Basics of Broadband and Gsm Technology

8/7/2019 Basics of Broadband and Gsm Technology

1/34


2/34

PROJECT REPORT

SUBMIT

TED BY:

Achal mehan

8209


3/34

PROJECT DONE AT

Mahanagar Telephone

Nigam Ltd.


4/34

ACKNOWLEDGEMENT

I extend my sincere thanks to Wg. Cdr. R. K CHOUBEY forallowing me carry out my project at MTNL and hence giving me

an opportunity to gain insight upon GSM network and learn about

the broadband technology.

I express my deepest sense of indebt ness to the DGM, MTNL for

supervising with utmost care and zeal throughout this dissertationwork. Under his suitable guidance, it was shear joy to my work.

I am also thankful to all of the engineers of technical department

for their help and encouragement during the course of project.

Also, I am immensely grateful to Mr.Verma for organising my

project in MTNL.

Achal mehan


5/34

CERTIFICATE

I certify that Mr. Achal mehan student of B.Tech (Electronics &

Communication), P.D Memorial College of Engineering

(P.D.M.C.E), Maharshi Dayanand University has completed the

project titled BASICS OF BROADBAND, COMPUTER

NETWORKING AND GSM TECHNOLOGY under MTNL.

The duration of project was from June to August. His punctually

and overall performance during his project period was good.


6/34

COMPANY PROFILE

Mahanagar Telephone Nigam Ltd is the government owned

telephone services in India. It was established in 1986 to improve

the quality of telecom services, expand the telecom network,

introduce new services and raise revenue for telecom

developmental needs of Indias key metros. It provides fixed linephones, cellular connections and Internet services. It has converted

100% of its telephone exchange network into the digital mode.

MTNLs fixed-line telecommunications networks in Delhi and

Mumbai had an aggregate of approximately 3.80 million fixed

lines in service. Its cellular services had approximately 2.75

million subscribers.

The company provides welfare activities and benefits

include: subsidized canteen facility, holiday homes, creches,

recreation and community centers, housing and medical facilities,

schooling, grant of scholarships and group insurancefor the

employees.


7/34

INDEX

BROADBAND

IN TELECOMMUNICATION

DATA COMMUNICATION

IN VIDEO

IN CABLE NETWORK

IN DSL

IN ETHERNET

COMPUTER NETWORKING

VIEWS OF NETWORK

NETWORKING METHOD

NETWORK TOPOLOGY

BROADBAND INTERNET ACCESS

ARCHITECTURE

TECHNOLOGY

TRAFFIC

GSM AND ITS ARCHITECTURE

Evolution of MOBILE TECHNOLOGIES


8/34


9/34

BROADBAND

In telecommunication

Broadband in telecommunications refers to a signaling method

that includes or handles a relatively wide range of frequencies,

which may be divided into channels orfrequency bins.Broadband

is always a relative term, understood according to its context. The

wider thebandwidth, the greater the information-carrying capacity.

In radio, for example, a very narrow-band signal will carry Morsecode; a broader band will carry speech; a still broader band is

required to carry music without losing the high audio frequencies

required for realistic sound reproduction. A television antenna

described as "normal" may be capable of receiving a certain range

of channels; one described as "broadband" will receive more

channels. In data communications a modem will transmit a

bandwidth of 56 kilobits per seconds (kbit/s) over a telephone line;

over the same telephone line a bandwidth of several megabits persecond can be handled by ADSL, which is described as broadband

(relative to a modem over a telephone line, although much less

than can be achieved over a fiber optic circuit, for example).

Bandwidth

Bandwidth is the difference between the upper and lower cutoff

frequencies of, for example, a filter, a communication channel, or asignal spectrum, and is typically measured in hertz. In case of a

baseband channel or signal, the bandwidth is equal to its upper

cutoff frequency. Bandwidth in hertz is a central concept in many

fields, including electronics, information theory, radio

communications, signal processing, and spectroscopy.
http://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Relative_termhttp://en.wikipedia.org/wiki/Bandwidth_(signal_processing)http://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Morse_codehttp://en.wikipedia.org/wiki/Morse_codehttp://en.wikipedia.org/wiki/Musichttp://en.wikipedia.org/wiki/Audio_frequencyhttp://en.wikipedia.org/wiki/Sound_reproductionhttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Fiber_optichttp://en.wikipedia.org/wiki/Cutoff_frequencieshttp://en.wikipedia.org/wiki/Cutoff_frequencieshttp://en.wikipedia.org/wiki/Electronic_filterhttp://en.wikipedia.org/wiki/Communication_channelhttp://en.wikipedia.org/wiki/Signal_spectrumhttp://en.wikipedia.org/wiki/Hertzhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Information_theoryhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Communicationhttp://en.wikipedia.org/wiki/Signal_processinghttp://en.wikipedia.org/wiki/Spectroscopyhttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Relative_termhttp://en.wikipedia.org/wiki/Bandwidth_(signal_processing)http://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Morse_codehttp://en.wikipedia.org/wiki/Morse_codehttp://en.wikipedia.org/wiki/Musichttp://en.wikipedia.org/wiki/Audio_frequencyhttp://en.wikipedia.org/wiki/Sound_reproductionhttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Fiber_optichttp://en.wikipedia.org/wiki/Cutoff_frequencieshttp://en.wikipedia.org/wiki/Cutoff_frequencieshttp://en.wikipedia.org/wiki/Electronic_filterhttp://en.wikipedia.org/wiki/Communication_channelhttp://en.wikipedia.org/wiki/Signal_spectrumhttp://en.wikipedia.org/wiki/Hertzhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Information_theoryhttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Communicationhttp://en.wikipedia.org/wiki/Signal_processinghttp://en.wikipedia.org/wiki/Spectroscopy


10/34

In computer networking and other digital fields, the term

bandwidth often refers to a data rate measured in bits/s, for

example network throughput. The reason is that according

Hartley's law, the digital data rate limit (or channel capacity) of a

physical communication link is related to its bandwidth in hertz,sometimes denoted analog bandwidth. For bandwidth as a

computing term, less ambiguous terms are, bit rate, throughput,

goodput or channel capacity.

Modem

Modem (from modulator-demodulator) is a device that modulates

an analog carrier signal to encode digital information, and also

demodulates such a carrier signal to decode the transmitted

information. The goal is to produce a signal that can be transmitted

easily and decoded to reproduce the original digital data. Modems

can be used over any means of transmitting analog signals, from

driven diodes to radio.

The most familiar example is a voiceband modem that turns the

digital 1s and 0s of a personal computer into sounds that can be

transmitted over the telephone lines of Plain Old Telephone

Systems (POTS), and once received on the other side, converts

those 1s and 0s back into a form used by a USB, Serial, or

Network connection. Modems are generally classified by the

amount of data they can send in a given time, normally measured

inbits per second, or "bps". They can also be classified by Baud,

the number of times the modem changes its signal state per second.

Baud is NOT the modem's speed. The baud rate varies, depending

on the modulation technique used. Original Bell 103 modems used

a modulation technique that saw a change in state 300 times per

second. They transmitted 1 bit for every baud, and so a 300 bit/s

modem was also a 300-baud modem. However, casual

computerists confused the two. A 300 bit/s modem is the only

modem whose bit rate matches the baud rate. A 2400 bit/s modem

changes state 600 times per second, but due to the fact that it
http://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Hartley's_lawhttp://en.wikipedia.org/wiki/Channel_capacityhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Bit_ratehttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Goodputhttp://en.wikipedia.org/wiki/Peripheral_devicehttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Carrier_wavehttp://en.wikipedia.org/wiki/Signal_(information_theory)http://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Demodulationhttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Binary_numeral_systemhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Plain_old_telephone_servicehttp://en.wikipedia.org/wiki/Bits_per_secondhttp://en.wikipedia.org/wiki/Baudhttp://en.wikipedia.org/wiki/Computer_networkinghttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Hartley's_lawhttp://en.wikipedia.org/wiki/Channel_capacityhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Bit_ratehttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Goodputhttp://en.wikipedia.org/wiki/Peripheral_devicehttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Carrier_wavehttp://en.wikipedia.org/wiki/Signal_(information_theory)http://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Demodulationhttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Radiohttp://en.wikipedia.org/wiki/Binary_numeral_systemhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Plain_old_telephone_servicehttp://en.wikipedia.org/wiki/Bits_per_secondhttp://en.wikipedia.org/wiki/Baud


11/34

transmits 4 bits for each baud, 2400 bits are transmitted by 600

baud, or changes in states.

