How A Call Is Made From Mobile Phone

How A Call Is Made From Mobile Phone

We all are crazy on mobile devices and the smart phone rocks today’s world, it does many and we all are getting addicted towards the technology. When it has all the need’s the basic by default is used for calls, when you talk about this we wonder of the Wireless Techniques and the way we are connected to people,

Have you ever wondered how a call is getting connected and how wireless makes you to get in touch with your loved ones? Here we go




In general We use to just open the call icon and dial the number that we are in need of and start to talk with them, but at backend there are things happening in jiffy which is quite interesting.

As soon as you dial a number from your mobile, the mobile phone transfers the Signal to the nearby Mobile tower called as Base Transceiver station and then starts the process

  • BTSBase transceiver station – This is nothing but the mobile Tower which radiates the signal to the devices and plays the initial role. BTS sends the request to BSC to which it is connected
  • BSC – Base Station Controller – BSC controls the BTS, we can say that a large number of BTS is being controlled by BSC depends on the number of users, so this can be called as a larger unit. So as soon as BSC receives the request from BTS, it in tern transfer the same to MSC
  • MSC – Mobile Switching Center – This is responsible for Switching calls to the subscriber’s. MSC controls the number of BSC, a number of BSC is connected With MSC and now here comes the more interesting information’s. MSC send the request to HLR
  • HLR – Home Location Register – this is the server which stores all the necessary details of the subscribers (Callers) permanently. HLR checks the information about the caller, i.e – HLR checks the account type (pre-paid, post-paid) , live user, area etc. If you are the Home subscriber then it moves to the next level, if not VLR – Visitor location register is a server which checks the visiting subscribers i.e., when you move out of your hometown this VLR helps to store the details on temporary basis.
  • So HLR checks the database for the details and then sends the acknowledgement to MSC , if the message is OK then the operation continues and MSC will again send’s a request to HLR to find out the details for whom the call is actually made (Receiving Party), If Both the Caller and receiver belongs to the same MSC, then HLR finds the details and inform the MSC that to which area the call party belongs , Therefore the MSC now establishes a connection via Air and thus the call will get connected.
  • If the HLR acknowledgement to MSC is not OK, then MSc in tern sends the message to BSC which has initiated the request, BSC acknowledges BTS and BTS send the same to Mobile and thus the call will get disconnected.
  • TheEIR – Equipment identity register – It is a database that contains information about the identity of the mobile device that prevents calls from stolen, unauthorized or defective mobile stations.

The HLR holds the billing server and thus after the completion of calls it calculates the bill.

I know that you will really wonder how these things are happening, we just dial and the opponent receives the call within fraction of seconds. Technology Always Rocks!!!!!!

When we discuss on the call connectivity’s it will not get completed without knowing about SIM, Mobile is transmitting signals and thus with the above explained techniques the call is getting connected but Sim plays the initial role.

SIM – subscriber Identity Module, it can also be called as Subscriber identification module – It is an integrated circuit chip that is intended or designed to store IMSI (international mobile subscriber identity) number which is used to find out and authenticate the subscribers, as we all know it is also possible to store contacts in Sim cards. SIM cards are always used on GSM phones.

Read: WIMAX Technology & Its Functionality

The Operation and Support System (OSS)

OMC- Operations and maintenance center is designed to connect to equipment of MSC- Mobile Switching Center and BSC-Base Station Controller. The implementation of OMC is called OSS-The Operations and Support System. OSS helps in mobile networks to monitor and control the complex systems.The basic reason for developing operation and support system is to provide customers a cost effective support and solutions. It helps in managing, centralizing, local and regional operational activities required for GMS networks.

Maintaining mobile network organization, provide overview of network, support and maintenance activities are other important aspects of Operation and Support System

Let us take a moment to appreciate or praise the Technology designed for Calls through mobile phones.

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  1. Key terms which people working in telecom sector should definitely be aware of…thanks for the clear and brief explanation…!

    Well done..

  2. Aw, this was a very nice post. In concept I want to put in writing like this additionally – taking time and precise effort to make an excellent article… but what can I say… I procrastinate alot and in no way seem to get something done.

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