作成 : 中村遼 ( 大学院情報科学府 ) physical layer ryo nakamura

: ( )作成中村遼大学院情報科学府

Physical Layer

Ryo Nakamura


Abstract

・ OSI reference model

・ Encoding

・ Protocol

- Protocol for Ethernet


・ Cable - Metal cable

・ Coaxial cable・ Twisted pair cable

- Optical fiber - Wireless Communication

・ Radio・ Free Space Optics (FSO)

・ Device


OSI reference model


OSI reference model

・ In 1977, work on a layered model of network architecture,

which was to become the OSI model, started in the American National Standards Institute (ANSI) working group on Distributed Systems (DISY). With the DISY work and worldwide input, the International Organization for Standardization(ISO) began to develop its OSI networking suite.

・ OSI has two major components: an abstract model of networking (the Basic Reference Model, or seven-layer model) and a set of concrete protocols. [Wikipedia]


OSI reference model

Application

Presentation

Session

Transport

Network

Data Link

PhysicalLayer 1

Layer 2

Layer 3

Layer 4

Layer 5

Layer 6

Layer 7

Media, signal and binary transmission

Physical addressing

Path determination and logical addressing

End-to-end connections and reliability

Signaling

Data representation and encryption

Network process to application

offer service

offer communication


OSI Upper Layer

・ Application Layer

・ Presentation Layer

・ Session Layer

DATADATA

Format

When to start

SignalingApplication


OSI Lower Layer

・ Transport Layer

・ Network Layer

・ Data Link Layer

・ Physical Layer

Reliability0101

0101Routing

Physical connection

Data transmissionat the node interval


Function of Physical Layer

⇒ Conversion data into electrical signal

DATA

LAN adapter

Buffer Ethernet controller

PHY tip

Electrical Signal

Ethernet controller : Encode data

PHY (Physical) tip : D/A (Digital / Analog) conversion


⇒ Conversion electrical signal into data

Electrical Signal

Trance PHY tip MAC tip

Buffer

Trance : Insulate the inside and the outside of LAN adapter

PHY tip : Judge a bit from electrical signal

MAC tip : Take out MAC frame based on Ethernet specifications from bit string

LAN adapter


Encoding


Encoding

・ NRZ(Non-Return to Zero)

0 → Low Level 1 → Hi Level

※ 1000BASE-X

・ NRZI(Non-Return to Zero Inversion)

0 → No Change Level 1 → Change Level

※ FDDI, 100BASE-FX

・ Manchester0 → Hi ⇒Low1 　→ Low⇒Hi

※ 10BASE5 、 2 、 -T

・ MLT-3 0 → No Change Level

1 → Change Level (Middle⇒Hi⇒Middle⇒Low )⇒

※ 100BASE-TX 、 CDDI


Encoding


Block Encoding

・ 4B / 5B (4-bit / 5-bit)

Decimal ／ 4-bit ／ 5bit0 ／ 0000 ／ 11110 1 ／ 0001 ／ 010012 ／ 0010 ／ 10100 3 ／ 0011 ／ 101014 ／ 0100 ／ 01010 5 ／ 0101 ／ 010116 ／ 0110 ／ 01110 7 ／ 0111 ／ 011118 ／ 1000 ／ 10010 9 ／ 1001 ／ 10011A ／ 1010 ／ 10110 B ／ 1011 ／ 10111C ／ 1100 ／ 11010 D ／ 1101 ／ 11011E ／ 1110 ／ 11100 F ／ 1111 ／ 11101


Protocol


Protocol

・ RS-232C (Recommended Standard 232C)

・ ISDN (Integrated Services Digital Network)

・ xDSL (x Digital Subscriber Line)

- ADSL (Asymmetric DSL)

・ IEEE 802.11 (Wireless LAN)

・ SDH (Synchronous Digital Hierarchy)

SONET (Synchronous Optical NETworking)

・ Protocol for Ethernet


RS-232C

⇒ Connect a peripheral devices to a PC

　（ Serial communication method ）

9 Pin Serial Port

25 Pin Serial Port

Pin No

signal name

IN/OUT contents

1 DCD IN Data Carrier Detect

2 RxD IN Receive Data

3 TxD OUT Transmit Data

4 DTR OUT Data Terminal

Ready

5 GND - Ground

6 DSR IN Data Set Ready

7 RTS OUT Request

transmission

8 CTS IN Clear To Send

9 RI IN Ring Indicator


ISDN

⇒ The digital communications network that unified telephone, FAX and data communication