Faster modems are used by Internet users every day, notably cable

modems and ADSL modems. In telecommunications, "radio

modems" transmit repeating frames of data at very high data rates

over microwave radio links. Some microwave modems transmit

more than a hundred million bits per second. Optical modems

transmit data over optical fibers. Most intercontinental data links

now use optical modems transmitting overundersea optical fibers.

Optical modems routinely have data rates in excess of a billion

(1x109) bits per second. One kilobit per second (kbit/s or kb/s or

kbps) as used in this article means 1000 bits per second and not

1024 bits per second. For example, a 56k modem can transfer dataat up to 56,000 bits per second over the phone line.

DSL

DSL orxDSL, is a family of technologies that provide digital data

transmission over the wires of a local telephone network. DSL

originally stood for digital subscriber loop, although in recentyears, the term digital subscriber line has been widely adopted as

a more marketing-friendly term for ADSL, which is the most

popular version of consumer-ready DSL. DSL uses high

frequency, while regular telephone uses low frequency on the same

telephone line.

Typically, the download speed of consumer DSL services ranges

from 256 kilobits per second (kbit/s) to 24,000 kbit/s, depending

on DSL technology, line conditions and service level implemented.Typically, upload speed is lower than download speed for

Asymmetric Digital Subscriber Line (ADSL) and equal to

download speed for the rarer Symmetric Digital Subscriber Line

(SDSL).
http://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Serial_communicationshttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Wavelength_division_multiplexinghttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Submarine_communications_cablehttp://en.wikipedia.org/wiki/Kilobit_per_secondhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Plain_Old_Telephone_Servicehttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Asymmetric_Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Symmetric_Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Serial_communicationshttp://en.wikipedia.org/wiki/Microwavehttp://en.wikipedia.org/wiki/Wavelength_division_multiplexinghttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Submarine_communications_cablehttp://en.wikipedia.org/wiki/Kilobit_per_secondhttp://en.wikipedia.org/wiki/Digitalhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Plain_Old_Telephone_Servicehttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Asymmetric_Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Symmetric_Digital_Subscriber_Line


12/34

ADSL

Asymmetric Digital Subscriber Line (ADSL) is a form ofDSL,

a data communications technology that enables faster data

transmission over copper telephone lines than a conventional

voicebandmodem can provide. It does this by utilizing frequencies

that are not used by a voice telephone call. A splitter - or

microfilter - allows a single telephone connection to be used for

both ADSL service and voice calls at the same time. Because

phone lines vary in quality and were not originally engineered with

DSL in mind, it can generally only be used over short distances,

typically less than 3 miles (4.8 km).

At the telephone exchange the line generally terminates at a

DSLAM where another frequency splitter separates the voice band

signal for the conventional phone network. Data carried by the

ADSL is typically routed over the telephone company's data

network and eventually reaches a conventional internet network. In

the UKunderBritish Telecom the data network in question is its

ATM network which in turn sends it to its IP network IP Colossus.

DSLAM

A Digital Subscriber Line Access Multiplexer (DSLAM, often

pronounced dee-slam) allows telephone lines to make faster

connections to the Internet. It is a network device, located in the

telephony exchanges of the service providers, that connects

multiple customerDigital Subscriber Lines (DSLs) to a high-speed

Internet backbone line using multiplexing techniques. By locating

DSLAMs at locations remote to the telephone company central

office (CO), telephone companies provide DSL service to locations

previously beyond effective range.
http://en.wikipedia.org/wiki/Digital_subscriber_linehttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Voicebandhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Telephone_callhttp://en.wikipedia.org/wiki/DSL_filterhttp://en.wikipedia.org/wiki/DSLAMhttp://en.wikipedia.org/wiki/Signal_(electrical_engineering)http://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/UKhttp://en.wikipedia.org/wiki/British_Telecomhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Internet_backbonehttp://en.wikipedia.org/wiki/Multiplexinghttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Telephone_companyhttp://en.wikipedia.org/wiki/Digital_subscriber_linehttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Telephone_linehttp://en.wikipedia.org/wiki/Voicebandhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Telephone_callhttp://en.wikipedia.org/wiki/DSL_filterhttp://en.wikipedia.org/wiki/DSLAMhttp://en.wikipedia.org/wiki/Signal_(electrical_engineering)http://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/UKhttp://en.wikipedia.org/wiki/British_Telecomhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/Telephonehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Internet_backbonehttp://en.wikipedia.org/wiki/Multiplexinghttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Telephone_company


13/34

Path taken by data to DSLAM

1. Residential/commercial source: DSL modem plugged

into the customer's computer.

2. Local loop: the telephone company wires from a

customer to the telephone company's central office, often

called the "last mile".

3. DSLAM: a device for DSL service. Sending on the

customer ordownstream side, it intermixes voice traffic and

VDSL traffic onto the customer's DSL line. Receiving on

that side, it accepts and separates outgoing phone and data

signals from the customer. It directs the data signals

upstream towards the appropriate carrier's network, and thephone signals towards the voice switch.

4. Main Distribution Frame (MDF): a wiring rack that

connects outside subscriber lines with internal lines. It is

used to connect public or private lines coming into the

building to internal networks. At the telco, the MDF is

generally in proximity to the cable vault and not far from the

telephone switch.

Role of the DSLAM

The DSLAM equipment at the telephone company (telco) collects

the digital signals from its many modem ports and combines them

into one signal via multiplexing. Depending on the product being

used, a DSLAM would aggregate the DSL lines with some

combination ofAsynchronous Transfer Mode (ATM), frame relay,

orInternet Protocol networks (i.e., IP-DSLAM that uses the PTM-TC stack)(Packet Transfer Mode - Transmission Convergence).

The aggregated signal is then loaded onto the telco's backbone

switching equipment, traveling through an access network(AN)

also known as aNetwork Service Provider(NSP)at speeds of up

to 10 Gbit/s and connecting to the Internet-backbone.
http://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Local_loophttp://en.wikipedia.org/wiki/Last_milehttp://en.wikipedia.org/wiki/DSLhttp://en.wikipedia.org/wiki/Downstream_(computer_science)http://en.wikipedia.org/wiki/VDSLhttp://en.wikipedia.org/wiki/Upstream_(computer_science)http://en.wikipedia.org/wiki/Main_Distribution_Framehttp://en.wikipedia.org/w/index.php?title=Cable_vault&action=edit&redlink=1http://en.wikipedia.org/wiki/Telephone_companyhttp://en.wikipedia.org/wiki/Digital_signalhttp://en.wikipedia.org/wiki/Multiplexinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Frame_relayhttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/w/index.php?title=PTM-TC&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=PTM-TC&action=edit&redlink=1http://en.wikipedia.org/wiki/Backbone_networkhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Network_service_providerhttp://en.wikipedia.org/wiki/Gbit/shttp://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Local_loophttp://en.wikipedia.org/wiki/Last_milehttp://en.wikipedia.org/wiki/DSLhttp://en.wikipedia.org/wiki/Downstream_(computer_science)http://en.wikipedia.org/wiki/VDSLhttp://en.wikipedia.org/wiki/Upstream_(computer_science)http://en.wikipedia.org/wiki/Main_Distribution_Framehttp://en.wikipedia.org/w/index.php?title=Cable_vault&action=edit&redlink=1http://en.wikipedia.org/wiki/Telephone_companyhttp://en.wikipedia.org/wiki/Digital_signalhttp://en.wikipedia.org/wiki/Multiplexinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Frame_relayhttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/w/index.php?title=PTM-TC&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=PTM-TC&action=edit&redlink=1http://en.wikipedia.org/wiki/Backbone_networkhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Network_service_providerhttp://en.wikipedia.org/wiki/Gbit/s


14/34

In terms of the OSI 7 Layer Model, the DSLAM acts like a

massive network switch since its functionality is purely Layer 2.

A DSLAM is not always located in the telephone company's

central office, but may also serve customers within a neighborhood

Serving Area Interface (SAI), sometimes in association with a

digital loop carrier. DSLAMs are also used by hotels, lodges,

residential neighbourhoods, and other corporations setting up their

own private telephone exchange.

Besides being a data switch and multiplexer, a DSLAM is also a

collection of modems. Each modem on the aggregation card

communicates with a subscriber's DSL modem. The modem

function is integrated into the DSLAM itself, rather than being

separate hardware like a traditional computer modem. Like

traditional, voice-band modems, the integrated DSL modem has

the ability to probe the line and train itself to compensate for

forward echoes and other impairments in order to move data at the

maximum rate the telephone line allows. This is also why twisted

pair DSL services have a longer range than physically similar

unshielded twisted pair (UTP) Ethernet.

