• Sudden disconnections
• Slow network speed

Unfortunately sometimes it is not obvious in identifying the root cause of a symptom, as many problem sources may result in the same symptom, and more often than not, the symptoms happen only sporadically. Only through careful observation and in-depth analysis can the real source be found. Below are some common problem sources that we have identified:

Outdated wireless card software driver

Manufacturers often release software driver updates at times, to enhance performance, add features and fix issues. It is therefore essential and advisable to update to the latest wireless card driver software.

Interference sources – from Non Wi-Fi Equipment

Air is a shared medium. When one speaks, other Wi-Fi devices will wait for their turn to speak up - everyone get some share of air time.

However, there is dumb equipment which also operates in the same 2.4 GHz frequency range as Wi-Fi. Most common ones are:

• Microwave oven: affecting Wi-Fi users in nearby rooms, on the same floor and on adjacent floors
• Bluetooth earphone, wireless audio headphones, and wireless game controllers: these tend to be of lower power and thus will only affect users in the same room
• DECT cordless phones that operate in the 2.4GHz range

Whenever they operate, they occupied a large percentage of air time, disregard of presence of nearby Wi-Fi equipment. As a result nearby Wi-Fi users will experience sudden lowering of network speed or even sudden disconnections.

Interference sources – from other Wi-Fi Equipment

Air is a shared medium with finite bandwidth. When nearby Wi-Fi equipment operate and has one or more of the following setting, bandwidth available to UST wireless’ users will be lowered:

• Their frequency channel overlap with more than one UST’s Wi-Fi devices
• They are set to transmit at high signal level
• They transmit at low speed (2Mbit/s for example), thus occupying more air time

Common Wi-Fi interference we have seen includes:

• Powerful broadband routers: Linksys, TP-LINK, Buffalo, etc.
• LG network phones
• Apple Airport Extreme, Time Capsule
• Wireless (2.4GHz) cordless phones
• Wireless (2.4GHz) karaoke microphones

If you operate one of these, please help your neighbors by:

• Lowering wireless signal level to lowest or next to lowest
• Set wireless channel to 1,6,11 or 13 (preferred, if available)
• Use 5GHz range only, if available, in Airport Extreme and Time Capsule
• Switch off wireless service on it if not being used
• Connect your computer to sMobileNet (wireless) or directly to wall network socket (wired)
• Power-off the unit when you leave your room

If you need assistance in adjusting the setting on your wireless device, we are more than glad to help - please contact us at cchelp@ust.hk 

End user equipment sensitivity

Our observation is that different notebook’s wireless sections are of similar sensitivity. On the contrary, we observed that handheld mobile devices (e.g. smartphones):

• Have vastly different radio sensitivity
• Are usually of lower sensitivity than a typical notebook
• Could be affected by the way it was hold, which absorb/weaken radio signal reception

As a result, handheld mobile users are more likely to experience these symptoms:

• Most mobile devices can only get a lower connection speed than a notebook
• At the same location, some mobile phones can connect while others can’t

Problem Reporting

We investigate each and every reported case. To speed up our investigation, we will need the following information about your observations:

• What did you see? Disconnections? Particularly slow program? No coverage?
• Where did you see them? In hostel? Library? Nearby room number?
• When did you see? Date/time of occurrence or random occurrence?
• On what device? Frequency band and model of your wireless device? OS version?

Please send the above to cchelp@ust.hk, we will response as soon as we can.