NG-PON2 Tech: A Done Deal?
TWDM-PON appears to have been chosen as the primary technology for the upcoming NG-PON2 fiber access broadband standard, even though the industry body behind the specification's development says a decision has not yet been finalized.
The Full Service Access Network (FSAN) group has been considering a number of options for NG-PON2 -- the next broadband access standard after XG-PON 1 (aka XGPON or 10GPON) -- since 2010. FSAN is an important industry body because it develops optical broadband standards specifications for the International Telecommunication Union, Standardization Sector (ITU-T) Study Group 15 (SG15) to formalize. (See Where's PON Going Next?)
Among the technologies under consideration for NG-PON2, which is expected to deliver the kind of bandwidths that will be required in five years or so, were: WDM-PON; coherent ultra-dense WDM-PON (UDWDM PON); Orthogonal Frequency Division Multiplexing (OFDM) PON; 40Gbit/s TDM PON; and TWDM-PON (TDM/WDM-PON), a hybrid system that stacks four 10GPONs onto a single fiber to deliver 40Gbit/s capacity downstream.
Talk at the FTTH Council Europe event held in Munich this February was that TWDM-PON and UDWDM PON were both under serious consideration. However, industry sources who attended that event suggested that FSAN had already written a specification for NG-PON 2 that called for 40-kilometer reach and 40Gbit/s total capacity, details that seemed to point toward TWDM-PON, which has been backed by Alcatel-Lucent (NYSE: ALU) and Huawei Technologies Co. Ltd.
At the time, though, FSAN told Light Reading that multiple solutions were still under consideration.
Now Huawei has announced that TWDM-PON has been identified by FSAN "as the primary solution for NG-PON2," and that Dr. Yuanqiu Luo, Huawei's top optical access technology expert, has been appointed an editor for physical-layer standards in NG-PON2. (See Huawei Lands NG-PON2 Role.)
Surely, then, it's a done deal?
Not so, says Derek Nesset, a Next Generation PON Task Group co-Chair at FSAN and a lead technology consultant at BT Group plc (NYSE: BT; London: BTA).
In an emailed response to questions from Light Reading, he says FSAN will be "further discussing NG-PON2" at a meeting in Santa Clara that started today "to finalise what to take into ITU for standardisation," with a view to announcing a decision shortly after.
That all points toward TWDM-PON as the favored technology, which is good news for AlcaLu and Huawei. They had pinned their hopes on operators seeking the least disruptive solution, and it seems they called it right: TWDM-PON is regarded as less risky, disruptive and expensive than the alternative solutions, according to a Heavy Reading white paper on NG PONs published earlier this year.
But it's not such good news for Nokia Networks , the main force behind UDWDM PON, which it refers to as its next-generation optical access (NGOA) solution. (See NSN Makes Optical Advances.)
Nor is it positive for those that have been backing pure WDM-PON. (See Ericsson Bulks Up GPON, Adds 40Gbit/s WDM-PON, BBWF 2010: Euro Vendor Joins WDM-PON Fray, ADVA Joins WDM-PON Project and ADVA Unleashes WDM-PON.)
So, no shocks are expected when FSAN makes the official announcement about NG-PON2. What's not known is whether than announcement might herald a new working group, this time for NG-PON3.
— Ray Le Maistre, International Managing Editor, Light Reading