1G (or 1-G) refers to the first-generation of - PowerPoint Presentation

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1G

(or 1-G) refers to the first-generation of

wireless

telephone

technology

,

mobile

telecommunications

. These are the

analog

telecommunications standards that were introduced in the 1980s and continued until being replaced by

2G

digital

telecommunications. The main difference between two succeeding mobile telephone systems, 1G and

2G

, is that the radio signals that 1G networks use are analog, while 2G networks are digital.

Although both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system, the voice itself during a call is encoded to digital signals in 2G whereas 1G is only modulated to higher frequency, typically 150 MHz and up.

2G

(or 2-G) is short for second-generation

wireless

telephone

technology

. Second generation 2G cellular telecom networks were commercially launched on the

GSM

standard in

Finland

by

Radiolinja

[1]

(now part of

Elisa

Oyj

) in 1991. Three primary benefits of 2G networks over their predecessors were that phone conversations were

digitally encrypted

; 2G systems were significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels; and 2G introduced data services for mobile, starting with

SMS

text messages.

After 2G was launched, the previous mobile telephone systems were retrospectively dubbed

1G

. While radio signals on 1G networks are

analog

, radio signals on 2G networks are

digital

. Both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system.

2G has been superseded by newer technologies such as 2.5G, 2.75G,

3G

, and

4G

; however, 2G networks are still used in many parts of the world.

3G networks are expected to provide wireless telecommunications

to mobile devices over a wide area, such as

mobile phones

. These networks are digital and in addition to

telephone

and

video calls

they may provide content in a similar format to any other wired internet connection, via

TCP/IP

protocol. Recent 3G releases, often denoted

3.5G

and

3.75G

(especially

soover

the

HSPA

subfamily and

EVDO

Rev. B format), also provide

mobile broadband

access of several

Mbit

/s

to laptop computers and

smartphones

.

4G

mobile technology is the name given to the next generation of mobile devices such as cell phones.

It became available from at least one provider in several parts of the US in 2009. There is not yet an agreed industry standard for what constitutes 4G mobile, so for now it is merely a marketing term.

The use of G, standing for generation,

in mobile technology covers the major advances of the past 20-30 years. 1G technology involved the first widely available mobile phones. 2G technology, which began in the early 1990s, switched to a digital format and introduced text messaging.

3G

technology improved the efficiency of how data is carried, making it possible to carry enhanced information services such as websites in their original format. The latest

iPhone

is the best known example of

3G technology

In

telecommunications

,

4G

is the fourth generation of

cellular

wireless

standards.

It is a successor to

3G

and

2G

families of standards. Speed requirements for 4G service set the peak download speed at 100 

Mbit

/s for high mobility communication (such as from trains and cars) and 1 

Gbit

/s for low mobility communication (such as pedestrians and stationary users).

[1]

A 4G system is expected to provide a comprehensive and secure all-

IP

based

mobile broadband

solution to laptop computer

wireless modems

,

smartphones

, and other mobile devices.

Facilities

such as

ultra-broadband

Internet access,

IP telephony

, gaming services, and streamed multimedia may be provided to users.

1 G , 2 G , 3 G , 4 G Comparison

1G refers to the first-generation

wireless analog technology standards used in mobile telephony.

These originated during the 1980s. It basically supported voice calls and sending text messaging services. It was later replaced by 2

G or second-generation wireless digital technology

.

2G network phones can use various digital

protocols such as

GSM, CDMA, TDMA,

iDEN

and PDC.

Phones belonging to this technology used narrow band wireless digital network for their operations. As compared to 1G, they also brought more clarity to the conversation.

These mobile phones also had a longer battery life, and a semi global roaming facility was available.

In between the launch of the

2G and 3G, the 2.5G

was introduced as a bridge between the two generations. There were not many critical introductions in this technology, so it was looked upon as a marketing gimmick.

802.11 and

802.11x

refers to a family of specifications developed by the

IEEE

for

w

ireless

LAN

(

WLAN

) technology. 802.11 specifies an over-the-air interface between a wireless client and a base station or between two wireless clients. The IEEE accepted the specification in 1997.

IEEE - I

nstitute of

E

lectrical and

E

lectronics

E

ngineers

, pronounced

I-triple-E

. Founded in 1884 as the AIEE, the IEEE was formed in 1963 when AIEE merged with IRE. IEEE is an organization composed of engineers, scientists, and students. The IEEE is best known for developing

standards

for the

computer

and electronics industry. In particular, the

IEEE 802

standards for

local-area networks

are widely followed.

There are several specifications in the 802.11 family:

802.11 — applies to wireless LANs and provides 1 or 2 Mbps transmission in the 2.4 GHz band using either frequency hopping spread spectrum (

FHSS

) or direct sequence spread spectrum (

DSSS

).

802.11a

— an extension to 802.11 that applies to wireless LANs and provides up to 54-Mbps in the 5GHz band. 802.11a uses an orthogonal frequency division multiplexing encoding scheme rather than

FHSS

or

DSSS

.

802.11b

(also referred to as 802.11 High Rate or Wi-Fi) — an extension to 802.11 that applies to wireless LANS and provides 11 Mbps transmission (with a fallback to 5.5, 2 and 1-Mbps) in the 2.4 GHz band. 802.11b uses only

DSSS

. 802.11b was a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.

802.11e

— a wireless draft standard that defines the

Q

uality

o

f

S

ervice

(

QoS

) support for LANs, and is an enhancement to the 802.11a and 802.11b wireless LAN (WLAN) specifications. 802.11e adds

QoS

features and multimedia support to the existing IEEE 802.11b and IEEE 802.11a wireless standards, while maintaining full backward compatibility with these standards.

