Getting SMSC (SMS Center) number using AT Commands SIM900A

Question

Hello I am trying to figure out the SMSC number of the SMS I am receiving using Arduino Uno and SIM900A.

Example of what I am receiving:

+CMT: "Facebook","","16/05/24,07:40:32+24"
Hello there, this is test message.

Is there a way to get the original number the message was sent from (SMSC)? As I'm only getting the sender name ex:"Facebook".

Answer 1

This is not possible.

For circuit switched calls there originating phone number is passed along in the network in the call setup all the way until the last MSC on the receiving end, and then depending on CLIP/CLIR/COLP/COLR supplementary service settings the calling number will be presented to the called phone.

For sms messages however there is only the originating number, inherently part of the message, and this is always filled out when you send a sms message to someone from a mobile phone. The protocol standards covering mobile to network communication do not in any way allow for sms messages to be sent without an originating number.

However, the network operators also have the possibility to inject sms messages directly into their network from non-mobile phone devices, and that way the network operators are able to provide a service that other companies can (pay to) use to send sms messages without a originating number and with a pre-set originating name (as opposed to the normal number-to-name phone book lookup).

Answer 2

A solution I found was to get the full PDU of the SMS, and then decode it, the SMSC and and the Sender name will be visible in the result.