2012 06 04 dsl seminar tno brink v08 - joepeesoft.com€¦ · 2 progressing g.fast -dr. rob f.m....

DSL Seminar, June 4-6, 2012, The NetherlandsProgressing G.fast - dr. Rob F.M. van den Brink - TNO / 4GBB consortium1

Progressing G.fastcontributions from 4GBB consortium to standards

Rob F.M. van den Brink – TNO

Chenguang Lu – Ericsson

[email protected]

mailto:[email protected]


2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

MUSE Consortium

1. Progressing G.fast – how did it originate?


2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

4GBB ConsortiumCELTIC

- show feasibility- initiate a standard- bring the industry into motion

Aims:

MUSE



2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

MUSE 4GBB ConsortiumCELTIC

2009 2010 2011 2012 2013 2014 2015

DSL seminar

San Francisco meeting

4GBB (up to 1 Gb/s)

FttH

Full

Hybrid

20-200m

Curb

Basement

Meter closet

FttH

FttH

(c) TNO

missing



2006 2007 2008 2009 2010 2011 2012 2013 2014 2015


2009 2010 2011 2012 2013 2014 2015

2011 2012 2013 2014 2015

start of G.fast consent of G.fast

DSL seminar


4GBB (up to 1 Gb/s)

FttH

Full

Hybrid

20-200m

Curb

Basement

Meter closet

FttH

FttH

(c) TNO

G.fast



2006 2007 2008 2009 2010 2011 2012 2013 2014 2015


HFCC/G.fastCELTIC

2009 2010 2011 2012 2013 2014 2015

2011 2012 2013 2014 2015

Phase 1start of G.fast

DSL seminar


Phase 2 - vectoring?Phase 3 - integration?

4GBB (up to 1 Gb/s)

FttH

Full

Hybrid

20-200m

Curb

Basement

Meter closet

FttH

FttH

(c) TNO

G.fast

1. Progressing G.fast – how will it continue?


1. Progressing G.fast – on what topics?

• Chapter 1 – Progressing G.fast• Chapter 2 – Progress on cable transmission modeling• Chapter 3 – Progress on crosstalk modeling• Chapter 4 – Progress on performance studies

e.g. by developing knowledge on cable modelling & simulations


1. Progressing G.fast – on what topics?

aimed service rates (US+DS rates) under noisy conditions from 8 disturbersnote: different service rate definitions are under discussion • agreed: at least 10Mb/s when deployed on loops with exceptional length and noise• agreed: 150 Mb/s @ 250m• agreed: 200 Mb/s @ 200m• agreed: 500 Mb/s @ 100m (typically a FTTB deployment) à 2×500 Mb/s with bonding• agreed: 500 Mb/s @ 50m when above 17.7MHz, and not too bad noise• agreed: up to 1Gb/s on shorter loops (protocol should not prevent 1Gb/s)

e.g. by developing knowledge on cable modelling & simulations

Bitrate targets for G.fast, as agreed within ITU

• Chapter 1 – Progressing G.fast• Chapter 2 – Progress on cable transmission modeling• Chapter 3 – Progress on crosstalk modeling• Chapter 4 – Progress on performance studies


2. Progress on cable transmission modeling

Z ×dxs

Y ×dxp

dx

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==



Z ×dxs

Y ×dxp

dx

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]

series resistance: Rs (per unit length)

(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]

series inductance: Ls (per unit length)

(c) TNO 2011

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]

shunt capacitance: Cp (per unit length)

(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]

shunt conductance: Gp (per unit length)

(c) TNO 2011

Rs

Cp Gp

Ls


Z ×dxs

Y ×dxp

dx

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Rs

Cp Gp

Ls

Legacy approach (see VDSL2 standard)Model Rs, Ls, Cp, Gp independently, using 4 functions of “w”(BT Model (1996): 13 parameters, KPN Model (1997), etc)modification needed to make impulse response causalproblem: this troubles time-domain simulations

