Ahead of E3 2013, Microsoft released an official statement clarifying some of the most debatable aspects of Xbox One.
As part of the statement, Microsoft revealed that Xbox One games will have to be authenticated periodically over the internet and that offline play won’t be available when the authentication period expires.
“You can game offline for up to 24 hours on your primary console, or one hour if you are logged on to a separate console accessing your library,” explained the statement. “Offline gaming is not possible after these prescribed times until you re-establish a connection, but you can still watch live TV and enjoy Blu-ray and DVD movies.”
As a result, Microsoft expects that all Xbox One consoles will have access to broadband internet.
For an optimal experience, we recommend a broadband connection of 1.5Mbps. (For reference, the average global internet connection speed as measured recently by Akamai was 2.9 Mbps). In areas where an Ethernet connection is not available, you can connect using mobile broadband.
While a persistent connection is not required, Xbox One is designed to verify if system, application or game updates are needed and to see if you have acquired new games, or resold, traded in, or given your game to a friend. Games that are designed to take advantage of the cloud may require a connection.”
While the above text implies that Xbox One doesn’t need constant internet access, other parts of the document indicate otherwise. “Because every Xbox One owner has a broadband connection, developers can create massive, persistent worlds that evolve even when you're not playing,” another section reads.