge or personal experience in this field, something that others will hardly have. And yes, as my ID insinuates, I'm not a member of some contempo influencer, selfie or likewise generation - which should not be mistaken as an assumption of 'ignorance, old fashion' and what have you; more like a different thinking, and maybe not inferior to what has become to be considered as 'modern'

 

 

--> All the following information stated according to best knowledge

 

When the precursor of today's digital mobile telephony appeared in the late 80s, the european-designed 2G/GSM standard, also prepaid cards were introduced; before that, only payment via credit was available. A usual method (thus not the only one) was to virtually deposit one's credit card in the provider's system; then you could transfer more airtime from the credit card to one's phone account, to which the SIM card was linked.

 

These operations were carried out (and still are) through USSD
https://en.wikipedia.org/wiki/Unstructured_Supplementary_Service_Data
Fx, checking one's balance was done by typing *121# then sending it; a moment later, the balance appeared on the screen.
(Providers are free to establish USSD codes themselves, they can therefore vary among providers.)
If you wanted more funds to make calls, like 20 'rubles', you would type *137*20# then send; a moment later, your topped-up balance was shown. This was in the era prior to packet-switched data, ie also data calls (internet) were treated like voice calls - by duration not data volume.

 

All this was a convenient system, not least because all that was needed to execute this business was mobile coverage, not an internet connection, nor some 'app'. Reason enough for me to stick with it, instead of thoughtlessly jumping on the manic-raging american 'innovation' bandwaggon, just because 'everyone else' does it.

 

Around the mid-90s, 3G/UMTS started to appear, and with it data packet switching ('always on') that offered charging data consumption by volume, rather than duration. Also, simultaneous voice calls and internet surfing became possible. It was also the time when special data tariffs were introduced. But you were free to just use your existing pre-paid balance also for data, if you so wished - no need to have a designated balance ear-marked for data usage.

 

Of course, I also have a laptop, and I usually use it via wifi. If there's no wifi and there's an 'urgent' need for internet access, then I connect the laptop to the mobile network via my 4G phone's modem - a process called tethering. The link between laptop and phone is established by wire (USB), or if without, then through Bluetooth or a kind of wifi. This situation doesn't arise very often, so until now I have felt no need to better understand how the prepaid systems for voice and data relate to each other in necessary detail. It would also be hard to find out here; even if one happens to speak sufficient thai, one would have to find an expert able and willing to explain how this is set up - good luck with that!

 

Presently, when my wifi is down (happens occasionally), then I just access the web via tethering. This works fine for the first five minutes, but then I receive a text from AIS on my phone telling me that for continued speed, I must buy a data package that costs 'so much' and will last 'so long'. If I ignore that and continue on my existing balance, speed will be throttled (it's still usable but feels less comfortable), theoretically until my balance has been consumed.

 

So I'm actually considering now to get such a data package, for such contingencies, but would prefer to know the inter-working between these two - thus pre-payment for data and voice services. Would anyone knowledgeable be interested to exchange thoughts?

 

 

 

 

 

 

[Centigrade32]

Currently, your SIM has a Base Plan, with voice calls and data charged at a per second/minute/MB. SMS per 160 characters. That will continue until your balance runs out.

You can change this by purchasing a suitable voice call/data/SMS package. You can buy these by the hour, day, week, month, annually.

Easily done by topping up with credit and then applying a USSD code.

[Tercera_Edad]

Yes, I understand I will finally have to try and advance by trial & error, short of a learning alternative here. Thanks for the nudge

 

[Centigrade32]

https://www.ais.th/en/consumers/package/prepaid/add-ons/home

 

Nothing much has changed in that regard. You can just use your SIM base package which will deduct from your credit if your use is VERY occasional or if you choose, buy a package that suits, which is just a less expensive way of doing things.

If I want to stream/download a film/video, using the base package with credit would be prohibitively expensive. At 2 baht per MB, a 3GB video would cost 6,000 baht to download. Instead, I could purchase a 1 Day 10Mbps package for say, 59 baht, which theoretically would allow me to download up to 108GB over 24 hours.

In other words, you choose a package suitable to your need.

Why would you need pre-payment for voice services? Do you actually make regular calls with your mobile phone? Many people use applications such a LINE or WhatsApp to make calls these days.

Do you keep Mobile Data switched off on your phone, only turning it on when you need to do so?

 

Most people have monthly or annual packages and leave Mobile Data switched on, as they actually use their Smartphones on a daily basis.

 

 

[Tercera_Edad]

[I will check your recent message {thankfully received} later, can we continue from our previous stage now that I have done work based on it?]

 

 

 

 

So I just provoked the time-out situation, and after several minutes of swift 4G surfing, I received this text from AIS (minor editing for my personal reading ease):

Today you have used internet for 10 baht. If you used until 49 baht you can enjoy unlimited internet until midnight. Buy internet 5G Max speed
25 baht 1.5 GB for 24 h press *777*7503#
or
99 B 4 GB 7 days press *777*75502#

Could we try to parse this mystery message?

Today you have used internet for 10 baht: d'accord

If you used until 49 baht you can enjoy unlimited internet until midnight: Huh?

Buy internet 5G Max speed...: That's probably irrelevant.

The rest seems to be clear; in my words:

Want 25 THB for 1.5 GB during 24 h? Press *777*7503#

Want 99 THB for 4.0 GB during 7 days? Press *777*75502#

Finally, I do not use a 'smart' phone, but a 'feature' phone
https://www.digitec.ch/de/s1/product/doro-7010-280-4096-mb-3-mpx-4g-tastenhandy-12236694

 

Also, I do not use the phone for surfing (would be technically possible), but only its modem, to connect my laptop via 4G to the web (so-called tethering) - the link between laptop and phone modem is established through either USB cable, or wireless (BT, or a kind of wifi).
https://www.youtube.com/watch?v=QwPb_5kbm10

 

Does this have impact on my ability to follow the SMS instructions? And wouldn't I have to register a credit card with the provider, to start with? Or how else am I supposed to make the payment?

 

[Tercera_Edad]

Ok, I felt audacious and just sent USSD code *777*7503#
That was the one where the SMS message mentioned earlier said (gist of it)
Want 25 THB for 1.5 GB during 24 h? Press *777*7503#

 

Few seconds later, I got back a number of commercial texts, then the one that would count (my assessment), reading

 

5G on-top package 25 THB
You have got internet 1.5 GB valid for 24 h
Excess usage will be charged as your main package

 

Unfortunately, I forgot to check my balance prior to this operation, but if my memory feeling serves as an indication, then I would say: The 25-THB charge has been deducted from my previously available balance.

 

My spontaneous reaction would be: That seems to make sense. I could live with that. 'Who dares wins'?

 

That should do it for now. I will archive your second post - this one

 

https://www.ais.th/en/consumers/package/prepaid/add-ons/home
Nothing much has changed in that regard. You can just use your SIM base package which will deduct [...]

 

- until I may no longer be happy with this new arrangement - presently it should meet my requirements. Thanks for jump starting me, it really seems I sometimes need it