All technologies have gradated points of reference now and such is the case with mobile technology as well. 3G, or third generation mobile telecommunications, in context of mobile phone technology, refers eponymously to the third generation in telecommunication technology. It is premised on enabling standards fulfilling the International Telecommunications - 2000 specifications as laid down by the International Telecommunication Union.

What does 3G enable? Today, with 3G services easily available across the globe, telecommunication has experienced a massive revolution in terms of connectivity as well as functionality. With various telecom operators offering 3G services with great connectivity and the lowest of prices, video calling, accessing the internet and wireless calling are all a factor of mobile communication. This and the prevalence of smartphones has completely changed the way we relate to mobile phones and technology on the go.
3G services were launched recently in India. However, even within 10 months or so, India's 3G network is pretty extensive with almost all Indian telecom operators offering 3G services at various speeds and plans. In that sense, besides being a factor of what plan you've chosen, 3G speeds vary from network to network. Airtel, Reliance and Aircel are figured to have the greatest spectrum across India; their 3G networks are, obviously then, amongst the most extensive and reliable in India as of now. There is a glitch here though: more often than not, 3G speed is dependent on not just the 3G plan but also on local, area connectivity. When you choose a 3G plan, you should then keep not just the scene of 3G in India - that is, the overall spectrum - but also local connectivity of the specific telecom operator in mind so that you get the best 3G plan which will meet all your specific 3G requirements given your location.