FTTH Tutorial 8-7-03
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Transcript of FTTH Tutorial 8-7-03
Fiber-to-the-HomeOverview & Technical Tutorial
Jim Farmer, Vice PresidentLeonard Ray, Government Relations Committee Chairman
Fiber-to-the-Home Council
FTTH Council FTTH Tutorial (8/07/03)2
Fiber-to-the-Home (FTTH)Overview and technical tutorial
• The FTTH Council
• FTTH market overview
• FTTH technical tutorial
• Standards update
• Questions
FTTH Council FTTH Tutorial (8/07/03)3
The FTTH CouncilVisit us on the web at www.ftthcouncil.org
• Mission:– Educate, promote & accelerate FTTH and the resulting quality-of-
life enhancements
• Objectives:– Supply a consistent and accurate view of FTTH– Promote FTTH market development– Be recognized by the industry as the FTTH resource
• 78 member companies, organizations and individuals
• We represent the interests of those interested in FTTH– Our members are from every telecommunications group– We do not represent any one group
FTTH Council FTTH Tutorial (8/07/03)4
The FTTH Council Represented in every layer of the FTTH value chain
Retail provider
Wholesale provider
Network owner
Network construction
Content aggregator
Content provider
OEM Feasibility consultants
ROW owner
Financial consultants
Network design
Project management
Fundingsource
Our members include service providers (RBOCS, CLECs, Municipalities, and Rural LECs), network design and construction companies, financial consultants, and equipment manufacturers.
FTTH Council FTTH Tutorial (8/07/03)5
Fiber-to-the-Home (FTTH)Overview and technical tutorial
• The FTTH Council
• FTTH market overview
• FTTH technical tutorial
• Standards update
• Questions
FTTH Council FTTH Tutorial (8/07/03)6
FTTH overviewList of ‘US Optical Fiber Communities’*
AlabamaSylacaugaCaliforniaAmerige HeightsCanyon HillsKenwoodParc MetropolitanPalo AltoPoppy Measdoss
* many more in construction and pre-construction
RosevilleSacramento TalaveraColoradoBuckhorn Valley Colorado CityEagle RanchRyeFloridaLPGA Community
KansasAlmenaHill CityNortonOsborneQuinterSharonWakeeneyWamegoMassachusettsPine HilsTautonMichiganCobblestoneMinnesotaAlbertaChokioEast OttertailEvermoorMorrisNebraskaBlair
OklahomaHinton OregonWoodburnPennsylvaniaKutztownSouth CarolinaDaniel IslandSandy PointTexasBurlesonLaredoCanyon Gate BrazosLakes on EldridgeNorthpointeRock CreekGrand Lake EstatesVictory LakesCrystal FallsUtahKamasProvo
GeorgiaDunwoodyIowaCambridgeGuthrie CenterHuxleySlaterIdahoBear Creek
VirginiaAshburnBrambletonBraemar-BristowBristolLeesburgPurcellvilleWashingtonChelan CountyDouglas CountyGrant CountyIssaquah HighlandsMason County
FTTH Council FTTH Tutorial (8/07/03)7
FTTH overviewFTTH homes passed in US and Canada
Source: Render, Vanderslice& Associates
19,400
72,100
315,000
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
2001 2002 2003e
Greenfield29%
Overbuild71%
2002 FTTH networks
110,000 as of March, 2003
FTTH Council FTTH Tutorial (8/07/03)8
FTTH overview FTTH homes connected in US and Canada
FTTH Homes Connected(United States and Canada)
10,350
22,500
38,000
5,500
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
Sep 01 Mar 02 Sep 02 Mar 03
Source: Render, Vanderslice & Associates
FTTH Council FTTH Tutorial (8/07/03)9
Fiber-to-the-Home (FTTH)Overview and technical tutorial
• The FTTH Council
• FTTH market overview
• FTTH technical tutorial
• Standards update
• Questions
FTTH Council FTTH Tutorial (8/07/03)10
FTTH technical tutorialWhat is FTTH?
