Eventually, every New Zealand household will have moved to digital TV, either through Sky or the rapidly expanding Freeview service backed by TVNZ and MediaWorks (TV3 & C4). Once that's happened, in a few years' time, they'll be an intriguing side effect:

the government will be able to auction off the UHF spectrum freed up by TVNZ and MediaWorks switching off their old analogue systems. It'll create a feeding frenzy of ISPs in search of some serious spectrum for wi-fi and wi-max broadband services.

In the US, where Congress has overseen an aggressive timetable for switching to standard digital and high definition digital broadcasting (good to see the boomers have their legislative priorities straight), they're already there. The government will auction the now useless (to TV broadcasters) UHF spectrum in January.

Google produced shockwaves when it said it was willing to place the minimum opening bid of $US4.6 billion.

The idea is that Google could use the spectrum to create a nationwide wi-fi/wimax network, which people could make calls over using any wi-fi handset - maybe even Google's rumoured gPhone, though it's still unclear whether that will be a piece of hardware, or a set of software services that sit on a partner's handset, such as the iPhone. Apple's hit mobile is currently locked into AT&T's network, but does have wi-fi to take advantage of a more open future. And former US Vice President/greenie/Nobel prize winner/all-round busy guy Al Gore sits on Apple's board and is a special advisor to Google's board, no doubt helping to facilitate the already close competition between the two companies on mobile versions of Google Earth and Google Maps for the iPhone.

When I was in the US last week, the big buzz was how far the traditional telephone companies would go to shut Google out. Some were saying the likes of AT&T, Verizon and Sprint (Telecom NZ's key technology partner) could bid as high as $US10 billion, $US15 billion or even $US20 billion.

Certainly, although the US telcos - like most around the world, including Telecom - are heaving with debt, they need to bid until it hurts.

For Google has yet to announce what business model it would use for a wireless network. But you can be sure that the data would be free, as with the company's free metro wi-fi trial in San Francisco. And a hot US start-up called Pudding Media has already essayed a business model for mobile voice calls that it's easy to see Google following: calls from your cellphone are free, as long as you're willing for an advertiser's text message or picture to appear on your mobile during the call. Under this model, ads can appear on the screen of the person you're calling, too. That's pretty rude. But then again, cellphone calls are pretty expensive. I'd trade ads for freebies.

The next major spectrum auction in New Zealand is scheduled for December when the government will take bids for the 2.3GHz and 2.5GHz radio bands - both suitable for wi-max. However, the winning bidders will not have to rollout wireless broadband until between 2012 and 2016. The government calls this a use-it-or-lose it provision designed to speed things along. But in previous auctions, the winners have mainly just sat on spectrum, and it's easy to imagine that if they're allowed to bid, Telecom and Vodafone could buy spectrum and then simply park it for at least a couple of years to keep out Google, or any wireless upstart (Kordia has begun, rolling out a wi-fi/wi-max network, albeit very slowly). 2012 seems a very long way away.