Wall Street is pushing back against Justice Department efforts to unwind a merger proposal between AT&T and T-Mobile that will leave America with three national carriers.  Some investment firms even believe three carriers are still “too many” and want mergers and acquisitions to accelerate to allow two dominant national carriers to emerge.

“It’s pretty clear what the end game is in wireless,” said Julie Richardson, managing director at Providence Equity Partners Inc. “LTE, 4G — you have to have those services to compete. One of the most interesting things to watch in telecom will be these players coming together.”

Richardson shares the view among many on Wall Street that carriers forced to build costly 4G services like LTE need less competition and more cash-on-hand to pay for upgrades and to obtain needed spectrum.

Only AT&T and Verizon Communications have the resources to support a national 4G Long Term Evolution network, Richardson said. Sprint, the third-biggest U.S. wireless operator, is struggling to compete against larger rivals and has lost money for 15 consecutive quarters, Bloomberg News reports.

Among smaller players, Richardson believes the future is clear: mergers, acquisitions, and partnerships.  Sprint is moving increasingly closer to the nation’s cable companies, which have sought a cost-efficient way to deliver the ultimate “quad-play” service package that includes wireless, landline, cable-TV, and Internet service, all from the cable company.  But talk of constructing competing cell networks has gone largely nowhere, and cable companies that do offer some type of wireless service typically resell an existing service under their own brand.  Road Runner Mobile, from Time Warner Cable, for example, is really Clearwire under a different name.  Same for Comcast’s wireless Internet service.  Cox is pitching “unbelievably fair” wireless phone service that actually comes from Sprint.

But cable operators currently don’t seem to be interested in outright acquisitions of cell companies like Sprint, preferring to partner with them instead.

Clearwire, which needs financing and better wireless spectrum, may eventually find a friend in Dish Networks, the satellite TV company.  Dish controls wireless frequency spectrum it currently does not use, and has expressed an interest in expanding beyond a traditional satellite television provider.  An acquisition of Sprint or Clearwire could help them accomplish that.