AT&T and Verizon Wireless are reportedly testing a special 4G LTE-enabled Nokia Lumia device. Windows Phone 7.5 (Mango) doesn’t officially support the faster data network, but Nokia has been testing a Lumia phone with carriers in an effort to accelerate the carrier approval process, CNET said Monday. We exclusively reported that Nokia will launch its upcoming flagship device in early 2012. The phone will is rumored to include Windows Phone “Tango,” which could be the missing link for 4G LTE support, as well as a 1.4GHz processor, a 4.3-inch ClearBlack AMOLED display and an 8-megapixel camera. It remains unclear if the new Lumia phone will be the first 4G LTE smartphone on AT&T and Verizon, or if Nokia has another device up its sleeves. CES is just a few weeks away though, so we should know soon enough.