I want a service to be active always in the background. Is this possible in the new SDK 7.1
I read through the Background File Transfers, Agents, and Alarms. I think these are only active for a period of time.
Short answer: you can't
Background agents can only run for 15 seconds every ~30 minutes. Attempting to run for longer will result in the agent being terminated and not rescheduled. Riho is referring to something different: if the user does not run the owner application for 14 days your agent won't be rescheduled (even if it's successful); the application must be run and reschedule the agent.
Your only real choice is to move the functionality to the server and use push notifications to update the phone.
Agent gets deactivated after 14 days. Within that time you must make user to open your foreground application - then you can restart the agent and 14 days counter again.