. You should also evaluate the bandwidth based on traffic inside work- groups and traffic over the backbone between workgroups. Clusters or workgroups are made up of users who form a community of interest, and therefore the majority of traffic sharing occurs within each cluster. However, there are reasons to have inter- departmental or interworkgroup communications as well, and therefore you need the backbone to provide connectivity between all the distinct clusters. The backbone should be engineered for great future capacity-provisioned to meet user needs in peak times with the ability to be upgraded as needed-and the workgroups should be set up SO that they can easily be adjusted for moves, adds, and other changes. The second consideration regarding LAN transmission media has to do with cost and ease of connectivity, and that speaks specifically to the installation, as well as to moves, adds, and other changes. In the average, rather stable environment, the majority of the employees are relocated at least once a year, so equipment, fea- tures, and services must move along with them. And, of course, some environ- ments have many reorganizations and require yet more consideration in this area. LAN Characteristics For example, in an enterprise where reorganization is common, using a wireless LAN is probably the easiest way to support such a dynamic environment. (Of course, if every desktop has an RJ-45 in place, moving may be just as easy as with wireless.) The tradeoff is that wireless media provide less bandwidth than, say, fiber, and with a wireless LAN, you have to create smaller clusters. Again, what media you choose depends greatly on the application. The third consideration regarding LAN transmission media is sensitivity to interference and noise. If a LAN is being deployed in a manufacturing plant where other equipment emits interfering levels of noise, the noise could play havoc with a twisted-pair or wireless LAN, whereas coax and fiber would be much less suscepti- ble to the interference. Finally, of co