Sprint is issuing RFPs (Requests For Proposals) on network equipment and this may suggest that it has plans for network improvements. There's no explicit details about how the improvements will be made, but it's being reported that the RFPs are being made on fiber, small cells, and network towers and that the carrier wants to expand its network reach and make things more reliable for subscribers.
According to the report and statements made by Wells Fargo Analyst Jennifer Fritzsche, Sprint is believed to be one of two different carriers which may have spent money on a long-term agreement with Crown Castle, with Verizon Wireless suspected to be the other carrier, though it's not mentioned how long the agreement is actually for and it's not guaranteed that Sprint is actually one of Crown Castle's customers in this particular agreement. If Sprint does happen to be one of the carrier's for this agreement with Crown Castle, this move by the U.S. now fourth-largest wireless carrier would be in addition to its plans to expand its network by putting up more cell sites around the country, something which it has already stated that it wants to do and plans to do so in the future.
That paired with Sprint's goal of improving its existing cell sites by fitting them with 2.5GHz and 800MHz antennas should help the carrier make substantial headway with its plans. Sprint also has another agreement that it made with Cox Communications, in which it plans to use the company's wireline network for backhauling of its small cell expansion. Sprint reinvesting in its network shouldn't be too much of a surprise as it had mentioned towards the end of last year that it was already aiming to invest more into its network improvements this year, though it wasn't mentioned how much it plans to invest in monetary terms. While Sprint could have more agreements or changes to its network on the way, its most recent moves intended to help expand its network seem to be the suspected agreement with Crown Castle, as well as the agreement with Cox Communications, which was reported back on January 18th of this year.