WDM-PON Introduction FAQ
WDM-PON uses multiple optical wavelengths to increase the upstream and/or downstream bandwidth available to end users. Once identified as a “technology for the future,” WDM PON promises to deliver optical technology that is cheaper and easier to deploy, and satisfy end-users demands for higher bandwidth.
FOT’s FTTH Blog try to explain the different PON technologies and why WDM-PON is the only answer for next generation’s bandwidth-hungry end-users.
i) The first question: we need to define, what exactly is the WDM-PON and the relevance in the industry?
WDM PON is really the idea of putting multiple wavelengths onto an existing passive optical network.Today’s PON networks tend to have something like one downstream and one upstream wavelength, they may have an additional wavelength in the downstream for our video, but they are limited in terms of the number of wavelengths they support.
Service providers are always looking for opportunities to expand the utility of the fiber infrastructure they may have placed.And the WDM PON is the idea that I can put something like 32 wavelengths down and maybe 32 wavelengths up, on the same PON fiber that they may have installed or thinking about installed and for a deep fiber access network.
ii) If say Other PONs technology is a little “out”? Is there WDM PON extension or revolution, or something new?
Today there’s really three different PON technologies available on the market place: you have BPON, GPON(10GPON) and EPON(10G-EPON), both BPON and GPON were developed by the full service access network, committee of the ITU-T. EPON was developed as part of the IEEE 802.3ah specification for fiber in the last mile.
When you look at the idea of multiple wavelengths moving beyond two or three wavelengths up on fiber that’s really tied to, So far, FSAN and the work coming out of the FSAN and committee vendor and service provider partners look to evolve beyond GPON. And where we go from there to increase the brandwidth utility of fiber that is out there.
iii) From an infrastructure and equipment perspective, what type of equipment is needed to deploy WDM PON? And is the same equipment that’s needed for GPON?
It is exactly the same type of equipment in today’s PON infrastructure you tend to have OLT (Optical Line Terminal) at the central office point of location, and then the unit that serving the customers to be cleared refer to as an ONT, optical network terminal.
So WDM PON would use those same OLT and ONT concepts.From the leading (WDM PON) companys’ portfolio perspective, the OLTs and the multi service access platform, both of those were designed with the high bandwidth, high switching capacity capabilities.That would lend themselves to an evolution from GPON to WDM PON.
That is said, those devices could be upgraded and would be upgraded for WDM PON support, with a software upgrade and a line card module that would go from a single wavelength type of module we use in EPON, GPON today, to something that would be multiple wavelengths of the land of wdm pon network.
In addition to that there’s a lot of work going on right now in the area of the wavelength grid that we would use for those multiple wavelengths.That work is predominately focused around the idea of having GPON ONT, this remain compatible with a WDM PON OLT network.With that case, the GPON ONT that’s already installed in the service provider could continue to be utilized and deployed literally side by side, with a WDM PON capable ONT in the future.
iv) Other end user services are driving to GPON and consequently to WDM-PON?
Absolutely, serviced providers are looking to evolve their networks and the services they offer, from voice and high speed internet to video and multimedia type of entertainment. When you look at where we’re heading in terms of increased high-definition content, more personalization in terms of the consumer being able to get the the type of content, where wants, what wants and how he wants that. All that leads to more and more bandwidth demands on the network.
So service provider certainly talking about revolution the GPON and fiber access networks like that, and then summer beginning to look at where do we go from here when terms of GPON and the continued service mix, mostly driven by video and personalized type of entertainment services.