Would this be legal in New Zealand and how would a wireless carrier like 2degrees or vodafone or telecom do this?
Be good in places where vodafone doesn't have coverage and 2degrees does so vodafone users can use 2degrees spectrum and vice versa.
Spectrum sharing and site/network sharing are two completely different things.
No operator in NZ has a shortage of spectrum unlike other places in the world where this is the case. All licences in NZ are also national unlike some other countries which also sell geographic licenes for spectrum usage. There is no need for anything like this in New Zealand.
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