telecommunications network technologies - ntt40 gbit/s dqpsk optical front -end contents what’s...

Telecommunications Network Technologies

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Objective Video Quality Assessment Technology for Video Delivery Services (ITU-T Recommendation J.247)

Network Service Platform for Web-telecom Coordination

Start of Basic Testing of Functionally-distributed Transport Technology on a CJK Test Bed

Countermeasures to Compensate Blocking of Radiowaves for Satellite Communication Systems

DC-power Supply Technology for Building a High-reliability Power-supply System

10-Tbit/s Class Ultra-high-capacity Optical Transmission Technology

120-GHz-band, 10-Gbit/s Wireless Transmission System

10 G-class Communication LSI Design Technology

40 Gbit/s DQPSK Optical Front-end

Contents

What’s Hot in R&D

Technologies for establishing a base network infrastructure including optical networks, wireless and satellite, all of which are essential to guaranteed bandwidth and broadband telecommunication.

Copyright © 2009 NTT

NTT Research and Development 2009 Review of Activities

What’sHot in R&D Telecommunications Network Technologies

Overview

Features

Application scenarios

To provide video delivery services to customers at an appropriate level of quality, wemust design and manage services in consideration of the user’s quality of experience(QoE). This technology objectively estimates the user’s QoE by analyzing the videosignal. It incorporates a visual psychology model that estimates perceptual video qualityby comparing pixel information in a reference and in degraded video. It enables efficientoperation/management, for example, by automating the current manual quality check toassess the coding video quality at the head end. This technology became an internationalstandard (ITU-T Recommendation J.247) in August, 2008.

■ Estimates the user’s QoE objectively■ Enables video quality assessment in consideration of content dependency■ Standardized as a ITU-T Recommendation J.247 (August 2008)■ Assesses video distortion caused by encoding and packet loss■ Enables software process to operate in real-time

■ Monitoring quality of real-time encoding at the head end■ Checking quality of archived video■ Performance testing for new services and systems■ Acceptance testing and parameter tuning of video delivery system■ Remote quality monitoring

IPTV QoE Standardization

User viewing

Q=f (X1, …, X5)Q: Objective video qualityf: Estimation functionXn: Distortion parameters

Coef.DB

Coding IP networkContent Deliveryserver

Decoding

Codingdegradation

Degradation bypacket loss

QoEmonitoring

Objectivevideoquality

Reference video Degraded video

Objective quality assessment

ObjectivevideoqualityDegraded

videosignal

Video Quality Objective Assessment Model

Referencevideosignal 1.Temporal-

spatial alignment processing of

reference/degraded video

2. Coding-related degradation estimation- Calculate degradation throughout video - Calculate degradation caused by block distortion - Calculate degradation associated with blurring

3. Packet-loss-related degradation estimation- Calculate local spatial degradation - Calculate freeze degradation

Weightedaddition

NTT Service Integration Laboratories

H-NW-1

Objective Video Quality Assessment Technology for Video Delivery Services (ITU-T Recommendation J.247)




Network Service Platform for Web-telecom Coordination

Overview

Features


The Network Service Platform is intended to allow third parties to easily develop newservices that involve cooperation between the Web and telecommunications on thenetwork. This technology provides telecom components that facilitate use of telecomfunctions and service coordination functions that allows those components to be usedtogether with Web services. This year we implemented new functions such as theParlay-X* media control function including voice recognition component. We alsoestablished basic technology for improving the performance of the service coordinationfunctions (by several orders of magnitude over commercially available products).

■ Telecom components for call control, speech synthesis and recognition, and othertelecom functions, and development tools for improving the usability of thecomponents

■ More advanced service coordination (adaptability to the user’s circumstances andhigher performance) with the service coordination functions

■ Greater control and higher processing performance through unified management ofprotection of disturbance, authentication and authorization, and other non-functionalrequired processing

■ Interoperability with web components based on standard technology (Web services)

■ Development of applications that use telecom functions by Web technologists - Schedule confirmation service using voice recognition - Service for character display according to conversational content - Building management service supporting voice communication with maintenance

personnel

* Parlay-X: Standard specifications for interfaces that allows control of telecom functions from the Web.

