第七章云计算与移动多媒体广播 Chapter 7 Cloud Computing and CMMB

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现代通信新技术导论

第七章云计算与移动多媒体广播Chapter 7 Cloud Computing and CMMB

电控学院电子工程学科部司鹏搏综合楼 825 室[email protected]

现代通信新技术导论第七章云计算与移动多媒体广播

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Main Contents• 7.1 Cloud Computing

– 7.1.1 One of the Most Promising Technologies

– 7.1.2 Major Players of Cloud Computing

– 7.1.3 What is Cloud Computing?

– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS

– 7.1.7 Cloud Computing Platforms

– 7.1.8 Security Issues

– 7.1.9 Cloud Computing in our Daily Life

• 7.2 CMMB


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Main Contents

• 7.1 Cloud Computing

• 7.2 CMMB– 7.2.1 What is CMMB?

– 7.2.2 Frame Structures, Channel Coding and Modulation

– 7.2.3 Multiplexing

– 7.2.4 Services

– 7.2.5 Emergency Broadcasting


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.1 Google Trends on the Terms


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7.1.1 Forecasts on Cloud Computing• IDC:

– “Spending on IT cloud services will triple in the next 5 years, reaching $42 billion & capturing 25% of IT spending growth in 2012 and nearly a third of growth the following year. With the overall IT market spend being $383 billion, this kind of growth validates that the opportunity deserves the attention it is getting” --2008

• Merrill Lynch: – by 2011, $160 billion

• Someone else:– Cloud computing is one of the Top 15 Technology Trends and that it

warrants investment now so you can gain the experience necessary to take advantage of it in its many forms to transform your organization into a more efficient and responsive service provider to the business


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7.1.1 Forecasts on Cloud ComputingPeak of the

inflated expectation


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.2 Major Players of Cloud Computing

Google

IBM

Microsoft

AmazonMOSSO

Force.com

Cordys


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.3 What is Cloud Computing?• Why it is called “Cloud”?

– The term cloud is used as a metaphor for the Internet, based on the cloud drawing used to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents.

• Cloud Computing– Internet- ("cloud-") based development and use of computer technology

("computing").

– In concept, it is a paradigm shift whereby details are abstracted from the users who no longer have need of, expertise in, or control over the technology infrastructure "in the cloud" that supports them.

– Describes a new supplement, consumption and delivery model for IT services based on the Internet, and it typically involves the provision of dynamically scalable and often virtualized resources as a service over the Internet.

• Resource (all kinds of IT services over the Internet) as a service


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7.1.3 What is Cloud Computing?• McKinsey

– Clouds are hardware-based services offering compute, network and storage capacity where: Hardware management is highly abstracted from the buyer, buyers incur infrastructure costs as variable OPEX(operational expenditure), and Infrastructure capacity is highly elastic

• FZI (Jens Nimis)– Building on compute and storage virtualization, cloud

computing provides scalable, network-centric, abstracted IT infrastructure, platforms, and applications as on-demand services that are billed by consumption


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7.1.3 What is Cloud Computing?• Simplified Concepts

– Cloud=Internet

– Cloud Computing=Everything as a Service(XaaS)• Standard Layers:

– Infrastructure as a Service (IaaS)

– Platform as a Service (PaaS)

– Software as a Service (SaaS)

