I have been taking conference calls using wifi when I had a subscription of a 256kbps connection. Before smart phones, I was the only one using wifi at home and most of the times my voice calls just went through. My latest speed test gave me 220Mbps and I faced more calls drops than I used to have in 1Mbps connections.
Not until covid situation pushed all of us at home to connect to calls at the same time I never analysed enough to fix my wifi problem.
First problem, Overcrowding of wifi signals. Every home in the apartment complex has a wifi connection, often only a thin wall separates the routers. Many overenthusiastic people select the 40 mhz wide channel (supposed to support more bandwidth) in the already overcrowded region and cause even more interference and introducing more noise to the signal. You have to choose a channel where your router can shout the loudest among other routers. It is less pronounced problem in the 5Ghz range and more pronounced in the 2.4Ghz range. Solution — Make a request to your neighbours if possible to choose 20Mhz channel width on 2.4Ghz network, this will help in reducing interference. Choose a channel with the least interference by using wifi analyzer tools. Switch to 5Ghz routers which has lesser interference problems but keep the channel width to a minimum. The wider the channel lesser the signal strength and higher the noise.
Second problem, too many devices. The off the shelf routers supplied by the service providers are not good at handling many devices at once. The conference calls needs a good quality of service. Contrary to what people think a 300kbps high quality throughput is all that is required for one voice call to work. If three devices are trying to share the router’s time at the same time, chances are high that network packets are getting dropped and retransmission is useless because calls have to be near realtime. Solution—Ditch your default router given by the service provider and install a high performance one like the ones used in offices. Examples are unifi access points and a few other routers which can direct wifi beams towards devices.
Third problem, range. There is a physical limit how far signals can travel and penetrate multiple walls. Solution—For houses smaller than 1500 sqft, one router is enough, it just has to be centrally located than keeping it at the corner of the house. I have seen people typically keep it near TV points. Cheap range extenders decrease the quality of service, so avoid using them. For larger houses, either mesh routers or multi access points are to be installed.
Fourth problem, network stability. Service providers promise the sky and give you a crater sometimes. My speed tests have a range of 2Mbps to 220 Mbps. Solution — An expensive option is to go for a business grade dedicated line, it is as much as 5 times the cost of a home network but very very stable. The other option is to get two connections from different service and then combine them. A few routers can take two input connections and expose as one access point, there are also network switches available to combine multiple connections into one network which can be connected to a single access point.
In my case, fixing the first 3 problems helped me with the stability and multiple people at home are able to take calls at the same time. The alternative I had for the fourth problem is to use my mobile hotspot as mobile data is stable for me and I usually lose a few seconds to switch to mobile data.