A:Answer I'm no expert, but the TiVo Roamio OTA device uses a broadband connection (and $15/mo service fee) to connect your TiVo Roamio OTA device to Tivo services, such as your TV channel guide info, Season Pass features, and most notably, streaming services, such as Netflix, VUDU, Hulu Plus, Amazon Video, YouTube, Pandora, etc.
Without a broadband connection, you should probably consider the Channel Master DVR+ instead, because without the TiVo Service, the TiVO Roamio OTA device would behave similarly to an old VCR, and you must manually schedule your recordings by knowing the channel, date and time of future programs in order to record them (no Season Pass, TiVo Suggestions, etc.)
The TiVo Service subscription also gives you mobile device control over your TiVo recordings, especially when you're not sitting in front of your TV.
The attached CNET review (and user comments) may assist:
http://www.cnet.com/products/tivo-roamio-ota/
Hope this helps.