Yesterday IMSI failed has appeared on my screen and is permanent with no phone function. I am an o2 subscriber on a philips cellphone which I use regularly for my business. What has happened?

Under contract still ... request the code from your service provider.

(Subscriber Identity Module lock) A function in GSM cellphones that restricts the phone's use to a particular cellular carrier identified by a SIM card. SIM locks are used to ensure subscribers finish their service contracts. If the contract period is over, the phone may be unlocked by entering a code from the carrier.

is its battery removable or sim card pull out and refit
restart phone

if you can turn the phone off

may have to use factory reset function

IMEI is International Mobile Equipment Identification, which is used to identify a physical phone device.

IMSI is International Mobile Subscriber Identification, which is used to identify a SIM (Subscriber Identification Module) card.

A subscriber identity module or subscriber identification module (SIM) is an integrated circuitthat securely stores the international mobile subscriber identity (IMSI) and the related key used to identify and authenticate subscribers on mobiletelephony devices


A SIM card contains its unique serial number (ICCID), international mobile subscriber identity (IMSI), security authentication and ciphering information, temporary information related to the local network, a list of the services the user has access to and two passwords: a personal identification number (PIN) for ordinary use and a personal unblocking code (PUK) for PIN unlocking.

Either the sim card failed or one of your friends swapped theirs out for yours.

You need to get a Sim card if your using and AT&T, or a T-Mobile Phone.
A Sim car is also know as a Smart Card.
Its to securely store the service-subscriber key (IMSI) used to identify a subscriber.

HI,

If you've got a SIM card for a mobile, and don't know what the phone number is - the easiest way to check, is to use the card to phone a landline phone number, and then from that landline phone, dial 1471. Caller identification should then repeat the number to you. For more, see our CLI page.

Alternatively, call Customer Services from the mobile - they should be able to see your number.

Note that the telephone number itself isn't stored on the SIM card (this is how you're able to change phone number without getting a new SIM). The phone stores a unique number called a Subscriber Identity number (IMSI). Provided that you're able to connect your phone to a PC, you may be able to use PC software such as Oxygen to extract the IMSI from the SIM. Once you have the IMSI, you may be able to contact the SIM network operator and ask them to tell you which number maps to the IMSI.

A Subscriber Identity Module (SIM) on a removable SIM Card securely stores the service-subscriber key (IMSI) used to identify a subscriber on mobile telephony devices (such as computers and mobile phones). The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device.

Well, I've asked Samsung for the generic firmware and am in the process of escalating this up the chain with O2. My guess is that the O2 firmware was customised by Samsung to O2's spec, so they've possibly just inadvertently left out a way to alter the function of the soft-buttons. I hope it's inadvertent as I suspect it's illegal under EU antitrust law to hard-code the button in this way. Of course if anyone reading this has access to a document from O2 specifying the button should be permanently set to O2 Active, that would be very interesting indeed.

In the meantime, if anyone is charged for accidentally accessing O2 Active, they should simply get a refund from O2 customer services and register a complaint each time. Any problems with this, please post a message here.
BTW I wouldn't recommend flashing the phone with anything other than O2's official firmware as it'll invalidate the warranty and there could be problems using it on O2's network. I don't know if this is the case though. I have seen various firmware versions on the Net (eg G600XEGL1), so if anyone's tried reflashing their O2 G600, perhaps they would post a message here as to how successful it was.
thank u.........vote it

Unlike the Electronic Serial Number or MEID of CDMA and other wireless networks, the IMEI is only used to identify the device, and has no permanent or semi-permanent relation to the subscriber. Instead, the subscriber is identified by transmission of an IMSI number, which is stored on a SIM card which can (in theory) be transferred to any handset. However, many network and security features are enabled by knowing the current device being used by a subscriber.

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.