MTN Group's South African arm said on Wednesday its network availability had improved by 15% as a result of ongoing investment to ensure its mobile network operates effectively during the worst power cuts on record. As the national power grid crumbles, leaving Africa's most advanced economy in the dark for up to 10 hours a day, mobile operators including MTN, Vodacom, and majority state-owned Telkom are scrambling to ensure their networks stay up and running. "It's an ongoing battle, but one that we're committed to winning as we fight to provide our customers with a reliable and resilient network," MTN South Africa Chief Executive Charles Molapisi said.