Thuyết trình transmission and switching

Thuyết trình transmission and switching

Tu Van Lam Nguyen Tan Luc

Ho Nguyen Van Man

Transmission and Switching

Gruop 5:

WIRELESS COMMUNICATIONS

OVERVIEW

2/19/16

2

Introduction to wave antennas

- Microwave - Infrared waves CONTENTS

Introduction to wireless network

For nearly 10 years over the wireless network being developed at a rapid pace

There are many types of networks, technologies, wireless standards have been standardized

Classification wireless network

PAN : Personal wireless network, with small coverage range of several meters to tens of meters

The technology used to connect peripherals such as printers, keyboards, mouse, hard disk, mobile phone with computers

Classification wireless network

LAN:

Wireless local area networks This group includes technology coverage range of several hundred meters

Classification wireless network

MAN:

Metropolitan wireless networks Its coverage will silkworms few km (range 4 ~ 5 km maximum)

Typical representatives

of this group is WiMAX.

Classification wireless network

WAN

Wide-area wireless network Its coverage also reach several kilometers to tens of kilometers range

This group covers network technologies such as UMTS mobile communication / GSM /CDMA2000

Classification wireless network

Organizations IEEE just About Us IEEE 802,22, called

is a regular connected WRAN (Wireless Regional Area Networks)

Purpose that helps to the user was captured Sóng Wifi even when the current moving speed cao above xe hoi, xe firewall

Microwave 1GHz-40GHz

Radio30MHz-1GHz Infrared waves

Microwave, also known as ultra high frequency signals (SHF), with a wavelength range of 30 cm (frequency 1 GHz) to 1 cm (frequency 30 GHz)

Because the radius of the earth r = 6,37.10^6 m

Call h1 [m] and h2 [m] 2 antenna height, the maximum distance information for microwave line is d [km].

Parabolic Antennas

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Microwaves ground commonly used parabolic reflector antenna.

If an electromagnetic energy source is placed

at the focus of the parabola, when the power output meets the surface it will revert back to a line parallel to the axis of the parabola

An antenna can be defined as an electrical conductor may be radiated electromagnetic energy or electromagnetic energy collected

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Terrestrial microwave transmission

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Wave propagation characteristics

Frequency within the range from 1-40GHz

Transfer efficiency

attenuation d is the distance is the wavelength

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In order to convey away the amplification system from 100Km

10-Downturn when it rains (especially at frequencies above 10GHz)Overlapping microwave frequencies

attenuation

Allocation of frequencies strict rules

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The satellites have the same frequency is not located close to each other

The number of satellites is limited

The satellites are geostationary satellites

Features

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Wave propagation characteristics

Optimal frequency bands for satellite TV in the range from 1

to 10 GHz

Under 1GHz noise (Natural and Artificial)

On 10GHz declined sharply (from atmospheric absorption and precipitation)

5.925 to 6.425 GHz

3.7 to 4.2 GHz

A satellite can not transmit and receive on the same frequency

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A common application is worth noting that the navigation system NAVSTAR (Global Positioning System - GPS)

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VHF & UHF TV

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Radio wave transmission characteristics

Frequency range of 30 MHz to 1 GHz is suitable for broadcast communications

Less decline when some rain and little else

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Infrared waves

Transmitted from one point to another

In the local applications and narrow range

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Infrared waves

Infrared communication is done by using the transmitter / receiver

that adjust infrared light intermittent

The receiver must be within sight of each other

Other infrared microwave in that it is not through walls, and use it

do not need to register frequency

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Guided media – wire

 Consist of:

− Copper

− Fiber

 Characteristics and quality of data transmission

is determined by the environment and the signal For wireline, greater environmental impact

Guided media – wire

1 Copper

b) Two-wire open line

• Insulation on each wire

Guided media – wire

1 Copper

b) Twisted-pair

Transmission characteristics

− Analog

• Need amplifier each 5km to 6km

− Digital

• Use the analog or digital signals

• Need a repeater each 2km or 3km

− The distance limit

− Bandwidth limits (1MHz)

− Speed ​​limit data (100Mbps)

− Susceptible to noise and the impact of the external environment

Guided media – wire

1 Copper

b) Twisted-pair

Guided media – wire

1 Copper

c) Coaxial

Guided media – wire

1 Copper

c) Coaxial

• The most flexible communications environment

• Cable TV

• Transmission distance phone

• Connect the device proximity

Guided media – wire

2 Fiber

a) Structure

High capacity

Small size and weight Attenuation of signal transmission in a low Isolate electromagnetic field