2 channels for communication64kbps(B channel)

1 channel for control16kbps(D channel)

INSNet64

　 B channel D channel speed

INSNet64 64kbps*2 16kbps*1 128kbps

INSNet1500 64kbps*23 64kbps*1 1.5Mbps


ISDNTA

DSU

Phone

IP Phone

PC

DTE DCE

TA (Terminal Adapter) : Convert Non-ISDN signal into ISDN signal

DSU (Digital Service Unit) : Synchronization control & Signal conversion

※DTE (Data Terminal Equipment) : Data handling device

DCE (Data Circuit-terminating Equipment) : Converting or Coding device


xDSL

⇒ The general term of high-speed digital data communication technology with telephone wire

　 Down speed Up speed

SDSL (Symmetric DSL)160kbps ～

2.0Mbps160kbps ～

2.0Mbps

ADSL (Asymmetric DSL)1.5Mbps ～

50Mbps500kbps ～

12Mbps

HDSL (High bit rate DSL)

1.5Mbps ～2.0Mbps

1.5Mbps ～2.0Mbps

VDSL (Very high bit rate DSL)

13Mbps ～ 52Mbps1.5Mbps ～

2.0Mbps


ADSL

Modem (MOdulator-DEMotulatot) : Convert Ethernet signal into ADSL signal

Splitter : Divide Voice signal and Data signal

Phone

PC

Modem

Splittermodular jack

Digital

Analog


IEEE 802.11

⇒one of the wireless LAN related standards

　 Decision timeFrequency

bandOfficial speed

IEEE 802.11 1997 2.4 ～ 2.5GHz 2Mbps

IEEE 802.11b

October, 　1999

2.4 ～ 2.5GHz11Mbps /

22Mbps

IEEE 802.11a

October, 　1999

5.15 ～ 5.35GHz5.47 ～

5.725GHz(Max)54Mbps

IEEE 802.11g

June, 2003 2.4 ～ 2.5GHz 54Mbps

IEEE 802.11j --4.9 ～ 5.0GHz

5.03 ～5.091GHz

54Mbps

IEEE 802.11n

-- 2.4GHz / 5GHz 100Mbps ～


SONET/SDH

⇒ The international standard of the high speed digital communication method with optical fiber

SONET SDHTransmission

speed

OC-1 ‐ 51.84Mbps

OC-3 STM-1 155.52Mbps

OC-9 ‐ 466.56Mbps

OC-12 STM-4 622.08Mbps

OC-18 ‐ 933.12Mbps

OC-24 ‐ 1244.16Mbps

OC-36 ‐ 1,866.24Mbps

OC-48STM-

162,488.32Mbps

OC-192STM-

649,953.28Mbps

Important

OC : Optical Carrier


Protocol for Ethernet

　 Transmission speed

Maximum length Cable Encoding

10BASE-5 10Mbps 500m Coaxial cable Manchester

10BASE-2 10Mbps 185m Coaxial cable Manchester

10BASE-T 10Mbps 100mTwisted pair

cableManchester

100BASE-TX 100Mbps 100mTwisted pair

cable4B/5B + MLT-

3

1000BASE-T 1Gbps 100mTwisted pair

cable4D-

PAM5(8BIQ4)

100BASE-FX 100Mbps

Multi mode:412m(half duplex)

Optical fiber 4B/5B + NRZI2km(full duplex)

Single mode:20km(full duplex)

1000BASE-SX 1Gbps Multi mode:550m Optical fiber 8B/10B + NRZ

1000BASE-LX 1GbpsMulti mode:550m

Optical fiber 8B/10B + NRZSingle mode:5km

1000BASE-ZX 1Gbps 100km Optical fiber 8B/10B + NRZ


Cable


Coaxial cable

1. Inner conductor2. Insulator surrounding the Inner conductor3. Metallic shield and outer conductor4. Outer insulating jacket

Characteristic

・ Few leaks of the electromagnetic wave to the outside.・ Able to bend.・ Able to transmit of a wide frequency range.・ Structure is complicated, and price is high.


