TWDM technology moves ahead: XG-PON1 is out

When talking about next-generation PON, operators weigh the pros and cons of XG-PON1 and TWDM technology. It’s an interesting discussion, but realistically, XG-PON1 is out of the race. TWDM offers both technology and market advantages. It not only boosts bandwidth, but generates more revenue and decreases cost and risk.

Debates about the merits of new technologies are nothing new.And when a decision needs to be made it can be a tough call. Just when you buy a new phone or PC, for instance, you might discover that a new model is coming. The issue is even more critical for operators, since network evolution requires major investment. Network operators need to look at all options not 1 - but 2 - steps ahead.


Ovum suggests operators should move directly to TWDM-PON and bypass XG-PON1. According to the Ovum article TWDM-PON is on the horizon: Facilitating fast FTTx network monetization:

“TWDM-PON is forecast to surpass XG-PON1 as the next-gen GPON architecture of choice. The bandwidth enabled by TWDM-PON is attractive to many CSPs (communications service providers) since it can support high-ARPU customers and services such as enterprises and MBH (mobile data backhaul). TWDM-PON will be adopted by both CSPs new to FTTx and those with existing GPON networks. TWDM-PON uses the same ODN (optical distribution network) as existing GPON networks enabling reuse of expensive FTTx assets. For CSPs evaluating FTTx network architectures, TWDM-PON is attractive given its ability to support multiple types of subscribers and applications thereby leading to faster network monetization.”
(page 2, revised by Julie Kunstler, 2015)

TWDM-PON is next generation PON technology that can co-exist with the current GPON technologies and reuse the existing fiber infrastructure. While current PON technologies use 1 wavelength downstream and 1 upstream, TWDM-PON uses multiple wavelengths and can deliver benefits such as:

  • 4x more bandwidth than xGPON1 or 20x more than current GPON networks
  • symmetrical or asymmetrical bitrates
  • flexibility to provide different bitrates on different wavelengths
  • wavelengths unbundling (a wavelength per operator)

TWDM-PON lets operators offer high revenue generating commercial services, consolidate all services (residential, business and mobile backhaul) over 1 network, or perhaps co-invest to share deployment cost and risk. As a result, TWDM-PON monetizes the network faster.

Although most would agree that TWDM technology has the better value proposition, some operators might argue that TWDM is too expensive and that XG-PON1 meets their current needs. But what if you could get more capacity, more services deployment, and more evolution potential for similar investment?

It is indeed possible.


Alcatel-Lucent launched its Universal TWDM technology solution in late 2014 as an enhancement of our existing TWDM line card and TWDM ONU. Since then, the company has done over 30 trials and demos with customers worldwide.

Universal TWDM is based on TWDM technology and its standard, so it’s easy to upgrade to full TWDM-PON. It works on the XG-PON1/10G EPON wavelength and makes use of existing, non-tunable, cheaper optics. Just as important, a fixed wavelength doesn’t consume any NG-PON2 wavelengths. So operators still have access to the original wavelengths for tunable optical network units.


Alcatel-Lucent’s Universal TWDM technology to accelerate deployment of superfast gigabit ultra-broadband access services press release
TWDM-PON: Taking Fiber to New Wavelengths article

To contact the author or request additional information, please send an email to