Improved approach (TNO model, 2009/2011):Model (Rs+jw.Ls) and (Gp+jw.Cp), using 2 functions of “jw”(7+1 parameters)you get causality almost for “free” (if done in a clever way)




Z ×dxs

Y ×dxp

dx

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Rs

Cp Gp

Ls


2. Progress on cable transmission modeling - expressions for impedance Zs

1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]


(c) TNO 2011

Rs Ls

Z ×dxs

Y ×dxp

dx

0sL

∞sL

0sR

ssR ωω×0

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==



1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]


(c) TNO 2011

Rs Ls

Z ×dxs

Y ×dxp

dx

( ) sssss qRLL //00 ω+= ∞

⋅⋅+−×+⋅= ∞

ssZsssss q

jQqqRLjjZω

ωωω 20 1)(

ssss qRL ,,, 0 ω∞

substitution

parameters

)( ΩjQZ glue (shaping function)→

Approach: take observations as parameters

0sR

ssR ωω×0

0sL

∞sL

Qz is restricted by certain analytical properties

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==



1k 10k 100k 1M 10M 100M0

0.5

1

1.5

2

[freq]

[ohm/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[nH/m]


(c) TNO 2011

Rs Ls

Z ×dxs

Y ×dxp

dx

( ) sssss qRLL //00 ω+= ∞

⋅⋅+−×+⋅= ∞

ssZsssss q

jQqqRLjjZω

ωωω 20 1)(

ssss qRL ,,, 0 ω∞

substitution

parameters

)( ΩjQZ glue (shaping function)→

Approach: take observations as parameters

0sR

ssR ωω×0

0sL

∞sL

Qz is restricted by certain analytical properties

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

⋅++−×+⋅= ∞

ssssss

jqsqrtqRLjjZωω

ωω 21)( 20The simplest form of Qz is already very good


2. Progress on cable transmission modeling - expressions for admittance Yp

Z ×dxs

Y ×dxp

dx

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp



Z ×dxs

Y ×dxp

dx

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp

0pC

0→pG

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

angle lossconstant ≈=⋅

)tan()(

)(φ

ωω

ω

p

pC

G



Z ×dxs

Y ×dxp

dx

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp

parameters

glue (shaping function) →Approach: take observations as parameters

Qy is restricted by certain analytical properties

dpC ωφ,,0

)( ωjQY

φ

ωω

ωω

×⋅=

dYpp

jQCjjY 0)(

0pC

0→pG

angle lossconstant ≈=⋅

)tan()(

)(φ

ωω

ω

p

pC

G

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==



Z ×dxs

Y ×dxp

dx

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp

parameters



dcp qC ωφ ,,,0

)( ωjQY

0pC

0→pG

cpcd

Ypp qCjqjQCjjY ×⋅+−×

×⋅= 00 )1()( ω

ωω

ωωφ

Refinement from Ericsson+LTHcontributed to last ITU meeting

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==

Relevant when dielectric loss becomes significant

angle lossdependent frequency==⋅

)tan()(

)(φ

ωω

ω

p

pC

G



Z ×dxs

Y ×dxp

dx

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp

parameters



dcp qC ωφ ,,,0

)( ωjQY

0pC

0→pG

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==


angle lossdependent frequency≈=⋅

)tan()(

)(φ

ωω

ω

p

pC

G

cpcd


×⋅= 00 )1()( ω

ωω

ωωφ

Refinement from Ericsson+LTHcontributed to last ITU meeting



Z ×dxs

Y ×dxp

dx

1k 10k 100k 1M 10M 100M0

20

40

60

80

100

[freq]

[pF/m]


(c) TNO 2011

1k 10k 100k 1M 10M 100M0

5u

10u

15u

20u

[freq]

[mho/m]


