What is soft and hard handover in LTE?

The handover in which radio links are added and removed in a way that MS always keeps at least one radio link to the UTRAN is known as soft handover. The handover in which all the old radio links in MS are removed before the new radio links are established is known as hard handover.

What is difference between soft handover and hard handover?

Hard Handover:- When mobile(in Call) switches to a new sector/Cell which is on different frequency , then it performs hard Handover. It is basically an inter-frequency handover. SOft Handover:- When mobile ( in Call) switches to a new sector/cell which is on the same frequency then it is called a soft handover.

What is the difference between soft handover and hard handover in a cellular communication?

Hard handover: This form of handover is essentially the same as that used for 2G networks where one link is broken and another established. Soft handover: This form of handover is a more gradual and the UE communicates simultaneously with more than one Node B or base station during the handover process.

Which of handover does LTE support?

LTE supports two types of handover: X2-based handover and S1-based handover. The X2-based procedure is the least complex handover and typically would be used when an X2 interface exists between the source eNB and the target eNB.

What is the difference between soft and softer handover?

Soft handover – handover between two sectors of the same cell of a NodeB is called soft handover. Softer handover – handover between two cells (different NodeB) is called softer handover.

Why soft handover and softer handover are used in Wcdma?

Handovers are an important part of every cellular communication system. Especially in WCDMA two special types of handovers have been introduced; soft and softer handovers, allowing a mobile user to use 2 separate air interface channels when being in the overlapping area of two adjacent sectors.

Why soft handover and softer handover are used in WCDMA?

How handover happens in LTE?

Abstract: Handover in LTE occurs when a device moves from the cell coverage serving it towards another; a process where the user established session must not be interrupted due to this cell change.

What is handover preparation in LTE?

The overall handover process may be described as the source access handling the procedures, such as UE and radio network measurements, to determine handover needs to be initiated, preparing the resources in the target radio and core network side, directing the UE to the new radio resources, and releasing the resources …

How do I trigger handover LTE?

The LTE standard supports several parameters to trigger the handover and select the target cells, such as hysteresis margin and Time-to-Trigger (TTT). When applying Time-to-Trigger, the handover is initiated only if the triggering requirement is fulfilled for a time interval.

What is X2 handover in LTE?

eNodeBs in LTE are interconnected with the X2 interface. If two eNodeBs are served by the same MME, handover from the source to the target eNodeB will take place over the X2 interface.

Can soft handover be dropped from LTE networks?

Cell-edge reception (which was at the core of Soft HO design in WCDMA) issue is not quite applicable in LTE networks because of orthogonality in both uplink and downlink. Therefore soft handover can be dropped from the LTE system.

Why soft handover is possible in CDMA?

Soft handover is possible in CDMA because adjacent cells can operate on the same frequencies as long as they use different scrambling codes. So, a UE can listen to two different cells by decoding the received signals twice, using a scrambling code from each cell on each for each decoded signal.

What is the difference between soft handover and hard handover?

Also soft handovers are only possible when UE is in connected state with the DCH (dedicated channel). In case of HSDPA communication there is only hard handover (break before connect). In there is no central node controller like the BSC or RNC.

How many radio links are there in soft handover?

This means at least one and maximum of 8 radio links are connected to the UE. Soft handover is a part of WCDMA system which is basically same in concept as in CDMA systems. In the case of soft handover the mobile station is in the overlapping cell coverage area of two sectors belonging to different base stations.