The news today that Telstra has threatened legal action against Optus for an alleged breach of Section 52 of the Trade Practices Act could have uncovered something very interesting about the upcoming iPhone launch in Australia.

To understand why, we need to get a little technical, so stick with me…

The 3G component of the new iPhone can work on 3 separate frequencies – 850, 1900 & 2100 Mhz

The Vodafone and Optus 3G networks run on a combination of 900 and 2100Mhz. The way this generally works is that in city areas they use 2100Mhz and beyond the cities they use 900Mhz.
The problem with this is that the iPhone will only run at 3G speeds on Optus and Vodafone where the service is using the 2100Mhz because there is no 900Mhz 3G capability on the device.

Telstra’s letter to Optus re: allegedly misleading or deceptive statements was based on Optus Chief Executive, Paul O’Sullivan’s, announcement that more iPhone 3G users could enjoy the Optus network as they expand to 98% population coverage over the next 18 months.

As we now know, the statement is probably misleading because a large portion of the network expansion will be at the 900Mhz frequency, which is of no additional benefit to 3G iPhone users.

The actual coverage for Optus 2100Mhz 3G is around 56% of the population, which they claim will jump up to 80% by then end of this year.

Knowing that Optus is expanding their 3G network outside of cities using 900Mhz it made me wonder how they intend to grow coverage at 2100Mhz by that much? I mean, surely all our cities are more or less completely covered by 2100Mhz…or are they?

It took a bit of effort, but I’ve finally found 2100Mhz coverage maps for both Optus and Vodafone (I’ll let you play around with them because I don’t know where you live.)

HERE is the Optus 2100Mhz 3G coverage map
HERE is the Vodafone 2100 Mhz 3G coverage map

There’s no key which explains what the different coloured pinks at 2100Mhz mean, but there must be a difference or else why not just use a single colour.

My guess? The vast areas of lighter gradient in most cities aren’t fully serviced by 2100Mhz i.e. the lighter areas are where the growth at 2100Mhz will be and where, until later on this year, 3G iPhone users might be getting GPRS download speeds.

GPRS speeds = not happy 3G iPhone users

The interesting thing? Telstra’s NextG network runs at 850Mhz, which will work with the 3G iPhone and which has much better coverage than both Optus and Vodafone.

HERE is the Telstra Next G coverage map. You’ll have to play with it a bit, but let’s just say that at 99% population coverage they’ve probably got your place covered.

I know that Telstra have made no announcements about selling the iPhone, but my prediction is that not long after the official launch on July 11 there will be complaints about the Optus and Vodafone 3G service and that Telstra will suddenly enter the market with prominent messaging about their superior coverage.

I could be completely wrong, and this might not happen, but when it does, remember you heard it here first