ASUS ZenFone 5Z gets VoLTE support on T-Mobile and VoWiFi on Jio

ASUS ZenFone 5Z gets VoLTE support on T-Mobile and VoWiFi on Jio

The ZenFone 5Z, a flagship smartphone released by ASUS back in 2018, is a pretty old device now yet still somewhat regularly receives software updates from its maker. Recently, an update which brings Wi-Fi Calling (VoWiFi) support on Reliance Jio has been rolled out, which is a function that the device lacked in the past. Moreover, the new build finally enables Voice over LTE (VoLTE) support on T-Mobile’s network. These might sound like small changes but something that many users in India and the U.S. will be happy to see.

ASUS Zenfone 5Z XDA Forums

Making a regular phone call means that your connection will drop to 3G or even 2G as most calls are made over either of those two connectivities. However, the old school circuit-switched voice networks are gradually being phased out in favor of IP Multimedia Subsystem (IMS). Features offered by IMS, such as VoLTE  and VoWiFi are particularly demanded across smartphones because of the increased voice clarity on call, along with keeping a consistent 4G (or 5G) data connection while on a call. Given the fact that major US carriers are going to block voice and data service for phones that don’t support VoLTE in the near future, the update from ASUS essentially breathes new life into the ZenFone 5Z.


The size of the incremental OTA package is merely 50MB and it will upgrade the global, Russian, and Japanese ZenFone 5Z variants from to The Android security patch level (SPL) of this build is Novemver 2020. Apart from the telephony related improvements, the update also optimizes the stability of touch responses.

You can find the full changelog of software version for the ASUS ZenFone 5Z below:

  1. Updated Android security patch
  2. Enabled VoLTE on TMO (US)
  3. Enabled VoWiFi on JIO (IN)
  4. Improved touch stability
  5. Fixed a delay issue when turning off Wi-Fi from quick settings

If you want to try out the latest build on your ZenFone 5Z and haven’t received the update yet, you can download the full firmware ZIP from the link below and manually flash it on your phone.

Download software version for the ASUS ZenFone 5Z

Thanks to Wichaya Polka for the screenshots!

About author

Skanda Hazarika
Skanda Hazarika

DIY enthusiast (i.e. salvager of old PC parts). An avid user of Android since the Eclair days, Skanda also likes to follow the recent development trends in the world of single-board computing.

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