802.11g

— applies to wireless LANs and is used for transmission over short distances at up to 54-Mbps in the 2.4 GHz bands.

802.11n

— 802.11n builds upon previous 802.11 standards by adding

m

ultiple-

i

nput

m

ultiple-

o

utput

(

MIMO

). The additional transmitter and receiver antennas allow for increased data throughput through spatial multiplexing and increased range by exploiting the spatial diversity through coding schemes like

Alamouti

coding. The real speed would be 100

Mbit

/s (even 250

Mbit

/s in PHY level), and so up to 4-5 times faster than 802.11g.

802.11r

-  802.11r, also called

Fast

B

asic

S

ervice

S

et

(

BSS

) Transition, supports

VoWi-Fi

handoff between access points to enable

VoIP

roaming on a

Wi-Fi

network with

802.1X

authentication.

802.1X

— Not to be confused with 802.11x (which is the term used to describe the family of 802.11 standards) 802.1X is an IEEE standard for port-based Network Access Control that allows network administrators to restricted use of IEEE 802 LAN service access points to secure communication between authenticated and authorized devices. 

1 G , 2 G , 3 G , 4 G Comparison

Then the

3G or third generation of mobile phone

standards and technology made a foray

. It is still making its place in the world of today. In this technology, the data is sent through packet switching and voice calls are interpreted through circuit switching.

The 3G technologies basically boast of faster data-transmission speeds, greater network capacity and more advanced network services like global roaming.

It also incorporated the Wide Band Voice Channel, which enabled two people located in any part of the world to talk and send messages.

Some of the other features this technology offers are internet, mobile T.V, video conferencing, video calls, multi media messaging service (MMS), 3D gaming, and multi-gaming.

Lastly, we are awaiting the introduction of

4G technology between 2012 and 2015.

They are known as the

“beyond 3G” or “fourth-generation”

cell phone technology. This technology promises a faster rate of

data transfer, high-quality multimedia in real-time, multi-media newspapers

etc.

IEEE 802.11

is a set of standards for implementing

wireless local area network

(WLAN) computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the

IEEE

LAN

/

MAN

Standards Committee (

IEEE 802

). The base current version of the standard is

IEEE 802.11-2007

.

The 802.11 family consists of a series of over-the-air

modulation

techniques that use the same basic protocol.

The most popular are those defined by the 802.11b and 802.11g protocols,

which are amendments to the original standard. 802.11-1997 was the first wireless networking standard, but 802.11b was the first widely accepted one, followed by 802.11g and 802.11n. Security was originally purposefully weak due to export requirements of some governments,

[1]

and was later enhanced via the 802.11i amendment after governmental and legislative changes. 802.11n is a new multi-streaming modulation technique. Other standards in the family (c–f, h, j) are service amendments and extensions or corrections to the previous specifications.

802.11b and 802.11g use the 2.4

GHz

ISM band

, operating in the

United States

under

Part 15

of the US

Federal Communications Commission

Rules and Regulations. Because of this choice of frequency band, 802.11b and g equipment may occasionally suffer

interference

from

microwave ovens

,

cordless telephones

and

Bluetooth

devices

. 802.11b and 802.11g control their interference and susceptibility to interference by using

direct-sequence spread spectrum

(DSSS) and

orthogonal frequency-division multiplexing

(OFDM) signaling methods, respectively. 802.11a uses the

5 GHz U-NII band

, which, for much of the world, offers at least 23 non-overlapping channels rather than the 2.4 GHz ISM frequency band, where all channels overlap.

[2]

Better or worse performance with higher or lower frequencies (channels) may be realized, depending on the environment.

The segment of the

radio frequency

spectrum used by 802.11 varies between countries. In the US, 802.11a and 802.11g devices may be operated without a license, as allowed in Part 15 of the FCC Rules and Regulations. Frequencies used by channels one through six of 802.11b and 802.11g fall within the 2.4 GHz

amateur radio

band. Licensed

amateur radio operators

may operate 802.11b/g devices under

Part 97

of the FCC Rules and Regulations, allowing increased power output but not commercial content or encryption.

[3]

History

802.11 technology has its origins in a 1985 ruling by the U.S. Federal Communications Commission that released the

ISM band

for unlicensed use.

[4]

In 1991

NCR Corporation

/

AT&T

(now

Alcatel-Lucent

and

LSI Corporation

) invented the precursor to 802.11 in

Nieuwegein

, The Netherlands. The inventors initially intended to use the technology for cashier systems; the first wireless products were brought on the market under the name

WaveLAN

with raw data rates of 1

Mbit

/s and 2

Mbit

/s.

[

citation needed

]

Vic Hayes

, who held the chair of IEEE 802.11 for 10 years and has been called the "father of Wi-Fi" was involved in designing the initial 802.11b and 802.11a standards within the

IEEE

.

[

citation needed

]

In 1992, the

Commonwealth Scientific and Industrial Research

Organisation

(CSIRO) obtained a patent in

Australia

for a method of wireless data transfer technology based on the use of

Fourier transforms

to "

unsmear

" the signal. In 1996, they obtained a patent for the same technology in the US.

[5]

In April 2009, 14 tech companies selling Wi-Fi devices, including

Dell

,

HP

,

Microsoft

,

Intel

,

Nintendo

, and

Toshiba

, agreed to pay CSIRO $250 million for infringements on the CSIRO patents.

[6]