Airtel Kenya, the local mobile unit of Indian telecoms operator Bharti Airtel, is upgrading its 3.5G HSPA+ network in the capital Nairobi, as part of its KES2.5 billion (USD25.9 million) investment programme announced earlier this year. IT News Africa writes that the cellco is utilising spectrum in the 900MHz frequency band to enhance indoor coverage penetration and improve the quality of its data service, which offers maximum download speeds of 21Mbps. According to a company statement, the Nairobi upgrade work is ‘due to be completed soon’. In February it was reported that sites in Mombasa and Kitale had already been upgraded, increasing the reach and coverage of Airtel’s 3.5G network. Nokia Networks is assisting with the upgrade project, which will also make the Airtel Kenya’s networks 4G LTE-ready.