City University of Hong Kong has full Wi-Fi coverage in the entire campus, powered by over 2,800 Access Points (APs).  These APs are all Wi-Fi 5 (802.11ac Wave2) compatible.  Subsequent to a recent Internet bandwidth upgrade, the individual bandwidth control is unleashed.  In other words, users using Wi-Fi 5 compliance devices on campus can now enjoy much faster campus network and Internet connection when they are connected with CityU’s Wi-Fi service.  For a modern notebook computer equipped with two spatial streams (2 + 2), an average of 300 Mbps upload / download speed can be reached:

Moving Foward

Wi-Fi 6, also known as 802.11ax, is the latest generation of the Wi-Fi standard.  This new standard has many new features and improvements over the Wi-Fi 5.  The Computing Services Centre (CSC) has installed a few Wi-Fi 6 access points for evaluation and will use it for new deployment, particularly in crowded areas such as Lecture Theatres and classrooms.  Table below summarized the features of Wi-Fi 6 and its improvements over Wi-Fi 5.

• Higher data rates – it delivers better throughput.  The maximum theoretical speed for Wi-Fi 6 is 9.6 Gbps as compared to the 3.5 Gbps on Wi-Fi 5 Wave 2.

  Wi-Fi Standard	Maximum theoretical speed	Frequency Bands
  802.11b	11Mbps	2.4 GHz
  802.11a	54Mbps	5 GHz
  802.11g	54Mbps	2.4 GHz
  802.11n (Wi-Fi 4)	600Mbps	2.4 GHz and 5 GHz
  802.11ac (Wi-Fi 5)	3.5 Gbps	5 GHz
  802.11ax (Wi-Fi 6)	9.6 Gbps	2.4 GHz and 5 GHz

• Better performance in crowded areas – it uses OFDMA (Orthogonal Frequency Division Multiple Access) technology to serve multiple clients at once within a single channel and supports full-duplex MU-MIMO (multi-user, multiple input, multiple output) to allow several clients to perform uploading and downloading simultaneously. 
  

  This is a major improvement over Wi-Fi 5 which allows only one client to send data to the AP at any one time.

• Lower power consumption for Wi-Fi 6 devices – its new “target wake time” (TWT) feature enables wireless access points and devices to negotiate when to wake up their Wi-Fi radio and when to go to sleep.  This feature enables devices to significantly conserve power and improve battery life, especially useful for IoT devices.

• Better network security - supports new security encryption using WPA3.  WPA3 provides a 192-bit security suite which greatly enhances Wi-Fi network security and makes it harder for hackers to break into the network.

Outdoor Wi-Fi Coverage

In addition to the performance enhancements, the CSC will be installing outdoor APs to improve and strengthen Wi-Fi coverage in outdoor areas, including:

• Chinese Garden
• Sky Garden of LAU and LI buildings
• University Circle
• Pathway between TYB and YEUNG buildings
• Other selected open areas

The CSC dedicates to improve the University’s Wi-Fi service by accommodating the latest technology and, as always, to improve campus experience.  If you experienced any Wi-Fi connectivity issues on campus, you are most welcome to inform us the time and location via csc.servicedesk@cityu.edu.hk for our investigation and improvement actions.