• Extra Layers:– Human as a Service

– Administration/Business Support


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Cloud ServiceDeveloper

Cloud ServiceConsumer

Cloud Service Provider

Service

De

livery P

orta

l

BSSBusinessSupportServices

Offering Mgmt

Order Mgmt

Accounting & Billing

Customer Mgmt

Entitlements

Contract Mgmt SLAReporting

Pricing / Rating

Peering & Settlement

Subscriber Mgmt

Service OfferingCatalog

Invoicing

OSSOperationalSupportServices

Service Automation Mgmt

Virtualization Mgmt

Reporting & AnalyticsMetering

Service

De

velop

me

nt Po

rtal

Common Cloud Platform

Security & Resiliency

Consumer Administrator

Consumer Business Manager

Partner Clouds

Customer In-house IT

Service Def. & Developm.. Tools

Image Creation Tools

Developer

Service Definitions

Software-as-a-Service - e.g. Lotus LiveCloud

ServicesPlatform as-as-Service - e.g. Desktop Cloud

Use

r In

terface

Service User

Infrastructure-as-a-Service - e.g. Compute Cloud

Virtualized Infrastructure – Server, Storage, Network

Managed Environm

entM

anagement Environm

ent

…

Operational Console

Provisioning

Monitoring & Event Mgmt

Service Delivery Catalog

Configuration Mgmt

Continuity Mgmt, Backup / Restore Asset Mgmt

Service Request Mgmt

Service Level Mgmt

Image Lifecycle Mgmt

Capacity, Perform. Mgmt

Incident, Problem & Change Mgmt

Service Provider Portal

Service Business Manager Service Operations Manager

AP

IA

PI


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7.1.3 What is Cloud Computing?

• Seven Types of Cloud Services– IaaS

– PaaS

– SaaS

– Cloud web service

– MPS (Management Service Provider)

– BSP (Business Service Platform)

– Network Integration


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7.1.3 What is Cloud Computing?

Infrastructure as a Service

Platform as a Service

High VolumeTransactions

Software as a Service

Servers Networking Storage

Middleware

Collaboration

Business Processes

CRM/ERP/HRIndustry

Applications

Data Center Fabric

Shared virtualized, dynamic provisioning

Database

Web 2.0 ApplicationRuntime

JavaRuntime

DevelopmentTooling


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.4 IaaS/Utility Computing• To provide user computing resources and storage

comprised with many servers as an on-demand and “pay per use” service– Data Center, Bandwidth, Private Line Access, Servers

and Server Room, Firewall, Storage space …..

• Examples: – Amazon ： EC2 (Elastic Compute Cloud)

– Rackspace: cheaper than EC2 www.rackspace.com

– 世纪互联： www.21vianet.com


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7.1.4 IaaS/Utility Computing• Benefits of IaaS

– Reduce capital expense• Less upfront hardware costs

– Reduce operational expense• Free your IT resources from infrastructure administration

– Improve security• Worry free

– Pay per use• No extra investment


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.4 PaaS

• Bundles all stack components (hardware, infrastructure, storage) together with database, security, workflow, user interface, and other tools that allow users to create and host powerful business applications, web sites, and mobile apps

• Examples ：– Sales force ： http://www.force.com

– 800APP( 八百客 ) ： http://www.800app.com


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7.1.5 PaaS• Benefits of PaaS

– Reduce capital expense• No upfront hardware or software infrastructure costs

– Reduce operational expense • Free your IT resources from infrastructure administration

– Faster time to value • Rapid development and instant deployment

– Improve resource productivity• Build more apps, more quickly, and free up developers for new projects

– Reduce integration costs • Every new app built on the platform is designed for easy Web services

integration


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.6 SaaS• A model of software deployment over the Internet.

– Provider licenses an application to customers as a service on demand, either through a time subscription or a “pay-as-you-go” model

– It allows vendors to develop, host and operate software for customer use.

– Rather than purchase the hardware and software to run an application, customers need only to download the application to run it.

• SaaS deployed initially for sales force automation and customer relationship management (CRM), its use has become commonplace by businesses for tasks – Such as computerized billing, invoicing, human resource management, service

desk management, and sales pipeline management, even Library management applications.

• SaaS developed rapidly and brought big challenges for the traditional software industry.


