 CDMA Capacity calls into roamer calls. They may not look like roamers on the wireless telephone bills, but they are roamers as far as signaling and inter-MSC communication are concerned. And having more MSCs in a system means more inter-MSC handoff activity. In determining the number of MSCs required, we should think in terms of a fully loaded maximum-configuration switch. Of course, we do not plan to equip every MSC with all the equipment it can support, but we should base our estimate of MSC count on the full capacity of each MSC. Once we have the number of MSCs, we can equip each MSC as needed in Sec. 34.3. 34.1.1 Main processor capacity The MSC processor handles call processing, short message service (SMS), other sig- naling, and handoffs, as discussed in Sec. 24.1. The total workload for an MSC is the total sum of these tasks, so it suffices to have a switch processor powerful enough to handle the combined peak load with some headroom to spare. This is not an area for traffic engineering or any kind of aggressive engineering. When a switch processor runs out of capacity, the system stops working. Calls are not completed, short messages are lost, and handoffs are mismanaged. There is some ability for switch-processor tasks to be put into a queue, but a telephone system, wireless or not, has little tolerance for switch-processor delays. Thus we can take the total call processing, SMS, and other sig- naling loads, add some fraction for inter-MSC handoffs, add some headroom factor, and divide that by the maximum processor capacity of one MSC. This gives us a lower bound for the number of MSCs we need. The good news for processor capacity is that data services typically involve propor- tionally less call processing. As demand for third-generation (3G) services grows, the ratio between air-interface demand and processor capacity demand actually will put less pressure on the MSC main processor. 34.1.2 Transport load capacity The transport load of a telephone switch is the total number of DS-1 or E-1 links from the