Regardless of the technology available, WiFi will always have inferior performance to a wired connection simply because it is shared spectrum, it is subject to interference from other devices and performance diminishes with distance from the access point.
In order to ensure top performance from your WiFi installation note the following points.
Use a non-overlapping channel: The 2.4GHz band is saturated and since it only has 12 or 13 channels with 3 of those channels that don’t overlap each other it is pretty clear that there are some severe performance limitations before you start. Many low-end Internet routers are only capable of 2.4GHz so it is safe to say that a significant percentage of houses are broadcasting 2.4GHz.
Move to the 5GHz band: The 5GHz band has 35 channels available of which 24 of those don’t overlap. This allows the aggregation of channels up to 160Mhz to allow for the high performance of the 802.11ac standard although there are still few devices that can fully utilise that channel bandwidth. Many of the access points allow band steering whereby if the access point detects the connecting device is capable of 5GHz then it will force it to use the higher frequency.
The 5GHz band does have some limitations in that some of the frequencies are reserved for other services and access points are required to limit their transmit power. The various frequencies and transmit powers are shown in the chart. More advanced access points have the ability to look for interference and select the best channel automatically. Some use one of their built-in radios while others have a separate radio that is constantly scanning.
Prior to 802.11ac Wave 2, WiFi only allows one device to transmit and receive at once. If any other devices start transmitting then call devices go silent for a random time until 1 starts to transmit again. This is very similar to an old Ethernet hub.
Consider 802.11ac Wave 2 access points: Wave2 introduces a technology called Multiple User – Multiple In Multiple Out (MU-MIMO) on the download side. This is good for throughput and accounts for the much higher overall performance of 802.11ac Wave 2. Even if you have Wave 1 devices, the overall throughput will be improved.
Ensure you have enough WAN bandwidth: In a large venue such as a convention centre or shopping centre if you only have an ADSL2+ connection then the overall user experience is going to be poor because there simply isn’t enough bandwidth to go around. For guest access it is well worth throttling the overall speed for each user to ensure everybody gets a reasonable experience. You may also choose to block certain applications altogether like BitTorrenting, Windows Updates, etc to ensure that a few people don’t clog the network up for everybody and to avoid large excess data bills.