Luis M. Contreras

An architecture for software defined wireless networking

Software defined networking, characterized by a clear separation of the control and data planes, is being adopted as a novel paradigm for wired networking. With SDN, network operators can run their infrastructure more efficiently, supporting faster deployment of new services while enabling key features such as virtualization. In this article, we adopt an SDN-like approach applied to wireless mobile networks that will not only benefit from the same features as in the wired case, but will also leverage on the distinct features of mobile deployments to push improvements even further. We illustrate with a number of representative use cases the benefits of the adoption of the proposed architecture, which is detailed in terms of modules, interfaces, and high-level signaling. We also review the ongoing standardization efforts, and discuss the potential advantages and weaknesses, and the need for a coordinated approach.

Towards cloud-ready transport networks

This article presents an operators view of the evolution towards a transport network ready to support cloud services, which are hosted in data centers and reachable through the network. This work shows the reasons why current transport networks are not efficiently designed for a cloud environment, and it describes the architecture for a cloud-ready network. To show the feasibility of such a cloud-ready network, we present three experimental validations of the concepts to support our network evolution.

Software-defined control of the virtualized mobile packet core

Mobile packet core networks are undergoing major changes to meet the requirements of the future data tsunami, enhance network flexibility, and reduce both CAPEX and OPEX. In this regard, SDN and NFV technologies have gained great momentum among the teleos, with the promise of interoperability, programmability, and on-demand dynamic provisioning. In this article, we present work being developed in the Mobile Packet Core project within the ONF Wireless & Mobile Working Group regarding SDN architecture for the Mobile Packet Core. In addition, we propose an SDN-based MPC in the NFV context in order to facilitate dynamic provisioning of MPC network functions. Finally, a potential control architecture considering both SDN and NFV is proposed.

A service-oriented hybrid access network and clouds architecture

Many telecom operators are deploying their own cloud infrastructure with the two-fold objective of providing cloud services to their customers and enabling network function virtualization. In this article we present an architecture we call SHINE, which focuses on orchestrating cloud with heterogeneous access and core networks. In this architecture intra and inter DC connectivity is dynamically controlled, maximizing the overall performance in terms of throughput and latency while minimizing total costs. The main building blocks are: a future-proof network architecture that can scale to offer potentially unlimited bandwidth based on an active remote node (ARN) to interface end-users and the core network; an innovative distributed DC architecture consisting of micro-DCs placed in selected core locations to accelerate content delivery, reducing core network traffic, and ensuring very low latency; and dynamic orchestration of the distributed DC and access and core network segments. SHINE will provide unprecedented quality of experience, greatly reducing costs by coordinating network and cloud and facilitating service chaining by virtualizing network functions.

Intercloud Architecture Framework for Heterogeneous Cloud Based Infrastructure Services Provisioning On-Demand

This paper presents on-going research to develop the Intercloud Architecture Framework (ICAF) that addresses problems in multi-provider multi-domain heterogeneous cloud based infrastructure services and applications integration and interoperability, to allow their on-demand provisioning. The paper refers to existing standards and ongoing standardisation activity in Cloud Computing, in particular, recently published NIST Cloud Computing Reference Architecture (CCRA) and ITU-T JCA-Cloud activity. The proposed ICAF defines four complementary components addressing Intercloud integration and interoperability: multi-layer Cloud Services Model that combines commonly adopted cloud service models, such as IaaS, PaaS, SaaS, in one multilayer model with corresponding inter-layer interfaces, Intercloud Control and Management Plane that supports cloud based applications interaction, Intercloud Federation Framework, and Intercloud Operations Framework. The paper briefly describes the Service delivery and lifecycle management as an important ICAF component that provides a basis for consistent management and security of the provisioned on-demand complex cloud based services. The paper describes an implementation of the Intercloud Control and Management Plane in the GEYSERS project to allow optimal provisioning of the combined Network+IT resources in the inter-cloud environment. The proposed architecture is intended to provide an architectural model for developing Intercloud middleware and in this way will facilitate clouds interoperability and integration.

Software-Defined Wireless Transport Networks for Flexible Mobile Backhaul in 5G Systems

Traditionally microwave backhaul has been configured and operated in a static manner by means of vendor specific management systems. This mode of operation will be difficult to adapt to the new challenges originated by 5G networks. New mechanisms for adaptation and flexibility are required also in this network segment. The usage of a signaled control plane solution (based on OpenFlow) will facilitate the operation and will provide means for automation of actions on the wireless transport network segment. In addition to that, a standard control plane helps to reach the multi-vendor approach reducing complexity and variety of current per-vendor operation. This paper presents the motivation for the introduction of programmability concepts in wireless transport networks and illustrate the applicability of such control plane with two relevant use cases for dynamically controlling wireless transport nodes in 5G networks. Extensions to OpenFlow protocol are also introduced for building Software Defined Wireless Transport Networks (SDWTNs).

Experimental Assessment of ABNO-Driven Multicast Connectivity in Flexgrid Networks

The increasing demand of internet services is pushing cloud services providers to increase the capacity of their data centers (DC) and create DC federations, where two or more cloud providers interconnect their infrastructures. As a result of the huge capacity required for the inter-DC network, the flexgrid optical technology can be used. In such scenario, applications can run in DCs placed in geographically distant locations, and hence, multicast-based communication services among their components are required. In this paper, we study two different approaches to provide multicast services in multilayer scenarios assuming that the optical network is based on the flexgrid technology: 1) establishing a point-to-multipoint optical connection (light-tree) for each multicast request, and 2) using a multipurpose virtual network topology (VNT) to serve both unicast and multicast connectivity requests. When that VNT is not able to serve an incoming request as a result of lack of capacity, it is reconfigured to add more resources. A control plane architecture based on the applications-based network operations (ABNO) one, currently being standardized by the IETF, is presented; workflows are proposed and PCEP extensions are studied for the considered approaches. The experimental validation is carried-out on a testbed setup connecting Telefonica, CNIT, and UPC premises.

Big Data-backed video distribution in the telecom cloud

The telecom infrastructure is undergoing a huge transformation since operators are deploying their own cloud infrastructure to provide cloud services and enabling Network Functions Virtualization (NFV). The resulting infrastructure is referred to as the telecom cloud. NFV decouples network functions from proprietary hardware appliances, so they can be implemented in software and deployed on virtual machines (VM) running on commercial off-the-shelf computing hardware.

Operational, organizational and business challenges for network operators in the context of SDN and NFV

Traditional operators deploy and operate telecom networks that rely on monolithic network elements that incorporate distinct network functions and implemented with a vertical integration of control and data planes. This mode of operation is transitioning towards a new situation where the control plane is separated from the data plane, and the network functions are no longer tightly bound to specific elements in the network. The two paradigms pushing in that direction are Software Defined Networking (SDN) and Network Functions Virtualization (NFV). This paper presents a number of challenges that traditional network operators must adapt to during this transition. We categorize these challenges using three important dimensions for telecom operators: operation, organization and business.

Software-Defined Mobility Management: Architecture Proposal and Future Directions

A common characteristic for all of the uses in 5G wireless networks is the ubiquity and the almost permanent connection to the mobile network to get access to external applications. This really imposes a challenge in the signaling procedures provided to get track of the user and to guarantee session continuity. The mobility management mechanisms will play a central role in the 5G networks because of the always-on connectivity demand. This article presents a software defined approach to mobility management procedures addressing the present challenges and proposing some future directions for a more efficient service provision and a better usage of the network resources. The feasibility of such a Software-Defined Mobility Management architecture is assessed in a specific test-bed.