Search Results for 'wdm'

[Rajguru M. MohanParticipant]

Hi nagesh kuknoor,

I have used symmetrical channel spacing in my design.
It is simple DWDM design using Symmetrical dispersion compensation technique.
With data rate of 40 gbps.

I have used 8 users in my design.

Again i am uploading the osd file of DRZ, MDRZ and CSRZ modulation formats DWDM system
Hope this time it will not shows any error.
I have no problem in opening these files.
Which version of optisystem are you using.

Seeking your response.

[Gede TeguhParticipant]

Hmm, i got same problem too mr. gagan. I design wdm with oadm and rof. I didnt realize why i always get BER > 10 ^-9 and Factor Q <6 if using 1 – 10 gbps bit rate. But when i used 622 mbps bit rate, i got BER > 10 ^-9 and Factor Q <6 . Can i get explanation too? Thank you guys

[Gede Teguh]

Hi guys,
I am having problem with BER and Q Factor in DWDM system with Radio over Fiber.
I have designed DWDM system with 4 channels.
Following parameters used are 1-10 gbps bit rate, variable transmission length.
When i used 622 mbps bit rate, i get good BER < 1e-09 and Factor Q >6 . But when i try to use 1-10 Gbps bit rate, BER Analyzer cannot detect it ( BER : 1 , Factor Q : 0 )
How could i get good BER and Factor Q with 1-10 gbps bit rate?
Suggest me some ways so that i could get the expected results.

Seeking your response. Thank you guys

[Gede Teguh]

Hello guys,
I so confused with my simulation about WDM because i don’t know about relation between bit rate with the Factor Q and BER. I’m trying with bit rate 622 Mbps and i get Factor Q >6 and BER >1e-09. And when i’m trying with bit rate 1 – 10 Gbps, i always get Factor Q : 2.2-2.5 and BER > 1e-09 . I hope anyone here can explain me about that or how to get Factor Q >6 and BER >1e-09 using bit rate 1-10Gbps . Thank you

[Rajguru M. MohanParticipant]

Hi,
We have a relation between OSNR and BER as:
We can also use WDM analyzer to check the OSNR.
Given the OSNR, the empirical formula to calculate BER for single fiber is

Log10 (BER) = 10.7-1.45 (OSNR)
Example:
Assume that OSNR = 10.5 dB
ThenLog10 (BER) = 10.7-1.45 (20.5) = -19.025
Therefore BER = 10^(-19.025)
BER is approx 10^-19
I think it is approated way to calculate BER from OSNR

Hope this will help you.

For more information you can refer to :

OSNR vs Log(BER)

How to plot BER versus OSNR

BER versus OSNR

plotting result graphs

[Rajguru M. Mohan]

Hi everyone,
I am having problem in designing DWDM system with channel spacing of 25 GHZ or 50 GHZ.
I have designed DWDM system with 100GHZ channel spacing, but find no results when when i decrease Channel spacing to
25 GHZ. I have used symmetrical compensation technique with different advanced modulation formats MDRZ, CSRZ and DRZ.
Following parameters used are 40gbps bit rate, variable transmission length.
We use advanced modulation formats because CSRZ has narrow optical spectrum then the conventional RZ format
and high tolerance to group velocity dispersion (GVP) and mixed effect of self phase modulation (SPM).
DRZ transmitter of their optical modulation bandwidth DRZ format is very
attractive. It can be compressed to the data bit rate B that
is half- bandwidth of NRZ format 2B.
How could i reduce channel spacing.
Suggest me some ways so that i could get the expected results.
Here i am uploading the osd file of DRZ DWDM system.

Seeking your response.

[Rajguru M. MohanParticipant]

Hi Deepak,
Fiber Bragg Grating is the application of Optigrating. The link which is depicted below states it.
https://optiwave.com/category/products/component-design/optigrating/optigrating-applications/
A complex grating is approximated by a sequence of uniform segments, and analyzed by connecting the segments with the well-known Transfer Matrix Method.
There are many applications of optigrating are:
WDM add/drop, narrow and broadband fiber and waveguide filters
Fiber Bragg reflectors
EDFA gain flattening elements
Dispersion compensators for fiber communications
Sideband suppression using grating apodization
Fiber and waveguide sensors
Long Period Gratings with coupling to cladding modes

Hope this will help you to understand.

