A combined T-Mobile and Sprint will lower costs for consumers and accelerate the development of fifth-generation wireless technology, the companies argued in a request this week for the Federal Communications Commission to approve their merger.

The two firms are doubling down on broadband as other Internet providers push into the content industry through acquisitions. A federal judge recently approved a $85 billion deal between AT&T and Time Warner, while Comcast submitted a counter-offer for 21st Century Fox assets that Disney had agreed to buy.