Software-defined Access Network Research Articles

Low-Latency PON PHY Implementation on GPUs for Fully Software-Defined Access Networks

In order to respond to the increasing diversification of requirements, studies on software-defined access networks to enhance the flexibility of network systems continues. For fully software-defined access networks to efficiently accommodate various passive optical networks (PONs), other interfaces, and services, the softwarization of physical-layer processing has been studied. However, current techniques do not achieve enough performance for practical applications, and the total latency of upstream processing and downstream processing is 39.0 ms. The load imposed by conventional inter-ruption-based implementation makes it difficult to reduce buffer size. This article proposes an accelerator-based polling implementation method, which has lower load than the conventional interrupt approach, and thus has superior latency. We evaluate the latency performance in real time when implementing the 10G-EPON functions. Our implementation realizes graphic processing unit (CPU) polling by adding a flag to the received data and repeatedly checking the flag on a dedicated core. Demonstration results show that a prototype system successfully implemented our polling method on CPUs with low latency of 0.586 ms.

Network Performance and Management-Complexity Evaluation of Software-Defined Access Network in Multi-Tenancy Scenario

Industrial revolution has transformed social life. Because of the digital disruption, companies reorganize and change their business model to face the challenges of industrial revolution 4.0. The multi-tenant architecture separates each tenant logically while they are physically integrated. This model has a problem in the management of network devices. The difficulty of changing and rigidity of the underlying infrastructure presents few possibilities for innovation or improvement since network devices have generally been vendor locked. A Software-Defined Access Network (SDAN) is a software-defined network that is implemented on an access network. SDAN aims to simplify complicated access management and improve service provision. This paper aims to analyze and evaluate SDAN design performance and complexity management of network devices. Evaluation is carried out by conducting a comparative survey between SDAN and non-SDAN in terms of performance and use case scenarios. Based on the results, it can be concluded that the SDAN has 10%-20% better performance in terms of elapsed times and throughput. It also significantly reduces time for managing network devices ten times faster than non-SDAN.

Research on Power Optimization Based on Adaptive Passive Optical Networks

Abstract For the commercial wavelength division multiplexing passive optical network (WDM-PON) with standard single-mode fiber SSMF-28 and 1:64 passive fiber branching at its far end (RN) and 100 GHz C-band continuous wavelength (CW) lasers, the maximum coverage and optimal transmission power of STM-16 and STM-64 with external modulators at different speeds and wave numbers (4λ, 8λ and 16λ) are obtained, respectively. The performance parameter of the high data rate WDM-PON system is analyzed with respect to a number of channels and reach. In order to improve the network utilization and receiving efficiency, the influence of different channels and transmission distances on the performance of high data rate WDM-PON system is analyzed. Simulation analysis with Optisystem15.0. The maximum transmission power required to achieve the maximum transmission distance under the condition of nonlinear constraints is obtained. In order to save power consumption, the configuration of each multi-band PON is optimized in terms of transmission power. It is found that WDM-PON system has to compromise between aggregated data rate and system reach. Future software defined access network reconfigure the access network depending on the dynamic demand and the resources available. Hence depending on the distance between the optical line terminal (OLT) and optical network unit (ONU) guaranteed data rate can be estimated. ONU is equipped with a tunable optical filter (TOF) hence future wavelength can be reconfigured by both service provider and user. It makes it possible for software to customize optical access network.

NFV and SDN-Based Differentiated Traffic Treatment for Residential Networks

Residential networks play a critical role in assuring that services or applications such as tele-work, tele-education, medical care, entertainment, home automation, among others, have the required resources to obtain an optimal performance. Although current residential gateways try to meet the Quality of Service (QoS) demands, the traditional networking paradigm does not have the appropriate mechanisms to address the heterogeneous and dynamic nature of the services running at home. In this context, a feasible solution consists of leveraging the flexibility and adaptability of the Software Defined Networking (SDN) and Network Functions Virtualization (NFV) paradigms to provide a differentiated traffic treatment intended to improve the QoS support of residential networks. The proposal takes advantage of the Service Function Chaining (SFC) concept intrinsic to NFV as well as the capacity of an SDN-based residential gateway to differentiate the traffic of a certain application. Thus, an association between an SFC and the differentiated traffic is stablished to apply a specific treatment. Besides, a comprehensive architecture composed of the software defined residential network (SDRN), the software defined access network (SDOAN) and the NFV-compliant ISP's edge cloud infrastructure is envisioned. This architecture would allow dramatically improving the life cycle management of the residential network from a centralized point which follows a user-centric approach.

