SIM lock
Network exclusivity code
A SIM lock is a restriction built into mobile phones that ties the device to a specific carrier's network.
Carriers often lock phones sold under contract, preventing customers from switching to competitors.
To use the phone with another carrier, you need to unlock it—sometimes requiring a code from the original carrier or waiting until a contract period ends.
Also called a network lock or carrier lock.
Cellular communication protocol
- CDMAWireless transmission protocol
- LTEWireless broadband standard
- IMEIMobile device identifier
- basebandSignal at original frequencies
firmware · bootloader · modem · radio · frequency band · 4G · 5G · VoLTE
Interconnected system
- providerOne who furnishes things
- operatorOne who works machinery
- contractEnforceable written agreement
- subscriptionPaid recurring access
plan · exclusive · agreement · tied · bound · subsidy · handset · prepaid
Mobile device identifier
- third-partyExternal, uninvolved entity
- jailbreakEscape from custody
- requestFormal act of seeking
- eligibilityState of meeting criteria
paid off · permanent · temporary · official · unauthorized · grey market · resale · freedom
Obstruction preventing passage
- constraintLimiting condition or rule
- limitationBound on extent
- inaccessibleCannot be reached
- preventStop in advance
impede · inhibit · bound · tied · compliance · obligation · clause · provision
GSM
Cellular communication protocol
baseband · firmware · bootloader · modem · radio · frequency band · 4G · 5G · VoLTE · device
network
Interconnected system
- providerOne who furnishes things
- operatorOne who works machinery
- contractEnforceable written agreement
subscription · plan · exclusive · agreement · tied · bound · subsidy · handset · prepaid · postpaid
IMEI
Mobile device identifier
- third-partyExternal, uninvolved entity
- jailbreakEscape from custody
- requestFormal act of seeking
eligibility · paid off · permanent · temporary · official · unauthorized · grey market · resale · freedom · untethered
barrier
Obstruction preventing passage
- constraintLimiting condition or rule
- limitationBound on extent
- inaccessibleCannot be reached
prevent · impede · inhibit · bound · tied · compliance · obligation · clause · provision · enforcement