In data communications

Broadband in data communications can refer to broadband

networks orbroadband Internet and may have the same meaning as

above, so that data transmission over a fiber optic cable would be

referred to as broadband as compared to a telephone modem

operating at 56,000bits per second.

However, broadbandin data communications is frequently used in

a more technical sense to refer to data transmission where multiplepieces of data are sent simultaneously to increase the effective rate

of transmission, regardless of actual data rate. In network

engineering this term is used for methods where two or more

signals share a medium.
http://en.wikipedia.org/wiki/OSI_modelhttp://en.wikipedia.org/wiki/Network_switchhttp://en.wikipedia.org/wiki/Data_link_layerhttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/Serving_Area_Interfacehttp://en.wikipedia.org/wiki/Digital_loop_carrierhttp://en.wikipedia.org/wiki/PBXhttp://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Forward_echohttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Data_communicationshttp://en.wikipedia.org/wiki/Broadband_networkshttp://en.wikipedia.org/wiki/Broadband_networkshttp://en.wikipedia.org/wiki/Broadband_Internet_accesshttp://en.wikipedia.org/wiki/Data_transmissionhttp://en.wikipedia.org/wiki/Fiber_optichttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/56k_modemhttp://en.wikipedia.org/wiki/Bit_ratehttp://en.wikipedia.org/wiki/Data_communicationshttp://en.wikipedia.org/wiki/Data_signaling_ratehttp://en.wikipedia.org/wiki/Network_engineeringhttp://en.wikipedia.org/wiki/Network_engineeringhttp://en.wikipedia.org/wiki/OSI_modelhttp://en.wikipedia.org/wiki/Network_switchhttp://en.wikipedia.org/wiki/Data_link_layerhttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/Serving_Area_Interfacehttp://en.wikipedia.org/wiki/Digital_loop_carrierhttp://en.wikipedia.org/wiki/PBXhttp://en.wikipedia.org/wiki/DSL_modemhttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/Forward_echohttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Data_communicationshttp://en.wikipedia.org/wiki/Broadband_networkshttp://en.wikipedia.org/wiki/Broadband_networkshttp://en.wikipedia.org/wiki/Broadband_Internet_accesshttp://en.wikipedia.org/wiki/Data_transmissionhttp://en.wikipedia.org/wiki/Fiber_optichttp://en.wikipedia.org/wiki/Modemhttp://en.wikipedia.org/wiki/56k_modemhttp://en.wikipedia.org/wiki/Bit_ratehttp://en.wikipedia.org/wiki/Data_communicationshttp://en.wikipedia.org/wiki/Data_signaling_ratehttp://en.wikipedia.org/wiki/Network_engineeringhttp://en.wikipedia.org/wiki/Network_engineering


15/34

Optical fibre

An optical fiber (or fibre) is a glass orplastic fiber that carries

light along its length. Fiber optics is the overlap ofapplied science

and engineering concerned with the design and application of

optical fibers. Optical fibers are widely used in fiber-optic

communication, which permits transmission over longer distances

and at higher data rates than other forms of communications.

Fibers are used instead of metal wires because signals travel along

them with less loss, and they are immune to electromagnetic

interference. Optical fibers are also used to form sensors, and in a

variety of other applications.

Light is kept in the "core" of the optical fiber by total internal

reflection. This causes the fiber to act as a waveguide. Fibers

which support many propagation paths or transverse modes are

called multimode fibers (MMF). Fibers which support only a

single mode are called singlemode fibers (SMF). Multimode fibers

generally have a large-diameter core, and are used for short-

distance communication links or for applications where high power

must be transmitted. Singlemode fibers are used for most

communication links longer than 200 meters.

Joining lengths of optical fiber is more complex than joining

electrical wire or cable. The ends of the fibers must be carefully

cleaved, and then spliced together eithermechanically or by fusing

them together with an electric arc. Special connectors are used to

make removable connections.

In Video

Broadband in analog video distribution is traditionally used torefer to systems such as cable television, where the individual

channels are modulated on carriers at fixed frequencies. In this

context, baseband is the term's antonym, referring to a single

channel of analog video, typically in composite form with an audio
http://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Lighthttp://en.wikipedia.org/wiki/Applied_sciencehttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Attenuationhttp://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Total_internal_reflectionhttp://en.wikipedia.org/wiki/Total_internal_reflectionhttp://en.wikipedia.org/wiki/Waveguide_(optics)http://en.wikipedia.org/wiki/Transverse_modehttp://en.wikipedia.org/wiki/Multimode_fiberhttp://en.wikipedia.org/wiki/Singlemode_fiberhttp://en.wikipedia.org/wiki/Cleave_(fiber)http://en.wikipedia.org/wiki/Mechanical_splicehttp://en.wikipedia.org/wiki/Fusion_splicinghttp://en.wikipedia.org/wiki/Electric_archttp://en.wikipedia.org/wiki/Optical_fiber_connectorhttp://en.wikipedia.org/wiki/Analog_signalhttp://en.wikipedia.org/wiki/Videohttp://en.wikipedia.org/wiki/Cable_televisionhttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Antonymhttp://en.wikipedia.org/wiki/Composite_videohttp://en.wikipedia.org/wiki/Sound_recording_and_reproductionhttp://en.wikipedia.org/wiki/Glasshttp://en.wikipedia.org/wiki/Plastichttp://en.wikipedia.org/wiki/Lighthttp://en.wikipedia.org/wiki/Applied_sciencehttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Attenuationhttp://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Electromagnetic_interferencehttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Total_internal_reflectionhttp://en.wikipedia.org/wiki/Total_internal_reflectionhttp://en.wikipedia.org/wiki/Waveguide_(optics)http://en.wikipedia.org/wiki/Transverse_modehttp://en.wikipedia.org/wiki/Multimode_fiberhttp://en.wikipedia.org/wiki/Singlemode_fiberhttp://en.wikipedia.org/wiki/Cleave_(fiber)http://en.wikipedia.org/wiki/Mechanical_splicehttp://en.wikipedia.org/wiki/Fusion_splicinghttp://en.wikipedia.org/wiki/Electric_archttp://en.wikipedia.org/wiki/Optical_fiber_connectorhttp://en.wikipedia.org/wiki/Analog_signalhttp://en.wikipedia.org/wiki/Videohttp://en.wikipedia.org/wiki/Cable_televisionhttp://en.wikipedia.org/wiki/Modulationhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Antonymhttp://en.wikipedia.org/wiki/Composite_videohttp://en.wikipedia.org/wiki/Sound_recording_and_reproduction


16/34

subcarrier. The act of demodulating converts broadband video to

baseband video.

However, broadband video in the context of streaming Internet

video has come to mean video files that havebitrates high enough

to requirebroadband Internet access in order to view them.

Broadband video is also sometimes used to describe IPTVVideo

on demand.

Cable television

Cable television is a system of providing television to consumers

via radio frequency signals transmitted to televisions through fixed

optical fibers or coaxial cables as opposed to the over-the-airmethod used in traditional television broadcasting (via radio

waves) in which a television antenna is required. FM radio

programming, high-speed Internet, telephony and similar non

television services may also be provided.

The abbreviation CATV is often used to mean "Cable TV". It

originally stood forCommunity Antenna Television, from cable

television's origins in 1948: in areas where over-the-air reception

was limited by mountainous terrain, large "community antennas"were constructed, and cable was run from them to individual

homes.

It is most commonplace in North America, Europe, Australia and

East Asia, though it is present in many other countries, mainly in

South America and the Middle East. Cable TV has had little

success in Africa, as it is not cost-effective to lay cables in sparsely

populated areas, and although so-called "wireless cable" or

microwave-based systems are used, "direct-to-home" satellitetelevision is far more popular, especially in South Africa.
http://en.wikipedia.org/wiki/Subcarrierhttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Bit_rate#Bitrates_in_multimediahttp://en.wikipedia.org/wiki/Broadband_Internet_accesshttp://en.wikipedia.org/wiki/IPTVhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Coaxial_cablehttp://en.wikipedia.org/wiki/FM_radiohttp://en.wikipedia.org/wiki/High-speed_Internethttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/North_Americahttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/East_Asiahttp://en.wikipedia.org/wiki/South_Americahttp://en.wikipedia.org/wiki/Middle_Easthttp://en.wikipedia.org/wiki/Africahttp://en.wikipedia.org/wiki/MMDShttp://en.wikipedia.org/wiki/Satellite_televisionhttp://en.wikipedia.org/wiki/Satellite_televisionhttp://en.wikipedia.org/wiki/South_Africahttp://en.wikipedia.org/wiki/Subcarrierhttp://en.wikipedia.org/wiki/Streaming_mediahttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Bit_rate#Bitrates_in_multimediahttp://en.wikipedia.org/wiki/Broadband_Internet_accesshttp://en.wikipedia.org/wiki/IPTVhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/Televisionhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Coaxial_cablehttp://en.wikipedia.org/wiki/FM_radiohttp://en.wikipedia.org/wiki/High-speed_Internethttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/North_Americahttp://en.wikipedia.org/wiki/Europehttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/East_Asiahttp://en.wikipedia.org/wiki/South_Americahttp://en.wikipedia.org/wiki/Middle_Easthttp://en.wikipedia.org/wiki/Africahttp://en.wikipedia.org/wiki/MMDShttp://en.wikipedia.org/wiki/Satellite_televisionhttp://en.wikipedia.org/wiki/Satellite_televisionhttp://en.wikipedia.org/wiki/South_Africa


17/34

In DSL

The various forms ofDigital Subscriber Line (DSL) services are

broadbandin the sense that digital information is sent over a high-

bandwidth channel above the baseband voice channel on a singlepair of wires.