Copper
Fiber
24 kbps - 1.5 MbpsOld networks, optimized for voice
CO/HE
19 Mbps - 1 Gbps +Optical networks, optimized for voice, video and data
CO/HE//
CO/HE//
//
Note: network may be aerial or underground
FTTH Council FTTH Tutorial (8/07/03)11
FTTH technical tutorialWhat is FTTH?
• “An OAN in which the ONU is on or within the customer’s premise. Although the first installed capacity of a FTTH network varies, the upgrade capacity of a FTTH network exceeds all other transmission media.”– OAN: Optical Access Network– ONU: Optical Network Unit– OLT: Optical Line Termination
CO/HE//
ONUOLT
Source: www.ftthcouncil.org
OAN
FTTH Council FTTH Tutorial (8/07/03)12
FTTH technical tutorialWhat is FTTH?
CO/HE
Optical fiber and lasers
Architecture (Electronics)- PON?- Active node?- Hybrid?
Transport- ATM?- Ethernet?
Philosophy- Retail- Wholesale
Technical considerations
//
FTTH Council FTTH Tutorial (8/07/03)13
FTTH technical tutorialWhy FTTH?
• Enormous information carrying capacity
• Easily upgradeable
• Ease of installation
• Allows fully symmetric services• Reduced operations and maintenance costs • Benefits of optical fiber:
– Very long distances– Strong, flexible, and reliable– Allows small diameter and light weight cables– Secure – Immune to electromagnetic interference (EMI)
FTTH Council FTTH Tutorial (8/07/03)14
FTTH technical tutorialWhy FTTH? - more capacity*
* Typical system capability for 100 m link
0
50
100
150
200
Gb
ps
Twisted Pair Co-ax Multimode Single-mode
Source: Corning Incorporated
FTTH Council FTTH Tutorial (8/07/03)15
0
10
20
30
40
50
60
70
80
90
100
kilo
mete
rs
Twisted Pair Co-axial Multimode Single-mode
FTTH technical tutorialWhy FTTH? - longer distances*
* Typical distance for 1 Gbps system capabilitySource: Corning Incorporated
FTTH Council FTTH Tutorial (8/07/03)16
FTTH technical tutorialWhy FTTH? - symmetric services
Source: Grant County Public Utility District
• Outbound Internet bursting to 80Mbps
• Inbound Internet (download) averaging about 35-40Mbps
• Upstream is consistently twice the download
FTTH Council FTTH Tutorial (8/07/03)17
FTTH technical tutorialWhy FTTH? - fiber versus copper
• A single copper pair is capableof carrying 6 phone calls
• A single fiber pair is capable ofcarrying over 2.5 millionsimultaneous phone calls(64 channels at 2.5 Gb/s)
• A fiber optic cable with the sameinformation-carrying capacity (bandwidth) as a comparable copper cable is less than 1% of both the size and weight
• A single copper pair is capableof carrying 6 phone calls
• A single fiber pair is capable ofcarrying over 2.5 millionsimultaneous phone calls(64 channels at 2.5 Gb/s)
• A fiber optic cable with the sameinformation-carrying capacity (bandwidth) as a comparable copper cable is less than 1% of both the size and weight
Source: Corning Incorporated
FTTH Council FTTH Tutorial (8/07/03)18
FTTH technical tutorialWhy FTTH? - fiber versus copper
Glass• Uses light• Transparent• Dielectric material-nonconductive
– EMI immune• Low thermal expansion• Brittle, rigid material• Chemically stable
Copper• Uses electricity• Opaque• Electrically conductive material
– Susceptible to EMI• High thermal expansion• Ductile material• Subject to corrosion and galvanic
reactions• Fortunately, its recyclable
//
FTTH Council FTTH Tutorial (8/07/03)19
• Core– Carries the light signals– Silica and a dopant
• Cladding– Keeps the light in the core– Pure Silica
• Coating– Protects the glass– Acrylate (plastic)
• Core– Carries the light signals– Silica and a dopant
• Cladding– Keeps the light in the core– Pure Silica
• Coating– Protects the glass– Acrylate (plastic)
FTTH technical tutorialHow do optical fibers work?
