144 CHAPTER 6: U SING RF P LANNING34 In the Wiring Closet list, select the wiring closet that contains the WXswitch or switches to be connected to the shared MAPs.If the MAPs will be directly connected to WX switches, a wiring closet isrequired. If all the MAPs in the coverage area will be indirectly connectedto WX switches through the network, a wiring closet is not required.35 In the Redundant Wiring Closet list, select the wiring closet that willprovide redundant connection to the MAPs. This is required for directlyconnected MAPs, if you require the MAPs to have redundantconnections. Otherwise, this is not required.36 Click Finish to complete the wizard and create the coverage area. Thecoverage area is now displayed on your floor.Compute and PlaceMAPsWhen you perform the Compute and Place procedure for one or morecoverage areas, 3WXM automatically calculates the number of MAPs yourequire and places them in appropriate locations on the floor. To do this,two calculations are performed in 3WXM. One is based on capacity(traffic engineering) and the other is based on pure RF coverage (at agiven data rate).After the calculations are performed, the number of MAPs from capacityand the number of MAPs from coverage are compared, and the biggercount “wins.” If capacity wins, a grid pattern of MAPs is established. TheMAP coverage positions are reused, with the excess MAPs remaining intheir original grid position.Using a “clean” RF model is imperative for best results. If you have manyparallel RF obstacles that are close together, the placement algorithmtends to add more MAPs than are required. So, even with the automaticclean layout mechanism in 3WXM, complex drawings demand additionalpruning and isolation of single RF obstacles objects to keep the RFobstacle count as low as possible. For more information about cleaningyour floor plans, see “Clean Layout” on page 130.When you are performing Compute and Place for a coverage area for thefirst time, the results do not account for existing MAPs. Manual overridesof the MAP results are not taken into account if you perform Computeand Place again.