In Ethernet

A baseband transmission sends one type of signal using a

medium's full bandwidth, as in 100BASE-T Ethernet. Ethernet,

however, is the common interface to broadband modems such as

DSL data links, and has a high data rate itself, so is sometimes

referred to as broadband. Ethernet provisioned overcable modem

is a common alternative to DSL.

COMPUTER NETWORKING

Computer networking is the engineering discipline concerned

with communication between computer systems or devices.Networking, routers, routing protocols, and networking over the

public Internet have their specifications defined in documents

called RFCs. Computer networking is sometimes considered a sub-

discipline of telecommunications, computer science, information

technology and/orcomputer engineering. Computer networks rely

heavily upon the theoretical and practical application of these

scientific and engineering disciplines.

A computer network is any set of computers or devices connectedto each other with the ability to exchange data. Examples of

networks are:

local area network(LAN), which is usually a small network

constrained to a small geographic area.
http://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/100BASE-Thttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Disciplinehttp://en.wikipedia.org/wiki/Computer_systemhttp://en.wikipedia.org/wiki/Peripheral_devicehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Request_for_Commentshttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Computer_sciencehttp://en.wikipedia.org/wiki/Information_technologyhttp://en.wikipedia.org/wiki/Information_technologyhttp://en.wikipedia.org/wiki/Computer_engineeringhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/Basebandhttp://en.wikipedia.org/wiki/100BASE-Thttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Disciplinehttp://en.wikipedia.org/wiki/Computer_systemhttp://en.wikipedia.org/wiki/Peripheral_devicehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Request_for_Commentshttp://en.wikipedia.org/wiki/Telecommunicationshttp://en.wikipedia.org/wiki/Computer_sciencehttp://en.wikipedia.org/wiki/Information_technologyhttp://en.wikipedia.org/wiki/Information_technologyhttp://en.wikipedia.org/wiki/Computer_engineeringhttp://en.wikipedia.org/wiki/Local_area_network


18/34

wide area network (WAN) that is usually a larger network

that covers a large geographic area.

wireless LANs and WANs (WLAN & WWAN) is the

wireless equivalent of the LAN and WAN

All networks are interconnected to allow communication with a

variety of different kinds of media, including twisted-paircopper

wire cable, coaxial cable, optical fiber, and various wireless

technologies. The devices can be separated by a few meters (e.g.

via Bluetooth) or nearly unlimited distances (e.g. via the

interconnections of the Internet).

Views of networks

Users and network administrators often have different views of

their networks. Often, users share printers and some servers form a

workgroup, which usually means they are in the same geographic

location and are on the same LAN. A community of interest has

less of a connotation of being in a local area, and should be thought

of as a set of arbitrarily located users who share a set of servers,

and possibly also communicate viapeer-to-peertechnologies.

Network administrators see networks from both physical andlogical perspectives. The physical perspective involves geographic

locations, physical cabling, and the network elements (e.g., routers,

bridges and application layer gateways that interconnect the

physical media. Logical networks, called, in the TCP/IP

architecture, subnets , map onto one or more physical media. For

example, a common practice in a campus of buildings is to make a

set of LAN cables in each building appear to be a common subnet,

using virtual LAN (VLAN) technology.Both users and administrators will be aware, to varying extents, of

the trust and scope characteristics of a network. Again using

TCP/IP architectural terminology, an intranet is a community of

interest under private administration usually by an enterprise, and

is only accessible by authorized users (e.g. employees) (RFC
http://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Wireless_networkhttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Coaxial_cablehttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Bluetoothhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Community-of-interest_networkhttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Network_bridgehttp://en.wikipedia.org/wiki/Application-level_gatewayhttp://en.wikipedia.org/wiki/Subnethttp://en.wikipedia.org/wiki/Virtual_LANhttp://en.wikipedia.org/wiki/Intranethttp://tools.ietf.org/html/rfc2547http://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Wireless_networkhttp://en.wikipedia.org/wiki/Twisted_pairhttp://en.wikipedia.org/wiki/Coaxial_cablehttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Bluetoothhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Community-of-interest_networkhttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Network_bridgehttp://en.wikipedia.org/wiki/Application-level_gatewayhttp://en.wikipedia.org/wiki/Subnethttp://en.wikipedia.org/wiki/Virtual_LANhttp://en.wikipedia.org/wiki/Intranethttp://tools.ietf.org/html/rfc2547


19/34

2547). Intranets do not have to be connected to the Internet, but

generally have a limited connection. An extranet is an extension of

an intranet that allows secure communications to users outside of

the intranet (e.g. business partners, customers)RFC 3547.

Informally, the Internet is the set of users, enterprises,and content

providers that are interconnected by Internet Service Providers

(ISP). From an engineering standpoint, the Internet is the set of

subnets, and aggregates of subnets, which share the registered IP

address space and exchange information about the reachability of

those IP addresses using the Border Gateway Protocol. Typically,

the human-readable names of servers are translated to IP addresses,

transparently to users, via the directory function of the Domain

Name System (DNS).

Over the Internet, there can be business-to-business (B2B),

business-to-consumer (B2C) and consumer-to-consumer (C2C)

communications. Especially when money or sensitive information

is exchanged, the communications are apt to be secured by some

form of communications security mechanism. Intranets and

extranets can be securely superimposed onto the Internet, without

any access by general Internet users, using secure Virtual Private

Network(VPN) technology.

When used for gaming one computer will have to be the server

while the others play through it.

Networking methods

Networking is a complex part of computing that makes up most of

the IT Industry. Without networks, almost all communication in

the world would cease to happen. It is because of networking thattelephones, televisions, the internet, etc. work.

One way to categorize computer networks is by their geographic

scope, although many real-world networks interconnect Local Area

Networks (LAN) via Wide Area Networks (WAN) and wireless

networks [WWAN]. These three (broad) types are:
http://tools.ietf.org/html/rfc2547http://en.wikipedia.org/wiki/Extranethttp://tools.ietf.org/html/rfc3547http://en.wikipedia.org/wiki/Internet_Service_Providershttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/Border_Gateway_Protocolhttp://en.wikipedia.org/wiki/Human-readablehttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Business-to-businesshttp://en.wikipedia.org/wiki/Business-to-consumerhttp://en.wikipedia.org/wiki/Consumer-to-consumer_electronic_commercehttp://en.wikipedia.org/wiki/Communications_securityhttp://en.wikipedia.org/wiki/Virtual_Private_Networkhttp://en.wikipedia.org/wiki/Virtual_Private_Networkhttp://en.wikipedia.org/wiki/Local_Area_Networkhttp://en.wikipedia.org/wiki/Local_Area_Networkhttp://en.wikipedia.org/wiki/Wide_Area_Networkhttp://tools.ietf.org/html/rfc2547http://en.wikipedia.org/wiki/Extranethttp://tools.ietf.org/html/rfc3547http://en.wikipedia.org/wiki/Internet_Service_Providershttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/Border_Gateway_Protocolhttp://en.wikipedia.org/wiki/Human-readablehttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Business-to-businesshttp://en.wikipedia.org/wiki/Business-to-consumerhttp://en.wikipedia.org/wiki/Consumer-to-consumer_electronic_commercehttp://en.wikipedia.org/wiki/Communications_securityhttp://en.wikipedia.org/wiki/Virtual_Private_Networkhttp://en.wikipedia.org/wiki/Virtual_Private_Networkhttp://en.wikipedia.org/wiki/Local_Area_Networkhttp://en.wikipedia.org/wiki/Local_Area_Networkhttp://en.wikipedia.org/wiki/Wide_Area_Network


20/34

Local area network (LAN)

A local area network is a network that spans a relatively small

space and provides services to a small number of people.

