NTT DOCOMO, Japan’s largest cellular operator, by subscribers, has announced plans to put more than 400 billion yen ($3.85 billion) this year into expanding its Long Term Evolution (LTE) 4G mobile network, in all areas currently covered by its slower 3G networks, TeleGeography writes quoting Nikkei.

By the end of its current financial year, March 31, 2015, DOCOMO expects to have around 100,000 LTE base stations, up from around 40,000 at present. It started 4G service under the ‘Xi’ brand, back in December 2010, and took almost a year to hit the 1-million subscriber milestone. It has since gotten considerably stronger, claiming above 19 million users, last December 31, adding more than 2.6 million new customers in the preceding three months alone.