internet access via cable tv

INTERNET ACCESS VIA CABLE TV NETWORK

Prepared byE. Nivetha

ECE Final Year

CONTENT Introduction Why cable TV Network? Cable Modem Working Cable Service Providers Changes in Cable Network Advantage & Limitations Conclusion

Introduction Internet is a network of networks in which various

computers connect each other throughout the world.

Internet connection may be wired or wireless. Internet via phone connection are painfully slow,

especially when downloading photographs or video images and large files.

The huge growth in the number of Internet users every years has resulted in the traffic congestion on the net resulting slower & expensive Internet access.

Why Cable TV Network? India has a cable penetration of 80millions home, it

is the best medium for providing the Internet to house holds with faster access at feasible rates.

Capacity of coaxial cable is huge. It is much larger than what is required for the TV

programs. So that unused capacity can be utilized to carry the

Internet traffic.

Cable Modem A "Cable Modem" is a device that allows high-

speed access to the Internet via a cable TV (CATV) network.

The cable modem attaches to computer through an Ethernet Network Interface Card.

The basic job for cable modem is to covert a computer’s digital data into analog signals that the wire can carry and vice versa.

It provide Internet access to multiple PCs, if they are connected via local area network.

Modern Cable Modem

Working A device called SPLITTER is used to split the signals inside

a coaxial cable into two parts. One part of the signal is the usual television signal and the

other part of the signal carries Internet data. Two separate parts of signal arrive in separate wires. One wire goes to the television set through Cable TV

adapter and the other wire carries Internet data is connected to the cable modem.

The user can now use the same cable connection to view television as well as to access the Internet.

Cable Service Providers Cable Company serves each town through a number

of central nodes. Each node services about 500 customers. Many such nodes are connected via high speed

optical fiber (HFC) links into a single Head End otherwise called as Cable Modem Termination System(CMTS).

CMTS typically connects about 4 to 10 nodes. It is responsible for delivery of Television programs

and Internet access to the cable customers.

Changes in Cable Network CMTS receives television signals from satellites and

has Internet access via high speed connections with other major NAPs.

The cable network was designed to deliver TV signals in one direction from the Head-End to the subscriber’s homes.

Operators had to upgrade the cable network so that signals could flow in both directions.

Downstream Frequency Upstream Frequency

DOWNSTREAM FREQUENCY: The frequency used for transmitting data from the

CMTS to the cable modem. Frequency 65-850 MHz Data-rate 27-56 Mbit/s

UPSTREAM FREQUENCY: The frequency used to transmit the data from the

CM to the CMTS. Frequency 5-65 MHz Data-rate 3 Mbit/s

ADVANTAGES: Advance High Speed Internet Access No new software is required. Cable modem connect multiple PCs. Always on connectivity High Bandwidth to low cost

LIMITATIONS: Traffic congestion on net High Security risk than dial up connection Usually tied with Cable TV subscription

Conclusion

Cable TV has a strong reach to the homes and therefore offering the Internet through cable be a scope for furthering the growth of internet usage in the homes.

In future this technology will implemented by India.