The simple answer is 4MB/hour, but it depends and you can tune it.
The system was designed from the ground up to work seamlessly on low quality internet connection because this is typical on the field. Data usage is optimised, network outage is handled, lost commands are sent again automatically after network recovery.
The traffic volume varies greatly, between 0,1MB/hour and 10MB/hour. The following factors affect it:
- Map usage: Maps are downloaded over the network so you can save some data with scrolling sparingly to previously unseen map areas. This is important on large areas, use a lower zoom if you work on a large area. (A high zoom is not very usable in that case anyway)
- The radio refresh rate (position update interval): This is the time between two synchronisation with the BattleTac server. You can change it to tune your data usage. Higher interval means lower data usage but not so accurate tracking of units on the map. The default is 30 secs which is a good balance. You can set it to 10 secs to have near-real time tracking, or you can set it up to 15 mins if you are on a really big area event where things do not happen very quickly. This setting is not available in the Lite version, it uses the default 30 secs!
- The number of units and POIs on the map and the number of messages you receive. This means that on a big event with lots of units you will have bigger traffic.
- Ad display: The Lite version displays ads which changes every minute. This also consumes some traffic.
What does it mean? If you want to play 6 hours per week, you will need 6hours x 4 weeks x 4MB/hour = 96MB monthly data plan.
If you have a smaller plan then I suggest you starting with normal settings, monitoring the traffic for 1-2 weeks and tuning the 'Position report interval' according to what you see.