In the coming 5G mobile communications era, a huge number of wireless access points will be densely deployed for networks such as mobile fronthaul and Internet-of-Things networks. A network-slicing-based time-division-multiplexing passive optical network (TDM-PON) is one solution for cost-effectively accommodating these access points. It enables us to converge these multiple networks that have different requirements by virtually isolating each sub-network on a single TDM-PON. To achieve this TDM-PON convergence, we propose a dynamic bandwidth allocation scheme that performs uplink bandwidth allocations in a different manner at every sub-network in order to simultaneously satisfy each sub-network requirement. Experiments show that the scheme can simultaneously provide low-latency transmission, bandwidth guarantee, and an auto-discovery process.

Dynamic bandwidth allocation scheme for network-slicing-based TDM-PON toward the beyond-5G era

Wireless network slicing (i.e., network virtualization) is one of the potential technologies for addressing the issue of rapidly growing demand in mobile data services related to 5G cellular networks. It logically decouples the current cellular networks into two entities; infrastructure providers (InPs) and mobile virtual network operators (MVNOs). The resources of base stations (e.g., resource blocks, transmission power, antennas) which are owned by the InP are shared to multiple MVNOs who need resources for their mobile users. Specifically, the physical resources of an InP are abstracted into multiple isolated network slices, which are then allocated to MVNO's mobile users. In this paper, two-level allocation problem in network slicing is examined, whilst enabling efficient resource utilization, inter-slice isolation (i.e., no interference amongst slices), and intra-slice isolation (i.e., no interference between users in the same slice). A generalized Kelly mechanism (GKM) is also designed, based on which the upper level of the resource allocation issue (i.e., between the InP and MVNOs) is addressed. The benefit of using such a resource bidding and allocation framework is that the seller (InP) does not need to know the true valuation of the bidders (MVNOs). For solving the lower level of resource allocation issue (i.e., between MVNOs and their mobile users), the optimal resource allocation is derived from each MVNO to its mobile users by using KKT conditions. Then, bandwidth resources are allocated to the users of MVNOs. Finally, the results of simulation are presented to verify the theoretical analysis of our proposed two-level resource allocation problem in wireless network slicing.

Wireless Network Slicing: Generalized Kelly Mechanism Based Resource Allocation

Centralized radio access network (CRAN) is getting considerable attention in 5G radio access network infrastructure because of supporting deployments of small cells at a massive scale. In particular, CRAN enables network operators to enhance network coverage and capacity without interference with one cell solution and centralized radio processing. This centralization decreases both the network capital and operational expenditures. However, all these technological advancements bring considerable challenges in the transport infrastructure of 5G such as the evolution of the mobile front haul (FH) interface which imposes strict latency and bandwidth requirements on the transport layer. In this paper, the architectural changes that CRAN brings in 5G cellular networks and the intrinsic demands of the FH transport network is discussed. Different techniques that constrain FH requirements to make it cost-efficient are also surveyed. The overall motivation of this work is to achieve the optimal FH transport solution through a passive optical network.

Towards the Shifting of 5G Front Haul Traffic on Passive Optical Network

Digital filter multiple access (DFMA) passive optical networks (PONs) exploit centralized software-defined networking (SDN) controller-managed and transceiver-embedded digital orthogonal filters in individual optical network units (ONUs) to enable end-users to adaptively and dynamically access and share a common fiber transmission medium. DFMA PONs have the potential of not only equipping NG-PONs with sufficient network operation flexibility, adaptability, elasticity, and reconfigurability, but also providing highly desirable backward compatibility with current PON standards. In this paper, for the first time to our knowledge, multipoint-to-point upstream signal transmission in intensity-modulation and direct-detection (IMDD) DFMA PONs is experimentally demonstrated using two real-time, reconfigurable, optical orthogonal frequency division multiplexing-modulated ONUs and an offline optical line terminal. The experimental demonstrations show that each ONU achieves a similar upstream bit error rate performance, excellent tolerance to inter-ONU sample timing offset, and a relatively large ONU launch power variation range.

