# Why IMEI no is required?



## techani (Nov 4, 2008)

Hello friends after a long time i am visiting the forum. But thats not imp at all. I have a confusion...
I have read in the newspaper that in order to trace the terror accused the police require the IMEI no of the handset incase of a terror attack. 
According to police since the terrorists use chinese mobiles which dont have IMEI nos or have duplicate IMEI nos they cant trace the culprit.
But if they get the phone no and the call details(which they easily get from the service provider) then they should easily track down the culprit coz no 2 persons can have the same mobile no.
Now why do they need the IMEI no?


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## Pathik (Nov 4, 2008)

To track the phone in case they change the sim and forget to change the sim. They can also find the location of a particular IMEI within a few hundred meters.


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## chinawall (Nov 4, 2008)

well if aware of recent blast in Assam exactly same happened 2 persons actually had  same phone number! ( its in times of india ,kolkata 4/11/08) pls read the paper for details.


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## techani (Nov 4, 2008)

@ Pathik, do the service provider track the phone through the IMEI no or the sim? I mean they will just check from which tower the sim is recieving the signal and track it. They cant do it when the set is off. Or am i wrong somewhere?
@Chinawall, i know about the Assam case, but thats just recently happened and in this case its ok. But from a long time security agencies are maintaing that they need the IMEI no. Like read this portion - "SIM card details can be traced from a mobile phone only if it has a valid IMEI number," a government official said, on conditions of anonymity.

"An IMEI number consists of 15-17 digits. Genuine branded phones carry valid IMEI numbers. When the SIM card in a mobile phone gets activated, the IMEI number gets automatically registered with the GSM service provider and it becomes possible to trace a call and find out the caller's identity and the location from where the call was made," the official said.

from here.


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## srinivasdevulapally (Nov 4, 2008)

IMEI is a unique number to every mobile phone.....
So eventhough you change the sim the phone IMEI won't change and one can be tracked easily..

Generally used to ban the phones in lost cases, theft etc.


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## techani (Nov 4, 2008)

@Srinivas, I agree that the phone can be tracked easily. But how will they know whose phone is it? Unlike the sim which the security agency can know through the service provider?


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## Cool G5 (Nov 4, 2008)

> When mobile equipment is stolen or lost, the operator or owner will typically contact the Central Equipment Identity Register (CEIR), which blacklists the device in all operator switches so that it will, in effect, become unusable, making theft of mobile equipment a useless business.
> 
> The IMEI number is not supposed to be easy to change, making the CEIR blacklisting effective. However, this is not always the case: a phone's IMEI may be easy to change with special tools and some operators may even flatly ignore the CEIR blacklist.



From Wikipedia


They can know the owner of the phone, by the bill which the owner gives to required authorities. The sticker which the dealers stick on a bill, has *IMEI* number. There are three stickers on the box when you purchase a new handset. One sticker is left on the box, second is stuck on customers invoice & third is kept by the dealer.


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## techani (Nov 4, 2008)

techani said:


> @ Pathik, do the service provider track the phone through the IMEI no or the sim? I mean they will just check from which tower the sim is recieving the signal and track it. They cant do it when the set is off. Or am i wrong somewhere?


What about this question?


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## moshel (Nov 5, 2008)

techani said:


> What about this question?



the service provider does not just know your IMEI number but also which handset ur using right now. there is a log too which gives all the details of when ur sim was put in which handset, complete with time and IMEI number.

even when u call customer care, the exec can check which handset ur using.....it helps when a nokia 1200 owner says that he is not able to use gprs on his handset.

as for the towers, yes they can know. my guess is they can track it by the mobile number, i mean, the phone always tries to stay on a network so the details will surely go to the service provider showing which mobile number is in which area.


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## techani (Nov 5, 2008)

@ Moshel, I know all these things. What I am trying to know is that why will the security agencies need the IMEI no? Coz if I am a terrorist and i make a phone call then they can easily trace the person with the sim information which the service provider have. The sec. agy can also find out incase i (terrorist) changes the handset coz the no remains the same. Now if he changes the sim then also there isnt any problem in tracing it.
How does the IMEI no becomes so important that without that the sec. agy. cant trace the culprit?


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## Anorion (Nov 6, 2008)

An IMEI can be useful for a lot of things. Basically it traces the phone irrespective of the sim. 
>Kidnapped people with mobile phones
>Criminals on the move or on the run
>Lost people, especially children who cannot say where they are
>Identifying dead people in disasters which effaces the bodies
>Rescue operations in earthquakes or avalanches
>Keeping track of employee movement

and a lot of other things


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## techani (Nov 6, 2008)

@ Anorion ur answer again takes me to my previous question asked in post #8.



