Sprint's Spark Phones Don't Support Simultaneous Voice/Data
Top message: LOLZ by Versed
Replying to: Re: LOLZ by DarkStar
>> This is completely wrong. The very first LTE phone for Verizon the HTC Thunderbolt could not only do voice and LTE at the same time but also voice and 3G.
From a technology perspective, 3G EVDO must pause when the voice call is active. The device puts the IP session into dormancy when you make/take the voice call and then comes back from dormant mode quickly enough the delay is mostly imperceptible - but, yes, it is not a full PDP context session re-establish. With the older 2G 1XRTT devices, the delay was more perceptible. Initial session start was longer than EVDO too.
With LTE devices, the same applies - it is just that the data session is back fast enough that it appears to be simultaneous to us slow-poke humans. I.e., with LTE data and CDMA voice devices today (since VoLTE is not yet in place yet), this is still valid. True simultaneity cannot occur till the voice is coded and sent on the LTE bearer channel with VoLTE.
With an implementation of SVDO, using multiple antennas and keeping the radios on simultaneously, it might be possible to do both the CDMA voice and LTE data on together. But, VoLTE will fix that - perhaps in a better way.