Japanese operator DoCoMo continues to see strong growth for its LTE business after it announced that its Xi service has passed 4 million users this week, after adding an additional 1 million new subscribers within 6 weeks.

The company — which is Japan’s largest operator with 60 million users — says that the growth is down to its latest rage of LTE-compatible devices launched this summer, which has almost doubled the number of Xi-phones on the market.

xi 520x322 Japans DoCoMo surges past 4m LTE customers, adding 1m in 6 weeks

We last wrote about Xi when it hit 2 million users in March. At that time, it had added 1 million customer in three months, which was impressive, but, fast forward four months, and that figure has already doubled.

Subscribers of Xi (pronounced ‘crossy’), enjoy download speeds of up to 75 Mbps to their device. Think about the next time you struggle along on 3G or EDGE.

Japan isn’t the only one stacking up the LTE users, just yesterday, we wrote that SK Telecom had also passed 4 million subscribers for its 4G network. The Korean operator put its recent spike in sign-ups down to the release of the LTE-flavoured Samsung Galaxy S3.

Earlier this year, an ABI Research report predicted that worldwide shipments of 4G-compatible smartphones and tablets would reach 61 million by the end of 2012, with “the lion’s share of the market backing LTE”.

That’s certainly happening in East Asia and the US, although other markets are some way behind. In the UK, for example, communications regulator Ofcom just announced that the national 4G spectrum auction will now not take place until “early next year”.

Well, at least Brits have the Olympics to look forward to in the immediate future. Right?

Image via Flickr / Kalleboo