> @ Pathik, do the service provider track the phone through the IMEI no or the sim? I mean they will just check from which tower the sim is recieving the signal and track it. They cant do it when the set is off. Or am i wrong somewhere?


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## Anorion (Nov 6, 2008)

The biggest use for an IMEI number is that it allows the police to block stolen mobile phones from operating. The other use is that service providers know the make of your model and can help you accordingly, or offer you services according to the specifications of your device.


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## techani (Nov 6, 2008)

@ Anorion plz tell me the use of IMEI no from the terrorist angle. My confusion is *why do police need the IMEI no to track down a terrorist or a culprit. That can be easily done through the sim also but why they need the IMEI no?* I only want to know the answer to this question. Waiting for a reply...


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## Anorion (Nov 6, 2008)

Ah... in that case you are right... I don't know why an IMEI number allows terrorists to work more freely... maybe someone else does... I just think that big phone manufacturing companies are pressurising the govt over trivial issues in china phones because of a drop in their sales. I donno how they are doing it, but that's my humble opinion.


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## techani (Nov 6, 2008)

I dont think its the phone companies that are pressuring the govt. to stop chinese phone sales in the country. Its the law enforcing agencies who want to stop those. oz read this ...


> "An IMEI number consists of 15-17 digits. Genuine branded phones carry valid IMEI numbers. When the SIM card in a mobile phone gets activated, the IMEI number gets automatically registered with the GSM service provider and it becomes possible to trace a call and find out the caller's identity and the location from where the call was made," the official said.


Source


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## Anorion (Nov 6, 2008)

Yeah. Is there something called as an IMI number? The september 10 issue of the afternoon dispatch has a similiar article about terror and mobile phones, but strangely, the IMEI number is referred to as the IMI number. Quoting the relevent part "normally, every cell phone has an 'IMI' number and based on this IMI number, the cell phone owner's details and usage can be made available. However, Chinese cell phones don't have any such IMI numbers, which makes it impossible to retrieve certain key technical information about the cell phone."

This means that somehow, the details of the cell phone are themselves necessary for the police to keep track of terror. Does this mean, what kind of features the cell phone has, like whether or not the person in question can send terror e-mails from his mobile phone? That could be one thing... or maybe they need both the sim and the IMEI number to access the details of the caller, as in their activities and their movement. Someone should clear this up...


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## techani (Nov 7, 2008)

Ah at last we came to the point! Thanks Anorion.


> whether or not the person in question can send terror e-mails from his mobile phone?


Cant it be traced through the sim?


> maybe they need both the sim and the IMEI number to access the details of the caller


This is where my question is!


> Someone should clear this up...


Nobody is participating in this thread. But only tracking it i guess...
Anyway atleast i got myself cleared now.
Any mobile expert here?
We r waiting......................................................


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## Anorion (Nov 7, 2008)

This part I am sure of... the IMEI number is required to give specifications of the model of the phone itself, as in whether or not GPRS is in the handset, what grade of GPRS is supported, what is the operating system, what applications can run on it etc. Since 100 or 1000 chinaphones have the same IMEI number, and there is no specification or brand for the model (sometimes the same phone is sold with different brand names), it becomes impossible based on the SIM alone to know what the handset is capable of doing.


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## Zangetsu (Nov 7, 2008)

techani said:


> @ Pathik, do the service provider track the phone through the IMEI no or the sim? I mean they will just check from which tower the sim is recieving the signal and track it. They cant do it when the set is off. Or am i wrong somewhere?


 
An IMEI no is just like IP address....they r unique for every fone...

"The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop a stolen phone from accessing the network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "ban" the phone using its IMEI number. This renders the phone useless, regardless of whether the phone's SIM is changed" - wiki

so..even if u remove the sim the phone can b traced using the IMEI no...


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## Anorion (Nov 7, 2008)

^ yeah but what kind of terrorist activities can terrorists indulge in using phones without IMEI numbers that they cannot do with phones that have a valid IMEI number?


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## neolithian (Mar 14, 2009)

I know this thread hasnt been used for a while, but i was reading and thought this question was relevant.

If the IMEI is used to track / trace and block the phone, how can a provider know whether the IMEI has been changed on the phone ?
For instance, a terrorist or thief has aquired the phone, they substitute the IMEI with one from a disused or broken phone, is there a preventative measure in place for this ?


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