I would like to point out that the reason for the cell phone oligopoly is that spectrum access is regulated - by the government. Poorly.
(Forgive me for the quick soundbite. I'm googling for the articles I remember about how horrendously difficult it is to buy spectrum use rights in the US. It's not like buying lemonade. Like many regulations, wireless regulation was designed to protect the established players.)
I did find that until very recently, spectrum rights were non-transferable. And they are still single use; a central planning commission decides which parts of the spectrum will be used for which purposes, and the owners of the spectrum aren't allowed to deviate from this. The central planning commission has a long history of snubbing new uses of the spectrum in response to lobbying from existing companies (ex. TV companies used the FCC to torment FM radio startups in the 40s, pushing back its adoption).
(Forgive me for the quick soundbite. I'm googling for the articles I remember about how horrendously difficult it is to buy spectrum use rights in the US. It's not like buying lemonade. Like many regulations, wireless regulation was designed to protect the established players.)