(c) TNO 2011

Cp Gp

parameters



dcp qC ωφ ,,,0

)( ωjQY

0pC

0→pG

( )( ) ωωω

ωωω/)()(/)()(

jYimagjCjZimagjL

pp

ss==

( )( ))()(

)()(ωωωω

jYrealjGjZrealjR

pp

ss==


angle lossdependent frequency≈=⋅

)tan()(

)(φ

ωω

ω

p

pC

G

cpcd


×⋅= 00 )1()( ω

ωω

ωωφ

cpcd

pp qCjqjCjjY ×⋅+−×

+×⋅=

⋅−

0

/2

0 )1(1)( ωω

ωωω

πφ

The simplest form of Qy is already very good


2. Progress on cable transmission modeling - results

1k 10k 100k 1M 10M 100M 1G-30

-25

-20

-15

-10

-5

0

[freq]

[dB]:100Ω

abs(S21), len=61.15m, model=[ASYMP.sqrt], WirePair=(1-5|2-6)

(c) TNO 2011

Measured S21

Measured S12

modelled v alue

1k 10k 100k 1M 10M 100M 1G-0.2

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

[freq]

[dB]

Relative error in S21: dB(S21./S21m), model=[ASYMP.sqrt], WirePair=(1-5|2-6)

(c) TNO 2011

CAT5e cabling

61m

232m


CAT5e cabling

61m

232m

1k 10k 100k 1M 10M 100M0

200

400

600

800

1k

[freq]

[ohm]

Characteristic impedance Z0, model=[ASYMP.sqrt], WirePair=(1-5|2-6)

(c) TNO 2011

extracted v alue (ignored)

extracted v alue (used)

modelled v alue

1k 10k 100k 1M 10M 100M 1G

-80

-60

-40

-20

0

20

[freq]

[degree]

Characteristic impedance Z0, model=[ASYMP.sqrt], WirePair=(1-5|2-6)

(c) TNO 2011

extracted v alue (ignored)

extracted v alue (used)

modelled v alue



PVC insulated drop cable

Dielectric losses become significant;

Use of proposed refinement from Ericsson and LTH offer valuable improvements


24m



New approach

has gained acceptance in ITU


3. Progress on crosstalk modeling - EL-FEXT, legacy approach

Signal

Noise (FEXT)

EL - FEXT = Signal

Noise (FEXT)S/N ratio

= 1



10-2

10-1

100

101

102

103

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode, CKT1:ETSI model) - (KPN, 100m, in-quad #2)

(c) TNO 2011

Signal

Noise (FEXT)

EL - FEXT = Signal

Noise (FEXT)S/N ratio

= 1


Legacy model: (FSAN)EL-FEXT is linear proportional with the frequency.

Too low for higher frequencies


Performance studies for G.fast will be too optimistic when this is ignored

10-2

10-1

100

101

102

103

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode, CKT1:ETSI model) - (KPN, 100m, in-quad #2)

(c) TNO 2011

ETSI, Near worst case level


KPN Access cable, 100m, in-quad, group 2

3. Progress on crosstalk modeling - EL-FEXT with dual slope

10-2

10-1

100

101

102

103

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode) - (KPN, 100m, in-quad #2)

(c) TNO 2012

10-2

10-1

100

101

102

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair FEXT crosstalk (diff mode, transfer) - (KPN, 100m, in-quad #2)

(c) TNO 2012

dif f mode FEXTdif f mode transf er

fq ×1

22 fq ×

MHz20

104m


KPN Access cable, 100m, out-of-quad


10-2

10-1

100

101

102

103

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode) - (KPN, 100m, out of quad)

(c) TNO 2012

10-2

10-1

100

101

102

103

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair FEXT crosstalk (diff mode, transfer) - (KPN, 100m, out of quad)

(c) TNO 2012


MHz12

fq ×1

22 fq ×

104m


Multi quad telephony cabling, 378m, in-quad, group 1


10-3

10-2

10-1

100

101

102

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode) - (TelCable/30q, 378m, in-quad, gw1|br1)

