Welcome back to CUHK! Are you getting online through CUHK Wi-Fi?
Before that, observe the following to have a better "internet life"!
1. Faster & More Stable with "CUHKa"
While connecting to campus Wi-Fi, SSID=CUHKa is highly recommended for faster speed and less interference.
If you are an advanced user with your device supporting 5 GHz (a/b/g/n frequency) band, switch towards this band. (Read the user guides at http://www.cuhk.edu.hk/itsc/network/wlan/cuhkwifi-overview.html )
2. "CSL" Comes & "PCCW" Goes
You may find a new SSID "CSL" while having your Wi-Fi connection. This is an SSID under CUHK Wi-Fi Hotspot Partnership Program and is to replace SSID=PCCW. The SSID=PCCW will be disabled on 10 Sept, 2014. (Read more at http://www.cuhk.edu.hk/itsc/network/wlan/index.html#connected )
For enquiries, please write to ITSC Service Desk at http://servicedesk.itsc.cuhk.edu.hk.