Possible to communicate VoIP text in crowded areas via Zigbee?

COMPLETE newbie here. I was curious if it was at all possible to communicate from one cell phone to another with a Zigbee module in a densely populated area (concert, etc). The thought is to apply an adapt to a smart phone that would let phones send VoIP text messages. Essentially turning your smartphone into a walkie-talkie for text messages. Is something like this possible? Sorry I don’t know all the technical terms, thanks.

No, the zigbee protocol you are referring to is simply two slow (vrery low data rates with large latencies (up to seconds)) and has very limited packet sizes that would not allow this to work.

Is there something else that could work instead?

You could try the 802.15.4 protocol but you really need to determine first what throughput you are going to need. Then you will have a better idea as to what protocols would work.

We can send texts over the cloud using the internet connection and which is possible due to VoIP technology that we can communicate in such an easy manner.
https://callhippo.com/signup/new-york-virtual-phone-number