Transcript 26Warzansky

Wiring (a small piece of) the world
Target and interim solutions
W. Warzansky
Telefonica I+D
TRIBAN Workshop
Bern, 17-19 November 1998
Access network: target architectures
• From conclusions of former EURESCOM work,
later adopted by FSAN, it is considered that the
access network target architecture for broadband
interactive services in residential areas is
ATM-PON
with ATM-PP as a variety.
• Full PON specification is now available (ITU-T
G.983)
TRIBAN Workshop
Bern, 17-19 November 1998
Present situation
• ATM-PON/PP deployment has not started, mainly
because there is not yet a significant market for
broadband interactive services.
• But there are already many access networks with
a real, or latent, broadband capability:
- Plain copper (POTS)
- Fibre access networks (active and passive)
- HFC
TRIBAN Workshop
Bern, 17-19 November 1998
Evolution paths towards B-ISDN access
networks
• EURESCOM (P-614) has performed a study of
possible (recommended) evolution paths from
existing access networks towards ATM-PON/PP,
with the aim of determining the possible
reutilization of part of the existing access
infrastructure.
TRIBAN Workshop
Bern, 17-19 November 1998
Evolutionary paths
•
•
•
•
From HFC to ATM-PON
From existing fibre to ATM-PON/PP
From existing copper to ATM-PON
From existing copper to ATM-PON through LMDS
• ... and also, some interim solutions
TRIBAN Workshop
Bern, 17-19 November 1998
From HFC to ATM-PON: step 1
CPN
ONU
set top
box
TV
set
Cable
modem
To PC or LAN
Coax
drop
E/O
O
ANN
/LTHE
PON
E/O
O
duplexer
return channel
Cable
modem
Port
TRIBAN Workshop
Bern, 17-19 November 1998
Step 1: use of cable modems
• Deployment of cable modems and return path
amplifiers
• Penetration level it can satisfy: around 1%
• Price tag: 670 Euro/user connected
TRIBAN Workshop
Bern, 17-19 November 1998
Step 2: B-ISDN ONUs and coax reuse
CPN
set top
box
TV
set
Coax
drop
NT
To LAN
TRIBAN Workshop
Bern, 17-19 November 1998
LTHE
(TV)
ONU
B-ISDN
ONU
Combiner
PON
OLT
Step 2: B-ISDN ONUs and coax reuse
• Deployment of B-ISDN ONUs and NTs with coax
line cards, combiners and return amplifiers (e.g.,
620-860 MHz).
• ONUs fed by spare fibres or WDM
• Penetration level it can satisfy: up to 10%
• Price tag: 1150 Euros/user connected @penetration
of 10%
TRIBAN Workshop
Bern, 17-19 November 1998
Step 3: Enhancement of coax drop
• Upgrade of coax drop by replacing junction and
distribution boxes. Deployment of extended band
return amplifiers (e.g. 1-2 GHz).
• Price tag: increment from step 2 of 162
Euros/user connected.
TRIBAN Workshop
Bern, 17-19 November 1998
From existing fibre to ATM-PON/PP
• Existing active fibre access networks are not
standardised. There are many proprietary
solutions deployed.
• Three starting situations have been considered:
- PDH based active optical networks
- SDH based active optical networks
- Narrow band passive optical network
TRIBAN Workshop
Bern, 17-19 November 1998
Example of SDH based AON
drop sg.
distribution segment
feeder
section
NT
FP2
A
FMUX
D
STM-1/ 4
STM-1/4
FMUX
FP
2
NT
FMUX
TRIBAN Workshop
Bern, 17-19 November 1998
D
M
D
L
E
X
M
A
NT
SNI
A
M
STM-1
OLT
M
L
L
N
Evolution paths for fibre based ON
• NB-PONs evolve naturally to ATM-PONs
• The recommended evolution of PDH AONs is to
overlay an ATM-PP. Evolution to SDH is very
expensive.
