'Tis the season to expand your network coverage. December is apparently the month to announce 4G-LTE network expansion plans, the most recent announcement made today by T-Mobile. The value-focused carrier said it'll be increasing its 4G coverage to 14 new markets, raising the total number of cities serviced by its 4G network to 37. 

Although the carrier's 4G isn't technically LTE, T-Mo promised earlier this year that true LTE service will coming in 2013.

Additionally, T-Mo mentioned that potential customers serviced within its areas will soon have a roundabout way to obtain and use iPhones on its network. The carrier has partnered with a smaller, no-contract company named Solavei. As it turns out, Solavei can hook up customers to T-Mobile's network via an attractive $49 unlimited-everything plan. Alternatively, customers can bring their own unlocked iPhones.

This week, Verizon had also announced plans to introduce its 4G-LTE service to 29 new markets. Those areas include Selma, AL, Clarksburg, VA and Port Angeles, WA. These additions bring Verizon's total U.S. coverage to 470 cities and counties. For a more detailed look the company's coverage, interested parties can visit Verizon's 4G-LTE coverage map.

Next up, Sprint claims its 4G-LTE reach will be growing to another six markets, spanning to parts of Indiana, Pennsylvania and California and most notably Chicago, IL. The company also claims it'll be introducing 4G-LTE coverage to over 100 new markets "in the coming months". Currently, Sprint's trails its two largest competitors with 49 markets serviced.

And to round out this holiday network expansion extravaganza, AT&T also voiced plans to expand its own 4G-LTE coverage the same day Verizon did. The rollout will include only seven additional cities, but will bring AT&T's total 4G market count to about 125 – or very roughly one-third of what Verizon is offering.