Japanese giant NTT Docomo switched on its much-anticipated LTE network on Christmas Eve (24 December) in the major cities of Tokyo, Nagoya and Osaka. The launch of the new service – branded as ‘Xi’ (pronounced ‘crossy’) – means the firm has met its target of launching LTE before year-end 2010. The operator is planning to cover 70 percent of the Japanese population by March 2015 and is boasting “seamless handover” to its nationwide FOMA 3G network when outside of LTE coverage area. However, Docomo does not expect to introduce LTE-compatible handsets until March 2012 and voice services will continue to be made via FOMA.

Docomo noted that, in most outdoor areas, transmission speeds can reach 37.5Mb/s in the downlink and 12.5Mb/s in the uplink, but in heavily used indoor areas, such as the terminals at Tokyo International Airport, download speeds of 75Mb/s are possible – approximately ten times faster than the operator’s current HSPA-enabled 3G service. It added that transmission latency is just one-fourth that of HSPA.

Xi is based on 3GPP Release 8 and operates in the frequency-division duplex (FDD)  mode, which uses separate frequencies for both downlink and uplink transmissions in the 2GHz band. Docomo – which claims to have played a major role in developing the LTE standard – has been testing LTE since 2007. In late 2009, the company revealed new remote radio equipment (RRE), which allowed LTE base stations to be installed in existing WCDMA base stations.

Docomo’s LTE launch makes it one of the earliest operators to commercially deploy the technology. Nordic giant TeliaSonera switched on coverage at the end of last year, whilst US operator Verizon Wireless launched LTE earlier this month.

A recent Wireless Intelligence study forecasts 300 million LTE connections by 2015 led by growth in major Asia Pacific markets such as Japan.