Len Ray
CORE
CLADDING
COATING
245 μm 125 μm 8 - 62.5 μm
Source: Corning Incorporated
FTTH Council FTTH Tutorial (8/07/03)20
FTTH technical tutorialHow do optical fibers work?
• Optical fibers work on the principle of total internal reflection
• Light waves (“modes”) are reflected and guided down the length of an optical fiber
Source: Corning Incorporated
CORE
CLADDING
FTTH Council FTTH Tutorial (8/07/03)21
FTTH technical tutorialTypes of lasers used
• There are two laser technologies that are used for nearly all single mode communications applications– Fabry-Perot (F-P) lasers
• Lower in cost, lower in power• Poorer wavelength stability
– Distributed Feedback (DFB) lasers• Higher cost, higher power• Excellent wavelength stability• Excellent temperature stability
– Internally modulated• Good for moderate powers and distances
– Externally modulated• Ultimate today for quality in broadcast applications
• Vertical Cavity Surface Emitting Lasers (VCSELs)– Coming technology, promises lowest costs
FTTH Council FTTH Tutorial (8/07/03)22
FTTH technical tutorialTypes of lasers used
• Wavelengths used for Single Mode Fiber (long distances) communications– 1310 nm
• Usually lowest cost lasers• Used for shorter broadcast runs and short to moderate data runs
– 1550 nm• Can be amplified with relatively low-cost erbium doped fiber amplifiers
(EDFAs)• Lasers are fabricated on a number of different wavelengths (about 1535 –
1600 nm) for wave division multiplexing (WDM) applications• Slightly lower fiber loss at 1550 nm
– 1490 nm• Increasingly popular for downstream data in 3 systems.
– Cannot be amplified as easily– Somewhat higher device cost
FTTH Council FTTH Tutorial (8/07/03)23
FTTH technical tutorialSingle and Dual Fiber Systems
• Single Fiber– Downstream broadcast* on 1550 nm– Upstream data on 1310 nm– Downstream data on either 1310 or 1490 nm* depending on
system– Advantages
• Less fiber deployed• Fewer optical passives (taps or splitters)• Fewer labor-intensive connections
* Downstream data can be carried at 1550 nm if not used for broadcast
FTTH Council FTTH Tutorial (8/07/03)24
FTTH technical tutorialSingle and Dual Fiber Systems
• Dual Fiber– Various plans, usually one fiber will be used for downstream and
one for upstream, or one will be used for broadcast and one for data. Sometimes one will be used for specialized services, such as returning RF-modulated data from set top terminals
• Advantages– Simplifies terminal passive components– Somewhat lower signal loss
FTTH Council FTTH Tutorial (8/07/03)25
FTTH technical tutorialWhat is FTTH?
CO/HE
Architecture (Electronics)- PON?- Active node?- Hybrid?
Transport- ATM?- Ethernet?
Philosophy- Retail- Wholesale
Technical considerations
//
Optical fiber and lasers
FTTH Council FTTH Tutorial (8/07/03)26
FTTH technical tutorialTransport - ATM
Destination header
53 byte cell
Data Next cell5B
FTTH Council FTTH Tutorial (8/07/03)27
• ATM has its roots in the telephone business• Connection-oriented protocol with excellent QOS• When a connection is made, it exists for the entire
communication session, ensuring a reliable channel
Ted Alice
JimKathy
Jeannie Travis
Susan Kyle
Joy Craig
FTTH technical tutorialTransport - ATM
FTTH Council FTTH Tutorial (8/07/03)28
FTTH technical tutorialTransport - Ethernet
Pre
amb
le
& S
FD
Des
tin
atio
n
add
ress
So
urc
e
add
ress Data and pad
Fra
me
chec
k
Typ
e/le
ng
th
Idle until the
next cell arrives8 4
Packet of data
6 6 2 up to ~1500 bytes
FTTH Council FTTH Tutorial (8/07/03)29
• Ethernet has its roots in office data systems• Connectionless-oriented, with excellent efficiency• Packets are transmitted individually, requiring resources only
when they are being transmitted
Ted Alice
JimKathy
Jeannie Travis
Susan Kyle
Joy Craig
Opportunistic data moves during idle times
Opportunistic data
When data is available, it gets the first available chance to be sent.
