T-Mobile has announced a major expansion to its iPhone-compatible HSPA+ network. The company on Thursday revealed its high-speed network is now available in 14 new markets, including large metropolitan areas such as New York City, Newark, Boston, Providence, Philadelphia, Detroit, Dallas, Austin, San Antonio and Tampa, among other locations. The network operates on the 1900MHz frequency, which means popular devices sold by AT&T (T), including Apple’s (AAPL) iPhone 5, will be able to access HSPA+ data speeds on T-Mobile. The company’s improved network is now available in more than 30 markets across the country and covers 100 million people.