10BASE5 (Thick cable, yellow cable)

N Connector

N Terminator

NIC

Transceiver

Transceiver Cable

AUI connector

Thick Coax2.5m~

~50m

10mm

Terminator : prevent the reflection of the signalNIC : Network Interface Card


10BASE2 (Thin cable)

Thin Coax

BNC T ConnectorNIC

5mm


Twisted pair cableSTP (Shielded twisted pair)UTP (Unshielded twisted pair)

TX ＋TX －RX ＋RX －

TX : Transmit pairRX : Receive pair

Characteristic

・ Cheap and Easy to treat.・ Wire freely.・ Affected by the powerful electricity and electromagnetic wave.


CategoryMaximum Frequency

Transmission speed

example

Cat1 ― 20kbps telephone wire

Cat2 1MHz 4Mbps ISDN

Cat3 16MHz 10Mbps 10BASE-T

Cat4 20MHz 16Mbps Token Ring, ATM

Cat5 100MHz 100Mbps100BASE-TX, ATM(OC-3), CDDI

Cat5-e 100MHz 1Gbps 1000BASE-T

Cat6 250MHz 1.2Gbps 1000BASE-TX

Cat6-e 500MHz 10Gbps 10GBASE-T

Cat6-a(STP only)

500MHz 10Gbps 10GBASE-T

Cat7(STP only)

600MHz 10Gbps 10GBASE-Te : enhanceda : augmented


Optical fiber

Core : Light advances.

Cladding : Light is reflected.

Buffer : Relax shock.

Jacket : Protect.


Multi mode Single mode

・ Strong to bend.・ Easy to connect.・ Cheap.・ Made of plastic.(Cladding:fluorine-based polymer)

・ Little transmission loss.・ Made of quartz glass.( Core:Ge,P , Cladding:B,F)


Conversion between Electricity and Light

Laser diode Photo diode

e.g. CATV


Wireless Communication

【 Radio 】・ Electric wave

・ strong for obstacle

( ・ license is necessary)

・ mobile phone, PHS

・ Bluetooth (IEEE 802.15.1)

【 FSO 】・ Infrared ray (IR)

or Visible spectrum

・ weak for obstacle

・ license is unnecessary

・ PC, remote controller

・ IrDA UFIR⇒

・ The wiring space is unnecessary.

・ Mobile communication is possible.

・ Able to build LAN immediately.

・ Able to communicate outdoors.


EM spectrum


Bluetooth

・ Use frequency band of 2.4GHz.

・ Transmission length is radius of 10~100m.

・ Low power consumption

・ Low cost

VersionSymmetry type Asymmetry type

Transmission speed down up

1.x (1.1,1.2) 432.6kbps 723.2kbps 57.6kbps

2.x(2.0, 2.1)+EDR

1.3069Mbps 2.1781Mbps 177.1kbps


IrDA (Infrared Data Association)

・ Use Infrared ray (IR).・ Used for mobile game.

　 Transmission speed 30cm 1m

SIR 115kbps IrDA ver1.2 IrDA ver1.0

MIR 1Mbps IrDA ver1.3 IrDA ver1.1

FIR 4Mbps IrDA ver1.3 IrDA ver1.1

VFIR 16Mbps 　 IrDA ver1.4

UFIR 100Mbps 　　


Other communication style

・ Communications Satellite ⇒The wireless communication

that use the microwave from artificial satellite

・ Power Line Communication (PLC)⇒Technology to use a power line

as telecommunication line.


Device


Repeater HUB

⇒ Reproduce and Relay signal.

A B C D

collision


Function of Repeater HUB

・ Retiming function ⇒ The transmission signal comes under various influence of decre

ment, the distortion of the wave pattern, increase of the jitter in a cable during transmission. Repeater HUB has a function to restore the signal that It received to keep quality as the electrical signal in a transmission process and call it “Retiming function".

・ Preamble reproducing function ⇒ Continuation of 1 and 0 of 7 bytes to be called Preamble is added

to the top of the communication frame that drifts to a cable, but there is the case that phenomena such as the bit loss occur for this preamble in a transmission process. We call a function to return this preamble to an original state “Preamble reproduction function".


Switching HUB

⇒ Repeater Hub + Bridge

A B C D

作成 : 中村 遼 ( 大学院 情報科学府 ) physical layer ryo nakamura

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作成 : 中村遼 ( 大学院情報科学府 ) physical layer ryo nakamura