AT&T has resurrected its unlimited wireless data plan as part of a new bundle that includes a pay TV subscription. Starting tomorrow (January 12), both new and existing AT&T customers that already have (or add) a DirecTV or AT&T U-Verse pay TV subscription will have the opportunity to purchase the new unlimited data plan.

AT&T's unlimited data plan, which also includes unlimited talk and text, will set you back $100 per month. Additional smartphones can be added to the account for $40 each with the fourth smartphone allowed at no additional cost.

As with other "unlimited" data plans, AT&T's does come with a catch.

The first 22GB of data usage per line, per billing cycle will be unabated. If the 22GB threshold is crossed, AT&T says it reserves the right to slow data speeds on that line during periods of network congestion.

The wireless landscape was vastly different several years ago when AT&T and others first offered unlimited wireless data as a plan perk. At that time, unlimited text messaging was all the rage (this was before messaging apps and services like BlackBerry Messenger and Apple's iMessage made the text messaging price wars irrelevant) and some even still offered metered talk minutes as a major selling point.

Once smartphones took root and wireless networks gained much-needed speed, it became increasingly obvious that mobile data could be levered in the same way that talk minutes and text messaging once were.