Upgraded AIS sim card for 4G, now does not connect to AIS

[ThaiCoconut]

I wonder if anyone else has experienced a problem after upgrading an AIS SIM card. Here is what happened:

A SIM card I used for a few years was working great on my Samsung smart phone. Only problem was the Internet was a bit slow because it was not upgraded to support 3G/4G. I went to an AIS office to upgrade the SIM (so I could keep the same number), they gave me a new one and said it I would receive an SMS on my old when the new one was ready to use, usually a few days. I received the SMS a few days later about I could now use my new SIM. I discarded the old SIM and put the new one in my unlocked Samsung phone that works also in other countries. Unfortunately the new SIM can not connect to the AIS network (it can connect to TH GSM network but that will not allow me to use 3G/4G), almost as if the phone's IMEI is blocked (infact that is what one AIS shop though what happened). The AIS SIM works fine in my other smartphone (that I don't like to use because its old and bulky) and 4G works great. As a test, I tried a dtac SIM card as well in my regular Samsung phone (the one where AIS is not working), and dtac works great also with 4G.

I went to a dtac shop to change my AIS number to dtac, they gave me a new SIM and said it would start working in about a week. 3 weeks later, my number still rings to my AIS sim.

I don't want to do anything like change the IMEI number to try to fix it. Perhaps I will wait a while buy a new phone.

Anyone else with this issue or any suggestions?

One tip that might work for anyone else to avoid this issue: during the few days wait to upgrade a SIM card, do not keep the SIM in your regular phone, perhaps during the upgrade, the AIS network detected connection failures and blocked my phone's IMEI number.

[CharlieH]

MOVED to Telecoms

[RichCor]

Where is AIS providing 4G/LTE coverage for mobile phones?

AIS (AWN) 3G (3.9G HSPA+) on 2100 on 520 03 (GSM roaming with TH GSM)

520 01 - 900 MHz Band AIS 2G

520 03 - 2100 MHz Band AWN

520 18 - 1800 MHz Band (no longer operational)

AIS migrated their existing UMTS-900 3G users to their new AIS AWN 2100MHz

[casualbiker]

Are you sure your phone has the correct APN settings?

[merijn]

Little bit strange as AIS doesn't provide 4G yet in Thailand.

[bamnutsak]

What is the exact model number of your Samsung phone?

Are you pre-paid or post-paid with AIS?

Seems weird that they didn't give you a new AWN SIM immediately, and activate it with your old number? This might be the primary issue?

Are you still with AIS or have you switched to DTAC? IME, a successful port out/in takes three business days at most.

Chances are that your phone is improperly configured (APN: using the "old" one, wrongly configured, correct one not selected), or cellular data turned off, or you have not subscribed to a data plan, or you do not have coverage.

What do you see under Settings, About phone, SIM status (Android 5.1.1, not sure about earlier revs., maybe just Status?)?

AIS has too many customers, and not enough spectrum to offer 4G/LTE on their 2100 MHz license. They are waiting for the 1000 MHz and 900 MHz auctions; their old GSM900 concession ends in September of this year. They are also non-indigenous (Shin-aporean) so doubt any auctions will occur with the current "government".

[ThaiCoconut]

I thought AIS does provide 4G

http://www.ais.co.th/4g/home.html

Anyway, the AIS SIM card does work for 4G in other phones. So, this means there is no issue related to coverage or no data package.

The AIS SIM card is pre-paid.

After taking the phone to a few AIS shops, the staff were not able to set APN settings, I suspect as they could not connect to the AIS network on the phone.

The phone that can not connect to the AIS network is a Samsung Galaxy Exhibit T599

[RichCor]

From what I understand, the AIS 4G 'field testing' trial is operating on 2300 LTE-TDD and 1800 LTE-FDD.

AIS partnered with TOT's Broadband Wireless Access, 20 MHz LTE Technology Trial in the 2300 MHz band with Time Division Duplex (TDD) Project

AIS 4G Mobile Telecommunication, 10+10 MHz LTE Technology Trial in 1800 MHz with Frequency Division Duplex (FDD) Project agreement with WTO.

Trial coverage areas are:

Rama I road from MBK Hall, Siam Discovery, Siam Square, Siam Paragon, and Central World

Chaengwatthana Road from Headquarter of TOT / Ministry of Information and Communication Technology

Mahasarakarm University - LTE signal is available across the university

Rajabhat Mahasarakarm University - LTE signal is available across the university

As for the mobile phone:

The Samsung Galaxy Exhibit is marketed by Samsung as a phone capable of " '4G' data speed", but none of the model variations I've come across offer LTE/4G radios, only UTMS/HSPA 3G (3.9G marketing speak).

