ribers would arrange to be able to use this one picocell as a pri- vate data node in its own data network. Data packets could go directly from the pico- cell to their internal network without taking a detour through the mobile switching center (MSC) or the public packet data network (PPDN). The private network wireless data terminals might be configured to use the MSC and PPDN for their packet routing if they are not being served by their private picocell. A picocell also can be used for a private voice network in a large building. Special cell phones could be configured so that their voice calls would use the private voice network from inside the building. The picocell would send the voice traffic from these user ter- minals directly to a private branch exchange (PBX) inside the building on a private net- work. These special cell phones might be allowed to use the MSC and PSTN when be- ing served by another base station outside the building. We can use picocells for very small spot service but also for specific service in a build- ing. Such specific service can be high-rate data service using the most advanced 3G technology, or it can support private networks for wireless data or voice subscribers. 42.7 Handoff Management New cells mean new neighbor lists for handoffs. When a growth cell is added next to an old cell, the growth cell should be put on the handoff neighbor list for the old cell. Per- haps there is an old cell that used to be a neighbor that now has an entire growth cell in between, so it should be taken off the handoff neighbor list. And the new cell itself needs a list of handoff candidates. The first step in creating new handoff neighbor lists is to draw a picture of the cell layout. The base stations are dots on the map, and we can draw cookie-cutter lines halfway in between the dots for cell boundaries. Then we can draw sector boundaries radiating from the base station dots. The resulting shapes on the map are the cells and sectors represented geometrically. We are using distance to represent r