Advantages of 3G:

- Overcrowding is relieved in existing systems with radio spectrum
- Bandwidth, security and reliability are more
- Provides interoperability among service providers
- Availability of fixed and variable rates
- Support to devices with backward compatibility with existing networks
- Always online devices – 3G uses IP connectivity which is packet based
- Rich multi media services are available

Disadvantages of 3G:

- The cost of cellular infrastructure , upgrading base stations is very high
- Needs different handsets.
- Roaming and data/voice work together has not yet been implemented
- Power consumption is high
- Requires closer base stations and are expensive
- Spectrum-license costs, network deployment costs and handset subsidies subscribers are tremendous.

- Packet data speed is higher in 3G, and it is up to 384 KBPS
- Voice and sms speed is also 384 KBPS in 3G
- 2G utilizes different switching techniques for voice and data, where as  3G uses single switching, irrespective of data
- 3G has at least 2MB of data link of a mobile, where in 2G the data rate is in KBPS
- 3G has WiMAX facility for faster VOIP and internet
- 2G uses GSM TDMA technology with narrowband 200Khz.
- 3G uses CDMA technology with broadband 5Mhz, with same frequency carrier and time.

Definition: 3G, known as 3rd Generation, is a standard for mobile / cellular phones. It provides the services that fulfill the International Telecommunication Union specifications.

The application services of 3G include wireless voice telephone, mobile internet access, video calls and mobile television – all in a mobile environment.

3G allows simultaneous use of speech and data services
3G provides peak data rates of at least 200 KBits according to the IMT-2000 specification.
Mobile broadband access of several MBits to laptop computer systems, smart phones is provided by latest 3.5G, 3.75G versions.

3G standards:

UMTS:

  -  Universal Mobile Telecommunications System – One of the 3G mobile telecommunications technologies, also being developed into a 4G technology.
  -  Most common form of UMTS uses W-CDMA as an underlying air interface.
  - UMTS also covers Radio Access Network – UMTS Terrestrial Radio Access Network (UTRAN), and Mobile Application Part (MAP).
  -  Users are authenticated via USIM cards (Universal Subscriber Identity Module).

CDMA2000

   -  Also known as IMT Multi-Carrier (IMT-MC), uses CDMA channel access for sending voice, data and signaling data between mobile phones and cell sites.
   -  The standards are CDMA2000 IX, CDMA2000 EV-DOR Rev.0, CDMA2000 EV-DO Rev.A and CDMA2000 EV-Rev.B. They are approved radio interfaces for the ITU’s IMT-2000.

Video: Videos can be edited, shared. High quality VGA video can be shot in portrait or landscape.

- 3 Megapixel Camera: Still photos with greater quality can be taken

- Voice control: It recognizes the names in contacts and recognizes the music on iPod.

- Compass: iPhone 3GS has built-in digital compass, used to point the way.

- Internet Tethering: Internet surfing can be done from anywhere. A 3G connection can be shared on Iphon3 with Mac notebook or laptop..