Why we need distinct SSIDs for different Wi-Fi services?

A service set identifier (SSID) is a unique code attached to all packets on a wireless network to identify each packet as part of that network. This code is a case sensitive text string that consists of a maximum of 32 alphanumeric characters. Wireless devices must share the same SSID if they want to communicate with each other.

Hence, in order to identify different Wi-Fi services in HKUST, we must use different SSIDs. A user with a wireless device must choose the right SSID in order to use the corresponding wireless service.