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Scenario:

“Suppose “We-Connect” is a telecommunication company having a large digital cellular network. This company has a wireless network distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station (BS). A mobile phone is a portable device which receives or makes calls through a cell site (base station), or transmitting tower.

When the vehicle containing the Mobile Station (mobile phone) and the data terminal moves from one cell to another, handover occurs. This whole handover event can take 400ms and results in a line break during this time”.

 

Requirements:

  1. 1.     Which type of Line discipline is most suitable between mobile stations (mobile phone) and base station in this scenario? Give one solid justification.

  1. 2.     Which technique can be used to avoid data loss during handover event?

Views: 4126

Replies to This Discussion

Just Idea Guizzz Please batao k in me se konsa network better hy???

Attachments:

WHat is answer of 2nd question bro 

     Which technique can be used to avoid data loss during handover event?

 today is last date

ANS:1= Poll / Select type of  Line Discipline is most suitable, bcz it is used for "Primary-Secondary Communication". In primary-secondary, one device controls many other devices  and other must transmit through it.

According to GDB, a mobile phone recieves or send data through cell site or base station. BS is primary and mobile phones are secondary.

So i thnk Poll / Select type is suitable for this.

An advantage of the hard handover is that at any moment in time one call uses only one channel. The hard handover event is indeed very short and usually is not perceptible by the user. In the old analog systems it could be heard as a click or a very short beep; in digital systems it is unnoticeable. Another advantage of the hard handover is that the phone's hardware does not need to be capable of receiving two or more channels in parallel, which makes it cheaper and simpler. A disadvantage is that if a handover fails the call may be temporarily disrupted or even terminated abnormally. Technologies which use hard handovers, usually have procedures which can re-establish the connection to the source cell if the connection to the target cell cannot be made. However re-establishing this connection may not always be possible (in which case the call will be terminated) and even when possible the procedure may cause a temporary interruption to the call.

One advantage of the soft handovers is that the connection to the source cell is broken only when a reliable connection to the target cell has been established and therefore the chances that the call will be terminated abnormally due to failed handovers are lower. However, by far a bigger advantage comes from the mere fact that simultaneously channels in multiple cells are maintained and the call could only fail if all of the channels are interfered or fade at the same time. Fading and interference in different channels are unrelated and therefore the probability of them taking place at the same moment in all channels is very low. Thus the reliability of the connection becomes higher when the call is in a soft handover. Because in a cellular network the majority of the handovers occur in places of poor coverage, where calls would frequently become unreliable when their channel is interfered or fading, soft handovers bring a significant improvement to the reliability of the calls in these places by making the interference or the fading in a single channel not critical. This advantage comes at the cost of more complex hardware in the phone, which must be capable of processing several channels in parallel. Another price to pay for soft handovers is use of several channels in the network to support just a single call. This reduces the number of remaining free channels and thus reduces the capacity of the network. By adjusting the duration of soft handovers and the size of the areas in which they occur, the network engineers can balance the benefit of extra call reliability against the price of reduced capacity.

ANS:1= Poll / Select type of  Line Discipline is most suitable, bcz it is used for "Primary-Secondary Communication". In primary-secondary, one device controls many other devices  and other must transmit through it.

According to GDB, a mobile phone recieves or send data through cell site or base station. BS is primary and mobile phones are secondary.

So i thnk Poll / Select type is suitable for this.

Bhai Sir Mat khurkain Please help idea send krain

in my point of view poll/select type of line disipline is correct plz discuss

yes i listen relative lec 37, and whole lec i found is poll/select method for first point.

salam 

any one who make assignment plz share it 

thanx

2nd Answer:

Stop-and-wait  technique is best because in this technique is handover occur and data lost then data sent again.....

reply anyone?????

is it true????

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