A UIMID (user identity module identifier) is a 32-bit Electronic Serial Number (ESN) stored in a R-UIM or

CSIM A CDMA subscriber identity module (CSIM) is an application to support CDMA2000 phones that runs on a UICC, with a file structure derived from the R-UIM card. By porting the application to the UICC (Universal Integrated Circuit Card), a card wi ...

('smart card') used for TDMA or CDMA2000 phones (mainly the latter). It is given a different name to avoid confusion with the hardware ESN stored in the phone. In all known systems the UIMID displaces the ESN in signaling (based on setting bit 1 of the 'UsgInd' field to '1' in the card). Because the UIMID is allocated from the same numbering space as ESN its existence is transparent to the network. The reason the UIMID is transmitted instead of the ESN is because the card contains the

MIN Min or MIN may refer to: Places * Fujian, also called Mǐn, a province of China ** Min Kingdom (909–945), a state in Fujian * Min County, a county of Dingxi, Gansu province, China * Min River (Fujian) * Min River (Sichuan) * Mineola (Am ...

or IMSI and devices such as the HLR running the Asbi mobility management protocol insist on a static association between these identifiers for subscription validation. The HLR will store the MIN or IMSI alongside the ESN in each record, and if an ANSI-41 message is received containing a different pair it will be rejected as invalid. UIMID codes are allocated by the

TIA TIA or Tia may refer to: Aviation * Tampa International Airport, US, IATA code TPA * Texas International Airlines, US, ICAO code * Tirana International Airport Nënë Tereza, Albania, IATA code * Trans International Airlines, former U.S. airl ...

using industry-defined guidelines and with codes that have been transferred from the ESN administrator (also the TIA).3GPP2 SC.R4004-0, Version 2.0. May, 2010
User Identification Module ID Manufacturer’s Code Assignment Guidelines and Procedures
/ref> ESN and UIMID codes were exhausted by late 2008 at which point only reclaimed codes could be assigned to manufacturers including portions of blocks assigned to manufacturers but never used and portions used for technologies other than CDMA2000. The

stopped accepting applications for UIMID blocks on June 30, 2010. Only one assignment has been made since 2010. The replacement identifier for UIMID is

EUIMID EUIMID (expanded UIMID) is a unique identifier for an R-UIM (Removable User Identity Module) or CSIM (CDMA SIM application) card in CDMA2000 cellular systems that replaces the older UIMID identifier. There are two forms of EUIMID, known as Shor ...

although for backwards compatibility a pseudo-UIMID (pUIMID) is still retained in cards. The pUIMID is composed of the prefix 0x80 to make it distinct from unique UIMID codes and a 24-bit SHA-1 hash of the EUIMID. pUIMID codes are not unique as there are only 2²⁴ of them and many times more EUIMID codes. The pUIMID can usually be used in place of a unique UIMID, except when uniqueness is important.

References

External links

Official TIA Resource Page for ESN and UIMID

CDMA Development Group MEID and EUIMID resource page
Mobile technology Wireless Identification {{Wireless-stub