There are two well established icons or symbols that are used when we’re talking wireless networks. There is a difference between the two. One is the transmitter of a wireless network, the other is a hot-spot of a wireless network.
When drawing and explaining at the same time, it doesn’t have to be pretty. It has to be clear. What’s important is to capture the essence of the thing you’re trying to draw. The essence of a tree isn’t it’s beautiful and detailed leaves. It’s a trunk with two branches. No need to use time on drawing anything else, if people get that what you’ve drawn is a tree.