Depending on the number of people that use a Local Area Network, a peer-to-peer or client-server method of networking

may be used. A peer-to-peer network is where each client shares

their resources with other workstations in the network. Examples

of peer-to-peer networks are: Small office networks where

resource use is minimal and a home network. A client-server

network is where every client is connected to the server and each

other. Client-server networks use servers in different capacities.

These can be classified into two types: Single-service servers,where the server performs one task such as file server, print server,

etc.; while other servers can not only perform in the capacity of file

servers and print servers, but they also conduct calculations and

use these to provide information to clients (Web/Intranet Server).

Computers are linked via Ethernet Cable, can be joined either

directly (one computer to another), or via a network hub that

allows multiple connections.

Historically, LANs have featured much higher speeds than WANs.This is not necessarily the case when the WAN technology appears

as Metro Ethernet, implemented overoptical transmission systems.

Wide area network (WAN)

A wide area network is a network where a wide variety of

resources are deployed across a large domestic area or

internationally. An example of this is a multinational business that

uses a WAN to interconnect their offices in different countries.The largest and best example of a WAN is the Internet, which is a

network comprised of many smaller networks. The Internet is

considered the largest network in the world.[6]. The PSTN (Public

Switched Telephone Network) also is an extremely large network
http://en.wikipedia.org/wiki/Metro_Ethernethttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Data_communications#cite_note-5http://en.wikipedia.org/wiki/PSTNhttp://en.wikipedia.org/wiki/Metro_Ethernethttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Data_communications#cite_note-5http://en.wikipedia.org/wiki/PSTN


21/34

that is converging to use Internet technologies, although not

necessarily through the public Internet.

A Wide Area Network involves communication through the use of

a wide range of different technologies. These technologies include

Point-to-Point WANs such as Point-to-Point Protocol (PPP) and

High-Level Data Link Control (HDLC), Frame Relay, ATM

(Asynchronous Transfer Mode) and Sonet (Synchronous Optical

Network). The difference between the WAN technologies is based

on the switching capabilities they perform and the speed at which

sending and receiving bits of information (data) occur.

For more information on WANs, see Frame Relay, ATM and

Sonet.

Wireless networks (WLAN, WWAN)

A wireless network is basically the same as a LAN or a WAN but

there are no wires between hosts and servers. The data is

transferred over sets of radio transceivers. These types of networks

are beneficial when it is too costly or inconvenient to run the

necessary cables. For more information, see Wireless LAN and

Wireless wide area network. The media access protocols for LANscome from the IEEE.

The most common IEEE 802.11 WLANs cover, depending on

antennas, ranges from hundreds of meters to a few kilometers. For

larger areas, either communications satellites of various types,

cellular radio, or wireless local loop (IEEE 802.16) all have

advantages and disadvantages. Depending on the type of mobility

needed, the relevant standards may come from the IETF or the

ITU.Network topology

The network topology defines the way in which computers,

printers, and other devices are connected, physically and logically.

A network topology describes the layout of the wire and devices as
http://en.wikipedia.org/wiki/Point-to-Pointhttp://en.wikipedia.org/wiki/HDLChttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/ATM_(Asynchronous_Transfer_Mode)http://en.wikipedia.org/wiki/ATM_(Asynchronous_Transfer_Mode)http://en.wikipedia.org/wiki/Sonethttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Sonethttp://en.wikipedia.org/wiki/Wireless_LANhttp://en.wikipedia.org/wiki/Wireless_wide_area_networkhttp://en.wikipedia.org/wiki/IEEEhttp://en.wikipedia.org/wiki/IEEE_802.11http://en.wikipedia.org/wiki/Communications_satelliteshttp://en.wikipedia.org/wiki/Cellularhttp://en.wikipedia.org/wiki/IEEE_802.16http://en.wikipedia.org/wiki/IETFhttp://en.wikipedia.org/wiki/ITUhttp://en.wikipedia.org/wiki/Network_topologyhttp://en.wikipedia.org/wiki/Point-to-Pointhttp://en.wikipedia.org/wiki/HDLChttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/ATM_(Asynchronous_Transfer_Mode)http://en.wikipedia.org/wiki/ATM_(Asynchronous_Transfer_Mode)http://en.wikipedia.org/wiki/Sonethttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Frame_Relayhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Sonethttp://en.wikipedia.org/wiki/Wireless_LANhttp://en.wikipedia.org/wiki/Wireless_wide_area_networkhttp://en.wikipedia.org/wiki/IEEEhttp://en.wikipedia.org/wiki/IEEE_802.11http://en.wikipedia.org/wiki/Communications_satelliteshttp://en.wikipedia.org/wiki/Cellularhttp://en.wikipedia.org/wiki/IEEE_802.16http://en.wikipedia.org/wiki/IETFhttp://en.wikipedia.org/wiki/ITUhttp://en.wikipedia.org/wiki/Network_topology


22/34

well as the paths used by data transmissions. Commonly used

topologies include:

Bus

Star Tree (hierarchical)

Linear

Ring

Mesh

partially connected

fully connected (sometimes known asfully redundant)

The network topologies mentioned above are only a generalrepresentation of the kinds of topologies used in computer network

and are considered basic topologies.


23/34

BROADBAND INTERNET

ACCESS

Broadband Internet access, often shortened to justbroadband, is

high data rate Internet accesstypically contrasted with dial-up

access over a 56k modem.

Dial-up modems are limited to abitrate of less than 56 kbit/s

(kilobits per second) and require the full use of a telephone line

whereas broadband technologies supply more than double this rate

and generally without disrupting telephone use.

Although various minimum bandwidths have been used indefinitions of broadband, ranging up from 64 kbit/s up to

1.0 Mbit/s, the 2006 OECD report is typical by defining broadband

as having download data transfer rates equal to or faster than

256 kbit/s, while the United StatesFCC, as of 2008, defines

broadband as anything above 768 kbit/s.]The trend is to raise the

threshold of the broadband definition as the marketplace rolls out

faster services.

Data rates are defined in terms ofmaximum downloadbecauseseveral common consumer broadband technologies such

as ADSL are "asymmetric"supporting much slower maximum

upload data rate than download.

"Broadband penetration" is now treated as a key economic

indicator.

Broadband architecture

A traditional fixedbroadband network provides its services to a

location/port. Multiple devices may connect to these services

through the residential LAN and a common residential gateway.

However, services are typically not individualized for these
http://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Dial-up_internet_accesshttp://en.wikipedia.org/wiki/Dial-up_internet_accesshttp://en.wikipedia.org/wiki/56k_modemhttp://en.wikipedia.org/wiki/Bitratehttp://en.wikipedia.org/wiki/Bithttp://en.wikipedia.org/wiki/OECDhttp://en.wikipedia.org/wiki/Data_transfer_rateshttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/FCChttp://en.wikipedia.org/wiki/Broadband_Internet_access#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Market_penetrationhttp://en.wikipedia.org/wiki/Economic_indicatorhttp://en.wikipedia.org/wiki/Economic_indicatorhttp://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Port_(computing)http://en.wikipedia.org/wiki/LANhttp://en.wikipedia.org/wiki/Residential_gatewayhttp://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Dial-up_internet_accesshttp://en.wikipedia.org/wiki/Dial-up_internet_accesshttp://en.wikipedia.org/wiki/56k_modemhttp://en.wikipedia.org/wiki/Bitratehttp://en.wikipedia.org/wiki/Bithttp://en.wikipedia.org/wiki/OECDhttp://en.wikipedia.org/wiki/Data_transfer_rateshttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/FCChttp://en.wikipedia.org/wiki/Broadband_Internet_access#cite_note-1%23cite_note-1http://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Market_penetrationhttp://en.wikipedia.org/wiki/Economic_indicatorhttp://en.wikipedia.org/wiki/Economic_indicatorhttp://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Port_(computing)http://en.wikipedia.org/wiki/LANhttp://en.wikipedia.org/wiki/Residential_gateway


24/34

devices or the users using them. A mobile broadband network, on

the other hand, typically deliver services to individual devices and

users, providing them access to the subscribed services wherever

they are.

In a Full Service Broadband network, these two service paradigms

are combined, providing users with services anywhere and from

any device. Users can authenticate themselves and reach all their

services from any device. A device can either connect through a

mobile access or a fixed access, enabling a transparent experience,

i.e. the same or very similar. Devices connected to the residential

LAN are reachable also from devices on the move, enabling

transparent access to e.g. stored media (figure below). All these

features needs to be enabled in ways that are simple enough for theaverage user, available more or lessplug-and-play.

