What is the suitable bandwidth for COMMCARE to function properly? Upload and Download bandwidth ?
The suitable bandwidth will depend somewhat on what features of CommCare you are implementing, and your expected usage pattern.
CommCare is designed Offline First, so once the initial app install and first sync occur, the app will function offline indefinitely, and all network actions (upload, sync, update) have clearly visible user prompts and queues, to give users control if they need to, say, use the app offline for a week, then seek out good network before performing certain actions.
If you are not performing regular updates of multimedia content over data network, and are not submitting any multimedia content, CommCare requires a negligible amount of bandwidth to perform normal sync and update operations (over the wire, a form submission is often < 2kb due to the compression applied by the app) and can be used over a 2g network with high latency. If you need to remotely add or change multimedia, CommCare is designed to robustly enable that even on poor networks by “trickling” down data in the background over time, but it may take longer for updates to be received on phones when network is limited.
Generally speaking I expect that most organizations using CommCare are on a 3g equivalent network at least some of the time, to be able to do regular updates of rich app content in an efficient way, but the software can be used in various network conditions as long as the apps built with the tool are conscious of the limitations.