Nothing to send
FTTH technical tutorialTransport - Ethernet
FTTH Council FTTH Tutorial (8/07/03)30
FTTH technical tutorialWhat is FTTH?
CO/HE
Architecture(Electronics)- PON?- Active node?- Hybrid?
Transport- ATM?- Ethernet?
Philosophy- Retail- Wholesale
Technical considerations
//
Optical fiber and lasers
FTTH Council FTTH Tutorial (8/07/03)31
FTTH technical tutorialArchitectures
• Passive Optical Networks (PONs)– Shares fiber optic strands for a portion of the networks distribution– Uses optical splitters to separate and aggregate the signal– Power required only at the ends
• Active Node– Subscribers have a dedicated fiber optic strand
– Many use active (powered) nodes to manage signal distribution
• Hybrid PONs– Literal combination of an Active and a PON architecture
FTTH Council FTTH Tutorial (8/07/03)32
FTTH technical tutorialArchitectures – PON (A-. E- or G-)
//
//
//
//
//
////
//ONU
OLT
Optical splitter
1x16 (1x2, 1x8)
1x32 (1x4, 1x8)
Usually 10-20 km
FTTH Council FTTH Tutorial (8/07/03)33
FTTH technical tutorialArchitectures – PON (2) (A-. E- or G-)
//
//
//
//
//
////
//
1550 nm broadcast (if used)
1490* nm data
1310 nm data
* Data may be transmitted at 1550 nm if not used for video
ONU
OLT
FTTH Council FTTH Tutorial (8/07/03)34
FTTH technical tutorialArchitectures – Active Node
//
//
//
//
////
//ONU
Processing (powered)
Up to 70 km Up to 10 km
OLT
FTTH Council FTTH Tutorial (8/07/03)35
FTTH technical tutorialArchitectures – Active Node (2)
//
//
//
//
////
//
1550 nm broadcast (if used)
Data, 1310 or 1550 nm (depending on
distance) on separate fibers
OLT
ONU
FTTH Council FTTH Tutorial (8/07/03)36
FTTH technical tutorialArchitectures – Hybrid PON
//
//
//
//
////
//ONU
OLT
Processing (powered)
Up to 70 km
//
//
Up to 10 km
Optical splitter
Optical splitter
FTTH Council FTTH Tutorial (8/07/03)37
FTTH technical tutorialArchitectures – Hybrid PON (2)
//
//
//
//
////
//
//
//
1550 nm broadcast
Data, 1310 or 1550 nm (depending on distance)
on separate fibers
Single fiber, 1550 broadcast, 1310 bidirectional data
OLT
ONU
FTTH Council FTTH Tutorial (8/07/03)38
FTTH technical tutorialWhat is FTTH?
CO/HE
Architecture(Electronics)- PON?- Active node?- Hybrid?
Transport- ATM?- Ethernet?
Philosophy- Retail- Wholesale
Technical considerations
Optical fiber and lasers
FTTH Council FTTH Tutorial (8/07/03)39
FTTH technical tutorialPhilosophy
• Two types of FTTH networks exist today– Retail
• Vast majority of FTTH builds today• Network owner sells services directly to subscribers• Follows traditional telecommunications and cable television
models
– Wholesale• Market created by a few state laws• Network owner sells capacity to multiple providers who in turn
sells services to subscribers• Only examples in US today are some municipal FTTH networks
FTTH Council FTTH Tutorial (8/07/03)40
FTTH technical tutorialWhat is FTTH?
