Note that this could be a room at a client's offices, not necessarily your own. Radio-based wireless LANs have distinct advantages. They also have the capability to use wider bandwidths than infrared. Wireless LANs have always been, and look set to stay, slower than wired networks. This makes using wireless LANs a far more attractive option where large files are being transferred, or where response times are important, such as database queries.
Radio is an inherently shared medium.
Even techniques like spread spectrum, which allow several channels to co-exist in the same frequency band, don't allow more than one station to transmit on a particular channel at once. Thus, it's feasible to make a system that can use more than one channel simultaneously, but this pushes the complexity, and hence cost, up. Access points are used to connect wireless LANs into the wired network. Both the systems in this review claim to handle roaming well. However, the 802.11b specification's coverage of roaming is loose enough so that one vendor's equipment interoperating with another's while static may not roam correctly.