Web-telecommunications coordination SDP Parlay-X

NTT Network Service Systems Laboratories

Business services

NGN

Service coordination functions Scenario

Network Services PF

Internet

Creation of application

Implement many kinds of services easily by changing scenarios

Telecom componentsMedia control (media playback,

voice recognition, etc.)

Events from telecom (incoming call, recognition results, etc.)

Instructions to telecom (originate call, play video, etc.)

Shopinformation

Mapinformation

Scheduler

Coordination with telecom services

Call control (call connection, disconnection, etc.)

Uh-huh

■ Application Example 2On-line character moves according to the conversational content

Taro is in a meeting now.

■ Application Example 1Operation of a scheduler function based on the results of voice recognition to display a schedule

That movie was good, wasn’t it?

Higher usability through modularization of telecom functions

Taro’s schedule?

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Application developer




Overview

Features


By separating the packet-transfer function (i.e., forwarding element, FE), the route-control function (control element, CE), and the transfer service-addition function (serviceelement, SE), functionally distributed transport technology enables independent expansionof various functions. Moreover, aiming at realization of stable operation of future large-scale packet networks, research and development on this technology is progressingsteadily. At NTT Laboratories, targeting standardization of an interface forsubstantializing this technology, basic testing with a pilot unit on a CJK test bed startedin June 2008.

■ Scalability of node size is assured by accommodating the number of FEs accordingto the performance of CEs

■ Number of neighbors is reduced by consolidating CEs, and stable operation of large-scale network is achieved

■ Consolidation of CEs and consolidation on SEs of service functions makes itpossible to curtail function-addition operations

■ Renewal of software for CEs is possible without affecting packet-transfer functions(FEs)

■ Connection architecture of SEs and CEs can be changed without affecting packet-transfer functions (FEs)

■ Stable operation of a large-scale network composed of a hundred million terminals■ Curtailment of operations for renewing CE files and adding service functions■ Low-power-consumption operation of network by switching configuration of

connections between CEs and FE/SEs according to network status■ Efficient NW operation by placement of SEs according to demand

- This research is being performed as part of a commissioned research project—called “Research and development on next-generation networks (NGNs)”—of the National Institute of Information and Communications Technology (NICT).

Packet network (NW) Functionally-distributed architecture CJK (China, Japan, Korea) test bed

NTT Network Service Systems Laboratory

Present transport networks Functionally-distributed transport network

・When number of units increases:- Stabilization of route

calculation is difficult.- File-renewal operations

for each node are multiplied.

・Packet transfer is stopped for file renewal

CE

FE FEFE

CE

FEFE

SEFE

CEs, FEs, and SEs are separated, and independent expansion becomes possible.

CEFE SE Routing

packets

Data packets

Data packets (via SEs)

CEFE SE

CEFE SE

CEFE SE

CE (control element): route-control function FE (forwarding element): packet-transfer function SE (service element): service-addition function

Routing-information exchangeRouting-information exchange I/F is

standardized

CE files can be renewed while packet transfer by FEs continues as is.

Renewal software

Japan-Korea basic test

Musashino (NTT)

Addition of functions to CEs is possible without affecting packet-transfer function (FEs).

Korea (ETRI)

CJK test bed

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Start of Basic Testing of Functionally-distributed Transport Technology on a CJK Test Bed




Countermeasures to Compensate Blocking of Radiowaves for Satellite Communication Systems

Overview

Features


In the case that satellite communication is used for vehicles moving on the ground (suchas cars and trains), it is a problem that the radio waves transmitted from the satellite areblocked by various large and small obstructions (like buildings and tunnels) and,consequently, communication quality is degraded.As for the developed system, transmission is stabilized by utilizing two technologies asa solution to address the problem of satellite-communication interruption due toobstructions, and a higher-quality satellite-communication service for moving vehiclesis thereby provided.

■ Layer 3 diversity system- Technology for handling small obstructions like buildings- Data received from multiple channels is selected on the IP layer- Seamless communication is made possible

■ Gap-filler system- Applicable to long obstructions like tunnels- Satellite-communication data received outside a tunnel is relayed to the train by a

separate wireless system- Data is selected in combination with a layer 3 diversity system

■ Internet services can be provided in a train moving at high speed■ Internet service is provided for company buses, etc.

