What is the basic concept behind Handoff mechanism?
In mobile communication when the user switches from one base station to other base station there takes place the mechanism called Handoff. What exactly is the concept behind handoff?Posted in: #Electronics
Consider the scenario, where you're travelling in a car and using your mobile device. In order to provide smooth transition with no signal loss, process called handoff is done between UE and enodeB ; where UE is disconnected from current antenna and latched to other one.
UMTS has an interesting feature of soft-handover, where UE is connected to two antennas at a point of time before breaking connection from lesser strong connection, making the handoff process seem smooth.
Technically in LTE, soft handoff was not possible as your mobile device need to resync with the frequency of new enodeB [OFDMA]. Device transits to slotted/compressed mode, where it remains connected to current enodeB and searches for new one at same time duration. It happens so fast, that we no longer require soft-handover in LTE network.
Handoff is the mechanism of switching channel associated with the current connection (frequency, time slot, spreading code, or their combination) when a call is in progress. Sometimes, it is caused either through crossing a cell boundary or by worsening signal quality in the current path.