ECEN5553 Telecom Systems
Dr. George Scheets
Week 15 & 16
Read
[36a] "Dish network for the enterprise"
[36b] "Lighting up Copper"
[36c] "Bell Labs Claims New Speed Record Over Old
Copper Wiring"
[37a] "IPTV and Video Networks in the 2015 Time
Frame: The Evolution to Medianets"
[37b] "Netflix Factor has University Networks
Creaking Under Streaming Video Strain"
[38] "The Broadcast Empire Strikes Back"
Final Exam
Friday, 11 December, 1400 – 1550 (Live)
< 18 December (Distance Learning)
Comprehensive Final Exam

Everything from Day 1 is testable
 Notes
 Power
Point slides
 Required Readings

Work 5 of 7 pages on final.
 2-3
pages will be from last year
Address the question
 Use the space provided

 Give
the instructor the feeling you could've said
more!
 Rule of thumb: Provide > one fact per point
MPEG 1
Standard since 1992
 Compression of motion video & audio at
about 1.5 Mbps (VHS Quality < NTSC)
 Targeted at digital playback & storage
 Has Random Access capabilities
 Somewhat Obsolete


Divides picture up into 8x8 pixel blocks
Converts blocks to bit stream
MPEG 2
Targets higher quality compression,
typically at 3-6 Mbps bit rates
 Being used for Direct Broadcast TV
 Large chunks of MPEG2 used in
U.S. HDTV standard
 Standard since 1994

MP3
Web audio clips
 Uses audio compression from MPEG 1

 12-1
typical compression ratio
MPEG 4
Aimed at Multimedia Coding
 Bit rates from 8 Kbps - 40+ Mbps
 Can codes objects as opposed to NxN blocks

 Ability
to interact & manipulate objects
Standard in 1999
 Used in Quicktime 6, Direct TV

H.261, H.263, & H.264
 Target
real time videoconferencing
 Subset of MPEG
 Wide variety of bit rates
 64
Kbps - 128 Kbps: Face shot (video phone)
 384 Kbps: considered to be minimum speed
for decent full screen videoconferencing
 New
 H.264
OSU gear is using H.263/4 @ 1.92 Mbps
quality > H.263 > H.261
 Newer
protocols require more processing
power
 H.261 less common today
Thermal Noise Power in 6 MHz

70 degrees Fahrenheit?
≈

24.01(10-15) watts
32.3 Mbps →
Channel Capacity says SNR needs to be > 40.64
Signal Power > 975.8(10-15) watts
out of receiving antenna
 Need

Analog NTSC required SNR ≈ 15,800…
…
for a good quality picture
 Needed Signal Power = 379.4(10-12) watts
out of receiving antenna
Video Delivery: Over the Air
300 m
ATSC
Digital FDM
Since June 2009
(FCC edict)
40-50 miles
Video Delivery Systems

Geo-Synchronous Satellite
Analog NTSC (Obsolete)
1
channel per 6 MHZ of RF bandwidth
 10 foot satellite dish
Newer Systems digital MPEG2/4
 Can
get 4-6 "NTSC quality" SDTV channels
per 6 MHz of RF bandwidth (TDM)
 1-2 HDTV signals per 6 MHz RF bandwidth
 18 inch satellite dish
 MPEG4 = same quality, fewer bps
Video Delivery Systems
Cable TV
Headend
AMP
...
configuration
 Distribution systems originally all coax
 Originally Analog NTSC
 BW ≈ 700 MHz
AMP
...
 Tree
AMP
...

Initially Simplex Copper Coax
Video Delivery Systems
Cable TV
Headend
AMP
...
configuration
 Fiber deployed from Head End side moving
out
AMP
...
 Tree
AMP
2nd Generation
Hybrid Fiber Coax
a.k.a. FTTx
Fiber
...

Copper Coax
Video Delivery Systems
Cable TV
 Now
mostly digital ATSC, MPEG2/4
 Cable Modems require 2-way commo
Headend
AMP
...
6 MHz channels pulled from TV pool
AMP
...
 Some
AMP
2nd Generation
Hybrid Fiber Coax
FTT curb
Fiber
...

Copper Coax
Video Delivery Systems
Cable TV
 Ultimate
Goal: Fiber to the Home (FTTH)
 Passive Optical Network
Splitter
Headend
...
active electronics in access network
Splitter
3rd Generation
FTT home
Splitter
Fiber
...
 No
...

