Wired vs. WiFi
For best quality of voice, video and screen sharing, it is always better to be wired. While wireless networks are convenient, they are susceptible to interference from other devices broadcasting in the same range and channel. Since VoIP has high network requirements for optimal call performance, it is a best practice to use wired connections to reduce interference and signal delay.
Corporate Wi-Fi is regularly deployed, and while useful for many enterprise applications, is not the best connectivity for real time VOIP traffic. If you are planning on including an element of Wi-Fi in your Skype for Business deployment, please review the link below for a list of Microsoft approved WI-Fi devices and vendors. If designed specifically for Real Time VOIP protocols, Wi-Fi could provide a quality user experience, allowing for mobility within the office.
Wi-Fi devices and vendors: http://technet.microsoft.com/en-us/office/dn788945.aspx