• For SDH based AONs:
- Add B-ONU to N-ONU. Provide ADSL interfaces
- Overlay ATM-PP to ADMs
TRIBAN Workshop
Bern, 17-19 November 1998
Enhanced SDH based AON
Combined ONU
ONU-N
POTS
MUX
ISDN II
STM-1
OLT-N
n x 2Mbit/s
NT
xDSL
UNIs
ONU-B
xDSL
OLT-B
ATM
ATM
ATM
MUX
STM-1
SNIs
Terminal
multiplexer
TRIBAN Workshop
Bern, 17-19 November 1998
From existing copper to ATM
• xDSL from the exchange is NOT a long term
solution
- The bandwidth achievable in copper links is low
(probability of provision 15%)
- Noise from HDB3 (and others)
- Copper OAM costs are on the rising
- Very long payback time for new installation cables
- For high penetrations xDSL is more expensive than fibre
- Small number of DSL lines per cable
TRIBAN Workshop
Bern, 17-19 November 1998
Step 1 (900 Euros/client)
V
Drop Segment
T
ATU-R
+
U
DP
DSLAM
Distribution Segment
BB
Twisted Pair
Splitter
FP2
DP
POTS
splitters
FP1
Twisted Pairs
ATU-R
+
DP
Splitter
NB
M
D
F
MUX
MUX
DP
ATU-R
+
Splitter
DP
DP
FP2
Twisted Pair
TRIBAN Workshop
Bern, 17-19 November 1998
A
T
U
C
Optical Fibre
DLC
O
D
F
DLC
From copper to ATM: Step 2
• Option 1: Overlay ATM-PON for BB services
Price: 1150 Euros/client @10% penetration
• Option 2: Integrate NB and BB transport
- Implement V5.x protocols in the ONU and use AAL1 for
transparent transport of 2 Mbit/s frames to NB switch
- Implement AAL2 at the ONU
• Efficient bandwidth usage through VBR
• Supports voice compression
• Multiple voice channels on a single ATM connections
- Price: add 700 Euro/client @10% penetration
TRIBAN Workshop
Bern, 17-19 November 1998
From copper to ATM: step 3
• The third step is to go all the way to ATM-PON
with fibre deeper into the network and ONUs
closer to the customer than in step 1
• Price: 1300 Euros/client @10% penetration
TRIBAN Workshop
Bern, 17-19 November 1998
LMDS as an intermediate solution
•
•
•
•
Starting situation: existing copper
First step: LMDS
Second step: augmenting LMDS
Third step: ATM-PON
• The advantages of LMDS are those of wireless
systems
TRIBAN Workshop
Bern, 17-19 November 1998
4,000
LMDS Cost: 1 Base Station
3,500
3,000
2,500
Cost Per
2,000
Connected
1,500
1,000
500
90%
60%
TRIBAN Workshop
Bern, 17-19 November 1998
15%
0%
14%
13%
12%
11%
9%
10%
Penetration
30%
8%
1%
2%
3%
4%
5%
6%
7%
0
Interactivity
LMDS cost @10% penetration
3,500
3,000
10% Coverage
2,500
2,000
1,500
1,000
500
Interactivity
0
0%
10%
TRIBAN Workshop
Bern, 17-19 November 1998
20%
30%
40%
50%
60%
70%
80%
90%
100%
Interim solutions
• Set of unconventional systems to deliver
somewhat more than NB but less than BB (e.g.,
200- 1000 Kbit/s)
• Some of these “interim solutions” look at
circumventing the existing fixed access
infrastructure, . . ., and the incumbent operator
TRIBAN Workshop
Bern, 17-19 November 1998
Reflections on interim solutions
• Most of these “interim solutions” looks dubious,
at least now.
• Consequently, we heartily recommend them to
new entrant operators, though it seems unlikely
they will follow the recommendation.
