Sprint is expanding its nascent 4G LTE network even further in the coming months, as it has announced that San Francisco and 21 other new markets will soon get access to the faster network. Sprint currently offers LTE service in 24 metropolitan areas, and will light it up in over 100 more cities in the near future, including Boston, New York, and San Francisco, as mentioned. Unfortunately, the carrier has not provided any dates for when customers in these markets will be able to take advantage of the LTE network, other than that it will be available in the "coming months." Eventually, Sprint plans to have its LTE network's coverage match that of its current 3G network, though it will take a few years before that happens. And given Verizon's rapid deployment of its own LTE network, Sprint needs to turn on LTE as fast as it can. Perhaps involvement with a certain Japanese carrier will help Sprint out in this regard. Take a look at Sprint's press release to check out the full list of markets added to the rollout.