(c) TNO 2012

10-3

10-2

10-1

100

101

102

-140

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair FEXT crosstalk (diff mode, transfer) - (TelCable/30q, 378m, in-quad, gw1|br1)

(c) TNO 2012


This cannot be ignored for even VDSL frequencies!(roughly 1.5 MHz)

MHz5.1

378 m


Low quality telephony cable found in consumer shop (Gamma), 50m


10-3

10-2

10-1

100

101

102

103

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair EL-FEXT crosstalk (diff mode) - (Unshielded "Gamma", 50m)

(c) TNO 2012

10-3

10-2

10-1

100

101

102

103

-120

-100

-80

-60

-40

-20

0

20

freq:[MHz]

[dB]

Wire-pair FEXT crosstalk (diff mode, transfer) - (Unshielded "Gamma", 50m)

(c) TNO 2012

dif f mode FEXTdif f mode transf erCrosstalk is soo

high, dual slope effect not present

51m


3. Progress on crosstalk modeling - EL-FEXT via 2nd-order transfer

10-3

10-2

10-1

100

101

102

-140

-120

-100

-80

-60

-40

-20

0

20

40

freq:[MHz]

[dB]


(c) TNO 2012

Models dual-slope effect very well, …

… models even the resonation peak, …

How to model this?

à Dual slope = 2nd order transfer function



10-3

10-2

10-1

100

101

102

-140

-120

-100

-80

-60

-40

-20

0

20

40

freq:[MHz]

[dB]


(c) TNO 2012

+

⋅+

+×

=⋅×

− 2

22

22

1

1

/21

1)(

ωω

ωω

ωωωω

ωω

ωjj

jj

FEXTELq

jH

Models dual-slope effect very well, …

… models even the resonation peak, …

10-3

10-2

10-1

100

101

102

-100

-50

0

50

100

150

200

250

300

freq:[MHz]

[deg]


(c) TNO 2012



Models dual-slope effect sometimesvery well, …

… and also the phase (in quad cables)

+

⋅+

+×

=⋅×

− 2

22

22

1

1

/21

1)(

ωω

ωω

ωωωω

ωω

ωjj

jj

FEXTELq

jH



New approach

is gaining acceptance in ITU


4. Progress on performance studies – approach

Traditional approach: Frequency domain calculations› How:

– Calculate SNR from cable models and noise assumptions (from frequency domain calculations)

– Run bit loading algorithm with the SNR– Remove overhead of Cyclic Extension (prefix + suffix) and coding.

› Advantages– Simple – Adequate for channels dominated with additive white Gaussian

noise (AWGN)

GOAL: Predict attainable bitrateswithin a given scenario(Important in system design phase)



Advanced approach: Time domain calculations› Why: G.fast channel can be more ISI limited, especially with short

cyclic prefix,• High tone spacing -> short symbol period• Long dispersion due to bridge taps• CP may not cover the whole channel dispersion.

› How: Take inter-symbol interference (ISI) into consideration for estimating Signal to Noise and Interference Ratio estimation (SINR)

– Calculate that via impulse response of (improved) cable model• Estimate SINR from a time domain simulation from training symbols

Implementation of symbol timing detection (or frame detection) and Frequency domain equalizer (FEQ) are needed.

• Upsampling is needed to reduce windowing effects of Inverse Discrete Fourier Transform (IDFT) when generating impulse noise

GOAL: Predict attainable bitrateswithin a given scenario(Important in system design phase)



0 20 40 60 80 10010

15

20

25

30

35

40

45

50

55

60

Frequency (MHz)

dB

Time-domain: AWG 24, 100 m, CP=0.8 µs Frequency-domain: AWG 24, 100 mTime-domain: AWG 24, 200 m, CP=0.8 µs Frequency-domain: AWG 24, 200 m