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7.1.6 SaaS• Benefits of SaaS

– From general people: • We want to deal with an application or a service, not software

• We want those applications and services to be as intuitive as possible, and we want to have to know only as much as we need in order to use them

• We don't want to have to worry about extraneous error messages we don't understand or new software releases we don't know what to do with

• We want a quality experience, as we do with other things in work and life we enjoy using


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.7 Cloud Computing Platforms• Google

– Architecture• Google file system

• Map/reduce model

• Chubby

• BigTable

– Some APIs are available• Google web toolkit (GWT), Google Map API, …

– Infrastructures are private

• Azure from Microsoft– With the OS Widows Azure

• Resource management, load balancing, geo-replication, etc

– Applications such as SQL Azure

– Some APIs available


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7.1.7 Cloud Computing PlatformsProject Names Leading Organizations Descriptions

AbiCloud Abiquo

Open-source cloud computing platform for fast, simple and scalable creation and management of complicated IT infrastructures, including virtual servers, applications, networks and storages.

Hadoop Apache Foundation Open-source platform similar to Google’s.

Eucalyptus UC

Open-source interface for the users to access the resources of a company, compatible with Amazon EC2.

MongoDB 10gen Open-source document database.

Enomalism

Provides a cloud computing framework similar to Amazon EC2 based on Linux, supporting Xen and Kernal Virtual Machine (KVM).

Nimbus Globus IaaS for scientific computing.


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.8 Security Concerns in Cloud Computing

• Security concerns arising because both customer data and program are residing in Provider Premises

• Security is always a major concern in Open System Architectures


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7.1.8 Dangers and Vulnerabilities• Dangers

– Disrupts Services

– Theft of Information

– Loss of Privacy

– Damage information

• Vulnerabilities– Hostile Program

– Hostile people giving instructions to good programs

– Bad guys corrupting or eavesdropping on communications


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7.1.8 Common Security Requirements


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7.1.8 Security Issues• How much Safe is Data from Natural Disaster?

– Data can be redundantly store in multiple physical location.

– Physical location should be distributed across world.

• Data Location– When user use the cloud, user probably won't know exactly where your data

is hosted, what country it will be stored in.

– Data should be stored and processed only in specific jurisdictions as define by user.

– Provider should also make a contractual commitment to obey local privacy requirements on behalf of their customers,

– Data-centered policies that are generated when a user provides personal or sensitive information, that travels with that information throughout its lifetime to ensure that the information is used only in accordance with the policy


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7.1.8 Security Issues• Backups of Data

– Data store in database of provider should be redundantly store in multiple physical location

– Data that is generated during running of program on instances is all customer data and therefore provider should not perform backups

– Control of Administrator on Databases

• Data Sanitization– Sanitization is the process of removing sensitive information from a

storage device.

– What happens to data stored in a cloud computing environment once it has passed its user’s “use by date”

– What data sanitization practices does the cloud computing service provider propose to implement for redundant and retiring data storage devices as and when these devices are retired or taken out of service.


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7.1.8 Security Issues• Host Security Issues

– The host running the job, the job may well be a virus or a worm which can destroy the system

– From malicious users

– Solution: A trusted set of users is defined through the distribution of digital certification, passwords, keys etc. and then access control policies are defined to allow the trusted users to access the resources of the hosts.


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7.1.8 Security Issues• Information Security

– Security related to the information exchanged between different hosts or between hosts and users.

– This issues pertaining to secure communication, authentication, and issues concerning single sign on and delegation.

– Secure communication issues include those security concerns that arise during the communication between two entities.

– These include confidentiality and integrity issues. Confidentiality indicates that all data sent by users should be accessible to only “legitimate” receivers, and integrity indicates that all data received should only be sent/modified by “legitimate” senders.

– Solution: public key encryption, X.509 certificates, and the Secure Sockets Layer (SSL) enables secure authentication and communication over computer networks.


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7.1.8 Security Issues


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7.1.8 Security Issues• Network Security

– Denial of Service: • Where servers and networks are brought down by a huge amount of

network traffic and users are denied the access to a certain Internet based service.

• Like DNS Hacking, Routing Table “Poisoning”, XDoS attacks

– QoS Violation : • Through congestion, delaying or dropping packets, or through resource

hacking.

