Third Generation Technology(3G)
3G refers to the third generation of mobile telephony (that is, cellular) technology. The first generation (1G) began in the early 80′s with commercial deployment of Advanced Mobile Phone Service AMPS cellular networks. Early AMPS networks used Frequency Division Multiplexing Access
FDMA to carry analog voice over channels in the 800 MHz frequency band.
The second generation (2G) emerged in the 90′s when mobile operators deployed two competing digital voice standards. In North America, some operators adopted IS-95, which used Code Division Multiple Access .CDMA to multiplex up to 64 calls per channel in the 800 MHz band. Across the world, many operators adopted the Global System for Mobile communication GSM standard, which used Time Division Multiple Access TDMA to multiplex up to 8 calls per channel in the 900 and 1800 MHz bands.
The International Telecommunications Union ITU defined the third generation (3G) of mobile telephony standards – IMT-2000 – to facilitate growth, increase bandwidth, and support more diverse applications. For example, GSM could deliver not only voice, but also circuit-switched data at speeds up to 14.4 Kbps. But to support mobile multimedia applications, 3G had to deliver packet-switched data with better spectral efficiency, at far greater speeds.
Features:
Data Rates:
ITU has not provided a clear definition of the data rate users can expect from 3G equipment or providers. Thus users sold 3G service may not be able to point to a standard and say that the rates it specifies are not being met. While stating in commentary that “it is expected that IMT-2000 will provide higher transmission rates: a minimum data rate of 2 Mbit/s for stationary or walking users, and 384 kbit/s in a moving vehicle,”the ITU does not actually clearly specify minimum or average rates or what modes of the interfaces qualify as 3G, so various rates are sold as 3G intended to meet customers expectations of broadband data.
IPOD:
We use ipod nano by importing songs,audiobooks,movies, nad podcasts into ur computer and then addimg to ipod nano.
Apple iPod Touch (third generation, 64GB):
The third generation of Apple’s iPod Touch is still the king of the hill when it comes to portable, Wi-Fi-wielding media players. New additions such as Voice Control, graphics enhancements, improved accessibility, higher capacity, and a faster processor help to refine an already excellent product.
Applications:
The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users. Some of the applications are:
Mobile TV – a provider redirects a TV channel directly to the subscriber’s phone where it can be watched.
Video on demand – a provider sends a movie to the subscriber’s phone.
Video conferencing – subscribers can see as well as talk to each other.
Tele-medicine – a medical provider monitors or provides advice to the potentially isolated subscriber.
Location-based services – a provider sends localized weather or traffic conditions to the phone, or the phone allows the subscriber to find nearby businesses or friends.
Evoltuion:
Both 3GPP and 3GPP2 are currently working on extensions to 3G standard that are based on an all I1p -network infrastructure and using advanced wireless technologies such as MINO these specifications already display features characteristic for IMT Advanced (4G), the successor of 3G. However, falling short of the bandwidth requirements for 4G (which is 1 Gbit/s for stationary and 100 Mbit/s for mobile operation), these standards are classified as 3.9G or Pre-4G.
3GPP plans to meet the 4G goals with LTE Advanced whereas Qualcomm has halted development of UMB in favour of the LTE family.On 14 December 2009, Telia Sonera announced in an official press release that “We are very proud to be the first operator in the world to offer our customers 4G services.” With the launch of their LTE network, initially they are offering pre-4G (or beyond 3G) services in Stockholm, Sweden and Oslo, Norway.
Article by AYESHA HASSAN CHAUDARY
