Sending UCS2 Encoded SMS with WP7504

I’m trying to send a UCS2 encoded SMS via WP7504 AT Commands.

So far I have determined SMS Text mode is my only option because the WP7504 does not seem to support PDU mode (+CMGF=0) or Block Mode (+CESP).

Therefore, I need to change the character set to UCS2 (+CSCS=“UCS2”) and change the Data Coding Scheme (+CSMP) to UCS2 also to send (+CMGS) the UCS2 (hex) encoded characters via SMS text mode.

However, +CSMP is not reacting how I would expect. When I query the present value of +CSMP, I get the following:

+CSMP: 4098,0,,0,

What i expected, based on 3GPP TS 27.005, was the format:

+CSMP: <fo>,<vp>,<pid>,<dcs>

There are a few discrepancies:

  1. <fo>, literally “first octet”, should be an 8 bit number between 0-255, not 4098
  2. There should only be four parameters (i.e. 3 commas) instead of 5

Most importantly, I am unable to set these text mode parameters how I would expect - particularly the <dcs> parameter for UCS2:


Can anyone let me know what I am not understanding about this command? I am using the latest Release 15 firmware and can send “IRA” encoded SMS without any problems.