CO/HE
Architecture (Electronics)- PON?- Active node?- Hybrid?
Transport- ATM?- Ethernet?
Philosophy- Retail- Wholesale
Technical considerations
Optical fiber and lasers
//
FTTH Council FTTH Tutorial (8/07/03)41
FTTH technical tutorialTechnical considerations
• Data– How much per home?– How well can you share the channel?– Security – how do you protect the subscriber’s data?– What kind of QoS parameters do you specify?– Compatible business services?
• SLAs• T1
• Support for voice?• Support for video?
– Broadcast– IPTV
FTTH Council FTTH Tutorial (8/07/03)42
FTTH technical tutorialTechnical considerations
• Data– How much per home?– How well can you share the channel?– Security – how do you protect the subscriber’s data?– What kind of QoS parameters do you specify?
FTTH Council FTTH Tutorial (8/07/03)43
FTTH technical tutorialTechnical considerations - Speed
• Data requirements– Competition: ADSL, cable modem ~0.5 to ~1.5 Mb/s shared,
asymmetrical– FTTH ~10 to 30 Mb/s non-shared or several 100 Mb/s shared,
symmetrical– SDTV video takes 2-4 Mb/s today at IP level– HDTV takes maybe 5 times STDV requirement– Pictures can run 1 MB compressed– 5.1 channel streaming audio would run ~380 kb/s
FTTH Council FTTH Tutorial (8/07/03)44
FTTH technical tutorialTechnical considerations - Speed
Service
Required Data Rate
VoIP
Streaming audio
Picture in 15 seconds SDTV
HDTV
FTTH
DSL or cable modem
FTTH Council FTTH Tutorial (8/07/03)45
Technology Minutes Hours Days
Modem 56 kb/s
2
ISDN 128 kb/s
20
12
DSL 1 Mb/s 2.5
Cable 2.5 Mb/s
1
45
FTTH 0.4
Estimated minimum time to acquire BraveheartAugust 17, 2001:MGM, Paramount Pictures, Sony Pictures, Warner Brothers, and Universal Studios unveiled plans for a joint venture that would allow computer users to download rental copies of feature films over the Internet.
December 9, 2002:“Hollywood's Latest Flop”
Fortune Magazine“The files are huge. At 952 Megabytes, Braveheart took just less than five hours to download using our DSL Line at home… in the same time we could have made 20 round trips to our neighborhood Blockbuster”
FTTH technical tutorialTechnical considerations – Speed (IPTV Reference)
FTTH Council FTTH Tutorial (8/07/03)46
• Security– Data is shared in the downstream direction in most systems– Your Gateway filters out all packets not intended for you– But there is fear that someone will snoop on your data– FSAN has a low-complexity, low-security encryption scheme– 802.3ah has formed a committee to study security– Manufacturers have taken their own tacks on security, from
none to robust
FTTH technical tutorialTechnical considerations
FTTH Council FTTH Tutorial (8/07/03)47
FTTH technical tutorialData Flow and Security - Downstream
//
//
//
//
////
//
Tom Dick
Harry
T D H
T D
HBox on side of home separates out only the data bound for that subscriber. But the fear is that someone will fool his box into giving data intended for another subscriber. Solution is to encrypt the data.
Time division multiplex (TDM) – each subscriber’s data gets its turn.
FTTH Council FTTH Tutorial (8/07/03)48
FTTH technical tutorialData Flow and Security - Upstream
//
//
//
//
////
//
Tom Dick
Harry
T D H
HDue to the physics of the network, Harry’s data flows upstream but does not come to Tom’s box, so Tom cannot see Harry’s data
Time division multiple access (TDMA) – similar to downstream, with gap for
laser start/stop
FTTH Council FTTH Tutorial (8/07/03)49
FTTH technical tutorialData Flow and QoS
//
//
//
//
////
//
Tom Dick
Harry
T D H
T D
H
If Dick has paid for more bandwidth, he gets more
If Tom’s packets need higher priority (e.g., telephone), they go first
FTTH Council FTTH Tutorial (8/07/03)50
FTTH technical tutorialTelephony Considerations
Depending on whether the FTTH system is based on ATM or Ethernet, the basis of the phone technology is either conventional switched circuit or the newer VoIP
FTTH Council FTTH Tutorial (8/07/03)51
FTTH technical tutorialConventional Switched-circuit Telephone
. . . . . .
