Telecommunications Essentials

1
Telecommunications Essentials

• Chapter 10
• Next-Generation Networks

2
Broadband Growth

• Information demand
• Wideband applications
• Video streaming
• Networked gaming
• E-commerce
• Convergence
• Shift to machine-to-machine communication
• More microprocessors than people
• Bandwidth cost is dropping

3
Broadband for Multimedia

• Applications
• Video conferencing
• Collaboration
• Requirements
• Minimum delay
• Streaming synchronization

4
Video

• Analog standards
• NTSC
• PAL
• SECAM
• DTV
• Reduced bandwidth requirements due to compression
• Nearly immune to interference
• Can become interactive

5
NTSC

• Baseband bandwidth 4.5 MHz
• Broadcast bandwidth 6 MHz
• Uncompressed digital bit rate 160 Mbps
• Aspect ratio 43
• Frame rate 30 fps
• Number of lines 525
• Scanning interlaced

6
PAL

• Broadcast bandwidth 8 MHz
• Uncompressed digital bit rate 200 Mbps
• Aspect ratio 43
• Frame rate 25 fps
• Number of lines 625
• Scanning interlaced
• UK Germany

7
SECAM

• Broadcast bandwidth 8 MHz
• Uncompressed digital bit rate 200 Mbps
• Aspect ratio 43
• Frame rate 25 fps
• Number of lines 625
• Scanning interlaced
• France USSR

8
DTV Standards

• Convergence of broadcasting computing
• Next generation of TV
• New features
• Multiple windows
• Interactive viewing options
• 6x improvement in video quality
• CD quality sound
• May have to compete with webTV

9
International Standards

• ATSC - Advanced Television Systems Committee
• Adopted by Canada U.S.
• U.S. Analog switch-off date Dec 31, 2006 ?
• DVB Digital Video Broadcasting
• Europe Australia
• Similar to ATSC except for audio compression
  transmission
• U.K. Analog switch-off date 2006 2012 ?

10
ATSC DTV Standard
Vertical Horizontal Aspect Ratio Frame Rate Scanning
HDTV 1080 1920 169 30, 24 progressive
1080 1920 169 60 interlaced
720 1280 169 60, 30, 24 progressive
DTV 480 704 43 60, 30, 24 progressive
480 640 43 60, 30, 24 progressive
SDTV 480 704 43 60 interlaced
480 640 43 60 interlaced
11
MPEG

• MPEG-1
• Video CDs 1.5 Mbps
• MP3 audio
• MPEG-2
• DVD and DTV
• MPEG-4
• Object based encoding
• WMP, QuickTime
• MPEG-7
• Multimedia content
• MPEG-21
• Software libraries for production and delivery of
  content

12
MPEG-2 Bandwidth

• NTSC 2.7 Mbps
• Broadcast Quality 7.2 Mbps
• DVD 10.8 Mbps
• HDTV 20 Mbps
• Video delivery requires
• More sophisticated video compression
• Fiber to the home or curb
• New generation of wireless equipment

13
Broadband Service Requirements

• High speed capacity
• Bandwidth on demand
• Bandwidth reservation
• Support isochronous traffic
• Agnostic platforms
• Support for unicasting multicasting
• QoS

14
Technology Enablers

• Erbium-doped fiber amplifiers
• DWDM
• Optical add/drop multiplexers, cross-connect
  switches, routers
• HFC, FTTC, FTTH
• Broadband wireless satellite
• Intelligent networks, softswitches, media
  gateways

15
Delay Jitter

• ITU recommendations
• Maximum setup delay 150 mSec
• Packet loss lt 1
• Presently it is up to 40
• Round trip latency lt 80 mSec
• Presently it is up to 1000 mSec

16
Next-Generation Networks
17
IP

• IP a LAN protocol
• Connectionless
• Discards packets when congested
• Traditional routers cannot deliver service
  quality
• VoIP streaming media require low latency
  jitter (voice compression 30 50 mSec)
• Increase Bandwidth
• Short term solution
• IP Switching
• Long term solution

18
IP Switching

• Connection oriented
• Routes the first packet
• Switches the other packets
• Replaces Layer 3 hops with Layer 2 switching
• Enables
• Voice, video, graphics applications
• Objectives
• Scale economically
• Improve QoS
• Limitation
• Not enough QoS control

19
ATM

• A WAN technique
• Connection oriented
• Provides real-time traffic management
• Supports CoS and QoS provisioning
• Supports voice, IP, frame relay, X.25 etc.
• Limitation
• Scaling problems
• A virtual circuit is required between every IP
  router
• Possible solutions
• Abandon a full-mesh architecture
• Migrate to MPLS

20
IP vs. ATM
-
IP Pervasive at the desktop No QoS
ATM CoS QoS High cell overhead
21
Terabit Switch Routers

• Proprietary
• Backbone platform
• Article by Amit Singhal

22
Todays Networks
23
Current Broadband Architecture

• Current systems use overlay networks
• Access and transport functions are separated
• Adds capacity service without disruption
• Problem
• High OM costs
• New services require new provision management
  troubleshooting systems

24
Multiservice Network
25
Three Tier Architecture

• Outer Broadband Access
• Customer service
• Middle Intelligent Edge
• Protocol and data service integration
• Inner High-Speed Core
• Core switches

26
Broadband Access

• Provides the end-user with a broadband link
• Class 5 local exchange
• DLC
• DSLAM
• IAD
• Remote access servers

27
Intelligent Edge

• Establishes QoS, authentication, authorization
  etc.
• Equipment type
• MSPP
• VoIP, Media, Trunking Gateways
• ATM switches
• IP routers switches

28
Multipurpose Switch
29
Critical Objectives

• The next generation network edge must
• Eliminate the bottleneck between user LANs and
  network core
• Improve the serviceability of carrier networks
• Converge and simplify carrier networks

30
New Developments

• New developments to support broadband access
  switches
• Advance network processors
• Advances computing memory
• High-capacity switching
• Standardized support software

31
Next-Gen Network Edge
32
Intelligent Edge Functions

• Broadband access
• Adaptation of native traffic
• Data concentration
• QoS mapping
• Service provisioning
• Encryption
• Accounting
• Address administration
• The Edge is becoming more intelligent and the
  network more dumb
• A reversal of the traditional PSTN

33
High-Speed Core

• Scalable
• Fast
• Dumb

34
Softswitch

• A software-based distributed switching control
  platform
• No industry-standard definition
• China may be the first to develop an
  interoperable switch
• Ericsson

35
ATM Service Category

• CBR- Constant bit rate
• Highest class of service
• Streaming media
• VBR Variable bit rate
• Highest class of data service
• Adequate for real-time voice
• ABR Available bit rate
• LAN interconnect
• UBR Unspecified bit rate
• Text data, image transfer, messaging

36
IP Service Levels

• IntServ
• Bandwidth reservation
• Internet virtual circuits
• Three service classes
• Guaranteed Service
• Controlled Load Service
• Best-Effort Service
• DiffServ
• A CoS model
• Priorities different data streams
• Cannot specify traffic control parameters

37
MPLS

• Uses local labels to identify
• Traffic types
• Path
• Destination
• Supports bandwidth reservation
• Operates at Layer 2
• Supports tunneling
• Issues between IETF and MPLS Forum