Satellite communication Layer 3 diversity Gap filler

NTT Access Network Service Systems Laboratories

Schematic image of Layer 3 diversity operation

Packets received for the first time are output

L3DIV Rx

Satellite Antenna

Tx1 Tx2

RxRxRx

Transmitter (WiFi)

Inside tunnel

Schematic image of Gap-filler operation

Example of application for Internet-connection service for high-speed trains

Gap-filler

Auto-tracking antenna

L3DIV

AP AP

Base earth station

Satellite link

AP

Internet

Layer 3 Diversity

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a b c

a c

b c

timeOutput

Input AInput B

Already received packets are rejected




DC-power Supply Technology for Building a High-reliability Power-supply System

Overview

Features


To sustain a high-reliability communications network, it is necessary maintain acontinuous electrical power supply to communications equipment. At NTT, for manyyears, we have been constructing high-reliability power-supply systems that supplypower to switching equipment and transmission equipment without interruption. Inrecent years, ICT (information-communication technology) equipment—which has takenon a main role in place of switching equipment—has become more densely packed, andthe amount of such equipment with high power consumption has been growing.Consequently, high-reliability direct-current (DC) power-supply technology (forsupplying electricity safely) has also been established for ICT equipment with largepower consumption.This technology can prevent oscillation trouble before it happens and minimize adverseaffects in the case of power-source short circuits.

■ Power supply is maintained without interruptions even during power outages■ High current (up to 140 A) per single line can be supplied■ Oscillation faults (which periodically vary with supply voltage) can be prevented■ Voltage fluctuation during short-circuit faults is suppressed, and its influence on

operation of other ICT equipment is avoided■ Recommended conditions of ICT equipment are published in Technical Requirements

■ Power supply for large-capacity ICT equipment used for next-generation networks(NGNs)

■ High-reliability power-supply system for data centers■ DC power-supply systems forecast to become popular in the home an offices of the

future*1 PDC: Power Distribution Cabinet *2 PSU: Power Supply Unit

DC power supply High reliability Power consumption

NTT Energy and Environment Systems Laboratories

PSU*2

ICT equipment

AC200V

PSU

電源部

Short-circuit current

ICT equipment

Volta

ge[V

] -57.0 V

-40.5 V

Normal operating voltage

Input voltage to device of another system

Backup batteries

Rectifier (AC to -48 V DC)

Capacitor box

Fuse

PDC*1

Large-capacity ICT equipment

It is desired to keep voltage fluctuation within the normal operating voltage range.

Short-circuitaccident

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10-Tbit/s Class Ultra-high-capacity Optical Transmission Technology

Overview

Features


NTT has developed an ultra-high-capacity (13.5 Tbits per second) long-haul (7,200 km)optical transmission technology to meet expected increases in data traffic. The capacity-distance product (an important measure of transmission capability) is the highestreported for this type of technology. The 13.5 Tbit/s capacity enables 135 channels ofhigh-definition digital movies to be transmitted in one second. The signal multiplexes135 channels (or wavelengths), each with capacity of 111 Gbit/s, and each channel canaccommodate 100 GbE signal (next-generation Ethernet standard) reliably andefficiently. (T: Tera, 1012, G: Giga, 109)

■ Long haul transmission of ultra-high-capacity signal over 13 Tbit/s■ Guaranteed capacity to handle future increases in data traffic ■ Line rate supporting 100 GbE signal■ Accommodation of client signal by using OTN technology of ITU-T standard

■ Backbone optical core network of NTT Communications■ Metro optical network of NTT East and NTT West

100G transmission Fusion of light and wireless Digital signal processing

Application

Technology 1 Technology 1,2,4

7,200 km transmission of 135 wavelength-multiplexed 100 Gbit/s signalsTechnology 1: optical modulation and wireless communication technology

providing high spectral efficiency Technology 2: coherent detection technology for high receiver sensitivityTechnology 3: low noise technique to improve SNR at optical amplifierTechnology 4: digital signal processing to compensate for waveform distortion

8

9

10

11

12

13

14

5000 5500 6000 6500 7000 7500

Q-fa

ctor

(dB

)

Transmission distance (km)

1567.95 nm1590.41 nm1614.83 nm

AvMinMax

(a) Q-factor vs. transmission distance

Q-limit

8

9

10

11

12

13

14

5000 5500 6000 6500 7000 7500

Q-fa

ctor

(dB

)


