Free Affidavit - District Court of Delaware - Delaware

- Case 1 :05-cv—00866# Document 71 -8 Filed 12/14/2005 Page 1 of 4
TiEl.4J95-ID3
Project: Standards project for network and customer interfaces associated with twisted pair transmission
systems operating at maximum speeds in excess of 10 Mb/s.
Title: Simple Line Code System (SLC) for VDSL
Source Matthew Taylor
_ Tut Systems
2495 Estand Way _
Pleasant Hill, California 94523 `
Tel: 510-682-65lO
Fax: 510-682-4l25
e-mail: [email protected]

Date: August 21. 1995
Distribution: TIEI.4
Abstract: This contribution presents a solution for VDSL using a Simple Line Code (SLC)
baseband binary line code, high performance baluns, and baseband isolationlrestoration
to allow POTS and bi-directional channels. The SLC system achieves 52 Mbps date
rates over 750 feet of 24 gauge twism pair with an NRZ binary line code and 1.000 feet
using a non-NRZ binary line code. The SLC system is robust in the presence of narrow
band interferers and emits levels of EMI well below accepted thresholds. The SLC
' system can be built from approximately 100 transistors. Very cost effective SLC
modems can be developed without recourse to VLSI, and can therefore be produced
soon.
Notice: This contribution has been prepared to assist the Standards Committee Tl-
Telecommunications. This document is offered to the Committee as a basis for
discussion. This contribution should not be construed as a binding proposal on Tut
I Systems, any of its subsidiaries or any other company. The statements contained herein
are subject to change in any form and content. Specifically, Tut Systems reserves the
right to add to, amend, or modify the statements contained herein.
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Case 1 :05-cv—OO866#? Document 71 -8 Filed 12/1 $05 Page 2 of 4
TIE] AI95-103
Simple Line Code VDSL Systems
Abstract: This contribution presents ax solution for VDSL using a Simple Line Code (SLC) baseband
binary line code, high performance baluns, and baseband isolation/restoration to allow POTS
and bi-directional channels. The SLC system achieves 52 Mbps data rates over 750 feet of 24
gauge twisted pair with an NRZ binary line code and t,000 feet using a non-NRZ binary line
code. The SLC system is robust in the presence of narrow band interferers and emits levels of
EMI well below accepted thresholds. The SLC system can be built from approximately 100
transistors. Very cost effective SLC modems can be developed without recourse to VLSI, p ·
and can therefore be produced soon. . `
1. Introduction
Tut Systems herein proposes a line code and system for consideration under the TIEI.4 study project
for VDSL. The system comprises a class of transceivers Tut Systems designates Simple Line Code (SLC).
Utilizing analog technology devised for very high speed twisted pair transmission for LAN, private line, and
campus data communications, Tut SLC transceivers can transmit up to 52 Mbps over 1,000 feet of 24 gauge
wire.
The principal benefits of SLC for VDSL are the lower complexity, by a considerable margin, over
other candidate line codes. near term availability of cost effective products. and inherent robustness. While *
SLC has many signiiieant benefits it is solidly grounded in physics and consequently has some limitations as
well. It will not achieve the same distances theoretically realizable from more complex line codes. and SLC is
less adaptive to narrowband interferers than other candidate line codes. The focus of SLC is on functionality,
simplicity, availability and low power consumption. Tut therefore recommends that SLC be adopted for ·
distances and environments it can realistically support. If future applications or more thorough analysis of the
loop plant environment demand greater distances or operation under more harsh conditions, 'I`lB1.4 should
select a more complex line code to accommodate them. While a single line code would be desirable, market
demand for tow system costs and early implementation may favor a dual line code approach in this case. ·
l Tut Systems bases its statements of performance below on system analysis and the experience gained
from its Ethernet extension products using the same simple line code, which transmit 10 Mbps over 1500 feet
of twisted pair in campus environments. Several thousand modems of this type have been successfully installed
on many types of twisted pair wiring. Furthermore, Tut has built and demonstrated SLC transceivers operating
at 52 Mbps downstream and 2 Mbps upstream. over POTS, at distances up to 400 feet of twisted pair.
2. Basic System and Simple Une Code
Tut Systems proposes two versions of its Simple Line Code'. As suggested by Figure l, the first
version, SLC-2, takes in binary NRZ data, shapes it to suit the linc and channel separation requirements, and
passes it through a hybrid circuit for transmission on the line. The receiver side accepts both the received signal
and a residue ofthe transmit signal. Elters out the transmitter residue and equalizes the line. then restores the dc
content of the baseband signal lost in the transmitter. An output stage squares and rc-times the received data
stream. A POTS splitter divides modem signals from signals used for standard telephony. From there, signals
are coupled to and from the transmission line.
lT¤t's time-based modulator is the subject of certain intellectual property applications which have not been
completed as yet. Until they have been completed and tiled, Tut cannot disclose details of this modulation
scheme without compromising coverage.
Page 2 Tut Systems, Inc.

