KT, South Korea's dominant fixed line operator, plans to invest 20 K billion won to upgrade its systems. This decision was announced after some KT users were not able to make calls to Pusan, Taegu, Suwon and Anyang in Kyonggi Province for hours as KT's phone switches were overloaded. The company now plans to add a switch in these four regions to prevent such outages in the future. KT also plans to introduce an early warning system that sets off an alarm when telephone traffic reaches a pre-set mark.