During conversation, line is continually tied up in both directions To other class 4
and 5 switchesBob
Ted
Carol
Alice
Donald
Concentrator (DLC) Switch
Switched Circuit Telephony
FTTH Council FTTH Tutorial (8/07/03)52
FTTH technical tutorialExample VoIP System
To PSTNTelephone packets
Other data packets
During conversation, line is shared with other data packets on each side of the router
One Form of Voice on Internet Protocol (VoIP)
Customer Gateway
Customer Gateway
Media Gateway
Router (switch)
Customer Gateway
Customer Gateway
Customer Gateway
Bob
Ted
Carol
Alice
Donald
Data
Data
Data
Data
Data
Softswitch
FTTH Council FTTH Tutorial (8/07/03)53
FTTH technical tutorialVideo
Video is a popular service, which is a good basis for any new entrant FTTH provider. There is one way to provide video on cable and satellite (broadcast) and one way to provide video on DSL (IPTV). There are two ways to provide video on FTTH (broadcast and IPTV). The market place can sort out the use of each, to the benefit of the subscriber. We will describe the differences.
FTTH Council FTTH Tutorial (8/07/03)54
• Can send video several different ways on FTTH– Broadcast (cable TV standards)
• Analog• Digital• Cable TV good engineering practice is 47-48 dB C/N
– FTTH can achieve 48-51 dB C/N• Benefit from high volume and plethora of applications of cable boxes• RF return support for STTs
– IPTV – TV transmitted over Internet Protocol• Feasible, and some people are doing it in place of broadcast• Bandwidth hog, but statistics can work for you
– Interesting hybrid model awaits hybrid STTs, but can give the best of both worlds
FTTH technical tutorialTechnical considerations - Video
FTTH Council FTTH Tutorial (8/07/03)55
FTTH technical tutorialWays of transmitting video
Baseband analog video
Modulated analog video
Other channels
Digital compressed video...101101001...
Ch 2 55.25Ch 3 61.25
etc.
Analog optical
transmitter
OR
. . .Other
data sources
Digital optical network
Digital optical
transceiver
syncblack
white
MPEG-2 transport
stream
Broadcast optical network
Encoder
Analog RF modulator
Digital RF modulator
Place MPEG packets in IP packets
L2/L3 Switch
FTTH Council FTTH Tutorial (8/07/03)56
FTTH technical tutorialWays of transmitting video – wave division muxing
Analog (Broadcast)
optical transmitter
Digital optical
transceiver
Always 1550 nm
Several wavelength plans:1. 1310 nm bidirectional2. 1490 nm downstream,
1310 nm upstreamDigital optical
transceiver
Voice (typ POTS)
Data (typ 10/100Base-T), includes IPTV
Video to TVs and STTs
Analog optical
receiverRF
Diplexer
Headend, Central Office,OLT
Home terminal, NID, Gateway, ONT
Optical network
1550 nm
1310 and possibly 1490 nm
RF return from STTsWave
division multiplexer
(WDM)
Wave division
multiplexer (WDM)
AGC H
L
A/D & proc
Proc
FTTH Council FTTH Tutorial (8/07/03)57
FTTH technical tutorialWays of transmitting video – broadcast headend
. .
. Analog channels
Digital channels
To distribution plant
...
