International Mobile Station Equipment Identity
From Wikipedia, the free encyclopedia
The International Mobile Station Equipment Identity or IMEI // is a number, usually unique, to identify 3GPP (i.e., GSM,UMTS and LTE) and iDEN mobile phones, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone, but can also be displayed on-screen on most phones by entering *#06# on the dialpad, or alongside other system information in the settings menu on smartphone operating systems.
The IMEI number is used by a GSM network to identify valid devices and therefore can be used for stopping a stolen phone from accessing that network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "blacklist" the phone using its IMEI number. This renders the phone useless on that network and sometimes other networks too, whether or not the phone's SIM is changed.
The IMEI is only used for identifying 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 that 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.
Iridium Communications Inc. (formerly Iridium Satellite LLC) is a company, based inMcLean, Virginia, United States which operates the Iridium satellite constellation, a system of 66 active satellites used for worldwide voice and data communication from hand-heldsatellite phones and other transceiver units. The Iridium network is unique in that it covers the whole Earth, including poles, oceans and airways. The company derives its name from the chemical element iridium. The number of satellites projected in the early stages of planning was 77, the atomic number of iridium, evoking the metaphor of 77 electrons orbiting the nucleus.
The satellites are frequently visible in the night sky as satellite flares, a phenomenon typically observed as short-lived bright flashes of light.
Removable Subscriber Identity Modules (SIMs) are used in Iridium phones, much like those used for GSM. Prepaid SIM cards are usually green while post-paid cards are red. The 9602 SBD modem does not use a SIM card, it is identified by the network solely through its IMEIand the customer account associated with that IMEI.