r Case 1 :05-cv—OO866H: Document 71 -8 Filed 12/14/2005 Page 3 of 4
T1E1.4l95-103
H As an NRZ binary signaling system, SLC-2 requires bandwidth equal to half the data rate. However, it
compensates by providing the most robust signal (binary) in the presence of noise. The second version of 'I`ut`s
Simple Line Code. SLC-4. adds a time-based modulator to the system of SLC-2. halving the bandwidth
required, and thereby stretching t.he distance achieved. The SLC codes can be extended htrther to SLC-16 and
beyond to gain additional bandwidth reduction. ·As with all other line codes that transmit more than one bit per
cycle, further bandwidth reduction is done at the expense of SNR for a given error rate. ln environments where
the noise is minimal, SLC- I6 will make sense. However. in systems where the noise may be substantial SLC-2
or SLC-4 will be a more robust choice necessitating the resultant reduction in speed or distance.
Dam Out Transmitter Hi·p3,55 ' I
(NRZ) SLC Encoder Filter
. POTS _
H’b"d Splitter l-me
_ Baseline Bandpass
Data In {_ Receiver Compu., Film.
(NRZ) SLC Decoder Muon Equalizer POTS
El£1Lts.1.t The figure depicts the basic block diagram of a SLC encoder.
SLC modems use an inherently baseband modulation system. Since VDSL modems must operate over
POTS and provide bi-directional data paths. the Tut SLC system generates modulated signals in the baseband.
* filters out frequencies below a certain level. and then recovers these frequencies in the receiver by a method
known as baseline compensation. In addition. this technique also separates upstream from downstream signals.
frequency division multiplexing both channels as well as the POTS.
3. Transmission and performance parameters
Tut Systems‘ SLC-4 modems will achieve the following distances for two downstream data rates on
the designated wire size:
` 26 Mbps 1,500 feet on 24 ga. UTP 6.5 MI-Iz bandwidth
l,000 feet on 26ga. UTP
52 Mbps l.000 feet on 24 ga. UTP 13 Ml-Iz bandwidth i
750 feet on 26 ga. UTP
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Case 1 :05-cv—00866- Document 71 -8 Filed 12/14/2005 Page 4 of 4
TtEt.4l9S-103
Tut Systems' SLC-2 modems will achieve the following distances for two downstream data rates on
the designated wire size: _
· 26 Mbps 1,000 feet on 24 gat UTP 13 MHz bandwidth
750 feet on 26 ga. U'I'P
52 Mbps 750 feet on 24 ga. U'I'P 26 MHz bandwidth
500 feet on 26 ga. U'I`P
For all systems described above, the following performance parameters apply:
Upstream Rate 2 Mbps ' , ‘
Line Impedance 100 ohms _
Transmit Power < 24 dBm (-60 dBm/Hz)
Power Requirement (basic card) < 500 mW
Latency < l usec
Page 4 Tut Systems. Inc.