What is iPhone Baseband, Sim Lock and Jailbreak?
When you opt to jailbreak your iPhone it is important to understand the terms closely related it, so as not to make mistakes along the way.
The following are popular terminology related to iPhone jailbreak:
- Sim Lock
1. iPhone Baseband
The iPhone Baseband is a combination of modem hardware chip and a special low-level software called firmware. The hardware device is responsible for all cellular activities that require the antenna. The firmware is identified with figures such as 04.12.01 and 04.10.01.
On the other hand, Wi-Fi and Bluetooth hardware are managed by the iPhone processor, though the baseband firmware stores their MAC addresses.
2. iPhone Sim Lock Status
This refers to the status of the iPhone when first purchased in relation to a cellular network.
The iPhone basically sells in two states:
- iPhone locked to carrier network
- Factory Unlocked iPhone.
A locked one means that it can only function with a sim card provided by the retailing telecom company like AT & T or Verizon in the USA. The user enters into an agreement with them to pay for the iPhone in a period of up to two years. The starting price for a new locked iPhone can be as low as $99.00.
On the other hand, a factory unlocked iPhone comes open to all network sim card around the world. The drawback is that it must be paid for at once, making it rather pricey.
3. iPhone Jailbreak
This is the installation of third-party modification codes onto the iPhone OS firmware to allow a user customize it to their liking. It makes it to bypass the rather stringent restrictions that come with the factory operating system.
Apple allows installation of vetted software only through iTunes. Jailbreaking, on the other hand, allows the user to install other software through Cydia, which boasts of collections of third-party tweaks and apps in its partner repositories.
Relationship Between Baseband, Jailbreak and Unlock
If you own an iPhone that is locked to a specific carrier network, you can have it factory unlocked for free or for a fee.
Usually, the carrier network from it was purchased should unlock it for free. Third party unlock services will charge a fee. Both of these services will make use of the IMEI number.
The iPhone can also get temporarily unlocked using hardware or software hacks. Hardware solutions rotate around the popular sim interposers like R-sim or Gevey Sim. Popular software unlock solution is called Ultrasn0w and it is effective in iPhone 4 and below. Software-based unlock is not supported in the latter iPhones.
If you want to unlock your carrier locked iPhone, you normally have to first jailbreak it or have it unlocked officially by your network carrier: AT&T and other online stores offer IMEI based iPhone unlock solutions with or without contract agreements.
You can save yourself lots of headache by purchasing an unlocked iPhone from Apple stores.
In order to the old iPhones using Ultrans0w, you must jailbreak it first. And in order to do this safely, you must also know the iPhone baseband (BB) and IOS firmware status. Baseband is referred to as Modem Firmware and is identified by strings like 04.10.01. (see image below).
iPhone firmware is referred to as Version and identified with strings like 5.1 (9B176). (see image below)
In order to unlock an iPhone using Ultrasn0w make sure its baseband is supported.
Below is a list of some of the more popular iPhone basebands that can be unlocked via software:
Do Not Upgrade iPhone Baseband
If you unlock your iPhone using Ultrasn0w always take care not to update to the newer firmware. New firmware installations always upgrade your baseband. This is okay if your iPhone is factory unlocked or you are still on the original network carrier. If not and you upgrade without insight, your jailbroken iPhone will lose network after the update.
To avoid this nightmare, always use your jailbreaking software to update, and always ensure you preserve the baseband in the process.Redsnow can help preserve baseband during updating and jailbreaking.
© 2012 Alfred Amuno