ORGANIZERS:
Gabriel Charlet (Huawei)
Jeremie Renaudier (Nokia Bell Labs)
Chongjin Xie (Alibaba Cloud)

ABSTRACT:
C-band systems have been widely deployed for over 25 years. Once fiber capacity is saturated on one link, the option of lighting another (possibly wider) C-band system is the one selected by many operators owning their fiber. “Fiber-renting” operators (typical case of OTT) have deployed C+L systems in the past 5 years to reduce network bandwidth cost, even if a C+L system equipment may currently be more expensive than 2 C-band systems. However, these C+L systems may also be saturated given the ceaseless traffic growth.

The questions that will be addressed during the workshop are the following:
- What capacity growth is expected over the next 10 years? x10, x5, x2?
- Will “fiber-owning” operators keep C-band systems and increase the number of fibers used? Given WSS have a (physically) limited number of ports, which no longer increases, what is the risk of saturating WSS ports?
- What are the main challenges for deploying C+L systems: physical effects (SRS), cost/supply of L-band assets (lasers, WSS, OA)?
- Is C+L mostly for long-haul networks? Or could that also be interesting for DCI or metro in some regions of the world?
- Will C+L systems become the new standard, even for “fiber-owning” operators?
- Will operators renting fiber (mostly OTT) continue to deploy standard C+L (4.8THz+4.8THz) systems, or evolve toward wider bandwidth C+L (6+6THz) systems?
- C+L deployment only started ~20 years after C-band deployment. Should we wait 15 more years to see S+C+L? or could S+C+L appear in the next 5 years?
- What could trigger the development of S+C+L systems (up to 18THz, so almost doubling bandwidth of current 4.8+4.8THz C+L systems)?
- Technologies providing OA for additional bands is progressing and O/E/S/C/L/U bands research experiments have been reported. While worse performance is observed for additional bands, what could drive the adoption of such systems? Could “renting fiber” operators see interest despite potential higher cost per bit?
- Could new generations of fibers (MCF, HCF) become a game changer?

AGENGA:
Session 1: C+L vs. parallel-fiber C-band systems: Mostly for operators renting fibers or soon becoming the new “standard”?
Operators:
- Dong Wang (China Mobile)
- Véronique Guillot (Orange)
- System/subsystems vendors:
- Robert Keys (Ciena)
- Zhang Dejiang (Huawei)
- Rodney Dellinger (Nokia)
- Simon Warren (Lumentum)
OTT:
- Mattia Cantono (Google)
- Chongjin Xie (Alibaba Cloud)
Panel discussion and poll

Session 2: Looking forward to S+C+L, E+S+C+L, O+E+S+C+L: When could they be deployed? How could they be cost effective?
Operators/OTT:
- Ben Puttnam (Microsoft, previously NICT)
- Fukutaro Hamaoka (NTT)
System vendors:
- Antonio Napoli (Infinera)
Academics:
- Pierluigi Poggiolini (Politecnico di Torino)
- Periklis Petropoulos (Southampton University)
Panel discussion and poll