Representative Video Bit Rates
(Hi ↓ Lo Quality)








1.2 Gbps Uncompressed HDTV
19.4 Mbps ATSC ( ≈ HDTV quality)
8 - 9 Mbps MPEG4 ( ≈ HDTV quality)
90 Mbps Uncompressed NTSC (SDTV)
3 - 6 Mbps MPEG2 ( ≈ SDTV quality)
1.5 Mbps MPEG4 ( ≈ SDTV quality)
1.5 Mbps MPEG1 ( ≈ VHS < SDTV quality)
How Much More Compression is Still Possible?
 H.264

uses 30% less bits than MPEG4
November 2008 IEEE Communications Magazine
Compression

Requires a Signal with
Redundant information
 Must

be some predictability
Compressing a Signal
 Makes
Result Less Redundant
You can't compress forever
 Information Theory

 Math
that puts bounds on amount of
compression
Last Mile Options for Home & SOHO
Mbps for Data & DTV

Dial up Modems
 Pathetic

Point-to-Point Wireless
 WiMax,

LEOS
Power Lines
 Possible

WiFi, Proprietary
Satellites
 GEOS,

BW
in Europe, Not economical in U.S.
Cable Modems
PSTN 33.6 Kbps Dial-Up Modem

CO Input Line Card Low Pass Filter limits BW (3 - 3.5 KHZ)


M-Ary Signaling (256 QAM or something even more complex)
Channel Capacity says max transfer is around 35 Kbps
CO
CO
PC
Server
2 Wire
Modem
Protocol
‘4 Wire’
2 Wire
Digital TDM (1's & 0's)
64 Kbps
Modem
Protocol
56 Kbps Modem requires
Digital Source
ISP
Modem
Bank
CO
CO
PC
Server
Digital
StatMux
1's & 0's
Digital TDM
1's & 0's
(ISDN,
T Carrier,
SONET, OTN)
Discrete
Voltage
(128 possible values)
(7 bits, 8000x/sec)
PC to Server traffic will be slower, similar to previous slide.
Dial Up: PC to ISP Connectivity
Voice
network
Voice
Switch
Local Loop
Modem
PC
CO
Home
ISP Modem Bank
To Internet
This configuration used to cause
call blocking problems at some
CO switches due to longer than
designed-for call holding times.

Fine print indicates
 Uses
Acceleration (compression)
 Some material won't be compressed
 Actual data transmission rates =
standard dial up rates
Last Mile Options to the Home

Point-to- Point Microwave
 Cellular type technology
 Fixed sites using directional antennas
Last Mile Options to the Home

Geo-synchronous Satellite
 High
Speed down links
 Very Slow Speed Phone Line ‘up link’
Server
ISP
Phone
Last Mile Options to the Home

Geo-synchronous Satellite
 High
Speed down link
 Not-so-High speed up link
Server
Hughes Net (2013)
@ 15 Mbps, to go full blast need
TCP Window = 15 Mbps*RTT
= 15 Mbps*0.5/(8 b/B) = 937.5 KB
(Sat uplink & downlink)
Last Mile Options to the Home

Low Earth Orbiting Satellite
Teledesic 2004? 2005? Never!
 300+ Kbps
 Cellular type technology
Cells Move
Earth units ‘fixed’

Last Mile Options to the Home

Point-to-Point Laser



Currently proprietary. Up to 2.5 Gbps speeds.
Aimed at Businesses
Leased Lines (a.k.a. Private Lines)
 Expensive
 Aimed

at Businesses
Power Lines
 Not
as currently configured on MAN
 Usable in home LAN
Powerline HAN
10/100BaseT Ethernet: PC ↔ Adapter
500 Mbps: Adapter ↔ Adapter
Last Mile Options
Cable Modem Network (DOCSIS)
Headend
AMP
...
6 MHz downstream channels
 Simplex 200 KHz to 6+ MHz upstream channels
 All traffic traverses the Headend
AMP
...
 Simplex
AMP
2nd Generation
Hybrid Fiber Coax
FTT curb
Fiber
...

