Communication Technology 通信技术

1

Introduction

1.1

Introduction

of

the project

With the developments

of modern society,

communication technologies are becoming

more

and

more

essential

to

human

beings.

During

the

period

from

1920

to

2013,

researchers

made

a

comprehensive

improvement

in

the

fields

of

voice

quality,

connecting

speed,

communicating

security

and

so

on.

In

this

essay,

the

main

body

is

subdivided

into

three

aspects.

Firstly,

some

communication

technologies

applied

in

history are shown in

the first

session followed by

an overview of the technologies in

modern times which could describe the shift from 1G to 3G

. Then the second section is

mainly focusing on analyzing the advantages and disadvantages of each communication

technology. After that, a conclusion and a prediction is presented to sum up the whole

information and tell the improvements in the nearest future briefly.

In

the

process

of

working

on

this

project

I

could

learn

a

great

deal

of

knowledge

valuable for the future study lessons, meanwhile, some information of how to

use the

resources in the library or on the internet will be gained. What is the most essential is

that

my

academic

knowledge

is

not

so

broad

as

I

changed

my

major

from

Microelectronics(Undergraduate)

to

Communication

Engineering(Postgraduate),

so

I

need

to

chose

this

project

to

enrich

my

knowledge

through

reading

several

academic

1

journals and books.

1.2

Background information about communication technol

ogies

in history

In the ancient world, communication refers to the transmission of messages from one

place to the other and its aim is sending information. People used to send messages by

horse,

pigeon,

semaphore,

beacons

or

engraving

on

stone

pillars.

These

can

be

subdivided

into

two

categories:

optical

delivery

and

non-optical

delivery.

Optical

delivery

contains

several

methods

such

as

fire

alarm,

beacon,

body

language

,

while

non-optical

delivery

refers

to

the

conveyance

of

information

by

engraving

on

stone

pillars

or

sending

letters

which

are

transferred

by

horse

and

pigeon.

(Bamber

Gascoigne,1993)

The communication technologies in the ancient world were inefficient, especially when

the

travel

distance

was

remote

and

it

takes

months

or

even

years

to

send

a

letter

to

others.

However,

with

the

development

of

modern

technologies,

peoples

’

requests

on

quick

contact

resulted

in

the

investment

of

several

new

communication

technologies

such

as

Telecommunications.

According

Oxford

Dictionaries(2013)

and

Merriam-Webster Dictionaries(2013), Telecommunications refer to the transmission of

data,

telephone,

radio

and

so

on

from

one

place

to

the

other

by

using

technological

methods(

electrical

signals

and

electromagnetic

waves).

Also

this

technology

has

2

several

unique

characteristics

such

as

the

signals

will

not

be

influenced

by

time,

distance

and

place,

which

implicates

it

can

provide

people

with

a

rapid,

accurate,

reliable

contacting

mode.

Due

to

its

unique

features,

Telecommunications

are

developing rapidly and being widely used.

It

must

be

pointed

out

that

it

is

communication

technologies

shortened

the

distance

between different countries, increased the efficiency of economic and changed people

’

s

living styles greatly.

1.3

An overview of communication technologies from 1G to 3G

The development of modern communication can be subdivided into six main periods as

follows.

Firstly,

in

the

periods

from

1920

to

1940,

communication

technologies

experienced

an

initial

development.

For

example,

according

to

Regis

J.B.(2007),

car

phone

radio

system

was

first

equipped

in

the

St

Louis

police

on

June

the

17

th

1946

before it was widely used in North America in the 1980s. In the next twenty years, the

telephone

network

,

which

was

first

established

by

Bill

System

equipped

in

public

vehicles

around

the

world,

which

implicated

a

public

used

mobile

communication

service

had

appeared.

Then

American

realized

automatic

tuning

and

automatic

connection from

1960 to

1970. According to

W. Rae Young(1979), Bill

Lab invented

and realized the Advanced Mobile Phone System that can be seen as the first generation.

It also means a Cellular Mobile Communication Network was established. On the basis

of Networks & Communications(2005), the UK had developed another communication

3

system called TACS which was used in the UK and Ireland in 1983. After that, it can be

seen from Vijay K.G

.(2002), in around 1982, Europe put forward a Global System for

Mobile Communications System (GSM), which had been widely used in most European

countries in the world as it could

improve the voice quality

and increase

the network

security.

Lastly,

according

to

Patil

C.S.(2012),

at

the

end

of

20

th

century,

Asia

and

Europe

pointed

out

a

new

communication

system

called

W-CDMA,

while

American

launched CDMA2000. These two systems can not only transmit voice, but also transmit

digital

information,

which

could

provide

citizens

with

a

more

convenient

and

easier

access to wireless applications.

4

2

The First Generation

2.1

Definition of the 1

st

Generation

There

is

not

an

accurate

definition

of

the

1

st

Generation.

However,

according

to

Geography-dictionary(2008),

Your

Dictionary(2013)

and

Patil

C.S.(2012),

the

first

Generation refers to the Cellular Mobile Communication network which makes use of

analogue radio technologies.

2.2

The 1

st

Generation

The

First

Generation

cellular

technology

is

based

on

FDMA(frequency

division

multiple access) which can divide the communication band into different channels. Each

of them could be applied to transmit digital data produced by one certain conversation

on

the

mobile

phone

that

means

the

cellular

system

provides

special

frequency

for

different user.

According to Patil C.S.(2012), the First Generation cellular technology such as AMPS

offered

a

special

frequency

to

each

customer,

so

with

the

rising

number

of

users,

the

bandwidth

should

increase

eithe

r.

That

is

to

say,

the

efficiency

of

the

transmission

between

cell

centre

and

users

is

low.

Also,

it

has

no

security

method

to

prevent

the

conversation from being eavesdropped by criminals. According to James Guyton(2000),

compared

with

2G

and

3G,

the

First

Generation

has

a

lower

frequency

and

a

longer

5

wavelength, which means it also has a higher rate of being

interfered by

the noise.

According

to

the

opinions

mentioned

above,

different

ideas

can

be

seen

from

three

authors.

Dissimilar

from

James

G

.

,

Patil

C.S.(2012)

is

focusing

on

the

fields

of

customers.

It

told

us

that

1G

cannot

satisfy

general

people

’

s

desire

as

it

could

not

continue working when the number of customers is enormous. Patil C.S. compared the

analogue technology with the digital one in the fields of efficiency and security. Similar

with

Patil

C.S.,

James

G

.

also

compared

the

old

technology(1G)

with

the

advanced

technology(2G and 3G) in the area of noise cancelling. Thorough several disadvantages

of the 1

st

Generation are presented could implicate 1G must be replaced by other system,

some advantages of it should not be neglected. For instance, 1G is the first successful

standard network technology. Compared to

earlier technologies which relies on wired

connection to make telephone calls, 1G provides users with a real freedom and mobility,

which

ensure

them

communicate

with

the

others

while

in

the

outside.

Also,

with

the

help

of

1G

,

the

efficiency

of

military

actions,

scientific

researches

and

commercial

exchange ascended quite a lot.

3

The Second Gerneration

6