The Japanese mobile leader began verification tests of its Super 3G commercial LTE network in Tokyo in June and plans to launch services this December in Tokyo, Osaka and Nagoya.
The services, initially card-based, will offer peak rate downloads of 37.5 Mbps and in some areas 75 Mbps - a hefty speed boost for data-hungry users in the three largest cities.
The first LTE handsets - expected to hit the stores by next April - will be GSM-compatible and therefore capable of roaming to foreign GSM/LTE networks.
DoCoMo's initial 2-GHz LTE network overlays its 3G network, and around half of the LTE first phase will be new W-CDMA base stations equipped with new dual LTE/W-CDMA remote radio equipment (RRE) units.
Starting LTE with data card services will send DoCoMo head-to-head with start-up eMobile, which launches first with a 42-Mbps download data card service in October in the same three cities.
"eMobile seems to be the front runner currently in technology terms like data download speeds and is strong in Tokyo and urban areas, but it is likely to face tougher conditions in future," says Michito Kimura, senior analyst at IDC Japan.
DoCoMo's main rivals KDDI and SoftBank are surprisingly quiet about their LTE plans. KDDI is making a major investment in LTE infrastructure but commercial launch is only set for December 2012.