1567.95 nm1590.41 nm1614.83 nm1614.83 nm

AvMinMinMaxMax


Q-limit

λ1 MU

X

DE

MU

X

Optical Amplifierλn

λ1

λn

SignalWDM System

Fiber

Signal Signal

Signal

Technology 3

8

10

12

1560 1570 1580 1590 1600 1610 1620

Q-f

acto

r (d

B)

Intensity （10 dB/div

）

Wavelength (nm)

14

16

Q-limit

AvAv

MaxMin14

13

12

11

10

9

85000 5500 6000 6500 7000 7500

Q-limit


Q-fa

ctor

(dB

)

1567.95 nm

1614.83 nm1590.41 nm

Q-fa

ctor

(dB

)

8

10

12

14

16

1560 1570 1580 1590 1600 1610 1620

Q-limit


Wavelength (nm)

Intensity (10 dB/div)

(b) Optical spectra and Q-factor (after 6,248 km transmission)

Router/L2-SW

Router/L2-SW

Router/L2-SW

Router/L2-SW

LANRouter/L2-SW

Router/L2-SW

Router/L2-SW

Router/L2-SW

LAN

Transmission line100 GbE

100 GbE

Optical Transport Network(OTN)

Nodeequipment

Node equipment

NTT Network Innovation Laboratories

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120-GHz-band, 10-Gbit/s Wireless Transmission System

Overview

Features


This system utilizes a millimeter band (120-GHz frequency band) not yet used industriallyand provides high-speed wireless transmission (10 Gbit/s). These features makewireless transmission of uncompressed High Definition Television (HDTV) images onsix-channel possible. In 2008, at live broadcast sites at the Beijing Olympic Games,video material transmission tests using the wireless system were carried out incollaboration with Fuji Television network Ltd., and the practicality of the system wasthereby confirmed. From now onwards, this technology can be applied to, for example,large-capacity ad-hoc circuits and wireless communication between buildings equippedwith 10G Ethernet.

■ As a world’s first, uncompressed HDTV-image transmission on six channels ispossible wirelessly

■ Transmission over maximum distance of 3 km is possible (under clear skies withforward-error-correction device used)

■ Utilizing MMIC* developed at NTT Laboratories achieves compactness, weight-saving,and low power consumption with equipment of the same size and operability asexisting wireless equipment for transmitting broadcasting contents

■ Industrially untapped frequency band (120 GHz) is utilized, contributing to expandingradiowave resources

■ Video-content transmission (without delay or picture degradation) from live broadcastsites like golf tournaments

■ Large-capacity link-up line for areas where optical fiber is difficult to lay■ Ad-hoc large capacity lines for handling natural disasters, events, etc.

* MMIC: Monolithic Microwave Integrated Circuits

- Part of this research was performed as a research project called “Research and Development for Expanding Radiowave Resources” funded by the Ministry of Internal Affairs and Communications.

120-GHz-band wireless Uncompressed Hi-Vision 10 Gbit/s

NTT Microsystem Integration Laboratories

Application scenario in broadcasting field Application scenario in communication field

Carrier-wave frequency

Transmission distance

Antenna

Detection method

Occupied spectrum

Modulation method

Output power

125 GHz

2 km (under clear skies with no error correction)

Cassegrain antenna

Envelope detection

116.5-133.5 GHz

Amplitude shift keying (ASK)

20 mW

Wireless-system specification 120-GHz-band millimeter-wave moduleBased on design and packaging technologies of NTT Laboratories, a compact, low-power-consumption RF module can perform carrier-wave generation in 120-GHz band, modulation, amplification, and demodulation.

- Transmission module- Power-amp module- Receiver module

DMUXMUX

Multiple broadcasts of uncompressed HDTV contents (maximum of six channels)

Relay station

Mobile-broadcastunit

Wireless transmissionbetween buildings

Disaster recovery Remote medical services

120-GHz-band millimeter wireless system

H-NW-7




10 G-class Communication LSI Design Technology

Overview

Features


For next-generation communications systems, we are researching and developing LSIdesign technologies that enable frame processing at 10 Gbit/s. The high-speedcommunication LSI has to process two types of frames. One is a "user frame" thatrequires high-speed and continuous processing. The other is a "control signal" that doesnot have to be high-speed but must be able to handle different communication protocols.Our high-speed flexible LSI architecture accordingly uses software or hardware toprocess these frames. The main functions of the LSI were implemented in FPGAs*1, andframe processing at 10 Gbit/s was confirmed.

