Ok as for voice/data at the same time, I would say yes, if your in 4g coverage. 4g woul be a different radio, and you can use wifi while on a call, so its definately possible. Edge- no. Supersonic is cdma. Edge is gsm.
Wimax to lte via software? Definately possible. Wimax and lte are very very similiar, so I don't see why this would be a problem.
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