Exploiting flexible functional split in converged software defined access networks

5G targets to offer a huge network capacity to support the expected unprecedented traffic growth due mainly to mobile and machine-type services. Thus, the 5G access network has to comply with very challenging architectural requirements. Mobile network scalability is achieved by playing appropriately with the centralization of network functions and by applying the functional split introducing the fronthaul. Although more advantageous in terms of network management and performance optimization, low-layer functional split options require larger bandwidth and lower latency to be guaranteed by the fronthaul in the access network, while preserving other concurrent fiber-to-the-x services. Thus, advanced mechanisms for the efficient management of available resources in the access network are required to control jointly both radio and optical domains. Softwarized mobile and optical segments facilitate the introduction of dedicated protocols to enable the inter-working of the two control planes. This paper proposes a new cooperation scheme to manage the adaptive flexible functional split in 5G networks conditioned to the resource availability in the optical access network. Techniques for the accurate estimation of available bandwidth and the associated real-time selection of the best suitable functional split option are investigated. Results show that the proposed software defined converged approach to wavelength and bandwidth management guarantees the optimal allocation of optical resources. The triple exponential smoothing forecasting technique enables efficient coexistence of mobile fronthaul and fixed connectivity traffic in the network, reducing traffic impairments with respect to other well-known forecasting techniques, while keeping the same level of centralization.

Mobi-Flow: Mobility-Aware Adaptive Flow-Rule Placement in Software-Defined Access Network

In this paper, we propose a mobility-aware adaptive flow-rule placement scheme, named as Mobi-Flow, with an aim to maximize the overall performance in a software-defined access network (SDAN). The proposed scheme consists of two components — path estimator and flow-manager. The path estimator predicts future locations of end-users present in the network, depending on their history location sets, and delivers the predicted locations to the flow-manager. We use the order-k Markov predictor to predict the next possible locations of the end-users. Based on the predicted locations, the flow-manager determines access points (APs) in the network, which can be associated with the users to fulfill the requirements of the latter. We formulate an integer linear programming (ILP) to determine optimal number of APs, so that overall cost associated with flow-rule placement is minimized. Further, we propose a greedy approach to determine optimal number of APs, as solving the ILP is NP-hard. Consequently, the flow-manager implements the flow-rules at APs, so that adequate actions for the incoming requests can be taken in an adaptive manner, without querying the controller. We consider a practical scenario of an IoT environment, in which both static and mobile users are present. Therefore, the proposed scheme, Mobi-Flow, can be integrated atop the SDN controller to support the emerging concept of SDN-based IoT networking. Through extensive simulations, we show that Mobi-Flow is beneficial for minimizing the delay, number of activated APs, control overhead, energy consumption, and cost in the network, compared to the existing schemes—open shortest path first (OSPF), minimum occupied rule capacity (MRC), distributed (non-SDN), and MoRule. Particularly, the proposed scheme is capable of reducing the cost by 39, 38, 65, and 11 percent, compared to OSPF, MRC, distributed, and MoRule, respectively.

Detour: Dynamic Task Offloading in Software-Defined Fog for IoT Applications

In this paper, we consider the problem of task offloading in a software-defined access network, where IoT devices are connected to fog computing nodes by multi-hop IoT access-points (APs). The proposed scheme considers the following aspects in a fog-computing-based IoT architecture: 1) optimal decision on local or remote task computation; 2) optimal fog node selection; and 3) optimal path selection for offloading. Accordingly, we formulate the multi-hop task offloading problem as an integer linear program (ILP). Since the feasible set is non-convex, we propose a greedy-heuristic-based approach to efficiently solve the problem. The greedy solution takes into account delay, energy consumption, multi-hop paths, and dynamic network conditions, such as link utilization and SDN rule-capacity. Experimental results show that the proposed scheme is capable of reducing the average delay and energy consumption by 12% and 21%, respectively, compared with the state of the art.

Software-defined converged access network with cross-layer intelligent control architecture

Abstract The optical and wireless convergence technology is one of the principal means for the problem of last mile access. The software-defined network (SDN) supported by OpenFlow protocol is a promising centralized control architecture. Combining these two aspects, we propose a software-defined access network control architecture for the optical and wireless convergence technology, and design its functional modules and the overall interaction process. The proposed architecture adopts the idea of hierarchical control, introduces the OpenFlow agent, dynamically decentralizes some of the controller's authorities to the optical line terminal (OLT), and enhances its overall disaster response capability by extending the control depth of the controller to the optical network unit (ONU). The controller obtains relevant information in real time from a global perspective to achieve more comprehensive dynamic and flexible control, which effectively improves the network resource utilization and meets different service requirements of different users.

Software-defined access networks

Control-plane functions are migrating from dedicated network equipment into software running on commodity hardware. The Software- Defined Access Network (SDAN) concept introduced here extends the benefits of Software- Defined Networking and Network Function Virtualization (NFV) into broadband access. In a SDAN, access-network control and management functions for broadband access are virtualized, to streamline operations, speed services creation, and enhance broadband customer satisfaction, particularly in multi-operator environments. This article examines industry drivers, identifies software- definable control and management functions for broadband access, and presents some specific usage scenarios for the SDAN.