■ The LSI architecture divides the received frames into a user frame and control signal,and it uses hardware to process the user frame and software to process the controlsignal. This simultaneously speeds up data processing and makes the protocolcontrol more flexible

■ The frame separating and inserting circuits can pick out slow frames from fast framesand insert slow frames into fast frames precisely

■ The prototype system and communication-test environment have a communicationcapability of 10 Gbit/s

■ LSIs for high-speed communications systems such as 10G-EPON*2

■ LSIs for routers and other high-speed network equipment

*1 FPGA: Field Programmable Gate Array*2 10G-EPON: 10-Gigabit Ethernet Passive Optical Network

Communication-LSI 10Gbit/s Design-technologies

NTT Microsystem Integration Laboratories

Prototype system

Frame separate

Frame insert

User frames

User frames

Control signalsSoftwareProcessor

Structure of communication LSI

Usage of communication LSI

ApartmentBuilding Home

Telephoneoffice Internet

CommunicationLSI

10 Gbit/s

Low-speedblock

LSI

10 Gbit/s

Framein/out

Framein/out

Optic 10 Gbit/sinput/output

Trans-ceiver

Processor

ClientServer

10 Gbit/s

10 Gbit/s

10 Gbit/s

High-speedblock

Optic 10 Gbit/sinput/output

Trans-ceiver

Proc. circuit(FPGA)

Trans-ceiver

Processor

Trans-ceiver

Proc. circuit(FPGA)

Proc. circuit(FPGA)

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40 Gbit/s DQPSK Optical Front-end

Overview

Features


DQPSK*1 modulation offers advantages in terms of high spectral efficiency and gooddispersion tolerance, so it is utilized for transmission at more than 40 Gbit/s. An opticalfront-end*2 for DQPSK signals consists of two delay-line interferometers (DLIs) and twobalanced receivers. We have developed a very compact optical front-end with verycompact novel design DLIs and a one-package two-channel balanced receiver. Thecompact front end is expected to help to miniaturize a 40-Gbit/s optical receiver.

■ DLIs based on a silica-based PLC*3 provide high reliability and good producibility■ Very compact DLIs with a single-chip design■ Reduced power consumption of temperature control by half■ Single-package two-channel differential optical receiver with novel-design PDs and

dual-channel one-chip high-speed amplifier IC■ High-speed feed-through*4 signal output suitable for high-density board assembly

■ Optical receiver for 40-Gbit/s DQPSK communication with reduced module size andpower consumption

*1 DQPSK: Differential Quadrature Phase-Shift Keying (A digital modulation scheme that detects a 4-valued carrier-signal phase by comparing it with the phase of one-symbol-delayed part)

*2 optical front end: An optical-signal-to-electrical-signal converter with DQPSK.*3 PLC: Planar Lightwave Circuit (An optical waveguide fabricated on a substrate and utilized in a

wide variety of compact optical filters)*4 feed-through: A pin-formed interface that provides a more compact assembly than possible with

a connector-type interface.

DQPSK optical front-end 2-channel balanced receiver PLC type delay line interferometer

NTT Photonics Laboratories

Receiver performance

Delay-line interferometers Optical detectors

Balanced receiversOptical

fiber

Temperature controller

DQPSKsignal

■Basic configuration

1/4-wavelength delay

Fabricated optical module

40 mm16 17 18 19 20 21

Optical sig.-noise ratio (dB)

10-5

10-6

10-7

10-8

10-9

In phase ch.

Quad. phase ch.

Wave formBit e

rror

rate

Compact design, Low-power temp. control

Two-in-one package,High-density interface (feed-through)

DQPSK optical front-end

■Developedtechniques

Quadrature-phase channel

In-phase channelHigh-speed amp. IC

H-NW-9

- Single package- Feed-through output

Two-in-one package, High-density interface (feed-through)

2-channel balanced receiver

Compact design、Low-power temp. control

PLC-type DLI

- Single-chipcompact design

telecommunications network technologies - ntt40 gbit/s dqpsk optical front -end contents what’s...

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