The Telecom Development Company of Afghanistan (TDCA) officially launched Roshan - which means \"light\" in Pashto - on Thursday. The new GSM network will now undergo tests for the next four to six weeks before its commercial launch. The firm says it will roll out its service in Kabul and the main cities of Herat, Kandahar, Mazar-i-Sharif, Jalalabad and Kunduz by the end of the year, at a cost of about $55m (£33m). It will compete with customers of Afghanistan\'s first GSM provider, Afghan Wireless Communication Co, which is still offering a patchy service. Many officials and aid workers are still using expensive satellite phones due to the unreliability of the existing GSM network. TDCA is owned by an international consortium which includes France\'s Alcatel, US-based MCT and Monaco Telecom International. Its majority shareholder is the Aga Khan Fund for Economic Development, which commands a 51% stake. (BBC)