Thread: Telecom Domain

Hi,
First of all very sorry for late reply. I was involved in major delievry of a software.

Well as far pdf file is concerned, It explains the mobile attachment procedure in GPRS setup. Whenever a mobile comes up (i.e. we switch on our mobile), then this procedure starts. In very first step MS sends it's details to BSC which includes it's TMSI, MNC, MCC, LAC, RAC. BSC further passes this details to SGSN. I hope you are well aware that in GPRS SGSN and GGSN are two new entities which make sure minimum changes in a GSM setup.

These entities further checks identity and authenticate MS details. After various checks Location update procedure starts and so the current location of MS is updated. This ends the mobile attachement procedure.

After Mobile attachement PDP context activation process starts. PDP(Packet data protocol) context is a datastructure present on both the SGSN and the GGSN which contains the subscriber's session information . When a mobile wants to use GPRS, it must first attach and then activate a PDP context. This allocates a PDP context data structure in the SGSN that the subscriber is currently visiting and the GGSN serving the subscribers access point.

I have taken the reference from eventhelix . com and wikipedia . org

I will be glad to cotinue the discussion in case of any issue.

Thanks and regards.
Gaurav Bhatnagar

Hi,
Do you have any idea about Handover? How this is achieved in GSM?

hi friend..

When the phone is moving away from the area covered by call and entering the area covered by another cell, the call is transferred to the second cell in order to avoid call termination when the phone gets outside the range of the first cell

When the capacity for connecting new calls of a given cell is used up and an exixting new call from a phone, which is located in an area overlapped by another cell in order to free up some capacity in the first cell for another users, who can only be connected to the cell

In non-CDMA networks when the channel used by the phone becomes interfered by another phone using the same channel in a different cell, the call is transferred to a different channel in the same cell or to a different channel in another cell in order to avoid the interference

Again in non-CDMA networks when the user behaviour changes, e.g. when a fast-travelling user, connected to a large, umbrella-type of cell, stops then the call may be transferred to a smaller macro cell or even to a micro cell in order to free capacity on the umbrella cell for other fast-travelling users and to reduce the potential interference to other cells or users (this works in reverse too, when a user is detected to be moving faster than a certain threshold, the call can be transferred to a larger umbrella-type of cell in order to minimise the frequency of the handoffs due to this movement)

The most basic form of handover is when a phone call in progress is redirected from its current cell called source and its used channel in that cell to a new cell called target and a new channel. In terrestrial networks the source and the target cells may be served from two different cell sites or from one and the same cell site (in the latter case the two cells are usually referred to as two sectors on that cell site). Such a handover, in which the source and the target are different cells (even if they are on the same cell site) is called inter-cell handover. The purpose of inter-cell handover is to maintain the call as the subscriber is moving out of the area covered by the source cell and entering the area of the target cell.

A special case is possible, in which the source and the target are one and the same cell and only the used channel is changed during the hadover. Such a handover, in which the cell is not changed, is called intra-cell handover. The purpose of intra-cell handover is to change one channel, which may be interfered or fading with a new clearer or less fading channel.

Thanks
Deepasree

Hi Friend,
You have written that whenever a MS is moving out of coverage area of any cell then call is transffered to another cell. If MS is not on call then what will happen? Also who will transfer the call. Is it mobile initiated process or BTS initiated or BSC initiated. And what do you mean by capacity of cell?

I think that MS always exchange some messages with BTS. BTS has an attribute power capability. Power capability depands upon the distance of MS from BTS. If BTS senses that the value of power capability is going down then it initiate the Handover process.

Please make me right if I am wrong.

Gaurav Bhatnagar

Hello,
You said that when phone is moving then call is transffered to second cell . But if I phone is not on call then what will happen? And also who will transfer. Is it mobile initiated process or BTS initiate or BSC initiate? And also what do you mean by capacity of cell?

I hope a mobile continously transffered signals to BTS (it's nearest Cell). It does'nt depand whether MS is on call or idle. As per my knowledge, It is a BTS initiated process. Every BTS has an attribute i.e. power capability. Power capability attribute changes according to distance of a MS with BTS. Whenever a BTS finds that power capability is going down it sends Handover request new BTS(or BSC confused!!!!).

I will be glad to see your response.

Gaurav Bhatnagar

Hello,
Please see my response in next page.

Thanks
Gaurav Bhatnagar

hi friend,

I am sorry for late response, please view the attachment enclosed

Thanks
Deepasree

HI,
Thanks !!!! Please give me sometime. I will revert back soon.

Gaurav

Hello,
Right now I am working on GPRS Technology. Very specifically I am working on Gb Interface. At Gb Interface NS layer can communicate to peer with two method. 1) IP based 2) FR based.

I wish to know what is mostly used trends in market. What are the criteria for operator to choose between FR and IP?

Thanks in advance.
Gaurav Bhatnagar

I am a telecom engineer. and i hv started my career as a BTS engineer for new sites of vodafone. but fortunatelly i'v an interview for network profile/switching profile. in Reliance.
can anyone tell me how i can clear d interview ques for network proile. but i want dat job for comming in reliance?
wt kinda preparation shud i do?????
er.sahil munjal
9466231996
9990672319

Hello,

Please can some explain how testing is done on bandwith provisioning.

2. Can someone please explain cramer in OSS.


Thanks

Hi,

I have 4 years of Experience in testing (manual & Automation) working on Web based Applications. But the applications are for a Telecom company. Since I am from E&C background, planning to switch to Telecom Testing domain. Please help with details regarding

Specific Technology with in Telecom domain, good to work with?

hello frnds....no reply frm ur side...wat haapen???

Originally Posted by raja2010

Hi,

I have 4 years of Experience in testing (manual & Automation) working on Web based Applications. But the applications are for a Telecom company. Since I am from E&C background, planning to switch to Telecom Testing domain. Please help with details regarding

Specific Technology with in Telecom domain, good to work with?

Hi Raja,
There so many technology in telecom domain. You can go for GSM, GPRS, EDGE, LTE, Wimax etc. However it is difficult to move in telecom domain from Web based application with 4 yr experience. Mostly companies generally need relevant experience. If you need to know any specific technology, Please revert.

Gaurav

Originally Posted by gau_bhatnagar

If any body intrested in GSM, GPRS, 3G and other Telecom technology. please response. I wish to discuss various technical issues in same.

Hi,

I am interested. I am actually looking to learn this stuff

hi friends,
This are all very useful information,
can you also post information about Telecom VAS

thanks
karudan

Hi, Thanks for all the posts ... It really helped me in understanding call scenarios and other details ..