Frequency
Amplitude
Ch 2
Ch 3
Linear (broadcast, analog) optical transmitter
Earth station
Spectrum diagram:
Analog channels Digital
channels
IRD
Analog RF modulator,
stereo, scrambler
Analog RF modulator,
stereo, scrambler
Transcoder, digital RF
modulator, upconverter
Transcoder, digital RF
modulator, upconverter
RF return signals
VOD server
IRT
IRD
FTTH Council FTTH Tutorial (8/07/03)58
FTTH technical tutorialWays of transmitting video – broadcast subscriber
Analog (broadcast, linear) optical
receiver, one per endpoint
Set top terminal
Select channel by selecting frequency
Optics in
(Not required for analog-only service)
(opt. RF Return)
. .
.
Tuner Demod Descrambing Subscriber's TV
FTTH Council FTTH Tutorial (8/07/03)59
FTTH technical tutorialWays of transmitting video – IPTV headend
. . .
. . .
Analog channels
Digital channels
To groups of subscribers
Digital (binary) optical transceiver (part of router)
. . . . . .
Downstream data
H D H D
IRD
IRD
IRT
IRT
Encoder
Encoder
Transcoder
Transcoder
VOD server
Other data sources
Pac
ket-
s wi t
ched
net
wo
rk
FTTH Council FTTH Tutorial (8/07/03)60
FTTH technical tutorialWays of transmitting video – IPTV subscriber
Digital (binary) optical transceiver, one per
endpoint
FTTH interface
Other applications
IP Set top terminal
Select "channel" by requesting to join a multicast group, or requesting a stream from a VOD server
. . .
Optics in
Select data packets for subscriber
Packet request and selection
Decoding
H D H
In-home routing
Subscriber's TV
FTTH Council FTTH Tutorial (8/07/03)61
FTTH technical tutorialWays of transmitting video – IPTV unicast (VOD)
Router A(headend)
Router B
Router C(network)
Router D(NID)
Router E
Program request
Program stream
In-home routing
In-home routing
In-home routing
Subscriber's TVSet top terminal
In-home routing
VOD server
FTTH Council FTTH Tutorial (8/07/03)62
. .
.
Router A(headend)
Router B
Router C(network)
Router D(NID)
Router EProgram packets
1 multicast video program
Larry's STT and TV
Moe's STT and TV
Curley's TVSTT
In-home routing
In-home routing
In-home routing
In-home routing
Encoder
Transcoder
FTTH technical tutorialWays of transmitting video – IPTV unicast (VOD)
FTTH Council FTTH Tutorial (8/07/03)63
FTTH technical tutorialWays of transmitting video – IPTV multicast
. .
.
Router A(headend)
Router B
Router C(network)
Router D(NID)
Router E
?
?
?
?
Program packets
Program requests
1 video program
Larry's STT and TV
Moe's STT and TV
Curley's TVSTT
In-home routing
In-home routing
In-home routing
In-home routing
Encoder
Transcoder
FTTH Council FTTH Tutorial (8/07/03)64
FTTH technical tutorialWays of transmitting video – IPTV multicast
. .
.
Router A(headend)
Router B
Router C(network)
Router D(NID)
Router E
?
?
?
?
Program packets
Program requests
1 video program
Larry's STT and TV
Moe's STT and TV
Curley's TVSTT
In-home routing
In-home routing
In-home routing
In-home routing
Encoder
Transcoder
FTTH Council FTTH Tutorial (8/07/03)65
FTTH technical tutorialPON link budgets
A system is limited in the distance you can send signals and the maximum number of times you can split the signal to go to different subscribers. The main problem is usually that the signal level drops too low to be usable. Other considerations sometimes dominate.
FTTH Council FTTH Tutorial (8/07/03)66
FTTH technical tutorialPON link budgets
//
Fiber loss per km is 0.25 dB (1550 nm) to 0.4 dB (1260 - 1360 nm)
//
Every time the signal is split two ways, half the power goes one way and half goes the other. So each direction gets half the power, or the signal is reduced by
10log(0.5)=3 dB.
