Hi all,

I wonder what is curently state-of-the art in serial high-speed transmission
and what are the prevailing data rates? I know about some SerDes in the
gigabit-per-second range but I cannot imagine if 10 Gbps are really a
challenge or the applied method or if it's 1 Gbps (or something in
between)...?
I recently heard about some 60 GHz in the mobile communication sector and 10
Gbit Ethernet but as far as I know there are those multi-level modulation
methods (like QAM for example) that are able to provide 10 Gbit bandwidth
with a bitrate of some Mbps (is that correct?).
I'm not interested so much in those higher modulation methods (nor in
optical transmission) but in the baseband communication where bitrate =
clockrate, i.e. the line rate. What can be efficiently transmitted today
electrically (over wire or PCB)? What is the prevailing technology of those
circuits, is it CMOS or are there alternatives?
I am a senior electrical engineer and unfortunately did not manage to keep
up-to-date. After googling all night I'm really depressed because I finally
couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the anser and
are willing to share there knoledge with me?

Best regards
Geronimo


The fastest signaling over copper that I'm (being a software guy, and not

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about some
SerDes in the gigabit-per-second range but I cannot imagine if 10 Gbps
are really a challenge or the applied method or if it's 1 Gbps (or
something in between)...?
I recently heard about some 60 GHz in the mobile communication sector
and 10 Gbit Ethernet but as far as I know there are those multi-level
modulation methods (like QAM for example) that are able to provide 10
Gbit bandwidth with a bitrate of some Mbps (is that correct?).
I'm not interested so much in those higher modulation methods (nor in
optical transmission) but in the baseband communication where bitrate =
clockrate, i.e. the line rate. What can be efficiently transmitted
today electrically (over wire or PCB)? What is the prevailing
technology of those circuits, is it CMOS or are there alternatives?
I am a senior electrical engineer and unfortunately did not manage to
keep up-to-date. After googling all night I'm really depressed because
I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the anser
and are willing to share there knoledge with me?

Best regards
Geronimo
I'll go along with the crosspost this time....

Hi all,

I wonder what is curently state-of-the art in serial high-speed transmission
and what are the prevailing data rates? I know about some SerDes in the
gigabit-per-second range but I cannot imagine if 10 Gbps are really a
challenge or the applied method or if it's 1 Gbps (or something in
between)...?

In article <epo5g1$32h$1@pcls6.std.com>,
jhallen@TheWorld.com (Joseph H Allen) writes:

|> >I wonder what is curently state-of-the art in serial high-speed transmission
|> >and what are the prevailing data rates? I know about some SerDes in the
|> >gigabit-per-second range but I cannot imagine if 10 Gbps are really a
|> >challenge or the applied method or if it's 1 Gbps (or something in
|> >between)...?

|> 10 Gb/sec is commonplace (we're close to every PC having a 10 G port). ...

However, that doesn't help without affordable, reliable and usable cables
and connectors - and they are the problem.

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...
Hi all,

I wonder what is curently state-of-the art in serial high-speed transmission
and what are the prevailing data rates? I know about some SerDes in the
gigabit-per-second range but I cannot imagine if 10 Gbps are really a
challenge or the applied method or if it's 1 Gbps (or something in
between)...?
I recently heard about some 60 GHz in the mobile communication sector and 10
Gbit Ethernet but as far as I know there are those multi-level modulation
methods (like QAM for example) that are able to provide 10 Gbit bandwidth
with a bitrate of some Mbps (is that correct?).
I'm not interested so much in those higher modulation methods (nor in
optical transmission) but in the baseband communication where bitrate =
clockrate, i.e. the line rate. What can be efficiently transmitted today
electrically (over wire or PCB)? What is the prevailing technology of those
circuits, is it CMOS or are there alternatives?
I am a senior electrical engineer and unfortunately did not manage to keep
up-to-date. After googling all night I'm really depressed because I finally
couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the anser and
are willing to share there knoledge with me?

Best regards
Geronimo


The fastest signaling over copper that I'm (being a software guy, and not
involved in bleeding edge hardware development) aware of (in production) is
3Gig SAS/SATA cables. I'm not sure what the "baud" of the protocol is.

Perhaps Infiniband is faster?

- Tim

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
"Michael Weiss" <maerchenprinz@arcor.de> writes:
|
|> I wonder what is curently state-of-the art in serial high-speed transmission
|> and what are the prevailing data rates? I know about some SerDes in the
|> gigabit-per-second range but I cannot imagine if 10 Gbps are really a
|> challenge or the applied method or if it's 1 Gbps (or something in
|> between)...?

Oh, it's a challenge, all right. I went to a very interesting talk on
it, and heard about the issues. The worst problem seems to be cross-talk,
but losses are pretty bad, too. It's feasible, for short distances, but
is a lot harder than 1 Gbps. One of the reasons that 60 Gbps is being
touted is that some people are doubtful about being able to get to 100
Gbps in a realistic timescale for a feasible cost.

|> I am a senior electrical engineer and unfortunately did not manage to keep
|> up-to-date. After googling all night I'm really depressed because I finally
|> couldn't find an unambiguous answer.

