his information to retrieve the subscriber's service profile record stored in its home location register (HLR). If the subscriber is roaming, then the serv- ing MSC is not the home MSC, and it sets up a record in the visitor location register (VLR). The VLR record is temporary and only remains active while the user terminal is registered at that particular serving MSC. The HLR is informed of the location of the serving MSC and stores the current registered location and status of the user terminal inside the subscriber's record. In addition to establishing identity and location, the system must verify the sub- scriber's right to use the system. Are this subscriber's wireless telephone bills paid? If the subscriber is cut off from service at home, then we want to cut off service every- where else as well. The system must allow a roaming subscriber to use only services that are in the subscriber's contract and must track the usage of each service and bill it at the appropriate rates. Incoming calls may come to the home MSC and may then be routed to the MSC serv- terminal. Even in landline telephony, it is not unusual to involve multi- ple telephone switches in one call, but it is strange to have two telephone switches both involved in the local-loop termination of a call. However, this is a normal situation for incoming calls to roamers. 11.4.3.3 Roam dialing. A call from a roaming phone is an administrative task unlike any faced by a landline central office switch. Since the days of AMPS, the rule has been "When you roam, dial like home." This has become harder in today's international roaming world, and the wireless telephone systems seem to be keeping up, at least some of the time. In the Sprint PCS system, where the entire Sprint PCS North Amer- ican Network is the home system from the perspective of the subscriber and for billing and service purposes, the original dialing rule is not fully functional. As long as the sub- scriber dials from his or her home area code, there is no problem. Dialing either a 10- dig