– Man in the Middle Attack: • To overcome it always use SSL

– IP Spoofing: • Spoofing is the creation of TCP/IP packets using somebody else's IP address.


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7.1.8 Security Issues• Network Security (cont.)

– Solution: • Infrastructure will not permit an instance to send traffic with a source IP or

MAC address other than its own.

– Port Scanning:• If the customer configures the security group to allow traffic from any source to

a specific port, then that specific port will be vulnerable to a port scan.

• When Port scanning is detected it should be stopped and blocked.

– ARP Cache Attack: • To find out the MAC address associated with a particular IP address, a computer

simply sends an ARP request broadcast.

• An attacker sitting on the same Ethernet network (i.e., LAN), can easily sniff the network traffic of a victim on his Ethernet network by sending spoofed ARP messages to the victim.


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– 7.1.4 IaaS

– 7.1.5 PaaS

– 7.1.6 SaaS




• 7.2 CMMB


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7.1.9 Cloud Computing in our Daily Life

• 69% of Americans use cloud computing Services


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7.1.9 Cloud Computing at Libraries• OhioLINK library consortium ：

– Amazon’s Web Services to host Digital Resource Commons repository instances Kent State’s Centennial Collection

• District of Columbia Public Library: – Amazon’s EC2 service to host website; Amazon’s S3 service to backup ILS,

Flickr and Amazon EC2 for upcoming digital repository, and the District adopts the GAPE version of Gmail as its mail platform

• The Eastern Kentucky University Library: – Google Docs to collect responses to web forms, Google Calendar for instruction

and meeting rooms, and Google Analytics to collect statistics about their website, catalog and blogs

• Western State College in Gunnison, Colorado: – Google’s App Engine for ELibrary, also migrated other databases to this service


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7.1.9 Cloud Computing at Libraries


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Main Contents





– 7.2.4 Services



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7.2.1 What is CMMB?• CMMB

– China Mobile Multimedia Broadcasting

• Transmission– Satellites plus terrestrial wireless broadcasting

• Receivers/User Devices– PMPs (personal multimedia players), cell phones, PDAs,

IMPCs, Laptops, …, with small-size screens (smaller than 7 inches)

• Contents– Audio/video broadcasts, information services, …


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增补转发器

本地发射机

通信网

节目集成平台

广播电视节目

数据业务内容

接收终端

中继器

信号上行传输系统

S卫星A

同轨S波段双星网S卫星B

上行广播信道Ku 上行分发

信道Ku下行广播信道S

下行分发信道Ku

广播信道

本地节目平台


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Main Contents





– 7.2.4 Services



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7.2.2 Design Requirements• Requirements on the Receiving

– High quality receiving in different scenarios• Indoor, outdoor, highly mobile, …

– Power efficient

– Single, small-size receiving antenna

• Requirements on the Services– Flexibility for multi-services

– Efficient radio resource allocation for different services

• Requirement on the Networks– Single frequency point networking


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7.2.2 Key Technologies for CMMBSystem Bandwidth 8MHz， 2MHz

Modulation 4K-OFDM(8MHz)， 1K-OFDM(2MHz)

Outer Coding RS

Outer Interleave Byte Block Interleave

Inner Coding LDPC(1/2、 3/4)

Inner Interleave Bit Block Interleave

Scrambling Coding Plural Pseudo Random Sequence

Frame Structure Based on Time Slots


52

7.2.2 Key Characteristics for CMMB• Time Slot-Based Frame Structure

– For energy saving

• OFDM– For high-speed mobile receiving and single frequency point

networking

• LDPC and Interleaving– For high-performance receiving

• Beacon– For fast synchronization

• Logical Channel– For flexible services


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7.2.2 Frame Structure

• Duration of Each CMMB Frame– 1 second, divided into 40 time slots

• Structure of Each Time Slot is Exactly the Same– With beacon and 53 OFDM symbols

