Peter Öhlén

Rethinking Optical Transport to Pave the Way for 5G and the Networked Society

The fifth generation of mobile networks (5G) is the next major phase of mobile telecommunications, which will provide the foundation for the Networked Society. To support 5G, transport will need to cater for a wide range of service requirements. It will need to support emerging 5G radio systems in terms of higher capacity and increasing number of cell sites. It must also cater for increasing need for radio interference coordination between sites as well as cost effective radio access network deployment models, and provide a flexible platform for sharing of resources where different actors through transport application programming interfaces have access to network resources and diverse transport services. In this paper, we summarize the key defining factors for 5G transport and outline a concept for programmable transport based on WDM and exploiting emerging optical devices enabled by integrated photonics.

GigaWaM—Next-Generation WDM-PON Enabling Gigabit Per-User Data Bandwidth

The “Gigabit access passive optical network using wavelength division multiplexing” project aims to implement 64-Gb/s data transmission over 20-km single-mode fiber. Per-user symmetric data rates of 1-Gb/s will be achieved using wavelength division multiplexing passive optical network (WDM-PON) architecture with a 1:64 user split per PON segment. Enabling technologies being developed within the scope of the project include tunable transceivers and athermal 50-GHz array waveguide grating multiplexer devices. The future-proof WDM architecture will enable convergence triple-play (telephony, TV, and broadband internet) service over existing optical infrastructure, and also facilitate cost-effective dense wavelength division multiplexing for metro aggregation and mobile backhaul networks.

Data Plane and Control Architectures for 5G Transport Networks

Next generation 5G mobile system will support the vision of connecting all devices that benefit from a connection, and support a wide range of services. Consequently, 5G transport networks need to provide the required capacity, latency, and flexibility in order to integrate the different technology domains of radio, transport, and cloud. This paper outlines the main challenges, which the 5G transport networks are facing and discusses in more detail data plane, control architectures, and the tradeoff between different network abstraction models.

Building a cloud on earth

As cloud computing technologies finalize their transformation into the standard technologies for businesses of all sizes, they face more scrutiny than ever. Clients are expecting the benefits of turning infrastructure, platform and network into services payable per use without tolerating any service hiccups caused by performance bottlenecks or overprovision. This puts cloud providers under pressure to deliver data center management solutions and deployment plans in minimal time and with failure allowance close to none. Any comprehensive solution evaluation could gain much from the use of cloud simulators. Cloud simulators have the advantage of practicality over both mathematical proofs and real testbeds. They support any amount of heterogeneous use cases demanded by the cloud provider. Despite being a relatively new concept, multiple cloud simulators were developed. However, they are still in the phase of adapting to the scenarios, objectives and characteristics of the cloud. This paper examines a selected set of the current cloud simulators in terms of vision, features, and architecture. Strong points and limitations are discussed. Moreover, this paper presents a framework for cloud simulator design that can serve as an elaborate design checklist. A discussion of the open research challenges concludes the paper.

Software-defined networking in a multi-purpose DWDM-centric metro/aggregation network

A DWDM-centric solution is a promising approach to build a multiservice metro/aggregation network that meets the future requirements on capacity, cost, and energy-efficiency for both residential, business and mobile backhaul/fronthaul transport. We propose to use SDN to provide a suitable control mechanism of the optical and packet layers in the network. We also introduce a discovery unit, which detects newly connected DWDM clients and sets up the corresponding optical service. This is demonstrated for the case of a converged fixed and mobile infrastructure. We then describe how this network and control architecture can be used to provide services to different client network applications, where the details of the physical infrastructure are hidden through network virtualization.

Orchestration of RAN and Transport Networks for 5G: An SDN Approach

The fifth generation of mobile networks is planned to be commercially available in a few years. The scope of 5G goes beyond introducing new radio interfaces, and will include new services like low-latency industrial applications, as well as new deployment models such as cooperative cells and densification through small cells. An efficient realization of these new features greatly benefit from tight coordination among radio and transport network resources, something that is missing in current networks. In this article, we first present an overview of the benefits and technical requirements of resource coordination across radio and transport networks in the context of 5G. Then, we discuss how SDN principles can bring programmability to both the transport and radio domains, which in turn enables the design of a hierarchical, modular, and programmable control and orchestration plane across the domains. Finally, we introduce two use cases of SDN-based transport and RAN orchestration, and present an experimental implementation of them in a testbed in our lab, which confirms the feasibility and benefits of the proposed orchestration.

Multi-Domain Orchestration across RAN and Transport for 5G

End-to-End programmability across radio, transport and compute resources is a key enabler for the fifth generation of mobile communication networks (5G). In our work we look into how SDN can realize the required cross-domain programmability, as well as slicing of resources towards multiple clients. We present design and implementation of a hierarchical, modular and programmable orchestration architecture across radio access networks and transport networks. We demonstrate how the developed multi-domain orchestration improves the service creation as well as resource utilization across the domains using real-time monitoring.

Demonstration of dynamic resource sharing benefits in an optical C-RAN

The next generation of mobile communication (i.e., 5G) will bring new challenges for the transport infrastructure, e.g., in terms of flexibility and capacity. The joint orchestration of radio and transport resources can help to address some of these challenges. One example is the possibility of reconfiguring the use of the transport network resources according to the spatial and temporal variations of the wireless traffic patterns. Using the concept of dynamic resource sharing, a limited pool of transport resources can be shared among a large number of radio base stations (RBSs), thus reducing considerably the overall deployment cost of the transport infrastructure. This paper proposes a provisioning strategy for a centralized radio access network with an optical transport whose wavelength resources can be dynamically shared among multiple RBSs. The proposed strategy utilizes a hierarchical software-defined networking control plane where a global orchestrator optimizes the usage of radio and transport resources. The benefits of the proposed strategy are assessed both by simulation and by experiment via an optical data plane emulator developed for this purpose. It is shown that the dynamic resource sharing can save up to 31.4% of transport resources compared to a conventional dimensioning approach, i.e., based on the overprovi`sioning of wavelength resources.

Upstream FEC performance in combination with burst mode receivers for next generation 10 Gbit/s PON

FEC gain in DC-coupled burst mode receivers is limited because of a variance in BER between bursts. This BER variance is characterized in an XG-PON1 upstream prototype. It is shown that basic BER tests overestimate the FEC gain.

The role of DWDM for 5G transport

The 5th generation of mobile networks (5G) is the next major phase of mobile telecommunications. With the advent of Silicon Photonics, DWDM can provide the basis for 5G transport satisfying requirements on performance, low cost and flexibility.