to each other without these facilities in place. The inter-MSC handoff workload increases as more base stations are involved. This can happen because more cells are in border zones or because the cells in the border 1The handoff link also could go away if the handoff path gets complicated enough that a path minimization is done and removes the link. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. MSC Transport Planning Planning for CDMA Capacity zones are smaller. Smaller cells do not always have more handoff activity, but they can be more sensitive to the variations in radio propagation, and thus we can expect more handoffs. As more MSCs are added, there are more MSC border cells, and this means that there are more inter-MSC handoff opportunities. As we pointed out in Sec. 36.1, the in- crease in border areas is more than proportional to the increase in MSCs. Each new MSC added to a system causes a greater increase in border zone traffic. Therefore, we can expect a greater proportion of inter-MSC handoffs as MSCs are added. When more than two MSCs are involved in one wireless telephone call, things can get complicated. A call can bounce around from A to B to C and back to A and then to C. The people writing the ANSI-41 specifications for inter-MSC handoff thought of these problems and dealt with them, as discussed in Sec. 15.1. When more than two MSCs are involved, each handoff pair has to have dedicated facilities. A rough rule of thumb for estimating the amount of inter-MSC handoffs can be cre- ated based on the traffic in a 150-m-wide band (one-tenth of a mile) between the two MSC regions. Not all the traffic in this band is going to be handed off from one MSC to the other, but this band is a reasonable place to expect inter-MSC handoffs. We suggest a narrower band here for actual handoffs than the band for handoff measurements in Sec. 3