JPL's Wireless Communication Reference Website Chapter: Network Concepts and Standards Section: Data Systems, CDPD

CDPD Handover

When an M-ES in communication moves from one cell to another, a handover radio link transfer process is required to re-connect the M-ES in the new cell. The CDPD transfer process is controlled by the M-ES as follows.

• The M-ES monitors the radio link quality. If the quality falls below the pre-defined thresholds for the radio signal strength and error rates, the M-ES initiates the link transfer process by searching a better quality channel (a list of available channels are broadcast by the MDBSs).
• The M-ES tunes to the new channel and informs the new MDBS that it has entered the cell. The new MD-IS updates its Registration Directory) so that the future data for the M-ES are directed to the current cell.
• If the old MDBS and the new MDBS connect to different MDISs), the transport layer retransmission is required to re-establish the end-to-end connection.

JPL's Wireless Communication Reference Website © Yi-Bing Lin (Author) and Jean-Paul M.G. Linnartz (Ed.), 1996.