JPL's Wireless Communication Reference Website

Chapter: Cellular Telephone Networks
Section: Handover

Different Approaches to Handover

Centralized

In the GSM system, handover from one cell to another is completely centralized. Base stations continuously monitor the received signal quality and if this drop below a predetermined threshold, surrounding base stations perform a field strength measurement to find the best base station to which the call can be handed over.

Decentralized

On the other hand, in DECT handover are decentralized. The portable terminal continuously searches for the best, i.e., strongest or clearest, base station signal.

Handover approach: GSM DECT
Centralized: Decentralized
Initiated by BS Initiated by MS
To avoid poor reception Searches best channel
Separated from Part of Dynamic Channel
Frequency Management Allocation (DCA)
Needs tuning of BS-s Requires setting of parameters
Ping-pong effects Potential instability
H-O to other carrier May remain on same carrier

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