Stress test your WiFi before you find yourself in a stressful situation
Currently there is a territory wide roll out of WiFi in schools across Hong Kong. While this is a wonderful initiative and allows for much easier adoption of mobile devices in both primary and secondary schools, it needs to mentioned that the bandwidth that the schools receive is unclear. It is possible that the person responsible for procuring a broadband connection for the school and a WiFi system for the school is not very tech savvy. It is also possible that price point was the main concern when subscribing to a service and purchasing hardware. In that case it falls to the class teacher to test out and see what is actually possible in the classroom.
Quick and dirty glossary of terms
* These terms are simplified for non-tech based people, if you need absolute accuracy, please google these terms.
Bandwidth - the amount of information that can be passed through the network over time. usually measured in megabits (e.g. 1m = 1 million bits per second)
Ping - how responsive a network is. measured in milliseconds, lower ping = more responsive.
Download Speed - the amount of information that can be pushed from outside your network to a device on your network over time, e.g. watching a video on youtube on a computer. Usually measured in megabits
Upload Speed - the amount of information that can be pushed from your network to a system outside of your network, e.g. sending an email with an attachment. Usually measured in megabits.
Simple network: from a flood to a trickle
The best way to think of your WiFi connection at school is to think of it as a garden hose. If you open your hose all the way you only get so much water per minute. Its quite constant and you can get more out of a hose when it is completely open. Now think of splitting the hose between two people. You still have the same amount of water but now it's going to two different places at half the amount (if both people are using it) Now instead of just two people, imagine that hose is shared between 28 students and 1 teacher in the class. That hose that had only two people using it is pretty effective, but once you have a whole class using it, the amount of water that each person receives drops to a trickle.
So what does this mean for me and my class?
The challenge is not knowing what the limitations of your network is before setting up your activities. Many "free" teaching resources that use cloud-based solutions require a lot of bandwidth to work smoothly. The more videos and images you pull down and push out the more robust your network and wider your bandwidth need to be to be effective tools in class. Would a video for each iPad work if it took 1 minute to play 5 seconds worth of video? If individual videos don't work, then maybe groups might be better or downloading the video and storing it on each device might be better.
These are things that you should be aware of before you spend a lot of time making arrangements and finding those resources for class.
So how can you test your network?
1. Use a web-based site or app to help you run a stress test on one device.
There are a lot of free sites out there that will help you gather information about your network. Some popular tests are:
These are good tests to see what your network is capable of. Most of these services offer apps both on the App Store and on Google Play. Search for these apps using the names above. You should also conduct this test on multiple devices, e.g. a wired computer vs. WiFi connected device.
You should also run this test simultaneously on multiple devices. Your network may try to limit each device so that it cannot take too much of the network's bandwidth. Test this with multiple devices at the same time until you see a drop in performance and see if it affects all the devices or just the devices that you start a bit later.
2. See how many devices you can connect to your school WiFi at a time in one room.
Most schools are large and require multiple WiFi routers to provide service to the whole school. If the students are confined to one room, it may over tax that router. Test it to see how many devices can connect to one router using the test services listed above.
3. Test the coverage in your school.
There may be some spots or rooms that have weak or no WiFi coverage. Find these spots before you plan a lesson in a room with no or weak WiFi. You can check at a glance by looking at the WiFi signal bars on your device and also run the tests to see how the performance changes as the signal gets weaker.
Hopefully, by knowing the limitations of your network, you can design technology enhanced lessons that your students can access rather than having a lesson wasted on tech support.
