Sunday, June 15, 2008

Bandwidth got is less than what is specified

The question "Why is the bandwidth specified by the operators always less than the bandwidth which we get?" has bugged me for ages I did some research and here is a small explanation. I have made the image so sorry if not that good.

Image :
The bandwidth which the operators is the speed of the switch and the switch may be connected to 'n' number of computers. So if the bandwidth specified is 5 MBps and 5 computers are surfing from the switch the bandwidth each computer will get is 1 MBps. Which is less than specified the only case in which a computer will get full 5 MBps bandwidth is when rest of the 4 computers are off.
Hope this is enough...

EVDO in India

Evolution-Data Optimized or Evolution-Data only, abbreviated as EV-DO or EVDO and often EV, is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access.

It uses multiplexing techniques including Code division multiple access (CDMA) as well as Time division multiple access (TDMA) to maximize both individual user's throughput and the overall system throughput. It is standardized by 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world – particularly those previously employing CDMA networks.

For further information on EVDO visit

I m an EVDO user and its really cool.. In India as far as i know only BSNL has launched this service..
EVDO is basically wireless high speed internet. The speed which BSNL gives is as good as ADSL speed. This is NOT the same as TATA Indicom's 'Plug to surf' or Reliance's mobile internet as they us CDMA 2.75 G technology while BSNL uses EV-DO 3 G technology. The bandwidth which TATA or Reliance give is maximum 144kbps while the bandwidth of BSNL EVDO is 2.4 MBps, cost of the USB modem (for all is nearly) is Rs 2,800. The modem is chinese which really bugs it is of ZTE but service is good.
The main drawback of this service is that it covers only a perticular city but in BSNL MP attemmpts are being made to give CDMA coverage throughout the state.