GSM 850, 900, 1800, 1900 MHz

HSDPA 850 / 1700 / 1900 / 2100 [uMTS Band II Band IV Band V]

So the device doesn't have LTE radios, and doesn't operate on 1800. Double whammy.

[bamnutsak]

The phone that can not connect to the AIS network is a Samsung Galaxy Exhibit T599

Where did you purchase this phone?

A quick search indicates to me that this may be a T-Mobile (U.S.A.) version, and as such supports 1700/2100 (band 4/AWS). The 2100 portion is not the same as is deployed here (band 1).

So it might not work here on AIS (save 2G/GSM900). However it does support 3G/850 so would work with TrueMove H (CAT) and DTAC.

AIS does not support 4G/LTE here; they do not have enough spectrum to utilize 2100 as they need it all for their 3G customers.

TrueMove H and DTAC have 4G/LTE here on 2100 MHz.

Edited June 29, 2015 by bamnutsak

[ThaiCoconut]

The phone was purchased in the US. It works fine all around Europe and Asia. Here is an image of the phone showing it works find with dtac:

http://i58.tinypic.com/200ab08.png

Notice there it is connected to the "dtac" network. When I put in the AIS sim card, it can not connect to the "AIS" network.

[RichCor]

The phone was purchased in the US. It works fine all around Europe and Asia. Here is an image of the phone showing it works find with dtac:

http://i58.tinypic.com/200ab08.png

Notice there it is connected to the "dtac" network. When I put in the AIS sim card, it can not connect to the "AIS" network.

The phone is using false marketing by using "4G" as the connection type.

More accurately the Mobile Network Type is being reported as "HSDPA", which is not LTE/4G

...so, as bamnutsak pointed out, "However it does support 3G/850 so would work with TrueMove H (CAT) and DTAC."

[bamnutsak]

The phone was purchased in the US. It works fine all around Europe and Asia. Here is an image of the phone showing it works find with dtac:

http://i58.tinypic.com/200ab08.png

Notice there it is connected to the "dtac" network. When I put in the AIS sim card, it can not connect to the "AIS" network.

OK, sounds like the T-Mo version. It will not work with AIS's 3G/2100 network, although it should be able to connect to their old, GSM900 network (which goes away in September) for 2G data. But maybe they are not allowing any new subscribers onto that network?

It should work fine on TrueMove H/CAT (3G/850 Mhz) or DTAC (3G/850 Mhz). Obviously you'd be better off using one of these two providers. You can port your AIS number out, and then in to either one.

The phone is meant to display "4G" even when on 3G, just part of the firmware/radio/T-Mo spec. You can clearly see it is on 3G, by the HSDPA detail.

[skippybangkok]

DTAC 4G strangely is slower than their 3G - Go figure.

Would use True, as have largest 3G and 4G coverage to date, although AIS has built out a lot of 3G now.

[RichCor]

DTAC 4G strangely is slower than their 3G - Go figure.

Would use True, as have largest 3G and 4G coverage to date, although AIS has built out a lot of 3G now.

According to Yozzo, the Telecom Consulting Firm, DTAC is only allocating 5MHz to LTE, vs 10-25MHz allocation to 2G/3G

850 (band 5) DTAC 9.7Mhz (2G/3G), True 10MHz (3G)

900 (band 8) AIS 17.5Mhz (2G/3G)

1800 (band 3) DTAC 25MHz (2G/3G)

2100 (band 1) AIS 15MHz (3G), DTAC 15Mhz (3G 10MHz, 4G/LTE 5MHz), TOT-3G 15MHz (3G), True 15MHz (3G 5MHz, 4G/LTE 10MHz)

Both UMTS/HSPA and LTE can achieve an application layer throughput of approximately 18 Mbps with a 5 MHz channel bandwidth and 64QAM, or even higher speeds if Multiple-In/Multiple-Out antenna array are deployed on the tower.

Data Speed really comes down to prevailing conditions (Spectrum Interference dictating use of QPSK/16QAM/64QAM, User within MIMO antenna beam, User has a fixed or moving location and number of concurrent users).

But 5MHz bandwidth really sucks.

LTE Physical Downlink Shared Channel (PDSCH) is the main data bearing channel which is allocated to users on a dynamic and opportunistic basis

(Graphic from lte-bullets.com)

[bamnutsak]

DTAC's LTE implementation is much more symmetrical for me, say 15x10 vs. 30x3 on their 3G. LTE gives a lot more density, and may be better for symmetrical apps. (photo uploading, for example). The drawback for me on LTE is increased battery usage.

I find similar attributes in the U.S. - I use T-Mobile - (1700/2100 for LTE and 850/1900 for 3G).

I often force my phone (via a menu pick: Preferred network type, or *#*#4636#*#*) to 3G as that network actually suits my needs better and my battery lasts longer.