Sprint is offering a free 30-day trial of its overhauled network. (Reuters/Andrew Kelly)

Sprint announced that it's going to let consumers take a 30-day test run with its network as part of a push to advertise a string of network tune-ups it has made across the country.

The carrier, the nation's third-largest, has spent years overhauling its network. On Monday, the company said that it was launching 4G LTE networks in 28 new cities, offering high-definition voice service across the country and planning to launch its high-speed "Sprint Spark" service in three new cities. The company also said that it will begin offering consumers the option to call and send texts via WiFi networks in the coming weeks.

Given all of those changes, the company said, the firm is going to let users try out its network for 30 days, starting June 27. Those who take advantage of the offer can opt to cancel their service within 30 days for a full service and device refund, the firm said in a press release. The offer is available to new customers opening lines with Sprint, or to existing customers who wish to add a line to their accounts.

The promotion may help Sprint, which has struggled to retain customers during its network makeover, lure some who have switched to other competitors  such as Verizon, AT&T and T-Mobile back to the flock. Company spokeswoman Adrienne Norton confirmed that the trial period option is a promotion -- as in, it won't last forever -- but that Sprint has not yet set an end date.

Sprint's moves follow hard on the heels of last week's T-Mobile announcement that those interested in trying its network can get a free week with an Apple iPhone 5s, and could be seen as the latest "me-too" move T-Mobile has prompted with its "uncarrier" announcements.

T-Mobile, the nation's fourth-largest wireless carrier, has made a series of changes including eliminating the two-year contract, offering more flexible device upgrade plans and paying users to switch networks. All of those promotions have been imitated, in some measure, by competitors. Since launching its new initiatives in March 2013, T-Mobile has added 17 million new subscribers, putting extrapressure on Sprint to cut losses.

Rumors continue to swirl that T-Mobile and Sprint are poised to merge, most recently spurred on by a Reuters report that  Sprint has moved closer to financing a $40 billion bid for its competitor. Neither Sprint nor T-Mobile has officially commented on the speculation, though T-Mobile chief executive John Legere has said that, regardless of any future deal, he would like to see the changes made to T-Mobile's wireless pricing structures continue.