Which mobile antenna frequency do I need

[Williamthe2nd]

I am using an AIS SIM  card and on the packet it says Super Play 4G . I want to buy an external roof antenna to boost the signal . On the AIS web site it shows their 4G frequencies as -----

 

900MHz – 1800MHz – 2100Mhz 

 

I can't find just one external antenna that covers all the AIS 4G frequencies . So it looks like I have to use only one frequency .

 

How can I find out which frequency of external antenna I have to buy to match my current AIS SIM card. 

 

Thanks 

Edited December 11, 2017 by Williamthe2nd

[RichCor]

AIS will sometimes indicate the band in use along side the 'carrier label'.

For instance, on my smartphone it displays "AIS 2100" to indicate I'm connected to a 2100 cell tower. 

[mtls2005]

There are quite a few Android applications which can identify the currently used (and nearby) 3G and 4G signals. I would try a few of those with your AIS SIM installed, in/around your home, to identify which tower/service might be serving you.

 

example: https://play.google.com/store/apps/details?id=com.wilysis.cellinfolite&hl=en

 

But there are quite a few which should work.