[ishpreet kaur]

hi everyone,
i am trying to make WDM PON network with OFDM in my project work. it not working . the whole setup is done but its not good. as i am a beginner. i recently started learning optisystem tool. any help please.

[pooja rawatParticipant]

Hi Jyoti Raina.
I am designing a TWDM PON network. I wanted to know what values are permissible for the receiver sensitivity. I hope i get some replies that would answer my question.
Anyway Thanks for your effort.

Thanks
Regards

[Rajguru M. MohanParticipant]

Hi hi nguyan hai ha,
We couldn’t design hybrid TDM – WDM PON using optisystem 7.0.
You should upgrade your optisystem software version either 13.0 or 14.0.
Because previous version lacks some components.
In NGPON2 You can also use OFDM-WDM PON, Why are you to use hybrid TDM – WDM PON ?
Seeking your response.

[Manoj KumarParticipant]

hi amit garg….
As already discussed by Damian Marek in one of the post the buffer selector is a simulation tool to grab certain signals (from the different signal iterations) generated in bidirectional or loop simulations.
As suggested by him you can go through the bidirectional tutorial:

Lesson 5: Bidirectional Simulation — Working with Multiple Iterations

Also i am attaching a link of the post in which this topic was discussed.Hope you will get benefit from this.

Problem in simulation of Buffer selector in TWDM PON

With regards

[Manoj KumarParticipant]

Hi Fayiqa ma’m
All the TWDM ONTs must be colorless. The ONT transceiver must be able to tune to the correct wavelengths in upstream and downstream during end-user provisioning.
We can use a variety of techniques to control the wavelength in the upstream direction from the ONT to the OLT. Temperature is the primary parameter of control. all TWDM ONTs must be colorless. The ONT transceiver must be able to tune to the correct wavelengths in upstream and downstream during end-user provisioning.

Operators can use a variety of techniques to control the wavelength in the upstream direction from the ONT to the OLT. Temperature is the primary parameter of control.
n the long-term, it is hoped that photonic integrated circuits will provide other economical solutions to wavelength control.

In the downstream direction, thermo-controlled thin-film filters can be integrated into the ONT receiver to allow tuning. Photonic integrated circuits may provide a future solution.

[Manoj KumarParticipant]

hi.
Arrayed waveguide gratings are mainly applied in optical fiber communication systems, in particular in those based on multi-channel transmission with wavelength division multiplexing (WDM)……..where individual wavelength channels must be combined or separated e-g TWDM PONs etc…However i would like to mention that while using AWG for my implementation , my performance was not that gud but using WDM mux/demux separately my performance was better.
Thanks and regards

[Manoj KumarParticipant]

hi Zulkarnain…..
in order to understand about the filters in optiwave you should consult the link where it is already discussed…
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwiGyoqMvrHLAhXRCI4KHcUfDi8QFggpMAI&url=http%3A%2F%2Foptiwave.com%2Fforums%2Ftopic%2Foptical-filters%2F&usg=AFQjCNFUTFquKhAz5qpq0-jlOGd7MRbtHg&sig2=VDq57CqcgTNKd1KJpXDTgw

moreover if you want to understand their usage in optiwave consult this link
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiGyoqMvrHLAhXRCI4KHcUfDi8QFggbMAA&url=http%3A%2F%2Foptiwave.com%2Fresources%2Fapplications-resources%2Foptical-system-lesson-3-optical-systems-wdm-design%2F&usg=AFQjCNF57O1dfMJAajIUgzfWDvMftOtYkw&sig2=FDZzBWJr3E1ngpHYdpOFsA

best regards

[Manoj KumarParticipant]

Hi Aabid Baba

I believe you would be well aware of the theory and basics behind add module, drop module or add/drop multiplexer but since you want to know about the use of these modules in some example that would be existing in the examples. I have myself come across an example in which these modules were used . In examples of optisystem 14 go in the WDM system section and in there u would find an example of COADM and in that u will find that how add, drop modules are used. See for them if u find them well and good if not mention it i will upload the .osd file for you in that case.

Regards