Unfortunately, I am not, so I can merely tell you the above; there is
little point in me trying to go into details of what I remember, as I
will probably get them wrong.

What I am certain of is that an optoelectronic breakthrough (and there
are several possibilities) would kill medium distance, high speed
electrical transmission dead - almost overnight. As 'they' have spent
a couple of decades putting serious money into optoelectronic research,
I am not holding my breath. But, as with flat screens, it could happen
at any time.

Unfortunately, none of that gets you a lot further :-)


Regards,
Nick Maclaren.

Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication sector
and 10 Gbit Ethernet but as far as I know there are those multi-level
modulation methods (like QAM for example) that are able to provide 10
Gbit bandwidth with a bitrate of some Mbps (is that correct?).
I'm not interested so much in those higher modulation methods (nor in
optical transmission) but in the baseband communication where bitrate
= clockrate, i.e. the line rate. What can be efficiently transmitted
today electrically (over wire or PCB)? What is the prevailing
technology of those circuits, is it CMOS or are there alternatives?
I am a senior electrical engineer and unfortunately did not manage to
keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you ;)

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

PeteS wrote:
Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication
sector and 10 Gbit Ethernet but as far as I know there are those
multi-level modulation methods (like QAM for example) that are able
to provide 10 Gbit bandwidth with a bitrate of some Mbps (is that
correct?).
I'm not interested so much in those higher modulation methods (nor
in optical transmission) but in the baseband communication where
bitrate = clockrate, i.e. the line rate. What can be efficiently
transmitted today electrically (over wire or PCB)? What is the
prevailing technology of those circuits, is it CMOS or are there
alternatives?
I am a senior electrical engineer and unfortunately did not manage
to keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you ;)

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

(VHDL and CAD groups deleted)

It can be done now. IBM has a serdes core in 90nm CMOS that will
operate at 10Gb+ per second.

Fibre Channel now has a 4Gb version that is pretty common, and 10G (or
maybe it's 8G) is coming along.

the original 10G ethernet was 4 lanes at 3.125G.

At 10Gps, normal fiberglass boards can have problems with dielectric
absorbtion. Some versions are better than others. And alternative
materials are better still.

PeteS wrote:
Tim McCaffrey wrote:

In article <45bf1bb9$0$18833$9b4e6d93@newsspool4.arcor-online.net>,
maerchenprinz@arcor.de says...

Hi all,

I wonder what is curently state-of-the art in serial high-speed
transmission and what are the prevailing data rates? I know about
some SerDes in the gigabit-per-second range but I cannot imagine if
10 Gbps are really a challenge or the applied method or if it's 1
Gbps (or something in between)...?
I recently heard about some 60 GHz in the mobile communication
sector and 10 Gbit Ethernet but as far as I know there are those
multi-level modulation methods (like QAM for example) that are able
to provide 10 Gbit bandwidth with a bitrate of some Mbps (is that
correct?).
I'm not interested so much in those higher modulation methods (nor
in optical transmission) but in the baseband communication where
bitrate = clockrate, i.e. the line rate. What can be efficiently
transmitted today electrically (over wire or PCB)? What is the
prevailing technology of those circuits, is it CMOS or are there
alternatives?
I am a senior electrical engineer and unfortunately did not manage
to keep up-to-date. After googling all night I'm really depressed
because I finally couldn't find an unambiguous answer.
Maybe some guys in the silicon-business or practitioners know the
anser and are willing to share there knoledge with me?

Best regards
Geronimo

The fastest signaling over copper that I'm (being a software guy, and
not involved in bleeding edge hardware development) aware of (in
production) is 3Gig SAS/SATA cables. I'm not sure what the "baud" of
the protocol is.

Perhaps Infiniband is faster?

- Tim


Well, one of the architects of InfiniBand posted right above you ;)

The 1.2 spec has details for 2.5, 5 and 10Gb/s signaling per pair,
although as I recall from the discussions we had 10Gb/s was not easily
realisable on 'ordinary' materials at the time the 1.2 spec was being
written.

Cheers

PeteS

(VHDL and CAD groups deleted)

It can be done now. IBM has a serdes core in 90nm CMOS that will
operate at 10Gb+ per second.

Fibre Channel now has a 4Gb version that is pretty common, and 10G (or
maybe it's 8G) is coming along.

the original 10G ethernet was 4 lanes at 3.125G.

At 10Gps, normal fiberglass boards can have problems with dielectric
absorbtion. Some versions are better than others. And alternative
materials are better still.

OK so which technology is going to be cheaper for 100 G ethernet: fiber with
its expensive optical transceivers or all-electrical flexible waveguide?

OK so which technology is going to be cheaper for 100 G ethernet:
fiber with its expensive optical transceivers or all-electrical
flexible waveguide? TE propogation at 100 GHz is a waveguide
cut-off size on the order of just 1.5 mm...

OK so which technology is going to be cheaper for 100 G ethernet: fiber with
its expensive optical transceivers or all-electrical flexible waveguide? TE
propogation at 100 GHz is a waveguide cut-off size on the order of just 1.5
mm...