What is 4G Mobile Technology?
4G refers to the fourth generation of cellular wireless standards. It is a successor to 3G and 2G standards. The nomenclature of the generations generally refers to a change in the fundamental nature of the service. The first was the move from analogue (1G) to digital (2G) transmission. This was followed by multi-media support, spread spectrum transmission and at least 200 kbit/s (3G) and now 4G, which refers to all IP packet switched networks, mobile ultra-broadband (gigabit speed) access and multi-carrier transmission.
A 4G system is expected to provide a comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband Internet access, gaming services and streamed multimedia may be provided to users.
The remainder of this article uses 4G to refer to IMT Advanced (International Mobile Telecommunications Advanced), as defined by ITU-R.
An IMT Advanced cellular system must have target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access, according to the ITU requirements. Scalable bandwidths up to at least 40 MHz should be provided.
What's new in iPhone 4G Mobile Phone?
• Front-facing video chat camera
• Improved regular back-camera (the lens is quite noticeably larger than the iPhone 3GS)
• Camera flash
• Micro-SIM instead of standard SIM (like the iPad)
• Improved display. It's unclear if it's the 960x640 display thrown around before—it certainly looks like it, with the "Connect to iTunes" screen displaying much higher resolution than on a 3GS.
• What looks to be a secondary mic for noise cancellation, at the top, next to the headphone jack
• Split buttons for volume
• Power, mute, and volume buttons are all metallic
What's changed in iPhone 4G mobile Phones?
• The back is entirely flat, made of either glass (more likely) or ceramic or shiny plastic in order for the cell signal to poke through. Tapping on the back makes a more hollow and higher pitched sound compared to tapping on the glass on the front/screen, but that could just be the orientation of components inside making for a different sound
• An aluminum border going completely around the outside
• Slightly smaller screen than the 3GS (but seemingly higher resolution)
• Everything is more squared off
• 3 grams heavier
• 16% Larger battery
• Internals components are shrunken, miniaturized and reduced to make room for the larger battery
