Hitchhiker's Guide to Streaming Media: 3GP

>>>Lookup: 3GP

The increasing use of mobile phones to access video content raises the question what is the 3GP format? First-generation, analog cellular technology was introduced in the 1970s, followed almost 20 years later by second-generation (2G) digital cellular communications.

Second-generation mobile networks are based on low-band digital data signaling, and the most common 2G technology is known as GSM (global systems for mobile communication). GSM is a combination of FDMA (frequency-division multiple access) and TDMA (time-division multiple access). FDMA and TDMA are both channel access methods that allow numerous terminals connected to the same physical medium to transmit over it and to share its capacity.

FDMA is the sharing of a certain radio spectrums among multiple users, while TDMA allows multiple users to share the same frequency channel by dividing the signal into different time slots. Currently GSM systems operate in the 900MHz and 1.8 GHz bands.

3G is a single global system junction that includes both terrestrial and satellite components. By achieving greater network capacity through improved spectral efficiency, 3G offers users a wider range of services, including voice calls, video calls, and mobile videos. The 3G has the capability to deliver speeds of 14.4Mbps on the downlink and 5.8Mbps on the uplink. 3G is based on the family of standards under the IMT-2000, CDMA2000 3x (also known as EV-DO rev B) which is a telecommunication standard which provides enhancements to the 3G technology by having higher rates by bundling multiple channels together which enhances the user experience and enables services such as high definition video streaming.

The 3GP format was developed by the Third Generation Partnership Project (3GPP) and Third Generation Partnership Project 2 (3GPP2) to standardize mobile phone formats, aiming to allow reliable delivery of multimedia formats over 3G mobile phones all around the world. 3GP is a multimedia container format, meaning several different types of files—including audio and video—are stored within a single file. For mobile devices to stream video content or download, MPEG-4 has to be simplified and redesigned to decrease storage size and amount of bandwidth necessary. The birth of the 3GP file format created the vital ingredient for multimedia streaming on mobile phones, which allowing users to create and share video content through their mobile phone network.

3GP has two different formats, both based on MPEG-4 and H.263 Video and AAC or AMR audio:
• 3GPP uses the file extension .3gp and is used for GSM (global system for mobile communication)
• 3GPP2 uses the file extension .3gp2 and is used for the CDMA (code division multiple access) channel access method.

Depending on the mobile phone, video recorded on the phone is usually in .3gp format which can be transferred via Bluetooth, USB connection, or memory card to a user’s computer, where it can be viewed or transcoded into different formats depending on user requirements.