As Wi-Fi 7 specifications evolve in the IEEE P802.11be™ “Enhancements for Extremely High Throughput (EHT) Wireless LAN” amendment, there’s the usual buzz about whether wireless networks will make wired networks obsolete. As with previous Wi-Fi implementations, Wi-Fi 7 will have both associated theoretical maximum (46.1 Gb/s upstream and downstream combined) and “real world” (> 20 Gb/s upstream and downstream combined) throughput. Based on this impressive bandwidth, it’s tempting to think that IEEE 802.11be devices might support transmission speeds on par with structured cabling systems. However, there are two main reasons why this won’t be the case:
- Since wireless is a shared media, the maximum available “real world” bandwidth is split between multiple users. Considering that one 802.11be access point (AP) will likely serve 30 to 60 clients, it’s clear there’s substantial opportunity for network slow time due to lack of bandwidth depending on client needs at any given time. This is in significant contrast to a 1000BASE-T network, where each device always has the full 1 Gb/s bandwidth available.
- Total bandwidth is specified differently for wired versus wireless systems. For example, since 10GBASE-T transmits in full-duplex (transmitting and receiving over the same cable pairs at the same time), it operates at a maximum rate of 10 Gb/s in the upstream direction and 10 Gb/s in the downstream direction. This is different from wireless networks, which transmit in half-duplex and whose stated bandwidth is an indication of throughput in both directions combined. What this means is that, with overhead and depending on the number of clients, 802.3be devices can reasonably be expected to have access to an approximate wired-equivalent bandwidth of 150 – 300 Mb/s. Smaller hand-held Wi-fi devices, such as mobile phones, will have access to even less bandwidth as they typically only have one transmission antenna to to optimize power consumption.
The major shortcoming of an all-wireless data network is the high likelihood of periodic network slow down and saturation due to number of clients and applications in use. The bottom line is that, unless a device is connected to a dedicated (i.e., there are limited or no other clients on the wireless network) 802.3be access point, transmission speed won’t even be comparable to a 1000BASE-T structured cabling network. Given that market statistics show that enterprises are finally migrating to 10GBASE-T in the work area, it’s extremely unlikely that wireless networks will make cabled networks obsolete anytime soon.”
