Here’s how you know that Sprint’s (S) LTE network has become well established: When the company releases a list of new markets that are poised to get 4G service, none of them really qualify as major cities. And that’s the case this week, as Sprint announced that 28 more markets would be getting LTE in the coming months, headlined cities such as Decatur, Ala., Gettysburg, Penn. and Hot Springs, Ark. In all, Sprint has made admirable progress on getting the United States covered ever since its first launch this past summer and the carrier late last year said it had officially launched LTE in 49 markets throughout the country.