Join Sean Colins for an in-depth discussion in this video Understanding the difference between capacity and coverage, part of iPads for Educators: Deploying 1:1 iPads.
- When you turn on your laptop and see the little Wi-Fi symbol go to four full bars of coverage and yet you can't get to a webpage, what do you think is happening? It could be that your computer is not representing the way the network is working accurately. It is impossible for that one little icon to appropriately communicate all of the different things that could be going wrong with the Wi-Fi signal. On a Mac if you hold down the option key on your keyboard while you click on that Wi-Fi menu you'll get a much more detailed expression of how your network is operating.
Now those details may not mean very much to you if you don't have a full grounding in wireless network design, but to a network administrator this menu option describes many of the things needed to troubleshoot a wireless connection problem. You may be experiencing any one of a number of network failures. This may be a problem with a router being offline or the internet connection to the facility being down. But those are once in a blue moon occurrences that happen and get fixed and they probably have nothing to do with bad planning. If the Wi-Fi network was planned badly though, without enough capacity for the number of connected devices anticipated, it is more likely that you are on an access point that has too many other devices on it at the same time.
In an area where there is plenty of coverage, but there is no additional capacity on the Wi-Fi access point, a Wi-Fi access point could be located close enough to you and have enough power to get your device to report four full bars of power in the Wi-Fi menu, but that doesn't mean you can get anywhere. The access point can only talk to one device at a time, and it is connected to the rest of the network through one Ethernet cable, and that one Ethernet connection has a top end limit to how fast it can carry requests and replies.
All of these physical realities point to limitations that you need to plan around if you want a successful network deployment to support your 1:1 iPads. If the access point is overloaded with devices all trying to communicate at the same time, then that access point will no longer be able to effectively serve any of the devices that are connected to it very well. This is the functional difference between coverage, which is what most people think of when designing a network, and capacity, which is a crucial other component to successful wireless network design.
If you plan to put very few high-powered wireless access points on your network to cover a large number of devices, you will likely have too many devices connected to each access point for that access point to route traffic effectively. If you put too many wireless access points too close together, you'll end up overlapping the network with frequencies that cannot exist adjacent to one another without creating interference.
In the next few movies, we're going to talk about how the 2.4GHz and 5GHz network frequencies differently impact the way that you will design your network for both capacity and coverage, but specifically for how coverage can be made to overlap causing unwanted noise problems.
- Getting funding for your classroom technology
- Setting up an Apple Education account
- Choosing an iPad model
- Enrolling in Apple programs
- Planning a Wi-Fi network
- Setting up mobile device management (MDM)
- Getting free and paid apps
- Configuring MDM profiles
- Exploring 1:1 deployment alternatives