Wi-Fi is officially capable of handling upload and download speeds that can theoretically rival Ethernet connections, but why is it so hard to achieve these theoretical speeds in the real world? The answer has to do with bandwidth, congestion, and noise. When using an Ethernet cable to hardwire a device to your home network, that device — whether it be a PC, streaming box, or gaming console — has a private “fast lane” to your router or switch. The common pain points of wireless connections, like physical interference, congestion, or dropped signals, aren’t an issue. The device has a direct connection to your home network, and nothing can get in the way.
Basic networking best practices tell you to use Ethernet over Wi-Fi when possible to avoid congestion and interference, among other wireless problems. Naturally, the next question to ask is: what’s actually causing the congestion and interference on my home wireless network? Some of the root causes are simple. Physical obstructions such as walls or floors and competing appliances like microwaves can create interference.
The congestion issue can be tricky to diagnose, especially if you think your home network is light on connected devices. What you don’t realize is that many of these devices are constantly creating noise and congestion you can’t see via multicast and broadcast traffic.
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AirPlay and Google Cast are always making noise
This ‘one-to-many’ approach clogs up your home network
Wireless signals aren’t always specifically targeted to the device sending or receiving them. Instead, many kinds of “multicast” traffic involve sending out wireless signals to many or all the devices on your network. The connected devices on your network that need to receive the multicast signals accept them, and the ones that don’t reject them. The problem? The excess high-bandwidth multicast signals are adding congestion to your network and consuming a large portion of your network’s overall bandwidth, even if they aren’t necessary.
The best examples of multicast traffic on your home network include wireless communication protocols that involve “casting” or “streaming” content from one device to another. These protocols are preferred over, say, a Bluetooth connection, because they benefit from the extra bandwidth and speed of Wi-Fi. Google Cast, Apple AirPlay, or Sonos System all use multicast traffic to handle multi-device handshakes and discovery. The more devices on your network that have support for Google Cast, Apple AirPlay, or Sonos, the more background congestion and noise exists.
Here’s how it works — when you browse on a website or start an individual stream on a single device, you’re using a unicast Wi-Fi stream. The wireless transmission is flowing from your router to the client device, or vice versa. When you switch to multi-device streaming protocol like Google Cast, Apple AirPlay, or Sonos System, it’s the opposite. The sender will transmit signals over your home network that reach every device capable of receiving them. These communication protocols send out signals even before you start sharing, because that’s how devices discover each other and display which hosts or clients are available.
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Wireless printing is noisier than you think
Printers use broadcast traffic to connect with your device
Broadcast traffic is similar to multicast traffic, but it’s even more broad. Multicast signals are somewhat targeted, excluding devices that aren’t compatible or discoverable based on the communication protocol. For example, using AirPlay for streaming and discovery won’t send multicast signals to the Windows PC on your network. It will only send signals back and forth between AirPlay-compatible devices. By comparison, broadcast traffic is “one-to-all,” meaning every device on your network receives broadcast signals.
Basic wireless networking tasks use broadcast traffic, like connecting to a new Wi-Fi network for the first time or using a wireless printer. These are background activities that most of us never think about. When you connect to a Wi-Fi network for the first time, a background Dynamic Host Configuration Protocol (DHCP) onboarding process kicks off. The device asks your router for an IP address, but it doesn’t know the exact MAC address of your router yet — it needs to send a broadcast signal to every device on your network. Then, the router will respond with a unicast message that assigns an IP address and other characteristics.
It’s a similar story for wireless printing. Your laptop or computer might know a wireless printer’s IP address, but it doesn’t know the printer’s MAC address. So, it’ll send out a broadcast signal to every device on your home network, asking for the one matching your printer’s IP address. Every other device ignores the broadcast, but the extra signals add congestion and noise to your network.
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Cutting out multicast or broadcast traffic improves speed
Maybe turn off AirPlay or Google Cast if your network is struggling
Some of the so-called “invisible noise” on your wireless home network is unavoidable. Devices need to connect to your router, and this initial connection process requires sending out broadcast signals that consume overall network bandwidth. However, you can trim down traffic by limiting the amount of multicast discovery and handshake signals being sent and received on your network. If there’s a device supporting Google Cast or AirPlay that doesn’t need it, disabling these features could reduce the amount of multicast signals on your network, cutting out excess congestion and noise.
For most of us, the convenience of features like Google Cast, AirPlay, or Sonos is worth the extra toll it places on our home network. Still, it’s important to remember that this convenience does come at a cost. It’s a cost you can’t see, but it’s there, and it may be the reason your home network feels slow.
- Coverage
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Up to 2,200 square feet
- Wi-Fi Protocols
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Wi-Fi 6E – 2.4 GHz, 5 GHz, 6 GHz bands
Google’s reliable mesh Wi-Fi system helps ensure coverage throughout your whole home. The system uses Wi-Fi 6E for speeds up to 5.4 Gbps, and the 6 GHz band helps reduce interference for better performance.