Broadband Architecture
http://en.wikipedia.org/wiki/Plug-and-playhttp://en.wikipedia.org/wiki/File:FSB_Architecture.jpghttp://en.wikipedia.org/wiki/Plug-and-play


25/34

A network architecture is required that can enable these new

capabilities in a way that is cost efficient for operators and

affordable and simple enough for the users. Such architecture has

the following characteristics:

Based on Ethernet transport network, capable of co-housing

multiple access networks/technologies and services.

Combining multiple access technologies, including fixed

access (e.g. GPON and VDSL2) and mobile access technologies

(e.g. 3G High Speed Packet Access (HSPA) and 3GPP Long

Term Evolution).

Provides capabilities to manage the heterogeneity between

access technologies, e.g. for device/user authentication andmulti-access mobility.

A consistent UNI towards devices, facilitating

interoperability and economies-of-scale for device

manufacturers.

Access-independent service enablers for e.g. end-to-end user

reachability (tying a user to a device) and capability negotiation.

The IP Multimedia Subsystem is the key component for this.

LAN technologies such as DLNA/UPNP are extended toremote operation, yet with minimal need for technical know-

how, e.g. dynamicDNS.

To reach the desired economies-of-scale and interoperability, such

an architecture must be based on open protocols. IETF protocols

such as Mobile IP, Session Initiation Protocol (SIP)

and RADIUS/Diameterare essential components along with

e.g. IMS, TISPAN RACS and 3GPPSystem ArchitectureEvolution (SAE).
http://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/GPONhttp://en.wikipedia.org/wiki/VDSL2http://en.wikipedia.org/wiki/High_Speed_Packet_Accesshttp://en.wikipedia.org/wiki/3GPP_Long_Term_Evolutionhttp://en.wikipedia.org/wiki/3GPP_Long_Term_Evolutionhttp://en.wikipedia.org/wiki/User-Network_Interfacehttp://en.wikipedia.org/wiki/IP_Multimedia_Subsystemhttp://en.wikipedia.org/wiki/DLNAhttp://en.wikipedia.org/wiki/UPNPhttp://en.wikipedia.org/wiki/Domain_name_systemhttp://en.wikipedia.org/wiki/IETFhttp://en.wikipedia.org/wiki/Session_Initiation_Protocolhttp://en.wikipedia.org/wiki/RADIUShttp://en.wikipedia.org/wiki/Diameter_(protocol)http://en.wikipedia.org/wiki/IP_Multimedia_Subsystemhttp://en.wikipedia.org/wiki/TISPANhttp://en.wikipedia.org/wiki/3GPPhttp://en.wikipedia.org/wiki/System_Architecture_Evolutionhttp://en.wikipedia.org/wiki/System_Architecture_Evolutionhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/GPONhttp://en.wikipedia.org/wiki/VDSL2http://en.wikipedia.org/wiki/High_Speed_Packet_Accesshttp://en.wikipedia.org/wiki/3GPP_Long_Term_Evolutionhttp://en.wikipedia.org/wiki/3GPP_Long_Term_Evolutionhttp://en.wikipedia.org/wiki/User-Network_Interfacehttp://en.wikipedia.org/wiki/IP_Multimedia_Subsystemhttp://en.wikipedia.org/wiki/DLNAhttp://en.wikipedia.org/wiki/UPNPhttp://en.wikipedia.org/wiki/Domain_name_systemhttp://en.wikipedia.org/wiki/IETFhttp://en.wikipedia.org/wiki/Session_Initiation_Protocolhttp://en.wikipedia.org/wiki/RADIUShttp://en.wikipedia.org/wiki/Diameter_(protocol)http://en.wikipedia.org/wiki/IP_Multimedia_Subsystemhttp://en.wikipedia.org/wiki/TISPANhttp://en.wikipedia.org/wiki/3GPPhttp://en.wikipedia.org/wiki/System_Architecture_Evolutionhttp://en.wikipedia.org/wiki/System_Architecture_Evolution


26/34

ConnectionTransmission

data rate

DS-1 (Tier 1) 1.544 Mbit/s

E-1 2.048 Mbit/s

DS-3 (Tier 3) 44.736 Mbit/s

OC-3 155.52 Mbit/s

OC-12 622.08 Mbit/s

OC-48 2.488 Gbit/s

OC-192 9.953 Gbit/s

OC-768 39.813 Gbit/s

OC-1536 79.6 Gbit/s

OC-3072 159.2 Gbit/s

Broadband is often called "high-speed" Internet, because it usually

has a high rate of data transmission. In general, any connection to

the customer of 256 kbit/s (0.256 Mbit/s) or greater is more
http://en.wikipedia.org/wiki/DS-1http://en.wikipedia.org/wiki/E-carrierhttp://en.wikipedia.org/wiki/DS-3http://en.wikipedia.org/wiki/Optical_Carrier#OC-3http://en.wikipedia.org/wiki/Optical_Carrier#OC-12http://en.wikipedia.org/wiki/Optical_Carrier#OC-48http://en.wikipedia.org/wiki/Optical_Carrier#OC-192http://en.wikipedia.org/wiki/Optical_Carrier#OC-768http://en.wikipedia.org/wiki/Optical_Carrier#OC-1536_.26_beyondhttp://en.wikipedia.org/wiki/Optical_Carrier#OC-1536_.26_beyondhttp://en.wikipedia.org/wiki/DS-1http://en.wikipedia.org/wiki/E-carrierhttp://en.wikipedia.org/wiki/DS-3http://en.wikipedia.org/wiki/Optical_Carrier#OC-3http://en.wikipedia.org/wiki/Optical_Carrier#OC-12http://en.wikipedia.org/wiki/Optical_Carrier#OC-48http://en.wikipedia.org/wiki/Optical_Carrier#OC-192http://en.wikipedia.org/wiki/Optical_Carrier#OC-768http://en.wikipedia.org/wiki/Optical_Carrier#OC-1536_.26_beyondhttp://en.wikipedia.org/wiki/Optical_Carrier#OC-1536_.26_beyond


27/34

concisely considered broadband Internet. The International

Telecommunication UnionStandardization Sector (ITU-T)

recommendation I.113 has defined broadband as a transmission

capacity that is faster thanprimary rateISDN, at 1.5 to 2 Mbit/s.

The FCC definition of broadband is 768 kbit/s (0.8 Mbit/s).The Organization for Economic Co-operation and

Development (OECD) has defined broadband as 256 kbit/s in at

least one direction and this bit rate is the most common baseline

that is marketed as "broadband" around the world. There is no

specificbitrate defined by the industry, however, and "broadband"

can mean lower-bitrate transmission methods. SomeInternet

Service Providers (ISPs) use this to their advantage in marketing

lower-bitrate connections as broadband.In practice, the advertisedbandwidth is not always reliably

available to the customer; ISPs often allow a greater number of

subscribers than theirbackbone connection or neighborhood access

networkcan handle, under the assumption that most users will not

be using their full connection capacity very frequently. This

aggregation strategy works more often than not, so users can

typically burst to their full bandwidth most of the time;

however,peer-to-peer(P2P) file sharingsystems, often requiringextended durations of high bandwidth, stress these assumptions,

and can cause major problems for ISPs who have excessively

overbooked their capacity. For more on this topic, see traffic

shaping. As takeup for these introductory products

increases, telcos are starting to offer higher bit rate services. For

existing connections, this most of the time simply involves

reconfiguring the existing equipment at each end of the connection.

As the bandwidth delivered to end users increases, the marketexpects that video on demand services streamed over the Internet

will become more popular, though at the present time such services

generally require specialized networks. The data rates on most

broadband services still do not suffice to provide good quality

video, as MPEG-2 video requires about 6 Mbit/s for good results.
http://en.wikipedia.org/wiki/International_Telecommunication_Unionhttp://en.wikipedia.org/wiki/International_Telecommunication_Unionhttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/Primary_rate_interfacehttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Federal_Communications_Commissionhttp://en.wikipedia.org/wiki/Organization_for_Economic_Co-operation_and_Developmenthttp://en.wikipedia.org/wiki/Organization_for_Economic_Co-operation_and_Developmenthttp://en.wikipedia.org/wiki/Bitratehttp://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Internet_backbonehttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/File_sharinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Telephone_companyhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/MPEG-2http://en.wikipedia.org/wiki/International_Telecommunication_Unionhttp://en.wikipedia.org/wiki/International_Telecommunication_Unionhttp://en.wikipedia.org/wiki/ITU-Thttp://en.wikipedia.org/wiki/Primary_rate_interfacehttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Federal_Communications_Commissionhttp://en.wikipedia.org/wiki/Organization_for_Economic_Co-operation_and_Developmenthttp://en.wikipedia.org/wiki/Organization_for_Economic_Co-operation_and_Developmenthttp://en.wikipedia.org/wiki/Bitratehttp://en.wikipedia.org/wiki/Broadbandhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Internet_backbonehttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Access_networkhttp://en.wikipedia.org/wiki/Peer-to-peerhttp://en.wikipedia.org/wiki/File_sharinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Telephone_companyhttp://en.wikipedia.org/wiki/Video_on_demandhttp://en.wikipedia.org/wiki/MPEG-2


28/34

Adequate video for some purposes becomes possible at lower data

rates, with rates of 768 kbit/s and 384 kbit/s used for some video

conferencing applications, and rates as low as 100 kbit/s used

forvideophones using H.264/MPEG-4 AVC. The MPEG-4 format

delivers high-quality video at 2 Mbit/s, at the low end ofcablemodem and ADSL performance.

