What would influence a business's decision to choose WLAN over a wired network?
In most cases and within most businesses there is a combination of both, especially where there are server systems hosted internally. And actually, you need a wired network to support all of the wireless Access Points to link them together on a corporate network.
From a user connectivity perspective wireless LANs are simply more accessible than wired networks. Users don't need to find a cable and go scrabbling round the floor to find an active data point. They simply switch on their device and connect to the available wireless network. There are a lot of new computing devices that don't have a LAN connection nowadays including many new laptops so wireless is essential. Guest networks can easily be created to safely support guests and visitors within the workplace.
Also consider the growing number of non-user related devices that need 'internet' connectivity within the IOT space. Door entry systems, CCTV security, energy monitoring & control, clocks, digital signage, the list is endless! Wireless connectivity is both essential and enables flexibility. I don't need to worry about locating devices near data outlets, although I still might need a power source.
So why would I perhaps choose wired over wireless? Speed is most likely top of the list. Yes, I can now run up to 1 Gig on most modern wireless networks but the contention is generally higher so the 'available' bandwidth is lower assuming I really need a high constant stream of data. Wifi 6 improves availability to wireless devices but if I was streaming lots of video along with others then wired will give a more consistent experience. With Wifi 6 these niche examples are getting fewer.
Quality of service kind of goes hand-in-hand with speed where QoS is better supported on wired networks and therefore delivers a richer service.
In the IOT space, the provision of power and data over the same cable (POE) solves two problems in one for devices with a low power draw.
Security is probably the last on peoples list although there are lots of caveats here. It's harder for an attacker to access the wired network in order 'sniff' the traffic in the first place. But I can guarantee that almost every corporate wireless network requires user authentication and is encrypted by default. Not so with wired networks. So in order for security to be a reason Network Access Control (NAC) must be enabled along with traffic encryption to provide a more secure connection. VPN technology alone could mitigate some of the concerns btw.
In a greenfield application I would go with all wireless workplace. More people are working from home nowadays.
Why go with all that infrastructure cost. If the wireless LAN is done correctly and secure with authentication of users, no need to wire up all the workstations. The use of the soft phone has become acceptable for remote users.
Sometimes the best answer is a simple answer....do you want to pay to run physical lan connections to every location you think a team member/employee might want to work from...? Its like a static defense..you have set your location and now that's it. Versus giving your team members/employees/visitors/contractors/etc the flexibility of being able to work from anywhere in your facility. Huge savings in infrastrure and huge lift in the ability of people to work and work together (meetings anywhere).
A wireless solution has the advantage of mobility, it can also be cheaper than a wired solution. Wireless networks allow us higher speeds than wired, with the last 802.11ax.
You need both wired and wireless in your modern data infrastructure. Wireless is both less secure and often more costly if you factor labor to implement. Wired is less flexible but more secure.
Modern converged wiring gives the customer the most reliable and cost-effective solution for the desktop applications Each location should have two category 6 cable to each location. This enables two devices to be plugin at the same time. The relatively low cost of adding an additional Cat 6 wire to your infrastructure offsets the labor of pulling additional cables. It all so simplifies troubleshooting. In addition, you can install a wireless AP's to support bring your own device (BYOD) applications. I like to put those devices outside of the core network and quarantine them from important vital network infrastructure and they are a serious threat to security. Having two sperate networks greatly improves security and still enable your BYOD strategy
Flexibility is one of the greatest advantages of Wi-Fi and there are more and more devices that only come with a Wi-Fi adapter and no RJ-45 connector so you need to buy a converter adapter from USB to RJ-45. The biggest disadvantage of Wi-Fi versus the cable is throughput. Because Wi-Fi is a shared medium you need to share the bandwidth. The technology is also half-duplex while wired is full-duplex. Wifi 6 also called high efficiency will provide a higher throughput but it will take several years before all end devices are equipped with a Wi-Fi 6 adapter. But you can implement a policy that only devices with an 802.11ax adapter will be buyed.
That’s why an RF design is important. You need to plan carefully where you place the access points (APs). A best practice is to design for the 5GHz band because you have many more channels available. The decrease of the 5GHz signal through obstacles is larger than with the 2.4GHZ signal and therefore you need more AP’s.
Wi-Fi is also great to give (limited) network access for guests which can be difficult with a wired network.
A wired connection is more stable and faster than Wi-Fi.
Yes, as stated below, either way a wired network is mandatory to support the wireless access points. As far as which is better, it depends on what types of traffic the clients are generating. Wireless is more convenient for sure, but it is half duplex and your back to the old days with collision concerns on the network. For VOIP, video and security camera's, my opinion is to stay on a wired network. There are too many variables to say one way or the other, it also depends on the density of the clients without knowing the topology and traffic generators.