The distance between the remote repeater BER on the transmission line at about

High capacity

Small size and weight Attenuation of signal transmission in a low Isolate electromagnetic field

The distance between the remote repeater BER on the transmission line at about

Guided media – wire

2 Fiber

b) Benefits

Guided media – wire

2 Fiber

c) Applications

Wave propagation direction

Light Emitting Diode (LED) Injection Laser Diode (ILD) Wavelength Division Multiplexing

Wave propagation direction

Light Emitting Diode (LED) Injection Laser Diode (ILD) Wavelength Division Multiplexing

Guided media – wire

2 Fiber

d) Transmission characteristics

Guided media – wire

2 Fiber

e) Transmission mode

Transmission characteristic points - points

 Switching nodes are not

concerned with the content

 We always want to have

more than one path

through the network for

a pair of stations This

enhances the reliability

of the network.

Switching technique

 Data entering from a station is routed to the

destination by being switched from node to node.

Switching technique

Circuit switching

There is a dedicated communication path between two stations

Packet switching

Circuit switching

There is a dedicated communication path between two stations

Circuit switching

 Include 3 steps.

Circuit establishment

Data transfer

Circuit disconnect

• Before signals can

Circuit switching

 No congestion (fixed bandwidth)

 Data is transmitted at a fixed data rate with no delay.

Strong point:

Circuit switching: Space Division Switching

 Developed for the analog environment.

• and has been carried over into the digital environment.

 Each connection is a

secluded physical path.

 Each switch is a metallic

switch, or semiconductor

gate.

Crosspoint

Circuit switching: Space Division Switching

multiple-stage single-stage

Circuit switching: Space Division Switching

Circuit switching: Space Division Switching

• The number of crosspoints is large It

increases the cost price.

• Only a small amount of the crosspoints

are engaged.

• Loss a crosspoint, cause loss the

connection path whose lines intersect at

that crosspoint.

Crosspoint = Input x Output

Circuit switching: Space Division Switching

Circuit switching: Space Division Switching

• The number of crosspoints is reduced

• There are many connection path

connect 2 stations This enhances the

reliability of the network.

• To confuse the control system.

• It may be blocking.

Time Division Switching

 Divide low-speed data into small frame to transmit.

 Using digital signals.

 Using digital TDM technique to establish and

maintain connection line.

Time Division Switching

 Simple.

 Wasteful in transmission capacity

Time Division Switching

 Time Slot Interchange.

PACKET SWITCHING

What does Packet Switching mean ?

The technique of Switching ?

Advantages of packet switching

X.25

What is Packet Switching

Network Switch

Node Packet

What does Packet Switching mean ?

Principle of packet switching

A message is broken into small parts, called packets.

each packet have the length 1000 bytes.

Each packet adds header, which include: index,

addresses of the source and the destination,

error control code

The packet is received, temporarily stored and

transmitted to the next node (store and forward )

Packet Switching

Advantages of packet switching

 Increased transmission efficiency

 The package was received even when the

network is busy

 Offers improved delay characteristics: because

there are no long messages in the queue

(maximum packet size is fixed) Packet can be rerouted if there is any problem, such as, busy

or disabled links.

 Packet switching enable the ability to prioritize

The technique of Switching ?

 Station informed long divided into small packages

 Each packet is sent to the network switching node

 There are two types of packet switching,

datagram switching and virtual circuit switching :

 Virtual circuit

Datagram

 Each packet is handled independently

 Each package is called 1 datagram

 The package can :

 Take any appropriate route:

 The path of the packets are not the same

 Not in order to target posts

 Missing or lost along the way:

 An intermediate node temporarily damaged, the package

is waiting at the node that will be lost

corresponding processing

4

5 2

6 3

Datagram

Virtual Circuit

Roads are planned before sending the data packets

 When the path has been set, the packets transmitted

between two machines only follow the given line.