Experimental demonstration of upstream transmission in digital filter multiple access pons with real-time reconfigurable optical network units

Wireless network slicing (i.e., network virtualization) is one of the potential technologies for addressing the issue of rapidly growing demand in mobile data services related to 5G cellular networks. It logically decouples the current cellular networks into two entities: infrastructure providers (InPs) and mobile virtual network operators (MVNOs). The resources of base stations (e.g., resource blocks, transmission power, and antennas), which are owned by the InP, are shared with multiple MVNOs who need resources for their mobile users. Specifically, the physical resources of an InP are abstracted into multiple isolated network slices, which are then allocated to MVNO’s mobile users. In this paper, two-level allocation problem in network slicing is examined while enabling efficient resource utilization, inter-slice isolation (i.e., no interference among slices), and intra-slice isolation (i.e., no interference between users in the same slice). A generalized Kelly mechanism (GKM) is also designed, based on which the upper level of the resource allocation issue (i.e., between the InP and MVNOs) is addressed. The benefit of using such a resource bidding and allocation framework is that the seller (InP) does not need to know the true valuation of the bidders (MVNOs). For solving the lower level of resource allocation issue (i.e., between MVNOs and their mobile users), the optimal resource allocation is derived from each MVNO to its mobile users by using Karush–Kuhn–Tucker (KKT) conditions. Then, bandwidth resources are allocated to the users of MVNOs. Finally, the results of the simulation are presented to verify the theoretical analysis of our proposed two-level resource allocation problem in wireless network slicing.

Wireless Network Slicing: Generalized Kelly Mechanism-Based Resource Allocation

To meet the 5G mobile traffic demands, many small cells will be installed in the field. A promising candidate for reducing a large number of optical fibers connecting the central and distribution units is a tunable wavelength division multiplexing passive optical network. However, for systems in which multiple wavelengths are transmitted densely such as 100 GHz channel spacing, wavelength setting error and wavelength drift are major issues. In this paper, we describe a wavelength control method that uses an auxiliary management and control channel that complies with ITU-T G.989.3. Our method makes it possible to control the setting error of upstream signals at the initial connection between the optical line terminal and an optical network unit and also to control the wavelength drift due to the aging degradation of the laser diode. We also clarify the control conditions needed to minimize the control time.

Wavelength control method of upstream signals using AMCC in WDM-PON for 5G mobile fronthaul

We propose a bandwidth allocation scheme for converging 5G mobile fronthaul and IoT networks on a TDM-PON. Experiments show that the scheme can simultaneously provide low-latency transmission, bandwidth guarantee, and auto-discovery process.

First Demonstration of Bandwidth-Allocation Scheme for Network-Slicing-Based TDM-PON toward 5G and IoT Era

We propose the wavelength adjustment method of the upstream signal using the AMCC complied with G.989.3 against the wavelength drift in WDM-PON and demonstrate it in the evaluation platform implementing the AMCC processor.

Wavelength Adjustment of Upstream Signal using AMCC with Power Monitoring for WDM-PON in 5G Mobile Era

A WDM-PON system managed with an electrically embedded pilot tone to accommodate mobile fronthaul is proposed. Experimental results show a 128 kb/s pilot tone can be inserted into the low frequency area of CPRI signals with negligible insertion penalty.

Kazuaki Honda

Papers

Dynamic bandwidth allocation scheme for network-slicing-based TDM-PON toward the beyond-5G era

Wavelength control method of upstream signals using AMCC in WDM-PON for 5G mobile fronthaul

First Demonstration of Bandwidth-Allocation Scheme for Network-Slicing-Based TDM-PON toward 5G and IoT Era

Wavelength Adjustment of Upstream Signal using AMCC with Power Monitoring for WDM-PON in 5G Mobile Era

WDM passive optical network managed with embedded pilot tone for mobile fronthaul