SNR comparison: time vs. frequency domain approach


4. Progress on performance studies – initial studies

Term.DP

5 m

CA

D55

10 mCAD55

≤ 240 mCAD55

Term.DP30

mAW

G 2

6

45 mAWG 26

≤ 205 mAWG 26

22.5

mAW

G 2

6

15 m

AWG

26

7.5

mAW

G 2

6

3.8

mAW

G 2

6

0 m 0 m 0 m 0 m

Term.DP ≤ 250 mCAD55

Term.DP ≤ 250 mAWG 26

Topology 1

Topology 2

Topology 3

Topology 4

Zs = 100 ohmZt = 100 ohm

Initial studies: Selected loop topologies

References:• Loop topology: “G.fast: Wiring topologies and reference loops”, (ITU 11GS3-100)• CAD55 model: BT, “G.Fast: Cable Models ”, (ITU 11RV-026)• AWG 26 model: ANSI TP1 (ANSI T1.417-2003)



Initial studies: Simulation assumptions

• Channel bandwidth: 200 MHz• Channel is filtered with 53-tap FIR filter to reduce ringing

from windowing effects of IDFT.• Tone spacing: 48.84 KHz• Data Bandwidth: 3.5 - 100 MHz• Number of tones: 2048

• Tone 0 is DC. Tones below 3.5 MHz are not loaded.• FFT size: 8192. FFT oversampling is used for fitting

channel bandwidth. • Signal PSD: -76 dBm/Hz• AWGN noise: -140 dBm/Hz• Coding: RS + Trellis

• RS: N/R = 255/16.• Trellis: 0.5 bit/tone overhead.• Total coding gain = 5 dB.

• SNR gap: 9.75 dB• SNR margin: 6 dB• Bit loading: 1-12 bits• Cyclic Extension: 0.4 µs, 0.8 µs, 1.2 µs, 1.6 µs, 2.0 µs, 2.4 µs

(Prefix+Suffix)• Loop length (DP to terminal): 50 m, 100 m, 150 m, 200 m



Term.DP

5 m

CA

D55

10 mCAD55

≤ 240 mCAD55

Term.DP ≤ 250 mCAD55Topology 1

Topology 2

Initial studies: Bitrate results

• Topology 1&2: Optimal CP = 0.8 µs, CP overhead = 3.76%• Up to about 100 Mbps decrease due to a 5-meter bridge tap.

Topology 1 Topology 2



Initial studies: Bitrate results

• Topology 3: optimal CP = 0.4 or 0.8 µs, CP overhead = 1.88% or 3.76%.• Topology 4: optimal CP = 2 µs, CP overhead = 8.9%.• More than 300 Mbps rate loss can be seen due to multiple bridge taps of star topology.

Topology 3 Topology 4

Term.DP

30 m

AW

G 2

6

45 mAWG 26

≤ 205 mAWG 26

22.5

mA

WG

26

15 m

AW

G 2

6

7.5

mA

WG

26

3.8

mA

WG

26

0 m 0 m 0 m 0 m

Term.DP ≤ 250 mAWG 26Topology 3

Topology 4


5. Conclusions


G.fast standardization is progressing very well• Concept of Hybrid FttH via G.fast Initiated by 4GBB consortium• global industry is now active in ITU to develop G.fast• Aimed ITU deadline (dec 2012: consent on G.fast) is just a first phase

5. Conclusions



Improved models for performance simulations under development• New cable model gives causality “for free”• Dual slope FEXT model is very promising• ITU is adopting these models for performance studies

5. Conclusions




Initial performance studies are demonstrating the potentials for G.fast• Bitrates above 800 Mb/s over 100m cable• Even bridge taps can be handled, albeit with performance loss

5. Conclusions




Initial performance studies are demonstrating the potentials for G.fast• Bitrates above 800 Mb/s over 100m cable• Even bridge taps can be handled, albeit with performance loss

5. Conclusions

Cable models have been developed for hundreds of MHz,so use them to describe your cable plant

2012 06 04 dsl seminar tno brink v08 - joepeesoft.com€¦ · 2 progressing g.fast -dr. rob f.m....

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