Increased bandwidth has already made an impact on newsgroups:

postings to groups such as alt.binaries.* have grown

from JPEG files to entire CD and DVDimages. According

toNTL, the level of traffic on their network increased from a daily

inbound news feed of 150 gigabytes of data per day and 1 terabyte

of data out each day in 2001 to 500 gigabytes of data inbound and

over 4 terabytes out each day in 2002.

TECHNOLOGY

The standard broadband technologies in most areas

are DSL and cable modems. Newer technologies in use

include VDSL and pushing optical fiberconnections closer to the

subscriber in both telephone and cable plants. Fiber-optic

communication, while only recently being used in fiber to the

premises and fiber to the curb schemes, has played a crucial role in

enabling Broadband Internet access by making transmission of

information over larger distances much more cost-effective than

copper wire technology. In a few areas not served by cable or

ADSL, community organizations have begun to install Wi-

Fi networks, and in some cities and towns local governments are

installing municipal Wi-Fi networks. As of 2006, broadbandmobile Internet access has become available at the consumer level

in some countries, using the HSDPA andEV-DO technologies. The

newest technology being deployed for mobile and stationary

broadband access is WiMAX.
http://en.wikipedia.org/wiki/Video_teleconferencehttp://en.wikipedia.org/wiki/Video_teleconferencehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/H.264http://en.wikipedia.org/wiki/MPEG-4http://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Asymmetric_Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Newsgrouphttp://en.wikipedia.org/wiki/JPEGhttp://en.wikipedia.org/wiki/Compact_dischttp://en.wikipedia.org/wiki/DVDhttp://en.wikipedia.org/wiki/Disk_imagehttp://en.wikipedia.org/wiki/NTLhttp://en.wikipedia.org/wiki/Digital_subscriber_linehttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/VDSLhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber_to_the_premiseshttp://en.wikipedia.org/wiki/Fiber_to_the_premiseshttp://en.wikipedia.org/wiki/Fiber_to_the_curbhttp://en.wikipedia.org/wiki/Wi-Fihttp://en.wikipedia.org/wiki/Wi-Fihttp://en.wikipedia.org/wiki/HSDPAhttp://en.wikipedia.org/wiki/Evolution-Data_Optimizedhttp://en.wikipedia.org/wiki/WiMAXhttp://en.wikipedia.org/wiki/Video_teleconferencehttp://en.wikipedia.org/wiki/Video_teleconferencehttp://en.wikipedia.org/wiki/Videophonehttp://en.wikipedia.org/wiki/H.264http://en.wikipedia.org/wiki/MPEG-4http://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/Asymmetric_Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Newsgrouphttp://en.wikipedia.org/wiki/JPEGhttp://en.wikipedia.org/wiki/Compact_dischttp://en.wikipedia.org/wiki/DVDhttp://en.wikipedia.org/wiki/Disk_imagehttp://en.wikipedia.org/wiki/NTLhttp://en.wikipedia.org/wiki/Digital_subscriber_linehttp://en.wikipedia.org/wiki/Cable_modemhttp://en.wikipedia.org/wiki/VDSLhttp://en.wikipedia.org/wiki/Optical_fiberhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber-optic_communicationhttp://en.wikipedia.org/wiki/Fiber_to_the_premiseshttp://en.wikipedia.org/wiki/Fiber_to_the_premiseshttp://en.wikipedia.org/wiki/Fiber_to_the_curbhttp://en.wikipedia.org/wiki/Wi-Fihttp://en.wikipedia.org/wiki/Wi-Fihttp://en.wikipedia.org/wiki/HSDPAhttp://en.wikipedia.org/wiki/Evolution-Data_Optimizedhttp://en.wikipedia.org/wiki/WiMAX


29/34

ISDN

Integrated Service Digital Network (ISDN) is one of the oldest

broadband digital access methods for consumers and businesses toconnect to the Internet. It is a telephone data service standard. Its

use in the United States peaked in the late 1990s prior to the

availability ofDSL and cable modem technologies. Broadband

service is usually compared to ISDN-BRI because this was the

standard broadband access technology that formed a baseline for

the challenges faced by the early broadband providers. These

providers sought to compete against ISDN by offering faster and

cheaper services to consumers.

A basic rate ISDN line (known as ISDN-BRI) is an ISDN line with

2 data "bearer" channels (DS0 - 64 kbit/s each). Using ISDN

terminal adapters (erroneously called modems), it is possible to

bond together 2 or more separate ISDN-BRI lines to reach

bandwidths of 256 kbit/s or more. The ISDN channel bonding

technology has been used for video conference applications and

broadband data transmission.

Primary rate ISDN, known as ISDN-PRI, is an ISDN line with 23DS0 channels and total bandwidth of 1,544 kbit/s (US standard).

ISDN E1 (European standard) line is an ISDN lines with 30 DS0

channels and total bandwidth of 2,048 kbit/s. Because ISDN is a

telephone-based product, a lot of the terminology and physical

aspects of the line are shared by the ISDN-PRI used for voice

services. An ISDN line can therefore be "provisioned" for voice or

data and many different options, depending on the equipment

being used at any particular installation, and depending on theofferings of the telephone company's central office switch. Most

ISDN-PRI's are used for telephone voice communication using

large PBX systems, rather than for data. One obvious exception is

that ISPs usually have ISDN-PRI's for handling ISDN data and

modem calls.
http://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/DSLhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Provisioninghttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/Private_branch_exchangehttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/DSLhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Provisioninghttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/Private_branch_exchange


30/34

It is mainly of historical interest that many of the earlier ISDN data

lines used 56 kbit/s rather than 64 kbit/s "B" channels of data. This

caused ISDN-BRI to be offered at both 128 kbit/s and 112 kbit/s

rates, depending on the central office's switching equipment.

Advantages:

1. Constant data rate at 64 kbit/s for each DS0 channel.

2. Two way broadband symmetric data transmission,

unlike ADSL.

3. One of the data channels can be used for phone

conversation without disturbing the data transmission

through the other data channel. When a phone call is ended,

the bearer channel can immediately dial and re-connect itselfto the data call.

4. Call setup is very quick.

5. Low latency

6. ISDN Voice clarity is unmatched by other phone

services.

7. Caller ID is almost always available for no additional

fee.

8. Maximum distance from the central office is muchgreater than it is for DSL.

9. When using ISDN-BRI, there is the possibility of using

the low-bandwidth 16 kbit/s "D" channel for packet data and

for always on capabilities.

Disadvantages:

1. ISDN offerings are dwindling in the marketplace due to

the widespread use of faster and cheaper alternatives.

2. ISDN routers, terminal adapters ("modems"), and

telephones are more expensive than

ordinary POTS equipment, like dial-up modems.
http://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Caller_IDhttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/POTShttp://en.wikipedia.org/wiki/ADSLhttp://en.wikipedia.org/wiki/Caller_IDhttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/POTS


31/34

3. ISDNprovisioning can be complicated due to the great

number of options available.

4. ISDN users must dial in to a provider that offers ISDN

Internet service, which means that the call could be

disconnected.5. ISDN is billed as a phone line, to which is added the

bill for Internet ISDN access.

6. "Always on" data connections are not available in all

locations.

7. Some telephone companies charge unusual fees for

ISDN, including call setup fees, per minute fees, and higher

rates than normal for other services.

T-1/DS-1

These are highly-regulated services traditionally intended for

businesses, that are managed throughPublic Service

Commissions (PSCs) in each state, must be fully defined in

PSC tariff documents, and have management rules dating back to

the early 1980s which still refer toteletypes as potential connection

devices. As such, T-1 services have very strict and rigid servicerequirements which drive up the provider's maintenance costs and

may require them to have a technician on standby 24 hours a day

to repair the line if it malfunctions. (In comparison, ISDN and DSL

are not regulated by the PSCs at all.) Due to the expensive and

regulated nature of T-1 lines, they are normally installed under the

provisions of a written agreement, the contract term being typically

one to three years. However, there are usually few restrictions to

an end-user's use of a T-1, uptime and bandwidth data rates may be

guaranteed, quality of service may be supported, and blocks

ofstatic IPaddresses are commonly included.

