From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============9037739978753111710==" MIME-Version: 1.0 From: Denis Kenzior Subject: Re: Clarification on USSD support in ofono Date: Tue, 31 Aug 2010 11:07:09 -0500 Message-ID: <4C7D28AD.8030509@gmail.com> In-Reply-To: List-Id: To: ofono@ofono.org --===============9037739978753111710== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Hi Jeevaka, On 08/31/2010 10:48 AM, Jeevaka.Badrappan(a)elektrobit.com wrote: > = > Hi Denis, > = >> The original USSD API actually did look like this. It used binary > data >> + dcs field. However, we quickly found that all modems are screwed up >> in this area. The specification added binary PDU mode to SMS and CBS, > but never bothered with USSD. So all modems get this part wrong. > = >> Currently about the best we can do is pass UTF8 around. If you have a > modem that gets this part right, we'd like to hear about it. If the > Send USSD proactive command is = >> not handled by the modem, then oFono will try to do its best. > However, we make no guarantees ;) > = > I think its better to send the dcs and the binary data to the atom > driver. If the modem doesn't support other than GSM 7-bit alphabet, then > the conversion can be done in the atom driver. This way it will be > general to any modem. The send part is not really the problem, and can be easily done as pdu + dcs. However, it is the reception that is screwed up. By convention, all APIs in oFono must be symmetric. E.g. what the driver sends it must also accept. According to 27.007, +CUSD is converted into the current character set used by CSCS. It is not a binary PDU at all. So the driver now has to fake this information... Go ahead and send your suggested approach as a patch to this mailing list and we can continue from there. Just remember the symmetry part ;) Regards, -Denis --===============9037739978753111710==--