• One or More Time Slots for Each Broadcast Service

• Power Saving Design for User Equipments– Based on the ON-OFF of the time slots

TS0 TS1 TS38 TS39

1S

25ms

Beacon OFDM Symbol 0 OFDM Symbol 1 OFDM Symbol 52


54

7.2.2 Logical Channel

• Control logical channel– For control information transmissions in time slot 0

• Service logical channel– In other time slots


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7.2.2 Time Slot Structure• 1 Transmitter Identification

– To identify the transmitters

• 2 Synchronization Signals– For fast synchronization and assistant channel estimation

• 53 OFDM Symbols– For payload data transmission

同步信号同步信号 OFDM符号 OFDM符号 OFDM符号 OFDM符号

发射机标识

53个OFDM符号信标


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7.2.2 LDPC and Bit Interleaving• LDPC

– Highly structured LDPC, with the length of 9216 bits

– Code rate: ½ and ¾

– Optimized code structure to reduce the decoder complexity

– Error correction performance close to Shannon limit

• Bit Interleaving– Row in column out

– Interleave depth

BPSK QPSK 16QAM

Interleave depth 25ms 12.5ms 6.25ms


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7.2.2 Constellation Mapping

I

Q

0

1

b0比特顺序：

2

1

2

1

2

1

2

1

I

Q

00

11

比特顺序：b0b1

2

1

2

1

2

1

2

1

10

01

I

Q

比特顺序：b0b1b2b3

10

1

10

1

001010

3 0000

10

3

10

3

10

1

10

1

10

3

0011 0001

1000 1010

1001 1011

0111 0101

0110 0100

1101 1111

1100 1110

BPSK QPSK 16QAM


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7.2.2 System Structure


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7.2.2 ParametersSystem Bandwidth 8MHz 2MHz

Signal Bandwidth 7.512MHz 1.536MHz

Number of Sub-Carriers 4096 1024

Number of Sub-Carriers for Data Transmission 3076 628

Number of Time Slots 40

Duration of Time Slots 25ms

RS Coding 176 、 192 、 224 、 240

Number of Rows of Outer Interleaver

1/2LDPC 72 、 144 、 288 36 、 72 、 144

3/4LDPC 108 、 216 、 432 54 、 108 、 216

LDPC 1/2 、 3/4

Inner Interleaver 384*360 192*144

OFDM Prefix 1/8

Discrete Pilots 1/8

Continuous Pilots 16 Bits Transmission Indications


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7.2.2 Data Rates

ModulationLDPC Code

RateData Rate per TS

(Kbps)Total Data Rate (Mbps)

BPSK 1/2 64.5/13.8 2.6/0.55

BPSK 3/4 96.8/20.7 3.8/0.82

QPSK 1/2 129.0/27.6 5.1/1.09

QPSK 3/4 193.5/41.5 7.6/1.63

16QAM 1/2 258.0/55.3 10.1/2.17

16QAM 3/4 387.1/82.9 15.2/3.25


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Main Contents





– 7.2.4 Services



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7.2.3 Characteristics• Effective, for Narrow Band Data Transmission

– Bottleneck of traditional MPEG2 streaming for low bit rate multimedia services

• Fix TS packet length (188 bytes), too consumptive for only one video frame PES (2 PESs are not allowed in one TS packet)

• Overhead for PSI, PCR, etc

• Efficiency lower than 80% when the service data rate is lower than 500 kbps

– Efficiency of CMMB is always over 95%

• Tightly Joint to the Channel Specifications

• Flexible for Video/Audio/Data Transmission

• Error tolerant

• Scalable


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7.2.3 Frame Multiplexing

复用帧头复用子帧1 ……

复用帧0 复用帧1 复用帧0

广播信道帧广播信道帧

复用子帧2

子帧头视频数据段音频数据段数据段

控制信息表1……

网络信息表持续业务复用配置表持续业务配置表短时间业务复用配置表短时间业务配置表ESG基本描述表紧急广播

复用帧头


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7.2.3 Control Information Table• Network Information Table

