dynamic spectrum management the path to gbps dsls/ future of copper
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Dynamic Spectrum Managementthe path to Gbps DSLs/ future of copper
FCCVia video conferenceNovember 19, 2009
111/19/09
John M. CioffiProf Emeritus, Stanford U
Chairman and CEO, ASSIA Inc.
Broadband is DSL !
• DSL is largest fraction (over 70% of broadband)– And growing faster (even fiber connects are VDSL)– It costs a lot less
11/19/09 FCC 2
360M in 2012
Many are FTTBWith VDSL to customer
Source: Point Topic
How Fast is Copper?
• 10 Gbase-T is 2.5 Gbps/pair – at 100m on category 6 twisted pair
11/19/09 FCC 3
• 150Mbps – 500Mbps DSLs demonstrated– 100m on category 3 twisted pair
• Ubiquitous100Mbps to 1 Gbps DSLs?– Dynamic Spectrum Management (DSM)
• Soon, cheap, and energy efficient
• And, a lot of signal processing
4
Technical Challenges in DSL
• Changing environment– with daily DSL usage patterns– with daily appliance usage patterns– with customer adds and drops– with construction in the community
Crosstalk
Core Network
DSLAM
Radio Interference
Copper Impairments
In-home Interference Noise and interference
● interference from in-home sources● interference from outside sources● interference from other DSL lines● wiring problems (in-home and outside)
11/19/09 FCC
5
Basic DSM functions today
• DSM Improves– Operations cost– Data rate versus Length– Power consumption
Diagnostics Loop
Diagnostics● copper● DSL
Upgrade ident.
OSS, customer care
Reprofiling Loop
Automatic line repair
● QoS target● rate target
Daily collection from all lines
DSLAccessNetwork
FCC
FCC 6
DSM Unlocks xDSL Potential
25
50
75
100
125
2009 2010 2011 2012
DSM I- single line data & control
DSM II- multi-line data, single line control
DSM III & G.vector- multi-line data & control
DSL Potential
DSM server/software
- stability- diagnostics
- mgmt of power, - apps, crosstalk
- vectored- xalk cancel
CPE Noise Cancellation
- active noise cancellation- premises-based diagnostics- standards compatible, but independent
Date
Mbps
DSM Level 1 Example (23M+ today)
3%
47%
29%
19%
Dnstrm Rates Before DSM
14%
24%
21%
19%
11%
13%
Dnstrm Rates After DSM
Above 14.5Mbps
12~14Mbps
10~12Mbps
7~10Mbps
5.7~7Mbps
Below 5.7Mbps
40%
23%
16%
13%
8%
Stability Before DSM
61%
29%
3%1%5%
Stability After DSM
CV<=50 and Retrain<=0CV<=250 and Retrain<=1CV<=1000 and Retrain<=2CV<=5000 and Retrain<=3Others
• DSM Level 1 is deployed on– 17M lines in USA
• Will approach 30M by YE2010– 6M DSLs in Europe
• Will exceed 15M by YE2010
11/19/09 FCC 7
17a 998 Downstream - worst case data rate - 50 users
0
25
50
75
100
125
150
175
200
225
250
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
Loop Length (Meters)
Dow
nstr
eam
Dat
a Ra
te (
Mbp
s)
non-bonded 47 cancel min Bonded 47 cancel min Non-bonded 0 cancel min
Level 3 DSM: ITU G.993.5 VDSL2+
Vectoring - 1 pair
Bonding+Vectoring
Single-pair,No vectoring
• 100-pair Telco cable, 4x25-pair binders (NIPP-NAI model)• Does not include Telco cross-box, so gains may be larger!
EuropeResidential
North AmericaResidential
11/19/09 FCC 8
Bonding “GDSL” – 4-pair drop
7766
5544
3322
1100
0 100 200 300 400 500 600 700 800 900 10000.5
1
1.5
2
Cable Length in meters
Dat
a R
ate
in G
bps
Symmetric Data Rate vs Cable Length for 4 twisted pairs as a MIMO Channel 35 MHz band plan, 21 dBm aggregate power (US and DS combined), -150 to -140 dBm/Hz linear noise increase, Coding gain 6 dB
Bit cap = 20
1.0G
1.5G
3000’1500’
• Up to 7 channels• 30MHz
11/19/09 FCC 9
The DSM Opportunity• Dynamic Spectrum Management (DSM)
– Path to 100+ Mbps VDSLs and/or ADSL2+ • DSM Level 1 – line stability in use now worldwide• DSM Level 2 – politeness (higher speeds, lower power) - beginning• DSM Level 3 – “G.vector” – 100+ Mbps VDSLs
– Bonding of multiple lines, etc.
• DSL is global wire-line revenue growth vehicle • Major opportunity for new services triple/quadruple play• Video (IPTV, video-phone, You Tube)• Dual-Wifi (and/or Femto-cells) fed by DSL
Level 11$/line-mo Level 2
3$/line-mo Level 3> 10$/line-mo
11/19/09 FCC 10
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