Provision of Maintenance Services for the Public Address (PA) System, Induction Loop System, Intercommunication System, Burglar alarm and Security System, Integrated Security Management System, Panic Alarm System, Video Door Phone and Call Bell System, Carpark Management System and Communal Aerial Broadcast Distribution (CABD) System for Kwong Wah Hospital, Kowloon Central Cluster, Hospital Authority " (EXPIRED)