When will operators let me IP freely?

Writing a blog about mobile technology on 28 April almost necessitates holding forth on CDMA shutoff. But if you ask me, there's something far more disruptive happening in the wireless world right now.

Over the last couple of weeks, it seems that mobile VoIP has been slowly accumulating something of a head of steam, which could see the technology turn from clumsy cost-avoidance technique and operator-worrier to fully grown-up, everyday mobile offering.

While some operators have taken the ill thought-out route of banning VoIP over mobile altogether for fear of seeing their revenues cannibalised (a number of big name operators haven't exactly covered themselves in glory in the past in this respect), others have run screaming into its arms: Intel-funded Jajah has done a tie-up with Japanese operator Emobile, while Skype and 3 have been sitting in a tree for some time.

Skype, however, looks to be having some cross-operator ambitions, announcing last week that it's bringing out a beta client for Java mobiles, with a view to gathering some feedback and bringing out a client proper in the next few months.

While everyone can download it and take incoming Skype calls, only those in seven lucky markets — none of which is Australia — will be able to get all the traditional Skype functions like the ability to make Skype-to-Skype and SkypeOut calls.

Will Skype over mobile save you money? Possibly, possibly not. It takes a lot of mental arithmetic to work out whether a Skype call, as opposed to the bog standard cellular call, is cheaper, so it's safe to say operator's voice revenues won't be challenged any time soon.

That said, international calls is one area where you might stand to save a bob or two, assuming both of you are making a Skype call in your respective countries and you've got a flat rate data plan and an operator that's down with that sort of thing.

Others prefer to dodge the data issues and make mobile VoIP calls over Wi-Fi. It's not a bad plan, but it does mean you have to be within reach of a hotspot and willing to sacrifice your mobility. You might also find yourself on your operator's bad side: take UK VoIP mob Truphone, for example, which last year found itself blocked by Vodafone and Orange.

You might argue that a better way for operators to deal with the rise of mobile VoIP over Wi-Fi would be to bring out their own converged service which can bounce happily between mobile and Wi-Fi networks — companies like Fring already promise a client that can do just that — rather than send the toys sailing out of the pram, but there you go.

But whether we're talking VoIP over 3G or VoIP over Wi-Fi, it seems odd operators should resist the transition to IP for mobile on one hand while at the same time pushing the benefits of tethered VoIP over newly-installed IP backbones like Telstra's NextIP network or BT's 21CN, for example.

And, as communications brain Dean Bubley of Disruptive Analysis points out, IPification is only going to become even more prevalent as operators start rolling out so-called next generation mobile networks.

"If the carriers want to move to future networks (call them 3.9G or 4G) like LTE, UMB or WiMax for reasons of bandwidth, data capacity or better spectrum use, there's no choice. They're all-IP, so you have to use VoIP, or maintain parallel GSM/UMTS technology for circuit voice [...]

"Secondly, from HSPA+ or EV-DO Rev A onwards, you can get more calls/Hz/cell with VoIP than circuit switched. LTE should be able to get 100-200 percent efficiency gains. Given that voice pricing is coming down, capping the spectrum being used for voice makes sense," says Bubley in his excellent blog.

It looks like mobile operators' move to IP is unstoppable. It's less than certain when customers will be allowed to follow suit.