T-Mobile USA may not be launching its LTE network in New York until later this summer, but parts of the city are already seeing its 4G signal.I got connected to T-Mobile's LTE in the Fort Greene, Clinton Hill and Dumbo areas of Brooklyn this weekend. Downloads hit the 15.5Mbit/s mark, according to the RootMetrics speed test app.Other users have spotted it in Flushing, Queens and beyond.T-Mobile has officially said it will cover 100 million U.S. citizens by mid-year and 200 million by the end of 2013 with its LTE service. Staff at its New York stores have said the new network will arrive in the Big Apple this summer.— Dan Jones, Site Editor, Light Reading Mobile