Since a T-1 was originally conceived for voice transmission, and

voice T-1's are still widely used in businesses, it can be confusing

to the uninitiated subscriber. It is often best to refer to the type of
http://en.wikipedia.org/wiki/Provisioninghttp://en.wikipedia.org/wiki/Public_Service_Commissionhttp://en.wikipedia.org/wiki/Public_Service_Commissionhttp://en.wikipedia.org/wiki/Telecommunications_tariffshttp://en.wikipedia.org/wiki/Teletypeshttp://en.wikipedia.org/wiki/Uptimehttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Static_IPhttp://en.wikipedia.org/wiki/Provisioninghttp://en.wikipedia.org/wiki/Public_Service_Commissionhttp://en.wikipedia.org/wiki/Public_Service_Commissionhttp://en.wikipedia.org/wiki/Telecommunications_tariffshttp://en.wikipedia.org/wiki/Teletypeshttp://en.wikipedia.org/wiki/Uptimehttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Static_IP


32/34

T-1 being considered, using the appropriate "data" or "voice"

prefix to differentiate between the two. A voice T-1 would

terminate at a phone company's central office (CO) for connection

to the PSTN; a data T-1 terminates at apoint of presence (POP)

ordata center. The T-1 line which is between a customer'spremises and the POP or CO is called the local loop. The owner of

the local loop need not be the owner of the network at the POP

where your T-1 connects to the Internet, and so a T-1 subscriber

may have contracts with these two organizations separately.

The nomenclature for a T-1 varies widely, cited in some circles a

DS-1, a T1.5, a T1, or a DS1. Some of these try to distinguish

amongst the different aspects of the line, considering the data

standard a DS-1, and the physical structure of the trunk line a T-1or T-1.5. They are also called leased lines, but that terminology is

usually for data rates under 1.5 Mbit/s. At times, a T-1 can be

included in the term "leased line" or excluded from it. Whatever it

is called, it is inherently related to other broadband access

methods, which include T-3, SONETOC-3, and other T-

carrierand Optical Carriers. Additionally, a T-1 might be

aggregated with more than one T-1, producing an nxT-1, such as

4xT-1 which has exactly 4 times the bandwidth of a T-1.When a T-1 is installed, there are a number of choices to be made:

in the carrier chosen, the location of the demarcation point, the

type ofchannel service unit (CSU) ordata service unit (DSU) used,

the WAN IP routerused, the types of bandwidths chosen, etc.

Specialized WANrouters are used with T-1 lines that route Internet

orVPN data onto the T-1 line from the subscriber's packet-based

(TCP/IP) network usingcustomer premises equipment (CPE). The

CPE typical consists of a CSU/DSU that converts the DS-1 datastream of the T-1 to a TCP/IPpacket data stream for use in the

customer's EthernetLAN. It is noteworthy that many T-1 providers

optionally maintain and/or sell the CPE as part of the service

contract, which can affect the demarcation point and the ownership

of the router, CSU, or DSU.
http://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/PSTNhttp://en.wikipedia.org/wiki/Point_of_presencehttp://en.wikipedia.org/wiki/Data_centerhttp://en.wikipedia.org/wiki/Local_loophttp://en.wikipedia.org/wiki/Trunk_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/SONEThttp://en.wikipedia.org/wiki/OC-3http://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/Optical_Carrierhttp://en.wikipedia.org/wiki/Demarcation_pointhttp://en.wikipedia.org/wiki/Channel_service_unithttp://en.wikipedia.org/wiki/Data_service_unithttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Routershttp://en.wikipedia.org/wiki/VPNhttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Customer_premises_equipmenthttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/LANhttp://en.wikipedia.org/wiki/Central_officehttp://en.wikipedia.org/wiki/PSTNhttp://en.wikipedia.org/wiki/Point_of_presencehttp://en.wikipedia.org/wiki/Data_centerhttp://en.wikipedia.org/wiki/Local_loophttp://en.wikipedia.org/wiki/Trunk_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/SONEThttp://en.wikipedia.org/wiki/OC-3http://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/T-carrierhttp://en.wikipedia.org/wiki/Optical_Carrierhttp://en.wikipedia.org/wiki/Demarcation_pointhttp://en.wikipedia.org/wiki/Channel_service_unithttp://en.wikipedia.org/wiki/Data_service_unithttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Routerhttp://en.wikipedia.org/wiki/Wide_area_networkhttp://en.wikipedia.org/wiki/Routershttp://en.wikipedia.org/wiki/VPNhttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Customer_premises_equipmenthttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Ethernethttp://en.wikipedia.org/wiki/LAN


33/34

Although a T-1 has a maximum of 1.544 Mbit/s, a fractional T-

1 might be offered which only uses an integer multiple of 128

kbit/s for bandwidth. In this manner, a customer might only

purchase 1/12th or 1/3 of a T-1, which would be 128 kbit/s and 512

kbit/s, respectively.

T-1 and fractional T-1 data lines are symmetric, meaning that their

upload and download data rates are the same.

Cellular broadband

Cellular phone towers are very widespread, and as cellular

networks move to third generation (3G) networks they can support

fast data; using technologies such as EVDO, HSDPA and UMTS.

These can give broadband access to the Internet, with a cell phone,with Cardbus, ExpressCard, orUSB cellular modems, or with

cellularbroadband routers, which allow more than one computer to

be connected to the Internet using one cellular connection.

Broadband Traffic

Types of traffic carried by the network

Modern networks have to carry integrated traffic consisting of

voice, video and data. The Broadband Integrated Services Digital

Network(B-ISDN) satisfies these needs . The types of traffic

supported by a broadband network can be classified according to

three characteristics :

Bandwidth is the amount of network capacity required to

support a connection.

Latency is the amount of delay associated with a connection.Requesting low latency in the Quality of Service (QoS) profile

means that the cells need to travel quickly from one point in the

network to another.

Cell-delay variation (CDV) is the range of delays

experienced by each group of associated cells. Low cell-delay
http://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Symmetrichttp://en.wikipedia.org/wiki/Cellular_phonehttp://en.wikipedia.org/wiki/3Ghttp://en.wikipedia.org/wiki/EVDOhttp://en.wikipedia.org/wiki/HSDPAhttp://en.wikipedia.org/wiki/UMTShttp://en.wikipedia.org/wiki/Cardbushttp://en.wikipedia.org/wiki/ExpressCardhttp://en.wikipedia.org/wiki/USBhttp://en.wikipedia.org/wiki/Broadband_routerhttp://en.wikipedia.org/wiki/Broadband_Integrated_Services_Digital_Networkhttp://en.wikipedia.org/wiki/Broadband_Integrated_Services_Digital_Networkhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Laghttp://en.wikipedia.org/wiki/Quality_of_Servicehttp://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Fractional_T1http://en.wikipedia.org/wiki/Symmetrichttp://en.wikipedia.org/wiki/Cellular_phonehttp://en.wikipedia.org/wiki/3Ghttp://en.wikipedia.org/wiki/EVDOhttp://en.wikipedia.org/wiki/HSDPAhttp://en.wikipedia.org/wiki/UMTShttp://en.wikipedia.org/wiki/Cardbushttp://en.wikipedia.org/wiki/ExpressCardhttp://en.wikipedia.org/wiki/USBhttp://en.wikipedia.org/wiki/Broadband_routerhttp://en.wikipedia.org/wiki/Broadband_Integrated_Services_Digital_Networkhttp://en.wikipedia.org/wiki/Broadband_Integrated_Services_Digital_Networkhttp://en.wikipedia.org/wiki/Bandwidth_(computing)http://en.wikipedia.org/wiki/Laghttp://en.wikipedia.org/wiki/Quality_of_Service


34/34

variation means a group of cells must travel through the

network without getting too far apart from one another.

Requirements of the different types of traffic

The different types of traffic found in a broadband network (withexamples) and their respective requirements are summarized in

Table

Network traffic types and their requirements

TRAFFIC

TYPEEXAMPLE

REQUIRED

BANDWIDTH

CELL-DELAY

VARIATIONLATENCY

Constant

Voice,

guaranteed

circuit

emulation

Minimal Low

Variable

Compressed

video Guaranteed Variable Low

Available Data Not guaranteedWidely

variableVariable

Basics of Broadband and Gsm Technology

Documents

Transcript of Basics of Broadband and Gsm Technology