Intro to Wi-Fi Mesh Networking
Wi-Fi mesh networks may appear all-the-same to the Wi-Fi users, but to you they are quite different from traditional Wi-Fi networks in regards to their installation and design. Instead of all wireless access points (APs) having to be wired back to the network via Ethernet cables like in a traditional network, a mesh network is designed to have some of the APs wirelessly communicate between each other for their network and Internet connection. The idea that the APs are interconnected directly between each other is why you call them a mesh network.
A mesh network approach is useful where there’s no existing wired infrastructure, or a lacking wired infrastructure, and installing cabling for the APs isn’t possible or desired. This could apply when there’s a limited budget for the network or when a network needs to be installed quickly, or when setting up a temporary network for a venue or an outdoor network where running cables is costly. Furthermore, mesh networks are also great for networks that change often. You can move around mesh APs usually much easier than you can traditional APs. Even without moving them, if there are changes to the network or environment, the mesh nodes can usually utilize a different route.
Comparing to wireless bridging, repeating, or WDS
Wi-Fi mesh networks are similar to other wireless technologies, such as wireless bridging, wireless repeating, and wireless distribution system (WDS), but there are certainly some differences. Traditional wireless bridges are designed to be installed on traditional Wi-Fi networks. They wirelessly connect to the Wi-Fi network and then offer wired connections to computers and network devices nearby via the bridge’s Ethernet ports. It’s like an Ethernet switch, but connects wirelessly to the LAN instead by a cable. Wireless bridges are useful when trying to provide wireless network connectively to non-wireless computers and devices. Given that a wireless bridge typically has a better antenna than what most computers and devices would have, the bridge can also basically be used to help extend the wireless coverage.
Wireless repeaters wirelessly connect back to a traditional Wi-Fi network as well, but also allow wireless computers and devices to connect to the repeater too, in which case it looks and acts like a normal AP to them. The repeater is placed near the edge of the Wi-Fi network’s coverage and repeats the signal further out where the network signal is poor or non-existent. This technique is useful when you need to expand or extend a Wi-Fi network’s coverage for traditional wireless computers and devices. There are many wireless bridging and repeating combo devices that can do both simultaneously. Some traditional APs even support both as well.
The term WDS refers to a feature supported by many traditional wireless APs, which can support wireless bridging and/or wireless repeating as already discussed. Some WDS capable APs also support what is called by some as a relay base station mode, which means the AP can act as a repeater and also communicate wirelessly to another wireless repeater. This mode is the most similar to mesh networking, but there still are some notable differences.
Typical characteristics of mesh networks
A mesh network is more dynamic than what typical WDS functionality can provide. Mesh nodes typically support multiple wireless hops before reaching a node that’s wired into the network, whereas an AP with WDS might only be able to wirelessly connect to another AP wired onto the network. Mesh nodes are also usually self-healing, meaning a wireless node should choose the best node to wirelessly connect to rather than being statically configured with WDS to a single AP. Thus if the airwaves change, there’s interference or an obstruction blocking the signal to one node, it could automatically switch to another node within range that provides a higher quality connection. This provides redundancy, so if one mesh node goes down or has a poor connection, the remaining nodes should still be operational and serving end-users.
Keep in mind, like with wireless bridging, repeating, or WDS, mesh networking functionality is vendor specific. Though there are some standards that have been developed to help with interoperability, many vendors deploy their own proprietary technologies. So when shopping around for APs with these capabilities, be sure to evaluate their entire solution and all the product offerings. Bear in mind that in the future you may want to make changes and upgrades; so choose a vendor that looks like they’ll meet your future needs as well.
Wireless hops cut throughput
Keep in mind, although mesh networks can be very useful, they usually can’t provide the speeds or throughput that a traditional wireless network can. When a mesh node connects wirelessly to another node, the throughput can be cut in half. This happens for each wireless hop, so making two hops could cut throughput down to about a ¼ of what it is at the source. If your Internet connection provides download speeds around 15 Mbps, wireless computers and devices connected directly to a hardwired AP should be able to get those speeds. However, wireless computers and devices connected to a mesh node that has to make two wireless hops to a hardwired node will get 4 Mbps or less speeds. This is why many solutions suggest designing mesh networks where nodes don’t have to make more than two or three wireless hops to a hardwired node, often called a gateway node.
Keep in mind that the throughput drop has a lot to do with the mesh network design and placement of the wireless mesh APs. Adding more gateway nodes, those hardwired into the network backbone, can help alleviate the throughput issue. Additionally, placing wireless mesh APs in optimum spots can help increase the performance of the wireless interconnections of the mesh nodes.
Available mesh solutions
As mentioned, many APs and wireless routers support wireless bridging, repeating, or WDS. However, if you’re looking for more of a full-fledged mesh solution, your options are fairly limited.
If you’re looking to play around with mesh networking at home or a small office, perhaps checkout the new and unique offering from Eero. They currently provide one dual-band 802.11ac mesh node, designed for home or small networks. For more mesh node options and a more configurable solution for home or business networks, perhaps consider Open-Mesh. They provide a couple single and dual-band indoor and outdoor options, including 802.11ac, and their system is configurable via a cloud-based GUI. For large networks, consider enterprise-grade APs from vendors that support mesh functionality, such as Cisco, Meraki, Aruba, Strix Systems, Ruckus, and ExtremeWireless.
Remember, there are some practical differences between mesh networking and the typical wireless bridging, repeating, and WDS features offered by most APs. The former are more for extending existing Wi-Fi in select spots, whereas wireless mesh APs are designed to make up an entire network or network segment. The dynamic and adaptive natural of mesh APs also usually make them a better choice for changing environments and whose with fluctuating interference. However, you’ll have to balance the amount of pure wireless mesh nodes and gateway nodes hardwired into the network, so the throughput levels seen by users are acceptable. So for most mesh networks, some cabling is still in deed needed.