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Personal Unblocking Code
A personal unblocking key (PUK), sometimes called personal unblocking code (PUC), is used in SIM cards to reset a personal identification number (PIN) that has been lost or forgotten. Most mobile phones offer the feature of PIN protection. After switching on the phone, if the PIN security function is active, the user is required to enter a 4-8 digit PIN to unlock the SIM card and connect to the mobile network. Without this, functions such as phone calls (except for emergency calls), text messages and mobile data will not be available. If the wrong PIN is entered more than three times, the SIM card will become locked. It can be unlocked by entering the PUK code provided by the mobile service provider, which may be available on the SIM card's packaging, the contract, or provided by customer service after identity verification. After the PUK code is entered, the PIN must be reset. If the wrong PUK is entered ten times in a row, the SIM card will become permanently blocked and unrecove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIM Cards
A typical SIM card (mini-SIM with micro-SIM cutout) A GSM mobile phone file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s file:Tf sim both sides.png, A TracFone Wireless SIM card has no distinctive carrier markings and is only marked as a "SIM card" A SIM card (full form Subscriber Identity Module or Subscriber Identification Module) is an integrated circuit (IC) intended to securely store the international mobile subscriber identity (IMSI) number and its related key, which are used to identify and authenticate subscribers on mobile telephony devices (such as mobile phones and computers). Technically the actual physical card is known as a universal integrated circuit card (UICC); this smart card is usually made of PVC with embedded contacts and semiconductors, with the SIM as its primary component. In practise the term "SIM card" refers to the entire unit and not simply the IC. A SIM contains a unique serial number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Identification Number
A personal identification number (PIN), or sometimes redundantly a PIN number or PIN code, is a numeric (sometimes alpha-numeric) passcode used in the process of authenticating a user accessing a system. The PIN has been the key to facilitating the private data exchange between different data-processing centers in computer networks for financial institutions, governments, and enterprises. PINs may be used to authenticate banking systems with cardholders, governments with citizens, enterprises with employees, and computers with users, among other uses. In common usage, PINs are used in ATM or POS transactions, secure access control (e.g. computer access, door access, car access), internet transactions, or to log into a restricted website. History The PIN originated with the introduction of the automated teller machine (ATM) in 1967, as an efficient way for banks to dispense cash to their customers. The first ATM system was that of Barclays in London, in 1967; it accepted c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unstructured Supplementary Service Data
Unstructured Supplementary Service Data (USSD), sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator's computers. USSD can be used for WAP browsing, prepaid callback service, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network. USSD messages are up to 182 alphanumeric characters long. Unlike short message service (SMS) messages, USSD messages create a real-time connection during a USSD session. The connection remains open, allowing a two-way exchange of a sequence of data. This makes USSD more responsive than services that use SMS. Uses When a user sends a message to the phone company network, it is received by a computer dedicated to USSD. The computer's response is sent back to the phone, generally in a basic format that can easily be seen on the phone display. Messages sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIM Lock
SIM lock, simlock, network lock, carrier lock or (master) subsidy lock is a technical restriction built into GSM and CDMA mobile phones by mobile phone manufacturers for use by service providers to restrict the use of these phones to specific countries and/or networks. This is in contrast to a phone (retrospectively called SIM-free or unlocked) that does not impose any SIM restrictions. Generally phones can be locked to accept only SIM cards with certain International Mobile Subscriber Identities (IMSIs); IMSIs may be restricted by: * Mobile country code (MCC; e.g., will only work with SIM issued in one country) * Mobile network code (MNC; e.g., AT&T Mobility, T-Mobile, Vodafone, Bell Mobility etc.) * Mobile subscriber identification number (MSIN; i.e., only one SIM can be used with the phone) Additionally, some phones, especially Nokia phones, are locked by group IDs (GIDs), restricting them to a single Mobile virtual network operator (MVNO) of a certain operator. Most mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
