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This paper proposes multiplication-based parallel frequency offset compen-sation (FOC) for virtualized access networks and demonstrates real-time softwarization of the full DSP function suite, including polarization demultiplexing, FOC, carrier phase re-covery, and decoding, on a server.

This paper demonstrates that PHY processing for industrial network applications and PON can be realized on a common general-purpose server for flexible service creations; it realizes the level of latency performance required by IRT communication.

We propose a control method for in-service end-to-end optical paths, and experimentally demonstrate the simultaneous restoration of Ethernet, CPRI, and HDMI signals, which is the world’s first operation of protocol-independent control for end-to-end optical-path.

This paper summarizes studies on passive optical network (PON) virtualization, including the softwarization of physical-layer (PHY) coding and digital signal processing (DSP), as well as PON abstraction, which provide flexibility and agility to access networks.

Low latency services such as remote drone control are expected to be provided by future optical and mobile networks. This paper covers the issues and possible technology candidates to resolve them.

The specifications of passive optical network (PON) systems continue to evolve while access systems need to accommodate an ever-widening variety of new services. To deal with the various requests, virtualization is essential for optical access networks. So far, optical line terminal (OLT) abstraction technology, represented by software-defined-network-enabled broadband access, has been commercialized as a platform, but a remaining challenge is the softwarization of media access control and physical-layer (PHY) processing as OLT functionalities. However, in the virtualized PON, service chaining (SC) is also crucial to realize efficient access networks that meet user requirements by chaining the virtualized functions. In particular, no study, to our knowledge, has focused on PHY SC classification that supports adaptive coding and modulation. This paper reviews recent advances in PON virtualization techniques including abstraction and softwarization while showing our target optical access system, which is fully virtualized. Furthermore, it proposes an SC classifier adopting low-complexity modulation format identification (MFI). Experiments show that our proposed method achieves 100% identification accuracy if the bit error rate is within the forward error correction limit; real-time processing speed of 2.5 Gsymbols/s with 3% computation resource occupancy is achieved, as the proposal has much lower computation overheads than other MFI methods.

We experimentally evaluate the transmission characteristics of AMCC superposition with an SOA-integrated EA-DFB transmitter for the All-Photonics Network. The results demonstrate that direct optical connections with the power budget of 34.6 dB are achievable.

We propose the Photonic Gateway to provide direct and protocol-independent optical connections between any two user sites. An experimental demonstration verifies the feasibility of the Photonic Gateway and an optical-path setup procedure of the prototypes.

The use of digital coherent technologies offers many advantages to future optical access systems. This paper introduces approaches based on DSP technologies to realize long-reach TDM-PON systems.

An AMCC signal extraction method for a single coherent receiver is proposed. Experiments demonstrate the successful decoding of a 25 Gbps QPSK-signal and 128 kbps AMCC-signal with the penalty of less than 0.1 dB.

Passive optical networks (PONs) are widely deployed worldwide as access networks, and various standards have been created to serve the demands of different markets. In recent years, software-defined-network-enabled broadband access (SEBA) has been studied for the realization of flexible and cost-effective PONs, while the zero touch provisioning (ZTP) function of optical line terminals (OLTs) and optical network units (ONUs) is being studied for automatic management. However, although ZTP for ITU-T standards has already been implemented, ZTP for IEEE standards has not been achieved, since the workflow is significantly different for each access standard due to differences in the authentication method. The subdivided package specifications and medium access control (MAC) dress authentication are barriers that hinder achieving ZTP for the IEEE standards. This paper proposes a workflow driver based on a model that implements authentication compliant with IEEE PON packages A and B according to events produced by SEBA components and specification information obtained from OLT profiles. The feature of our proposal is to fabricate an IEEE-compliant driver package that automatically switches the authentication method by acquiring the technology profile of the orchestrator, and as soon as IEEE802.1X authentication or MAC address authentication is completed, the subscriber setting is registered to the SDN controller in order to enable data plane service. We demonstrate the proposed workflow driver on a system consisting of SEBA-focused commercially available OLT/ONU hardware and open source software. The results show that the orchestrator can automatically provision ONUs and that managing various access devices on a common access platform is feasible.

This paper introduces the concept of a symmetric 10 Gbit/s high power-budget TDM-PON based on digital coherent technology and confirms its feasibility through a bidirectional transmission experiment with a transmission distance of 40 km and power budget of more than 50 dB. Burst-mode upstream 10 Gbit/s binary-phase-shift-keying (BPSK) signals synchronized by the clock recovered from downstream 10 Gbit/s NRZ signals are detected by using an optical pre-amplifier and coherent detection based on real-time burst-mode digital signal processing (DSP) in the optical line terminal (OLT). The real-time DSP implements coefficient handover in the adaptive equalizer to allow the reception of burst-mode upstream BPSK signals with short preamble length. An experimental bit error performance evaluation of the real-time burst-mode DSP yields the receiver sensitivity of -45.1 dBm for upstream burst-mode BPSK with a preamble length of 1.3 μs. For downstream signals, the receiver sensitivity of -38.9 dBm is achieved by using a chirp-controlled transmitter with optical post-amplifier so as to avoid the signal distortion created by the chromatic dispersion of single mode fiber (SMF) when the launched power is increased.