Japan and South Korea have cemented their reputations as two of the most advanced mobile broadband services markets in the world with their rapid rollout and adoption of 4G services.

NTT Docomo Inc. announced Friday that it now has more than 15 million customers for its 'Xi' 4G service, which, it claims, delivers maximum downlink speeds of 112.5 Mbit/s. The Japanese operator, which launched its 4G service in December 2010, has added 5 million LTE customers in the past five months alone.

Docomo says it plans to introduce a commercial 150 Mbit/s downlink service in parts of Tokyo, Osaka and Nagoya this October, having just introduced a "pre-launch" version of the service. (See Docomo Preps 150MB 4G LTE.)

In South Korea, LTE-Advanced is the big talking point. SK Telecom signed up 300,000 users in the first month of its service, having switched on its LTE-Advanced network at the end of June. (See SK Telecom Adds 300K LTE-Advanced Subs.)

But it's not alone in offering the advanced service in South Korea. Rival LG Uplus (aka LG U+) launched its LTE-Advanced offer on July 18 with some help from its infrastructure partner Ericsson AB. (See this statement from the Swedish vendor.)

Excitement around LTE-Advanced is not restricted to the Asia/Pacific markets, though. Here are some other recent announcements about the next generation of mobile broadband.

— Ray Le Maistre, Editor-in-Chief, Light Reading