How Many Access Points?
Most home networks and public Wi-Fi hotspots function with a single wireless access point (a broadband router in the case of home networking). Conversely, larger business computer networks install multiple access points to expand the wireless network's coverage to a much larger physical area.
Each access point has limits for the number of connections and amount of network load it can handle, but by integrating multiple of them into a larger network, the overall scale can be increased.
Theoretical Limits of Wi-Fi Network Scaling
Many individual wireless routers and other access points support up to approximately 250 connected devices. Routers can enable a small number (usually between one and four) of wired Ethernet clients with the rest connected via Wi-Fi links.
The speed rating of access points represents the maximum theoretical network bandwidth they can support. A Wi-Fi router rated at 300 Mbps with 100 devices connected, for example, can only offer on average 3 Mbps to each of them. Naturally, most clients only use their network connection occasionally, and a router shifts its available bandwidth to the clients that need it.
Practical Limits of Wi-Fi Network Scaling
Connecting 250 devices to a single Wi-Fi access point, while theoretically possible, is not feasible in practice for a few reasons:
- On home networks, all devices normally share a single Internet connection. The performance of clients' Internet access will start to degrade as more devices join the network and start using it simultaneously. Even just a handful of active devices doing video streaming or heavy Web downloading can quickly max out a shared Internet link.
- Access points overheat (and stop working) when operating at extreme loads for extended periods, even if handling only local traffic and not accessing the Internet.
- Having large number of Wi-Fi clients concentrated in close physical proximity like a home or office building generates significant wireless signal interference. Radio interference among Wi-Fi clients degrades network performance (due to frequent re-broadcasting of messages that fail to reach their destination) and eventually causes connection drops.
- Some home routers include a feature that allows administrators to control the number of clients that can simultaneously connect. Many Linksys routers, for example, set a default maximum of 50 maximum clients. Smart administrators often keep a limit like this in place to keep the router and network running reliably.
Installing a second router or access point on a home network can greatly help distribute the network load. By adding more access points to the network, effectively any number of devices can be supported (though the network becomes progressively more difficult to manage).