Google's "bandwidth throttling" for mobile devices enables wireless carriers to set usage thresholds for data that is transferred during a certain timeframe and directly react with a bandwidth reduction. When the bandwidth cap is reached, the device can automatically limit the maximum bandwidth to a level that is permitted by the carrier.
However, there is also a very distinct note in which Google appears to be bowing to carrier pressure by stating that "the wireless carrier may limit traffic without actively managing or implementing the actual bandwidth throttling" and noting that bandwidth throttling would enable "mobile devices that are more adaptable and pleasing to the wireless carrier."
The upside of such a feature, as opposed to hard caps which automatically purchase another data volume package and potentially surprise the user with a high bill, is that a user may actually notice that an unusually large amount of data is transferred. The technology would also allow for a carrier to offer the user to purchase additional data volume upon request.
