VoWiFi through an SDIO card

[davidschwartz]

We are in the process of developing a VoWiFi solution that utlizes a PDA handset with an SDIO card. We have run into a problem in that the SDIO handset implementation is register based and every write requires the host controller to do register mapping which causes high CPU utilization and time outs. Does anyone know of a work around for this or af a Pocket PC Phone with an SDIO card that uses memory mapping for the SDIO card?

Thanks

[jsicuran]

actually that is what I have been testing myself. My goal is at http://www.amilabs.com/aminet.htm

I have been doing some exetnsive testing in the same area as you have. I have been testing with an audiovox PDA with an ambicom cf wifi card. I also have a palm tungsten t3 but awaiting the sd wifi card from sychip. The pda has two SIP softphones SJlabs and Xten. Both work well and the SJ is just a little easier to setup and use. By using a pda and headphones the pda is basically a SIP based wifi phone. It works pretty good. SIP is not the issue but the RF environment. IF you have preety good cell coverage then the the call quality is not bad. Some of the SIP phones for pda have g728/9 compression also. I am still testing the voip over wifi with different qos on the DS, pcf, interaccess point roaming etc. From my preliminary testing in a small cell using the pda calling another wifi laptop or a cisco fxs port it has not been bad. Very promising.

I also have been reading a new wifi book from Cisco Press that is pretty good and it has a chapter on qos with 802.11e. Basically mac enhancements like EDCF, HCF, DAC and so forth to controll the classification and marking of voice packets and admission control to the medium. That is the tricky part. Using advanced forms of pcf, sifs and dcf to acheive some form of deterministic access control for higher priority voice frames. Eventually I shall post the results of my testing from phase I here for everyone to enjoy..

As for the SDIO memory mapping issue take a look at this it may help you.

http://www.sychip.com/wlan-module.html

Regards...