Sprint announced some data plan changes this week, eliminating unlimited 4G on several of its devices.

“Users of tablets, netbooks, Mobile hotspots, and USB wireless cards will no longer have unlimited 4G data. Rates will not increase, but those who pay for 3GB, 5GB or 10GB of 3G data will no longer have unlimited 4G data as well,” Digital Trends reported.

Sprint officials said effective beginning with the next bill following notification, customers’ on-network monthly data allowance will no longer include unlimited 4G. The Overland Park, Kan.-based company also said there will not be changes to monthly recurring charges, on-network overage rates, off-network overage rate, or off-network data allowance.

In addition, Sprint outlined data usage limits when using the 3G/4G Mobile Hotspot add-on for smartphones.

“Currently, if you use your phone's Mobile Hotspot add-on, the Mobile Hotspot data usage is combined with your phone data usage. Effective on your next bill following notification, your monthly mobile hotspot on-network data usage will be limited to 5GB of 3G or combined 3G/4G usage dependent upon device capability,” according to a support message posted by Sprint.

Additional data use above 5GB is $.05/MB with monthly off-network data limit continuing to be 300MB, which is a combination of phone and Mobile Hotspot data usage.

The data plan changes may signal further modifications to come next year that are unfavorable for users, Digital Trends predicted.

“Usually when carriers implement a rate change like this, current users are ‘grandfathered’ in to their previous plan and the changes only affect new users. Sprint has broken this unsaid rule, applying the new limits and pricing structure to all current users come November,” the report said.

In other Sprint news, TechZone360 reported that Newsweek’s 2011 Green Rankings has positioned Sprint at the third spot. With the No. 6 spot last year, Sprint has been ranked in the top 10 for two consecutive years. Sprint has been placed among the greenest companies in the United States due to its efforts to reduce its carbon footprint. Apart from supporting device recycling programs, more sustainable mobile devices and emerging technologies have been introduced to the market.

“To be No. 3 on Newsweek’s Green Rankings is an honor. Given the rigorous measurement used by Newsweek, we are proud that our efforts have been recognized. We are committed to building a more sustainable company and will continue our aggressive environmental efforts,” Dan Hesse, CEO of Sprint, said in a statement.