In this illustration, we see a telephone at top right that is labeled "Correspondent." At top left we see a blue cloud representing the home network, which includes the outline of a house containing a mobile switching center (MSC). Below the correspondent, we see a blue cloud representing the public switched telephone network (labeled "PSTN"). To the left of the PSTN we see the outline of a house containing a mobile switching center (MSC). This is labeled "Anchor MSC." A second house and MSC is below the PSTN, and a third is just outside of it to the bottom right. Each of the three MSCs not in the home network connects to a series of cellular coverage areas and base transceiver stations. A mobile user, depicted as a car, appears next to the second cellular coverage area.

A blue arrow extends from the Correspondent through the PSTN and into the MSC in the home network. A blue arrow extends from there through the PSTN and into the Anchor MSC. A blue arrow extends from the Anchor MSC and into the Mobile User via the MSC in the second cellular coverage area.