EVDO Hyprid Mode

Matt93 · EVDO Newbie Joined: 21 Jun 2006 Posts: 3

Hello,

I am looking for information regarding Hybrid Mode. I have been able to find that while in a data session, the device (in this case a BlackBerry) will monitor the CDMA channel for incoming calls. Once a call comes in, the device will exit the EVDO channel. RIM advertises that the data session would be put in a hold state and once the phone call is complete, the data session would resume. How does this affect a data transfer where a user is connected via VPN? How does the device "pause" an EVDO session to answer a CDMA call? Any info would be a great help!

xenophon · EVDO Addict Joined: 30 Aug 2005 Posts: 1969

I have not done a lot of testing but when taking a call during the data session and doing VPN, it will depend on the timeout period set for the VPN client to retry. If the call is only 1 minute and the VPN client will retry for 2 minutes, you should be OK. If rety time is less than length of call, you'd likely have to re-login to the VPN.

Matt93 · EVDO Newbie Joined: 21 Jun 2006 Posts: 3

Thanks. I'm just looking for technical info of how exactly the device "suspends" the data session to receive a phone call.

xenophon · EVDO Addict Joined: 30 Aug 2005 Posts: 1969

I don't have technical details on how CDMA voice/data is dealing with it but I've done some testing on Treo 700p. Don't know if this applies to BlackBerry. Each EVDO device may have a slightly different behavior.

I ran PocketTunes to force a constant stream of audio in the background.

When dialing out, the data stopped. Hung up phone, data and music resumed.

When dialing in, phone rang, data stopped, message came up with options to Answer or Ignore.

If Ignore, data resumed, caller went into Voice Mail, music continued.

If Answered, data stopped through duration of call, when hanging up data and music resumed.

I haven't tried yet when tethered.