A serial number that the manufacturer assignsto cellular devices.Just aspeople have theirown ID number and every car has a vehicle number, everycellulardevice with a SIM card can be precisely identified by a so-called IMEI number–InternationalMobile Equipment Identity. The15-digit numberisguaranteed to be globally unique, meaning dual SIM deviceshave two IMEI numbers due to their two SIM card slots. To learn more about other cellular connectivity and SIM card identifiers, check out our previous blog on this topic which explainswhat the ICCID and IMSI numbers are. The IMEI numberconsists of15digits.The number is typically arranged in a sequence ofWW-XXXXXX-YYYYYY-Z, where:Breaking down theIMEI number
- WW:describes the reportingbody identifier showing Type Allocation Code (TAC) by GSMA approval group
- XXXXXX:representstheactualTAC digits
- YYYYYY:acts as an identifierfor theparticular device
- Z: isthe check digit. In GSM devices, this is 0
How does the network use the IMEI number?
In cellular IoT, your device’s TAC is typically associated with the cellular modem or module.
The IMEI number is used to identify the type of device and to verify that the make and model are approved. The fact that a reporting body has allocated a TAC is an indication that the device, modem or modulehas passed relevant regulatory scrutiny. Using that TAC, the network can approve the deviceandsignal that it is permitted to be connected.
Manipulating an IMEI number
With some knowledge of programming, the IMEI of adevicecan be changed, even if this is not actually intended by the manufacturer. Corresponding programs can be found in the Google and Apple app stores. Thieves like to take advantage of this option, because a stolensmartphone, for example,can no longer be identified with a changed IMEI. Anyone who makes changes to the number is legallyoperatingin a grey area.
Theft, location or complaint: Needingthe IMEI number
Very few users can remember a 15-digit sequence of numbers. Therefore, you should write down yourdevice’sIMEI and keep it in a safe place. Ifitis stolen or lost, you need the said number combination to report it to the police, for example. With the help of the number, the device can also be completely blocked by the network operator. For this reason, you should never pass on the IMEI of yourcellular devices to third parties.
Discoverthe IMEI number:How it works
The IMEInot only playsa central role if yourdeviceis stolen. Thedevicemanufactureror yourconnectivityprovidermayneed the number combination in the event of a complaint or for error analysis in support inquiries.
There are various options for determining the IMEI of yourdevice. In most cases, the number is printed on the packaging of yourdevice. If your device has a removable battery, it is worthlookingunder the battery cover. Manufacturers have often attached a sticker with the relevant information here. With the help of a special code, the IMEInumbercan also be queried viaa device’skeypad, where relevant.
IMEISV–Differentiation from IMEI number
You now know what the IMEI number is.Now we will tackle the IMEISV number.So,what does this similar sounding numberstandfor?
IMEISV stands for International Mobile Equipment Identity–Software Version. IMEISV differs from the regular IMEI in that it has a 16-digit long code–the last two numbers identify the software / firmware version (SV). This parameter is used to send the corresponding software version from the manufacturer to the device as soon as a newer update is available.
In contrast to the IMEInumber, the 16-digitIMEISVnumber is divided into the following sections:
- Type Approval Code (TAC) – Six-digit TAC code
- Final Assembly Code (FAC)–This code identifies the location of the last production stage and consists of 2 digits
- Sequence Number (SNR)–anindividual sequence number that uniquely identifies each device, including the same TAC and FAC,and is6digits’long
- Software Version Number (SVN)–Identifies the software version number of the mobile device with two digits
Each IMEISV element can only contain decimal numbers.Below is adiagram of the structure of the international mobile station identification number including the software version (IMEISV):
6digits(TAC) + 2digits(FAC) + 6digits(SNR) + 2digits(SVN) = IMEISV (16digits)
By marking the devices, the manufacturer protectsthe TAC, FAC and SNR fromunauthorizedchanges. The TAC type-approval code is set by the GSMA and themanufacturer gives the final location of the FAC device. You can find the IMEISV of your device in the menu of yourcellular device, modem or moduleand in most cases on the label of the original packaging.
Conclusion
The IMEI and IMEISV numbersmay look similar and sound similarbuttheyare two completelydifferent numbers. These digitsare an elementary part ofevery cellular device, especiallyregardingsecurity. This number is requirednot onlyfortheft and tracking,but for complaint purposes.
