From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============1751420334216894331==" MIME-Version: 1.0 From: Arun Ravindran Subject: Re: [PATCH] atmodem: CEREG support for LTE network status reporting in AT modem Date: Thu, 24 Feb 2011 12:34:14 +0200 Message-ID: <4D663426.7020706@nokia.com> In-Reply-To: <4D655760.3000701@gmail.com> List-Id: To: ofono@ofono.org --===============1751420334216894331== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Hi Denis, >>> -----Original Message----- >>> From: ofono-bounces(a)ofono.org [mailto:ofono-bounces(a)ofono.org] On >>> Behalf Of Denis Kenzior >>> Sent: Wednesday, February 23, 2011 5:50 PM >>> To: ofono(a)ofono.org >>> Cc: tomasz.gregorek(a)gmail.com >>> Subject: Re: [PATCH] atmodem: CEREG support for LTE network status >>> reporting in AT modem >>>> After discussing internally with Fred Joly I would like to come back >>> on the 4 properties : >>>> - Suspended is applicable in LTE in case of CS Voice Call using CSFB >>> My understanding was that CS Fallback physically switches technologies. >>> It is not 'suspending' LTE like it does with GPRS. Am I wrong on this >>> one? >> I would say yes. :) >> In case you are obliged to fallback from 4G to 2G without support of DTM= , exaclty like in GPRS. > From what I understood you physically lose the EPS network registration > and fall back to 3G / 2G. How is this the same as the suspended > property where your attached status does not change? >> For CSFB there are two settings. First one is that the UE should be = voice centric. A voice centric UE will always try to make voice service available = either using IMS or by CSFB. And if it cannot avail voice service using the above mechanisms, then it = should leave E-UTRA and re connect to GERAN/UTRA. A data centric UE in = turn will not leave E-UTRA if it cannot make a voice service available. = (23.221, section 7.2a) The second is that the voice call mode (domain), this can be set to CS, = CS preferred, PS or PS preferred. A UE with CS or CS preferred will = always try to make voice service through CS (CSFB or by re connecting to = GERAN/UTRA). 24.167 and also 23.221 describes these setting. I think the = AT commands for these in 27.007 are AT+CEMODE and +VCMOD A UE indicates its CSFB capability in attach and location/routing area = updates. The network in turn also indicates whether these are supported = in network. 23.272 section 6.2 details a CSFB for MO call, where PS handover is = supported. 6.3 where PS handover is not supported and 6.5 where how to = return to E-UTRA when PS is suspended. My understanding is that the context behaves the same way as in GPRS, = where it can be suspended, deactivated or handed over while doing CSFB = and the attach status will not change because when you are doing CSFB = you have done a combined attach (EPS/IMSI). >>> Perhaps, but again we have no control of the attach procedure with LTE. >>> So the implementation has to rely on vendor specific radio settings. >>> Same arguments about shoehorning logic apply here. >> I'm a bit puzzled by this statement. It is not specific to LTE, but rela= ted to +CFUN proprietary implementation against +COPS or +CGATT usage, is= n't it? >> > The current GPRS logic is controlled with the equivalent of CGATT. This > is a well-defined command by 3GPP, but it is not applicable to EPS > domain. It is applicable only to PS domain, correct? 27.007 release 10, section 10, lists all commands applicable to EPS and = CGATT is one of them. > If so, then the > powered property does not map to LTE at all. Your proprietary CFUN/COPS > map to the TechnologyPreference setting in RadioSettings. > Regards, Arun --===============1751420334216894331==--