What is a NETWORK LOCK?
From EjWiki
This is in comparison with a mobile phone (retrospectively called SIM-free or unlocked) that does not enforce any SIM restrictions.The key reason why lots of carriers SIM lock their devices is simply because they offer cell phones at a discount to consumers in return for for a contract to fund the use of the network for a given period of time, commonly between one and three years. This business model allows the organization to recover the cost of the cell phone across the life of the agreement. Such discounts are worth up to several hundred US dollars.
Unlocking Technology: A handset can be unlocked by entering a code supplied by the service operator. Different mechanisms consist of software operating on the handset or a computer connected to the handset, hardware devices that attach to the phone or over-the-air by the carrier. Generally the unlock procedure is permanent. The code required to get rid of all locks from a mobile phone is known as the master code, network code key, or multi-lock code. If the device is carrier locked it will generally display one of these messages: SIM network PIN blocked, Enter lock PIN.
Economics: Handset providers have financial incentives both to improve SIM lock security (which placates service companies and enables exclusivity deals) and weaken it (extending a device's appeal to users who are usually not interested in the service provider that offers it). At the same time, making it too hard to unlock a smartphone could possibly make it significantly less appealing to mobile phone network service providers that have a legal responsibility to supply unlock codes for some handsets or in particular countries.
Unlocking Services: Plenty of organizations provide a IMEI phone unlocking service. This service needs those people who would like to unlock a phone to supply their IMEI number to a unlocking company and frequently they will also need the country and network the device is locked to, either sent by email or entered on their website. The company then will supply (once you have paid) a unlock code for the mobile phone. For a lot of manufacturers as in Nokia and Samsung several services also provide unique remote-unlocking software with directions, when a cable is required to remove the SIM lock at home. Such organizations may well email the unlocking code or software which can remotely unlock the unit. The cost for unlocking a mobile phone can differ based on the network it's locked to and the smartphone model itself, as every unlock code is unique to each individual handset.
Unlocking Service Providers: Unfortunately there are a multitude of fraudulent organizations operating in the smart-phone unlocking industry. Consequently it is advisable to make sure you use a genuine service provider for such a service. Take the necessary precautions and investigate all prospective retailers prior to choosing to making an order. In the case of on line suppliers, ensure they provide their formal organization name and matching registration details (every authentic company is required to be lawfully registered with the official governing bodies for their country of origin) and ensure they give a legitimate registered address and contact information on their web site. Also make sure that any payments made are by legitimate methods as in a recognized bank or financial institution using a debt or credit card, but never make payment via a direct transfer since this offers no fiancial protection. To assist with the search for a trustworthy company, we have supplied a checklist below (and in no specific order) of a number of genuine organizations currently offering such services.
Reputable Mobile Phone IMEI Unlocking Service Providers: Mobile UnlockedDoctorSIMUnlock.ZoneUnlock BaseUnlock RiverCell Unlocker
