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I think you have been misinformed. Voice calls over plain old telephone service were band-limited to <4khz decades before cell phones became popular. This was n
by babypuncher 4y ago
I think you have been misinformed. Voice calls over plain old telephone service were band-limited to <4khz decades before cell phones became popular. This was necessary in order to cram more active calls into our existing telephone infrastructure.
Digital phone calls today are way better.
- toast0 4y agoToday's g.722 (HD Voice) is better, but GSM codecs are also 8kHz sampled, then lossily encoded. If the compression is appropriate, gsm is 13-bit per sample vs 8-bit per sample commonly used for POTS (minus robbed bit signalling in the US), but if the compression isn't appropriate, you get some pretty nasty artifacts. Encode/decode delay can be significant in some applications, but since GSM is TDMA anyway, you're going to have buffering and may as well use that to encode; a T1 PRI multiplexes one sample at a time, so a lot less delay there.
- ghaff 4y agoI’m sure that’s all true. I’m also pretty sure I wasn’t regularly shouting into my AT&T landline “I can’t hear you!” Obviously we’ve gained a lot with cell phones and portable music playing but it’s been mostly at the cost of consistent quality.