Practical loss is 3.5 dB nominal, so every two-way split costs about 10 km distance @ 1310 nm
Half
Half
FTTH Council FTTH Tutorial (8/07/03)67
FTTH technical tutorialPON link budgets
• Broadcast analog video often sets the budget– Maximum practical level without SBS issues ~16 dBm (long
spans)– Minimum receive level for 48 dB C/N ~-5 dBm
• Link budget is ~21 dB, a bit more if you are careful
– At 1550 nm, fiber exhibits loss of about 0.25 dB/km, so maximum distance without amplification is ~80 km• Requires good externally-modulated transmitters (available)
– Each two-way split results in a loss of nominally ~3.5 dB of level, assume 4 dB worst case.• Thus, each two-way split costs about 16 km distance
FTTH Council FTTH Tutorial (8/07/03)68
FTTH technical tutorialAnalog video link budgets
Split Nom. splitting loss (dB)
Avail. fiber loss (dB)
Nom. Distance
(km)
4 7 11 44
8 10.5 7.5 30
16 14 4 16
32 17.5 2.5 10
64 21 -1 -4
Notes: based on nominal fiber and splitter loss, not worst case. Practical distances are less. Includes 2 dB for connectorization loss, 1550 nm externally modulated transmitter
FTTH Council FTTH Tutorial (8/07/03)69
FTTH technical tutorialGigabit EPON link budgets (example, based on GBE best case)
Split Nom. splitting loss (dB)
Distance (km), 40 km
GBIC
Distance (km), 70 km
GBIC
4 7 14 44
8 10.5 4 34
16* 14 - 24
32 17.5 - 14
64 21 - 4
Notes: based on nominal fiber and splitter loss, not worst case. Includes 2 dB for connectorization loss, 1310 nm DFB laser
* EFM standard split ratio, 10 and 20 km optics
FTTH Council FTTH Tutorial (8/07/03)70
Fiber-to-the-Home (FTTH)Overview and technical tutorial
• The FTTH Council
• FTTH market overview
• FTTH technical tutorial
• Standards update
• Questions
FTTH Council FTTH Tutorial (8/07/03)71
FTTH technical tutorialStandards?
• Customers want to use standardized systems for maximum choice in equipment, lowest cost, and widespread availability
• There are two known groups working on standards– FSAN – Full Service Access Network
• Reports submitted to ITU as the standards body• Formed by 7 telecom companies in 1995• Now many more members• G.98x series of standards, most based on ATM but now adding others
– IEEE 802 EFM – Ethernet in the First Mile• First standards due out 2004• Fiber and copper Ethernet to the home and business
FTTH Council FTTH Tutorial (8/07/03)72
FTTH technical tutorial ITU-T G.98x series
• Only published international standard for FTTH
• Describes a Passive Optical Network carrying ATM traffic and TDMA subscriber access
• Several versions published since October 1998– G.983.1 - Basic ATM-PON system– G.983.2 - ONT management and control interface– G.983.3 - WDM system for enhanced services (i.e. analog
video)– G.984.1 and -.2 – GPON (hybrid ATM and Ethernet)– G.985 – 100 Mb/s point-to-point, Ethernet
FTTH Council FTTH Tutorial (8/07/03)73
FTTH technical tutorial IEEE 802.3ah - Ethernet in the First Mile (EFM)
• Organized informally via the IEEE 802.3 in Fall 2000
• Chartered as IEEE 802.3ah in Spring 2001
• Develop 1 Gb/s Ethernet access standards including FTTH– Point-to-Point (home run)– Point-to-Multipoint (PON)– Twisted pair standards too
• Publication expected September 2004
FTTH Council FTTH Tutorial (8/07/03)74
FTTH technical tutorial IEEE 802.3ah EFM status
• PON Physical Medium Dependent (PMD) based on ITU-T 983 series
• Home run PMD based on fast and gigabit Ethernet standards
FTTH Council FTTH Tutorial (8/07/03)75
Fiber-to-the-Home (FTTH)Overview and technical tutorial
• The FTTH Council
• FTTH market overview
• FTTH technical tutorial
• Standards update
• Questions
www.ftthcouncil.org