An impurity precipitation region is formed by introducing an impurity, e. Map information corresponding to the extending area is extracted from the map information stored in map information storage means. A receiver receives the packet of data over the time frame, and processes the received data accordingly to reproduce the block of data. The securing step may also include the step of distorting the elliptical shape of the internally-threaded collar. A new LSP linking the two regions is inserted into a routing database for a routing instance associated with the second region. Each zone has an arcuate timing field segment which extends across the zone and is angularly discontinuous with the timing field segment of an immediately adjacent zone.