Is it better to use one large packet or more smaller packet?

Question

Im working on a mobile project that involves gathering data from multiple phones that is then distributed to all the phones. Would it be better(power/data usage) to:

1) Send out a single update with the information from all the phones when a phone requests

2) Any time a phone updates a delta with just that information is sent to all the other phones

I am assuming each phone will have a diffrent update frequency.

EDIT: For clarity what is being passed is a simple location object, so it would be either a array of locaiton objects less often or single location objects more often, this will be over 4G or wifi whatever is avalable

Answer 1

It depends on how much data will be transferred and the frequency. If there are multiple changes that can be lumped together maybe you are bettered off sending it as a compressed binary to the server.

However, smaller amount might benefit from differential synchronisation something like git json patches. Google published an article on it: https://research.google.com/pubs/pub35605.html

Alternatively, for small packets of data you might benefit using the MQTT protocol and libraries such as https://github.com/eclipse/paho.mqtt.android

In regards to data persistence and sync, https://realm.io has a good solution going so it might speed up your project. I've only started using that DB on a personal project.