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Is there any way to access NAS messages from LTE network on Android platform? I have all needed software for decoding, but can't get actual message.

sigrlami
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1 Answers1

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NAS messages are present in Baseband log (modem). So, you have to capture Modem Logs in order to check NAS message (or any other OTA Message).

Those messages does not reach the AP (android) side. So, those messages are only present in Modem Logs.

Each modem vendor saves modem log in a different format. They also has its own tool to decode those logs. Some modem vendors are Qualcomm (which has QXDM/QCAT tool), Marvell, Spreadtrum, Intel (or Infineon), Broadcomm (which does not exist anymore), Samsung etc.

Moreover, each Brand (Motorola, Samsung, LG, Asus etc) may have a different implementation to save the logs (hidden keystrings which are usually blocked in end-user version or save logs in the sdcard etc).

So, for example: For Nexus 5, you can search how to save UART Logs and since it uses a Qualcomm modem, I think you can open and read the log using QXDM. However, same procedure wont work in a different model/brand.

guipivoto
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  • Thank you for explanation. While I can check modem logs, which is still cool idea. I thought I can somehow access raw message and get this info more generally for different hardware. I need to parse couple of fields that are sent from MVNO to do some business logic. It's in-house product, so we can roll-out our own firmware. – sigrlami Mar 15 '16 at 12:47
  • Nearest thing to a Modem log is the RIL logs. All information that must reach APP side is sent from Modem to AP via RIL. Anything more complete than that, only via Modem Log... RAW messages can not be decoded easily due to security (they are ciphered according to simcard used in tests and several other keys). It is not a easy task... However, in modem log, all info is displayed properly decoded. If you really need to check OTA messages, I don't see other option than a Modem Log. But, try to see if RIL logs can help you (adb logcat -b radio) – guipivoto Mar 15 '16 at 12:54