 Fixed path for each session

 Similarly switching circuit so-called virtual circuit

The control package is used to create connections

Each route is assigned an ID

Each packet contains the ID of the path rather than the

destination host address

No need to find a way for each package

4

5 2

6 3

Virtual Circuit

X.25 interface

User process

packet

Link access physical

packet

Link access physical

Multi-channel logical interface

DCE

to remote user process

lap-B link-level logical interface

DTE

X.21 physical interface

OSI

The Physical Layer

 perform physical communication between

workstation is connected to the (computer or terminal equipment) and the connecting this

workstation with packet switching node

Data Terminal Equipment:(DTE) the user's device Circuit terminating equipment:(DCE) network

node

Use the X.21 physical layer specification

(sometimes replaced by EIA-232)

X.25 interface

Link access layer

ability to provide reliable data

transmission through a physical connection

Data is transmitted in the form of

sequence of frames

Link Access Protocol Balanced (LAPB)

LAPB is the case subnet of HDLC

X.25 interface

Packet layer

 Packet Layer is the network layer

(level 3) of X.25

 provide a virtual circuit service, for

transmitting data from node to node

 error handling, congestion control and packet sequencing are functions of this layer

X.25 interface

User data

Layer 3 header

LAPB

User data into X.25 layer 3 X.25 additional control information (header)

then the entire package is passed down LAPB

I The introduction of softswitching

• First appeared around 1995

• Support for multiple services, from telephone / fax,

video calls and messages

• The switching system of software packages have made calls

 An important step development of switching technology

A Softswitching

1 Concept

II The concept of softswitching

The software performs the function call processing system capable of switching convey various types of information with different protocols

2 Terminology

Switching function is performed by physical means port Media

Gateway (MG), and call processing function of the media gateway controller Media Gateway Controller (MGC

III The main components of

softswitching

The structure of softswitching

• Media Gateway Controller

1.Media Gateway Controller (MGC)

The main function of the Media Gateway Controller

∗ Call control, maintaining the status of each call on an MG

∗ Control and operational support of MG, SG

∗ Messages exchanged between base 2 MG-F

∗ Handling QoS related news

a The main function of the Media Gateway Controller

 To set up call: H.323, SIP

 Media Gateway Control: MGCP, MEGACO / H.248

 Signaling Gateway Controller: SIGTRAN (SS7)

 To transmit information: RTP, RTCP

b The MGC protocol can use

2.Media Gateway (MG)

The structure of MG

MC functions

3.Signalling Gateway (SG)

4.Media Server (MS)

IV Essential activities of softswitch

Call processing flow chart of soft switching

Ability to attract customersTime short of market access

New opportunities for revenue

Advantage s

Use bandwidth efficiently v…v

V Advantages and applications of softswitching circuit

Applications

A historical Perspective

Overlay models create bottleneck from

the lack of segmentation and reassembly (SAR) functionality on interfaces faster than OC-48

What happened in mid-90’s?

The problems with overlay models reveal themselves:

 Overlay model results in an inefficient

use of network bandwidth due to the traditional ATM cell tax

A historical Perspective

 Classical IP over ATM requires the

deployment of n-squared routing adjacencies

What happened in mid-90’s?

The problems with overlay models reveal themselves:

 Overlay models increase complexity by

requiring providers to manage two separate control planes and two fundamentally different types of networking equipment

A historical Perspective

 No QoS for LANE and the IP Diffserv

approach to CoS does not map well to the existing ATM QoS mechanims

What happened in mid-90’s?

The problems with overlay models reveal themselves:

 LANE requires a client-server model

in place, e.g., LEC, LECS, LES, and BUS

A Historical Perspective (cont’d)

Multi-layer switching solutions

in the spotlight

IP switching by Ipsilon/NokiaTag switching by Cisco

Aggregate based IP switching (ARIS) by IBM

routing-Cell Switching Router (CSR) by Toshiba

IP Navigator by Cascade/Ascend/Lucent

Longest Prefix Match

IP Routing Software ATM Routing & Signaling

Software

Label Switching

Label Switching Signaling & label

binding

MPLS Basics (cont’d)

Generic label and label stacking:

LAYER-2 LAYER-3

MPLS Basics (cont’d)

ATM Based label and label stacking:

LAYER-2 LAYER-3

label to FEC binding where FEC = IP prefix

MPLS signaling protocols: distribute labels and maintain connectivity of an LSP

distributes

labels based on

source routing

Designed for QoS

Using raw IP and maintaining “soft state”

distributes

labels based on

source routing

Designed for QoS

Using raw IP and maintaining “hard state”

an upstream LSR maintains the received label binding for an FEC only if the label binding is received from the downstream LSR that the upstream LSR has selected as the next-hop for that FEC

upstream LSR has not selected as the next-hop for that FEC

Liberal label retention

 Label retention modes:

 Traditional shortest path based IP routing protocols provide enough information for LDP signaling

MPLS Basics (cont’d)

 Policy driven signaling protocols set up

an LSP based on the policy:

 A policy may enforce a manually configured

route

 A policy may use a route found by a

constraint-based routing protocol

 A policy may use a route found by a path based routing protocol

shortest- Routing for MPLS