• It seems advisable to keep an eye on these
solutions, because you never know what might
turn up
TRIBAN Workshop
Bern, 17-19 November 1998
Low-cost XDSL implementations
• ADSL
-
wide variety of implementations and vendors
HDSL (1- or 2-pairs) as symmetric counterpart
medium/high maturity, medium cost, service limitations
mostly rate adaptive and ATM based!
provide both ATM and ATM interfaces
typically PPP over AAL5
• CDSL (DSL lite)
- widely discussed, little known
- uncertain maturity, low cost, major service limitations
- probably IP based
TRIBAN Workshop
Bern, 17-19 November 1998
Example 1: Netspeed, key: modem sharing
ATU-C
ATU-C
DSLAM
ATU-R
ATU-C
POTS splitter
nxm
Off hook
detector
&
Switch
Controller
Local Exchange
DSLAM = Digital Subscriber Line Access Multiplexer
ATU-C = ADSL Terminal Unit - Central side
ATU-R = ADSL Terminal Unit - Remote side
n = number of ATU-C
m = number of ATU-R
n<m
TRIBAN Workshop
Bern, 17-19 November 1998
Customer Premises
Example 2: Paradyne, point-to-multipoint
POTS
4 kHz
broadband signal
20 kHz
100 kHz
ATU-R
ATU-C
Home
Working
PC
web
server
ATU-C
ATU-R
DSLAM
ATU-C
ATU-R
Customer Premises
Local Exchange
ATU-C = ADSL Terminal Unit - Central side
ATU-R = ADSL Terminal Unit - Remote side
TRIBAN Workshop
Bern, 17-19 November 1998
DSLAM = Digital Subscriber Line Access Multiplexer
shared
printer
Example: CAIS
system
NT
NT
NT
MDF
NT
CC
Router
Ethernet
Hub
Local Exchange
Customer Premises
twisted pair
CC = Cross Connect
fiber optical
MDF = Main Distribution Frame
NT = Network Termination
TRIBAN Workshop
Bern, 17-19 November 1998
Over
Voice
Powerlines
• Widely discussed, little proven, possibly
expensive
• IP based, to overcome noise problems
• Further concerns
- security aspects: maintenance of 240 V lines is
dangerous;
- privacy aspects: it is a physical bus, everybody receive
everything (like in HFC networks);
- electromagnetic emission: possible noises produced by
powerline systems affecting other electric devices (e.g.
complaints from HiFi users);
- regulatory aspects: e.g. ownership of the lines.
TRIBAN Workshop
Bern, 17-19 November 1998
Example: Nortel/Norweb approach
HV current
NT
LV current
NT
HV/LV transformer
NT
Tx
Rx
Router
Tx
Controller
Rx
OLT
Tx
Rx
power lines
building meter
splitter
Powering
NT
meter
Local Exchange
filter for inserting or extracting the BB signal
low voltage power line (Cu)
high voltage power line (Cu)
fiber optic
coaxial cable
TRIBAN Workshop
Bern, 17-19 November 1998
Base Station and transformer
HV/LV = High Voltage / Low Voltage
OLT= Optical Line termination
NT = Network termination
Customer Premeses
Conclusions (I)
• The residential broadband interactive services
market has not yet arrived.
• One of the reasons for this (among others) is the
high capital investment required, in an
environment where capital investment goes to
acquisitions and home networks are under
intensive pressure to reduce costs.
TRIBAN Workshop
Bern, 17-19 November 1998
Conclusions (II)
• Once way to reduce capital investment is to reuse
existing access infrastructure as much as
possible.
• EURESCOM has done this, studying how existing
access networks can be made to evolve gracefully
to ATM-PON, the already identified target access
network.
TRIBAN Workshop
Bern, 17-19 November 1998
Conclusions (III)
• Another activity performed by EURESCOM is the
keeping of an eye on new or “interim” solutions,
some of them a bit weird, because it might
happen that one of them might strike the right
combination of price/market demand
TRIBAN Workshop
Bern, 17-19 November 1998