Breaking News
How IBM Measured the Current Data Speed Record
3/25/2014

Image 1 of 2      Next >

Figure 1
The test setup consisted of a pattern generator, optical transmitter, optical receiver, and a BERT.
The test setup consisted of a pattern generator, optical transmitter, optical receiver, and a BERT.

Image 1 of 2      Next >

Return to Article

View Comments: Newest First | Oldest First | Threaded View
MeasurementBlues
User Rank
Author
Re: Testing Ethernet Compliance
MeasurementBlues   4/1/2014 8:28:54 AM
NO RATINGS
Sanjib,

In this case, the formatting of the bits into packets don;t matter. Speed experiments are done using a PRBS pattern to assure an almost random set of bits. The point is to prove that data rates are possible. What those bits represent is irrelevant here.

zeeglen
User Rank
Author
Re: Multimode?
zeeglen   3/31/2014 7:41:33 PM
NO RATINGS
@ DKuchta In general, 1310nm VCSELs have lower ouput power and, to date, much lower modulation speeds than 850nm devices.


Thanks, this answers my question.  Was thinking of an external modulator rather than laser keying.  Amazing that VCSELs can be directly keyed at this rate!


 

DKuchta
User Rank
Author
Re: Multimode?
DKuchta   3/31/2014 2:47:32 PM
NO RATINGS
Is your question about fiber properties or VCSEL poperties?

In general, 1310nm VCSELs have lower ouput power and, to date, much lower modulation speeds than 850nm devices.  In the literature, 30Gb/s over 10km of single mode fiber has been demonstrated from a 1270nm (~1310nm) VCSEL.

For 1310nm VCSELs, the single mode fiber distance will be in the 10km range, limited by either the available optical power or the spectral width.

zeeglen
User Rank
Author
Multimode?
zeeglen   3/30/2014 10:54:00 AM
NO RATINGS
Since the 850 nm multimode fiber lengths have such significance in the test results, wonder what would the maximum lengths be using singlemode fiber at 1310 nm?

Sanjib.A
User Rank
Author
Testing Ethernet Compliance
Sanjib.A   3/30/2014 3:36:18 AM
NO RATINGS

While reading this article, a question just occurred to me, which I came across a few days back and I did not know the answer. To implement Fast Ethernet or Giga-bit Ethernet, we generally use the off-the-shelf processors with in-built MAC, 0ff-the-shelf PHY chips compliant to the Ethernet standard and magnetics, connectors per standard. What are the test cases which need to be done to check whether Ethernet implemented actually complied to the respective standards?

Most Recent Comments
michigan0
 
SteveHarris0
 
realjjj
 
SteveHarris0
 
SteveHarris0
 
VicVat
 
Les_Slater
 
SSDWEM
 
witeken
Most Recent Messages
9/25/2016
4:48:30 PM
michigan0 Sang Kim First, 28nm bulk is in volume manufacturing for several years by the major semiconductor companies but not 28nm FDSOI today yet. Why not? Simply because unlike 28nm bulk the LDD(Lightly Doped Drain) to minimize hot carrier generation can't be implemented in 28nm FDSOI. Furthermore, hot carrier reliability becomes worse with scaling, That is the major reason why 28nm FDSOI is not manufacturable today and will not be. Second, how can you suppress the leakage currents from such ultra short 7nm due to the short channel effects? How thin SOI thickness is required to prevent punch-through of un-dopped 7nm FDSOI? Possibly less than 4nm. Depositing such an ultra thin film less then 4nm filum uniformly and reliably over 12" wafers at the manufacturing line is extremely difficult or not even manufacturable. If not manufacturable, the 7nm FDSOI debate is over!Third, what happens when hot carriers are generated near the drain at normal operation of 7nm FDSOI? Electrons go to the positively biased drain with no harm but where the holes to go? The holes can't go to the substrate because of the thin BOX layer. Some holes may become trapped at the BOX layer causing Vt shift. However, the vast majority of holes drift through the the un-dopped SOI channel toward the N+Source,...

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed