Detect current network (or country??) from incoming SMS message...

Detect current network (or country??) from incoming SMS message... SearchSearch
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Anonymous
 
Posted on Wednesday, February 04, 2004 - 03:02 pm:   

Hi:

Does anybody know if there is a way of detecting from an incoming sms message the network from which the sms originated?

Suppose a user is browsing on a foreign network and they send an sms back to their home country. Is it possible to detect what country (or network) they have sent the text from?

Anybody have any ideas??

Stephen.
Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 1798
Registered: 10-2002
Posted on Wednesday, February 04, 2004 - 06:23 pm:   

Hi Stephen,

You cannot determine this information from the SMS itself. You can only see the SMSC through which the message was sent, but that is going to be the user's home SMSC even if they are roaming.

The only thing that you can do, is after receiving the SMS message, query the HLR (home location register) to determine the subscriber's status. As long as the user didn't switch their phone off right after sending the SMS, you can then find the operator on which the subscriber is currently roaming through this query.

The problem is ... how do you do one of these HLR queries? Well, unfortunately you need to either be on an operator SS7 network (with appropriate interconnects), or you need to subscribe to a service provider that can perform HLR lookups over SS7 on your behalf.

I've seen a few commercial services that are performing HLR lookups. But for the ones that I've seen so far, they only seem to be telling you who the home operator is for a given phone number. They don't tell you the operator on which the phone is currently roaming.

So it may be a challenge for you to find a service from which you can get the current roaming information.

-bn
Stephen
Unregistered guest
Posted on Wednesday, February 04, 2004 - 06:44 pm:   

Bruce,

Thanks for your advice. You say that:

"You cannot determine this information from the SMS itself. You can only see the SMSC through which the message was sent, but that is going to be the user's home SMSC even if they are roaming."

This would actually be useful. How exactly do you determine this? Is it by reading the SCA of an incoming sms in pdu mode? Is there a way of getting the originators SMSC in text mode?

thanks again,

Stephen.


Bryce Norwood - NowSMS Support
Board Administrator
Username: Bryce

Post Number: 1831
Registered: 10-2002
Posted on Wednesday, February 11, 2004 - 06:42 pm:   

Hi Stephen,

Apologies for the delay getting back to you. But you're right, you have to be in PDU mode on a GSM modem, where the SCA is at the start of the PDU.

I don't believe this to be available in text mode. I also don't believe this to be available through most SMSC interfaces either, just with GSM modems.

-bn
Anonymous
 
Posted on Monday, February 16, 2004 - 04:26 pm:   

[moderator note: message deleted by user request]