Copper Coax
Cable Networks
Have a Lot of BW (XXX MHz)
 Allocate 6 MHz channels for various services

 FDM

6 MHz Channel can carry
2
MPEG4 HDTV signals
 3-6 MPEG2/4 SDTV signals
 30-40 Mbps Cable Modem Traffic
DOCSIS (Data over Cable Service Interface Specification)
 Internet
 VoIP
Cable Modem Connectivity
Voice
network
Legacy
Video
Data
IPTV
VoIP
Voice
Switch
Headend
Legacy
Voice
Mux
PC
Cable
Modem
Voice
ISP Router
To Internet
PC
Cable Modem uses shared
bandwidth to get to Cable TV
Headend.
Home
Cable Modems

Use FDM 6 MHz channels
 Ethernet
Frames mapped to QPSK or QAM RF signal
 30 - 40 Mbps downstream
 320 Kbps to 30 Mbps upstream

Downstream
 Head
End controls use
 TDM time slots, possibly assigned for a very short duration

Upstream
 Head
End assigns frequency band to end users (FDM)
 Head End assigns time slots (Vendor specific algorithms)
Long term assignments (TDMA-like)
 Short term assignments (StatMux-like)

Last Mile Options
Digital Subscriber Line (xDSL)
 Rides
on top of Telco access network
 Runs over twisted pair cabling
 Various flavors exist
CO
...

ADSL Connectivity
Voice
network
Home
Voice
Switch
CO
PC
PC
Legacy Voice
ADSL
Modem
DSLAM
Splitter
Data
IPTV
Data
ISP Router
To Internet
ADSL off loads data traffic from
CO voice switches, & provides
more CO↔Home bandwidth.
Voice
ADSL

Plain Vanilla ADSL
 384
Kbps - 8 Mbps downstream
 16 Kbps - 640 Kbps upstream

Uses FDM
 POTS
analog voice stays in 0 - 4 KHz band
 Upstream and Downstream signals mapped
to higher frequency bands
 Uses
 ATM
 To
OFDM
or Ethernet frame formats
& From CO
Some of the Flavored Versions

ADSL2
 Needs
higher SNR than ADSL
 8 -12 Mbps downstream
 800 Kbps - 3.5 Mbps upstream

ADSL2+
 Doubles
used Bandwidth & Bit Rates
 Can also bond multiple twisted pairs
Inverse Multiplex

VDSL2
4
- 8 MHz BW, Inverse Multiplexing
 100 Mbps over short distances
Asymmetric Digital Subscriber Line

Can carry
A
handful of 1.5 Mbps SDTV signals
 Internet traffic (in left over BW)
 Standard voice call
 0 HDTV signals

ADSL2+ potentially can carry 2 HDTV channels
 Two

9 Mbps MPEG4
To Support Triple Play Service
 TelCo's
need to drive fiber down towards homes
 FTTH: Gbps speeds possible
 VDSL2+ can support 100 Mbps on copper out to 1/3 Km
DSL Speeds
(Copper)
source: www.convergedigest.com/blueprints/ttp03/bp1.asp?ID=232&ctgy=Loop
(Triple) Double Play Provider

100 Mbps minimum BW
 Voice
 Several
Mbps for Data
 Several HDTV Channels
 May

Advantage Cable TV providers
 More

not be enough for 3D HDTV
BW available
May change depending on FTTH
 Who
get's there first?
Video Delivery Systems
Telco Digital Subscriber Line
 Ultimate
Goal: Fiber to the Home (FTTH)
 Passive Optical Network
Central
Office
Splitter
...
active electronics in access network
Splitter
3rd Generation
FTT home
Splitter
Fiber
...
 No
...

IPTV & ISP Backbones

150 HDTV MPEG4 TV channels
 1.45
Gbps of traffic to move
 StatMux, need ≈ 2.9 Gbps trunk capacity
 Two OC-48's
 Not a show stopper
 Especially
using multicast
One video stream services many customers

Video on Demand
 Could
be a problem
 One video stream may service one customer
IPTV & Last Mile Networks

On the Access Network
 Cable
TV/Cable Modem: No Problem
 FTTH : No Problem
 xDSL: Problem
 Unless Next Door to CO
 Or near FTTC termination
 Either way, can't stream 150 HDTV channels
 Solution: Selectively feed a few

On the Home Network
 100
Mbps can handle several HDTV channels
 Leaves significant BW available for data &
yet-to-be-invented apps
150 HDTV Channels?
Cable TV/Modem Network
 150
HDTV Signals over 75 RF Channels (450 MHz)
 Simulcast
Headend
AMP
...
– 1.6 Gbps (250 MHz) available for data
AMP
...
 1.2
(2 TDM over each 6 MHz FDM)
AMP
2nd Generation
Hybrid Fiber Coax
FTT curb
Fiber
...

