Sprint still has plenty of work to do before its LTE network can match the coverage Verizon and AT&T offer, but the carrier's latest rollout manages to scratch a few major cities off the list. The carrier has announced that it's today lighting up service in 21 cities including Los Angeles, Memphis, and Charlotte, North Carolina. From there, the new markets get a bit smaller in scope and population. In all, with today's additions Sprint's still-young LTE network is now available in 88 markets. America's number three carrier is also mapping out new destinations where it will enable high-speed data by the end of 2013. 34 markets in all have joined Sprint's existing roadmap, including Orlando, Portland, and Spokane.