Bangladesh's leading mobile phone firm Grameen Phone's subscriber base has gone up by a record 55 per cent in the first six months of the year to touch 8.5 million. The company has added 3 million subscribers since January, making it the fastest-growing mobile phone company in the country. One of the factors for the firm's success has been its aggressive investment in network coverage, adding 1,000 new base transmission stations during the first six months. Separately, Nokia is planning to focus on its presence in Bangladesh. It has already set up headquarters in the country to oversee its mobile handset business.