cell phones: why is there a transmit/receive delay?

Factual Questions
21

Note that both Android and iPhone 6 and later support what is called “HD Voice”, which can produce much better audio quality. Additionally enabling WiFi Calling may help in some cases. HD Voice can be implemented over VoLTE (voice over LTE data) or via WiFi. These can produce higher bandwidth, lower latency audio performance as compared with an overloaded cellular voice network.

Besides better audio quality, you may have improved conference call limits on some phone/carrier combinations. E.g, on certain Android phones and iPhone 6 and later if using HD Voice, you can conference up to six people in a multi-way call.

How to enable HD Voice on iPhone 6 and later:

  • Go to Settings>Cellular>Cellular Data Options
  • Enable LTE.
  • Set Voice & Data so it has a check next to it

How to enable WiFi calling on iPhone:

  • Settings>Phone>WiFi Calling
  • Set “WiFi Calling on This iPhone”

Android (must enable HD Voice first, then enable WiFi Calling)

Enable HD Voice:

  • Home Screen.
  • Open Apps menu
  • Settings>Advanced Calling (may be under Wireless Networks)
  • Activate Advanced Calling
  • Follow the onscreen instructions

Enable WiFi Calling:

  • Home Screen.
  • Open Apps menu
  • Settings>Advanced Calling>Activate WiFi Calling
  • Tap Advanced Calling
  • Tap Activate Wi-Fi Calling
  • Follow onscreen instructions to enter a US address for use in the event of an emergency call (911)
22

Good info. Thanks.

It’s worth pointing out that LTE & WiFi calling may create problems with carrier voicemail systems.

I have an AT&T Android device. I fond that when calling another AT&T phone their voicemail wouldn’t work. The call would ring a couple times, then forward to silence. It sure looked like something was wrong with the mailbox set-up of the person being called.

Not so.

Per AT&T tech support, the problem is when you use LTE calling, the attempt to forward the call from the callee’s phone to their voicemail box fails. Instead your call is forwarded to nowhere.

The fix is easy. Don’t use LTE / wifi calling. As soon as I turned that off, suddenly all those other AT&T voicemails started working again.

There’s no guarantee this problem will apply to you. The AT&T tech said they intended to eventually fix this problem in their systems. But if you have this mysterious problem now you know what to do.

23

It’s Hedley (Lamarr)

(Somebody had to do it.)