Copper Coax
Delivering 150 HDTV Channels
Fiber to the Home (FTTH)
Passive Optical Network (PON)
in the THz
 Shared via WDM, TDM, TDMA
Splitter
Splitter
Fiber
...
CO or
Headend
Splitter
...
 BW
...

Delivering 150 HDTV Channels
Digital Subscriber Line (ADSL)
 Can't
do it. BW ≈ XX MHz (lower double digit)
 At best, can simulcast 2 with ADSL2+
CO
...

Twisted Pair
Delivering 150 HDTV Channels
Fiber to the Curb & VDSL2
 Can't
do it
 100 Mbps over last 1,000 feet
selectively stream an extra channel or two
 Active electronics required on last segment
...
 Could
VDSL2
CO
Splitter
...

VDSL2
FTTC
Fiber
Twisted Pair
IPTV - Replacement for Cable TV?

On the ISP Backbone
 150
MPEG4 HDTV Channels
 Not a show stopper

On the Access Network
 Cable
TV/Cable Modem: No Problem
 FTTH: No Problem
 xDSL: Problem
 Unless
Next Door to CO or FTTC terminal
 Still won't be able to stream all 150 channels
IPTV on the Access Network

ISP Backbone
Regional Caches
 Streamed
All or Most
TV Network Programs
Regional
Cache

...
Local Cache
 House
Apartment Complex
 Streamed > 1 channel,
Access BW permitting.
Local
Cache
...
User
TV
User
User
TV
TV
User
TV

User TV
 Streamed
> 1 channel,
Home BW permitting.
IPTV on the Access Network
Want to change
channel?
 TV Cache Checked

ISP Backbone
Regional
Cache
 Available?
...
< 1/2 second to change
 Not available?
Packet request shipped to
Local Cache
Local
Cache
...
User
TV
User
User
TV
TV
User
TV
IPTV on the Access Network

ISP Backbone
Local Cache Checked
 Available?
Channel streamed to TV
May take > 1/2 second
 Not available?
Packet request shipped to
Regional Cache
Regional
Cache
...
Local
Cache
...
User
TV
User
User
TV
TV
User
TV
IPTV on the Access Network

ISP Backbone
Regional Cache Checked
 Available?
Regional
Cache
...
Local
Cache
...
User
TV
User
User
TV
TV
User
TV
Channel streamed to
Local Cache, then user
TV.
 Not available?
Packet request might
need to be shipped to info
source.
 If these are busy...
IPTV on the Access Network
ISP Backbone
Channel Change May
Take Several Seconds
 Channel Surfers Won't
be Happy
 Ongoing Research

Regional
Cache
...
Local
Cache
 Streaming
...
User
TV
User
User
TV
TV
User
TV
Techniques to
minimize channel change
time.
When they're
awake.
 Predicting
next
channel
Home Network

100 Mbps Believed Sufficient
 Several
HDTV streams
 Several Mbps left over for data

Options
 100
Mbps Ethernet
 802.11n or 802.11ac

May not be enough in a few years
Worst Case Household Video Demand
Source: "Future Fiber to the Home Bandwidth…", IEEE Communications Magazine, November 2012
HDTV Video On Demand
Roughly 80 TV's per 100 U.S. Population
 Current population about 322,400,000
 About 257.9 million TV's
 Worst Case Traffic Demand
257,900,000 x 9.66 Mbps/user =
2,492,000,000,000,000 bps

 All
aren't HDTV capable
 All won't be on
 Should be some multicasting
 etc.
Video On Demand- Reservations
I want to watch
"Dr. Strangelove"
at 7:12 pm.
Someone else in
vicinity commenced
watching at 6:58 pm?
Reservations 1 hour in
advance required?
System can plan ahead.
6:58 request could be streamed live and forwarded
(multicast) to my location, stored locally, played back
commencing at 7:12.
Unicast
Server
Router
Sink
Sink
3 Separate Streams
Required to service
3 users.
Sink
Multicast
Server
Router
Sink
Sink
For a portion of
the route, 1 stream
suffices.
Sink