HD Voice

Last night at CES 2013, T-Mobile CTO Neville Ray announced that AMR-WB (Adaptive Multi Rate Wideband) was enabled on the operator's network, instantly allowing capable phones to place higher quality voice calls over the cellular network between T-Mobile customers. This announcement makes T-Mobile the first GSM/UMTS based network in the US to enable AMR-WB, but not the first operator in the US to deploy "HD Voice," as Sprint has been rolling out 1x-Advanced's EVRC-NW (EVRC-Narrowband Wideband) wherever their network modernization and LTE upgrades are. HD Voice enables calls with a much wider dynamic range. AMR-WB is a direct successor to AMR-NB (narrowband) and offers higher frequency bandwidth of up to about 8 kHz (16 kHz sampling) as opposed to AMR-NB's 4 kHz. I'm unclear what...