– Provides the information on the network, including central frequency, bandwidth

• Multiplexing Configuration Table– Provides the configuration on the multiplexing frame on a

carrier, including time slot location, channel parameters

• Service Configuration Table– Provides the service allocation information on the

carriers


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7.2.3 Transmission of the Tables• Control Information Table Transmitted in the First

Multiplexing Frame in each Broadcasting Channel Frame

• Control Information Table and Multiplexing Configuration Table are Divided into Two Types, Taken into Account the Multi-Type Services in the Future– Continuous services——Standard broadcasting

– Short-time services——Bursty Servics

• Control Information Change is Informed to the Receivers by the Assistant Information in the Multiplexing Frame– Control information is only received when control information

change is informed


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7.2.3 Departure of the Control Information and Service Data

• Because of the Unreliable Wireless Transmission– To improve the reliability of control information transmission

– To guarantee the transmission rate of the control information

– A control information is sent in each broadcasting channel frame

复用帧0 复用帧1

控制信息

复用帧2 复用帧k 复用帧0

业务信息1 业务信息2 业务信息n

一个广播信道帧


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7.2.3 Variable-Length Multiplexing Frame

复用子帧1

视频段

数据段

音频段

复用子帧2

音频段

数据段

复用子帧3

数据段

复用帧净荷


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7.2.3 Multiplexing

复用帧

广播信道帧

视频

音频复用子帧

视频

音频复用子帧

控制信息控制信息表


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Main Contents





– 7.2.4 Services



71


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7.2.4 Service Components

数据信息

业务信息

内容信息

编排信息

业务参数信息

节目提示信息

基本描述信息

电子业务指南

业务扩展信息


73

Main Contents





– 7.2.4 Services



74


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7.2.5 Emergency Broadcasting

复用帧(MF_ID=0)

复用帧头复用帧净荷填充

控制信息表1控制信息表k

(表标识号=0x10)控制信息表n··· ···

紧急广播表头紧急广播数据段

消息ID

网络号

16

当前段序号

最后段序号

8 8

紧急广播数据

12

网络级别

4

协议版本号

4

CRC_32

协议最低版本号

4

保留

数据长度

3 13


76


类型

持续时间

发布机构标志

支持语种数量

文本数据长度

紧急事件辅助描述

0

参考业务标志

发布机构名称长度

3 20

1 1

语种

24 8

辅助数据类型

辅助数据长度

辅助数据

162

保留

8

紧急广播消息

级别

7

触发标志=0

1

编码字符集

发送时间

3 40

保留

2 4

语种相关紧急信息描述

0

···保留

辅助数据数量

···

紧急事件辅助描述

n(n<15)

语种相关紧急信息描述

m(m<15)

文本数据

发布机构名称

参考业务标识

16

保留

12 4

4 4

辅助数据索引

4


77


触发消息级别

3

紧急广播消息

触发消息类型

7

触发标志=1

1

保留

触发网络号

12

保留

5

触发频点编号

8

触发中心频率

32

触发带宽

4 4

触发网络级别

4


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A Brief Review• Cloud Computing

– On-demand• Lowered requirement to call-ahead forecasts

• Demand trends are predicted by the provider

– Self service • Resources directly/indirectly reserved with a GUI or API

– Measured service or usage-metered (i.e. an operating expense)• Pay-by-the-drink or over time, not up front

– Elastic scalability • Grow or shrink resources as required rapidly

– Mandatory and ubiquitous network• The network is essential to consume the service


79

A Brief Review

• CMMB– Technology Specifications

• Frame Structures

• Channel Coding and Modulation

• Multiplexing

– Services

– Emergency Broadcasting

Documents

第七章 云计算与移动多媒体广播 Chapter 7 Cloud Computing and CMMB

第七章云计算与移动多媒体广播 Chapter 7 Cloud Computing and CMMB