Op Center would be pretty easy. You can have wireless data transfer to/from the 2630's with a modem. 4G was the old name, M and R modem is the new name but they do the same thing. No subscription fee for Op Center or the modems, just the cost of modem itself. 

Or if you don't want the automatic data transfer, you can load USB data to/from Op Center and 2630 for free. See your maps on your phone or ipad etc. No cost at all from what you have