We have the technology required to record, transmit and play high fidelity audio and video. Why are the phone calls’ quality still so bad as if we’re talking over walkie-talkies?
In other words, we definitely \*can\* have high quality phone calls. Why is it that the carriers (or whoever responsible for building the underlying infrastructure) choose to not make this improvement yet?
Edit: the question came up after finishing a call with my bank. I’m pretty sure the CS on the other end used a landline phone and the audio quality was no bueno. Maybe my impression on the phone calls’ quality can have some recency bias involved. So please correct me if phone call qualities aren’t that bad in your region or in your experience .
In: Technology
You can chalk this up to the original digitization of the phone system which happened in the 1960s. Audio “resolution” is a function of the bandwidth of the digitized signal, and at the time, 56kbits per second* (a “DS0 channel”) was considered good enough to match the quality of analog phone lines of the time (by comparison, CD quality audio is roughly 700kbits per second). If you remember the days of dialup internet access, that 56kbps number probably sounds familiar.
Because of the installed base of phone network equipment that works at this bandwidth, it’s simply impossible to upgrade the whole network, and as such 56k. That said, Voice over LTE supports higher quality audio streams, and you may have noticed this if you’re calling someone who’s on the same mobile network (but only if both phones have an LTE or better signal. But DS0 bandwidth will always be a fallback.
(Yes, I know DS0 is technically 64kbps – but one bit out of every 8 is “robbed” from the audio stream, which leaves you with 56k)
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