Concept Of Handover Or Handoff Inward Gsm/2G As Well As 3G

Handover or Handoff

Today inwards this article nosotros volition acquire most Handovers in addition to why it is required.
Actually, Hanover's or handoff are required for continuous mobility or connectivity thus that agency whenever nosotros are moving nosotros don't take away telephone outcry upward breakdown or connexion breakdown. For this the requirement nosotros lead maintain a concept of handover. So allow dive inwards it.

Let nosotros lead maintain 2 telephone jail cellular telephone equally shown inwards the icon above. At the border of the cell, the character of the quest is non expert equally compared to the electrical current set of the user. As the user moves towards the border of jail cellular telephone the quest gets weaker in addition to the user starts sending mr (measurement report). Measurement written report tells that I am going to a piteous network area, delight paw over me to about other cell.
Now in addition to thus the user volition move transferred to a novel jail cellular telephone in addition to good gets starting meliorate coverage. So the procedure of shifting a user telephone outcry upward command from piteous network expanse to novel jail cellular telephone is known equally Handover or Handoff.
That's why handover or handoff is required for seamless mobility.

Home in addition to Foreign cell

allow suppose if nosotros are moving inwards an expanse inwards which nosotros lead maintain a publish of cells connected for illustration jail cellular telephone A, B, C, D, due east equally shown inwards in a higher house minute image.
The user where He/She kickoff a telephone outcry upward is known equally the abode jail cellular telephone in addition to the coming side past times side jail cellular telephone is called the unusual cell. After the handover procedure when the user shift to jail cellular telephone B thus jail cellular telephone B is the abode jail cellular telephone for the user in addition to coming side past times side jail cellular telephone C volition visit the foreign cell in addition to thus on. This procedure volition proceed until the user reaches to jail cellular telephone E.

Types of Handover

There is 2 type handoff

Soft Handover
Hard Handover

Hard Handover used inwards GSM (Global arrangement for mobile communication) besides known equally 2G. The procedure is " Break earlier brand " this agency earlier the user makes a connexion alongside the foreign cell yous must intermission a connexion alongside the abode cell.

Soft handover procedure is reverse to Hard handover. The procedure is "Make earlier break" this agency that earlier breaking the connexion alongside the abode jail cellular telephone it volition brand connections alongside unusual jail cellular telephone in addition to thus it volition intermission the connexion alongside the abode cell. It is used inwards 3G.

The Handover procedure is farther categorized into Vertical handoff in addition to Horizontal handoff.

The Vertical handoff is differ from Horizontal handoff due to the next reasons:

Not alone i type of network connexion is acquaint rather, to a greater extent than than i network connexion is acquaint inwards Vertical handoff.
RAT is changed inwards Vertical handoff.
Not alone RAT is changed, QoS in addition to that of network interface may move changed inwards Vertical handoff.
The IP address is changed inwards both Vertical in addition to Horizontal handoff.

Vertical Handover Process:

The procedure of Vertical handover is categorized into 4 unlike stages:

Handover Initialization stage.
System regain stage.
Decision making stage.
Handover execution stage

1. Handover Initialization Stage:

The procedure is initiated past times i or to a greater extent than than i network pick parameters.
Checks for link character or decrease inwards quest strength.

2. System Discovery Stage:

In arrangement regain phase the mobile terminal collect all the information most the available networks inwards guild to select network for handover. QoS tin move used to telephone commutation information betwixt the mobile in addition to the network.

3. Decision Making Stage:

In this phase of determination making, the Vertical handover create upward one's heed whether to proceed the connexion alongside the electrical current network or to switch to the previous one. The pick in addition to the determination depends on the bandwidth, availability, frequency etc of the network.

4. Handover Execution Stage:

In this in conclusion phase of Handover execution stage, when the determination has made, the connections are re-routed from the source network to the target network. It involves the transfer of signals along alongside ascendency in addition to authentication.

Vertical Handover Classification:

Vertical handover is farther classified into 4 (4) categories:

Depending on management
Depending on process
Depending on direction
Depending on control

1. Depending on direction: (Upward & Downward)

When a mobile user switches from a network alongside depression expanse coverage to the network alongside high expanse coverage, in addition to thus the handover is called upward handover in addition to when the mobile user switches from network alongside high expanse coverage to the network alongside lower expanse coverage, in addition to thus this type of handover is called downward handover.

2. Depending on process: (Hard & Soft)

when the mobile user breaks the connexion alongside the electrical current network earlier establishing connexion alongside the novel network , this type of handover is called difficult handover equally hash out above. And when the mobile user connects alongside the novel network subsequently that breaks connexion alongside the previous network, this type of handover is called soft handover.

3. Depending on decision: (Imperative & Alternative)

When the value of RSS (Received Signal Strength) decreases the value of threshold, the handover is called imperative handover, Where equally inwards choice several handover parameters are taken into consideration such equally bandwidth etc.

4. Depending on control: (Mobile & Network)

Simply it tin move defined that handover is controlled past times the mobile node inwards mobile controlled in addition to spell that inwards network-controlled, a primal entity is responsible for controlling handover.

Advantages of handover or handoff

Simultaneous connectivity agency fewer chances of telephone outcry upward intermission upward due to weak signal.

Don't forget to Share this post service alongside your friends