NEW YORK ( TheStreet) -- Time is ticking for Dish Network (DISH) - Get DISH Network Corporation Class A Report CEO Charlie Ergen to prove to his shareholders that holding his company's stock makes sense.

The field for possible merger partners is narrowing just as AT&T (T) - Get AT&T Inc. Report gets closer to completing its $48 billion acquisition of DirecTV (DTV) , Dish's chief rival.

Dish's stock has slipped 1.4% in 2015 as Ergen has balked at spelling out what he plans to do with the billions of dollars in wireless spectrum Dish acquired through acquisitions, auctions and tax loopholes. Even talk of a merger with T-Mobile US (TMUS) - Get T-Mobile US, Inc. Report, has failed to ease investor frustrations with a company whose immediate plans remain a mystery.

"Dish needs to do something," said Jeff Kagan, an independent media analyst. "If Dish doesn't make use of this spectrum, I'm sure every wireless carrier would love to sink their teeth into it."

For much of the past three years, Dish has been aggressively buying wireless spectrum, both to expand its satellite network and attract a wireless carrier partner. T-Mobile executives, eager for more spectrum to better compete nationally with Verizon (VZ) - Get Verizon Communications Inc. Report, AT&T and Sprint (S) - Get SENTINELONE, INC. Report, have reportedly spoke with Ergen about a possible merger, according to The Wall Street Journal.

Ergen has made clear that he wants to be able to offer consumers a quadruple play of Internet, pay-TV, mobile and phone. But whether any wireless carrier wants to pair up with Ergen is less certain, let alone T-Mobile's John Legere CEO, an equally independent-minded executive. Dish has entered into merger discussions in the past, only to see those talks fail to reach a deal.

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"While agreeing to the respective roles of these strong personalities is an important step, we are still doubtful that the two firms will be able to reach agreeable merger terms," Michael Hodel, a telecom analyst at Morningstar, said.

But with Verizon taking itself out of the running for Dish, T-Mobile may have the upper hand. Verizon Chief Financial Officer Francis Shammo earlier this week said his company has no interest in merging with Dish. Verizon said it doesn't need more spectrum, and it may be sufficiently cautious about trying to engineer a merger with the mercurial Ergen.

"You scratch your head and say 'What would Verizon really do with that spectrum?," said Robert Rosenberg, president of telecom market-research firm Insight Research.

Pressure may also be rising on T-Mobile after Comcast (CMCSA) - Get Comcast Corporation Class A Report said it has no interest in acquiring the wireless carrier. Wireless spectrum remains Dish's greatest calling card at a time when television has lost ground to streaming services led by Netflix (NFLX) - Get Netflix, Inc. (NFLX) Report

"T-Mobile is looking for a dance partner and they desperately need one," Rosenberg said.

Dish declined to comment, and T-Mobile didn't immediately respond to a request for comment.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.