GSM questions about HLRs

[lincolndsp]

How many HLRs can be in a GSM operator's network,
how and which HLR is chosen to store the Mobile Subscriber's
data, does the HLR change in the process of movement?

 

[pmonon]

Re: GSM question

I think there can be more than one HLR. Which one is chosen from a mobile user shud depend upon with which HLR he is physically closest to. HLR should not change due to mobility of user.

 

[amihomo]

GSM question

Hi

there is one HLR and one VLR and a number of BTS's in each MSC.
The subscriber information is stored permanently in the HLR he has purchased the SIM card (can be found from the phone number) and when the MS is moving out of the cells (one ore more BTS cover every cell)which are allocated to a VLR , the MS location information is handed over to the next VLR (which may belong to another MSC).

regards

Added after 3 minutes:

the HLR does not change when roaming in cells.only VLR could change

 

[ibrahimsayed]

Re: GSM question

How many HLRs can be in a GSM operator's network,
how and which HLR is chosen to store the Mobile Subscriber's
data, does the HLR change in the process of movement?

Dear amihomo

the number of HLRs are determined according to the dimensioning of the network which is done a the first phase of the network implementation,and so it depends on the number of subscribers the network expects to serve and the capacity of the HLR itself as HLR is just a storage mdium for different database of all subscribers at the network,so if the number of subscribers exceeds the capacity of one HLR we will need more HLRs to serve the subscribers,thus the number of HLR at the system depends on the number of subscribers it will seve and the HLR capacity.any way if there are more than one HLR they are connected together to become as one HLR,so it doesn't matter how many HLRs i have at the network as they are connected together as one HLR and so the data of the subscribers can be stored at any one as the most important thing is to restore the data of the subscribers when we need that.At the process of movement,the data at the HLR will not change at all as it is a fixed data,but the data at VLR may change.

Best Regards
Ibrahim Sayed

 

[lincolndsp]

GSM question

Dear ibrahimsayed, so why do many books
about Gsm show a pair of HLR and VLR
connected to each MSC. So the books are
pretty incorrect?

 

[zhov]

Re: GSM question

To avoid the concentration of signaling messages from all over a big country in
a single spot, a big PLMN, say 25 million subscribers, may have several HLRs,
so that each HLR has to maintain the data of about 1–4 million subscribers,
depending on the preferences of the network provider. One HLR may serve
several MSCs (most probably 2 or 3? - i'll try to find out), and every MSC has a VLR.
Hope this helps.

 

[ibrahimsayed]

Re: GSM question

Dear ibrahimsayed, so why do many books
about Gsm show a pair of HLR and VLR
connected to each MSC. So the books are
pretty incorrect?

Dear lincolndsp

What is explained in books is just for the illustration of the system to know the components of the system and know also the function of each one of them,but no book of them gives a detailed exlaination of the GSM network,because different networks exist in different countries according to many reasons.any way each network for example consists of many MSCs,did any book draw a figure that contains 10 or 20 MSCs,what is often drawn is just one or two MSCs just to explain the hierarchy of the network,and so the same foe HLR and VLR.each MSC is associated with VLR and the whole network contains multiple HLRs that are connected together and act as one HLR,because HLR has a limited capacity,and if the number of users exceeds it,we need an extra HLR.And if this is incorrect,how the MSC that serves you, searches for a person you want to call if this person in a nother MSC/VLR area.the MSC should goes to the HLR that contains the data of this user you want to speak to,so if there multiple HLRs in the network,how can the MSC determines the address of this specific HLR?

Best Regards

 

[kesuma]

GSM question

How many HLRs can be in a GSM operator's network,
how and which HLR is chosen to store the Mobile Subscriber's
data, does the HLR change in the process of movement?

Hello Bro..


I think there is a couple HLR n VLR in one MSC
BTS will be controlled by a BSC then all the BSC will be handled by a MSC
This configuration will create a local network
The HLR n VLR use for identifying where user coming from


Regards,

kesuma

 

[amihomo]

Re: GSM question

How many HLRs can be in a GSM operator's network,
how and which HLR is chosen to store the Mobile Subscriber's
data, does the HLR change in the process of movement?

