According to a Reuters report, the Independent Communications Authority of South Africa (ICASA) said it will challenge a court application by a telecom operator, MTN Group, seeking to review or overhaul the regulator's spectrum auction process that is vital for 5G rollout. Following a smaller rival, Telkom, that went to court in December to halt the sale, MTN became the latest mobile operator to the ICASA to court. These legal disputes threaten to further delay the auction that is scheduled for the end of March, after similar disputes halted sales in 2016. MTN is challenging the ICASA's decision to put operators in two categories, MTN and Vodacom in Tier 1 and Telkom, Cell C, and others in Tier 2. MTN says that this classification would exclude Tier 1 operators from an opt-in auction round, which would undermine their ability to secure access to the 3.5GHz radio frequency spectrum band that is seen as vital to their rollout of 5G technology. MTN calls the definitions used to classify the companies 'impermissibly vague, arbitrary and unreasonable'. The ICASA said the auction will continue as planned unless the court orders to delay or halt the process.