Method of rekeying roaming communication units
 A method of providing over the air rekeying information to roaming communication units in a secure wide area communications system including a home key unit 101, a first key unit 102, and second key unit 103 operably linked together. A communication unit 104 affiliated to the home key unit 101 roams to the locality of the first key unit 102. The roaming communication unit then transmits a key request 112 to the first key unit 102 that transmits a unit information request 108 to the home key unit 101. The home key unit 101 responds by transmitting a rekey information packet 109, that includes a unit key 110, to the first key unit 102. The first key unit 102 then transmits a key information packet 113, that includes the unit key 110, to the roaming communication unit. The roaming communication unit then uses the unit key 110 to communicate securely at the locality of the first key unit. 
Motorola, Inc.
H H H H H
H04L H04L H04L H04W H04L
inventional inventional additional inventional inventional
Kevin David A. Kevin
Cutts Green Gardeck