Dear amihomo

the number of HLRs are determined according to the dimensioning of the network which is done a the first phase of the network implementation,and so it depends on the number of subscribers the network expects to serve and the capacity of the HLR itself as HLR is just a storage mdium for different database of all subscribers at the network,so if the number of subscribers exceeds the capacity of one HLR we will need more HLRs to serve the subscribers,thus the number of HLR at the system depends on the number of subscribers it will seve and the HLR capacity.any way if there are more than one HLR they are connected together to become as one HLR,so it doesn't matter how many HLRs i have at the network as they are connected together as one HLR and so the data of the subscribers can be stored at any one as the most important thing is to restore the data of the subscribers when we need that.At the process of movement,the data at the HLR will not change at all as it is a fixed data,but the data at VLR may change.

Best Regards
Ibrahim Sayed

hi dear ibrahimsayed

you are right.
I meant the same as you said. but maybe I couldn't clarify what I meant



Each mobile phone has a home location register (HLR) and a visitor location register (VLR) assigned to it. The HLR contains information such as the identity of the user and phone number assigned to the user in the user’s home network, the services to which the user has subscribed, whereas the VLR contains information about the mobile phone when it is used outside the home network. So when a mobile phone initiates a call, it sends the information to the BTS about its identity and so on from the VLR or the HLR depending on the location of the phone at the time the call originates. The mobile switching center checks the data from its HLR or VLR to authenticate the call and gives permission for the phone to access the network. As the caller moves within the cell, the BTS monitors the strength of the signal between the phone and the receiver, and if this falls below a certain level, it may transfer control of the phone to the BTS in the next cell, which may offer a stronger signal. If no such cell is nearby, the caller is cut off (i.e., will not be able to receive or to send a call). As the caller moves from one cell to another cell, the BTS serving it will transfer control to the BTS in the cell that it has moved to.


regards

 

[ibrahimsayed]

Re: GSM question

How many HLRs can be in a GSM operator's network,
how and which HLR is chosen to store the Mobile Subscriber's
data, does the HLR change in the process of movement?

Dear amihomo

the number of HLRs are determined according to the dimensioning of the network which is done a the first phase of the network implementation,and so it depends on the number of subscribers the network expects to serve and the capacity of the HLR itself as HLR is just a storage mdium for different database of all subscribers at the network,so if the number of subscribers exceeds the capacity of one HLR we will need more HLRs to serve the subscribers,thus the number of HLR at the system depends on the number of subscribers it will seve and the HLR capacity.any way if there are more than one HLR they are connected together to become as one HLR,so it doesn't matter how many HLRs i have at the network as they are connected together as one HLR and so the data of the subscribers can be stored at any one as the most important thing is to restore the data of the subscribers when we need that.At the process of movement,the data at the HLR will not change at all as it is a fixed data,but the data at VLR may change.

Best Regards
Ibrahim Sayed

hi dear ibrahimsayed

you are right.
I meant the same as you said. but maybe I couldn't clarify what I meant



Each mobile phone has a home location register (HLR) and a visitor location register (VLR) assigned to it. The HLR contains information such as the identity of the user and phone number assigned to the user in the user’s home network, the services to which the user has subscribed, whereas the VLR contains information about the mobile phone when it is used outside the home network. So when a mobile phone initiates a call, it sends the information to the BTS about its identity and so on from the VLR or the HLR depending on the location of the phone at the time the call originates. The mobile switching center checks the data from its HLR or VLR to authenticate the call and gives permission for the phone to access the network. As the caller moves within the cell, the BTS monitors the strength of the signal between the phone and the receiver, and if this falls below a certain level, it may transfer control of the phone to the BTS in the next cell, which may offer a stronger signal. If no such cell is nearby, the caller is cut off (i.e., will not be able to receive or to send a call). As the caller moves from one cell to another cell, the BTS serving it will transfer control to the BTS in the cell that it has moved to.


regards

Dear amihomo

Don't worry,but there is something i want to explain,when the caller moves within the cell, the BSC IS THE ONE THAT monitors the strength of the signal between the phone and the receiver, and if this falls below a certain level, it may transfer control of the phone to the BTS in the next cell,IF AND ONLY IF THIS CELL IS WITHIN THE COVERAGE AREA OF THE SAME BSC which may offer a stronger signal.as handove which you are explaining is controlled in GSM by BSC not by BTS

Best Regards
Ibrahim Sayed

 

[amihomo]

Re: GSM question

hi dear ibrahimsayed

again, you are right

 

[Nimer]

Re: GSM question

hi

for answering your questions and otheres on the wireless world attend dr.proakis lecture

understanding wireless tech

on techonline.com

regards

 

[ibrahimsayed]

Re: GSM question

hi dear ibrahimsayed

again, you are right

Dear amihomo

Don't worry,we are just co-operating to exchange our knowledge

Best Regards
Ibrahim Sayed