Mauro Boldi

The road to IMT-advanced communication systems: State-of-the- art and innovation areas addressed by the WINNER + project

Phases I and II of the WINNER project contributed to the development, integration, and assessment of new mobile network techniques from 2004 to 2007. Some of these techniques are now in the 3GPP LTE and IEEE 802.16 (WiMAX) standards, while others are under consideration for LTE-Advanced and 802.16m. The WINNER+ project continues this forwardlooking work for IMT-advanced technologies and their evolution, with a particular focus on 3GPP LTE-advanced. This article provides an overview of the WINNER system concept and several of its key innovative components.

5G Radio Access Network Architecture: Design Guidelines and Key Considerations

While there is clarity on the wide range of applications that are to be supported by 5G cellular communications, and standardization of 5G has now started in 3GPP, there is no conclusion yet on the detailed design of the overall 5G RAN. This article provides a comprehensive overview of the 5G RAN design guidelines, key design considerations, and functional innovations as identified and developed by key players in the field.1 It depicts the air interface landscape that is envisioned for 5G, and elaborates on how this will likely be harmonized and integrated into an overall 5G RAN, in the form of concrete control and user plane design considerations and architectural enablers for network slicing, supporting independent business-driven logical networks on a common infrastructure. The article also explains key functional design considerations for the 5G RAN, highlighting the difference to legacy systems such as LTE-A and the implications of the overall RAN design.

Heterogeneous Backhaul for Cloud-Based Mobile Networks

To meet the increasing capacity demands of future mobile networks, dense deployment of radio access nodes in combination with partly centralized processing by means of a cloud-based architecture is a promising option. In such an architecture, the design and optimization of the backhaul plays a crucial role. In this paper, we review different backhaul technologies available and discuss their characteristics for use in cloud-based networks. We point out how a heterogeneous backhaul network and a flexible centralization enables the proposed architecture and give an outlook on how a joint design of access and backhaul can help in meeting the increased demands.

Energy efficient transmission techniques for LTE

The goal of the European ICT Project EARTH is to enhance energy efficiency of current LTE cellular networks by 50 percent, enabling operators to provide more extensive coverage, namely to less densely populated areas, while ensuring high levels of efficiency, hence, reducing the carbon footprint. In order to achieve this objective, different strategies, at different levels, are being addressed. Energy efficient transmission techniques for LTE, proposed within the framework of EARTH, are addressed and discussed, with an emphasis on beamforming and MIMO. It is concluded that the strategic objective of EARTH is achievable. Combined MIMO mode selection, resource allocation, scheduling and precoding strategies will allow an energy consumption reduction of more than 50 percent in macro-cells. A reduction in MIMO power consumption of 91.7 percent (factor of 12) can be achieved in pico-cells.

Beamforming Strategies for Energy Efficient Transmission in LTE

The actual internet traffic growth is challenging the sustainability of mobile networks, therefore, the energy efficiency of the mobile communication infrastructure becomes a topic of particular relevance. Decreasing CO2 emissions and energy demands while expanding the mobile infrastructure to satisfy traffic demands is essential. In this paper the energy efficient use of beamforming techniques and active antennas, in which an advanced antenna is utilized to direct the transmitted signal in a narrow direction, is evaluated. Slow beamforming based on reconfigurable antennas, exploits medium/long term variations of traffic in order to save energy. Fast beamforming, on the contrary, is immediately following the traffic distribution and can even allow saving more energy. From simulations it is observed that, when compared to existing state-of-art bases base stations, in a dense urban environment reconfigurable beamforming allows a maximum gain of about 8%. Adaptive beamforming, allows an additional consumed power reduction of up to 40%. Hence, the overall power consumption reduction that can be achieved by combining these techniques can be as high as 50%.

How does passive optical network tackle radio access network evolution

This paper describes full service access network operator group perspectives on the feasibility of optical access networks to carry radio access network traffic for the existing and future mobile generations. The paper discusses topics related to the evolution of radio access interfaces, such as backhaul, midhaul, and fronthaul, their transmission through optical distribution networks, and passive optical network technology feasibility based on both time and wavelength division multiplexing and multiple accesses. Technology extensions are also discussed to provide guidance for future research.

The 5G architecture

Introduction The design of a mobile network architecture aims at defining network elements (e.g. Base Stations [BSs], switches, routers, user devices) and their interaction in order to ensure a consistent system operation. This chapter discusses basic considerations and provides an overview of current research activities. Network architecture can be considered from different angles that are needed in order to fulfill objectives like integration of technical components into an overall system, proper interworking of multi-vendor equipment and efficient design of physical networks from cost and performance point of view. As 5G systems have to integrate a plethora of partly contradicting requirements, enablers such as Network Function Virtualization (NFV) and Software Defined Networking (SDN) are to be applied in order to provide the needed flexibility of future networks, especially for the core network. Applying these tools may require a rethinking of some traditional aspects of network architecture design. This chapter will give the reader an impression of the most important topics influencing architecture design of future networks. NFV and SDN Todays operator networks include a large and increasing variety of hardware appliances. Launching new services often requires integration of complex hardware dedicated to the service including costly procedure design and is associated with lengthy time to market. On the other hand, hardware life cycles become shorter as technology and service innovation accelerates. At the end of 2012, network operators have started an initiative on NFV [1]. NFV aims at consolidating the variety of network equipment onto industry-standard high-volume servers. These servers can be located at the different network nodes as well as end-user premises. In this context, NFV relies upon but differs from traditional server virtualization. Unlike server virtualization, Virtualized Network Functions (VNF) may consist of one or more virtual machines running different software and processes in order to replace custom hardware appliances (Figure 3.1). As a rule, multiple VNFs are to be used in sequence in order to provide meaningful services to the customer. NFV requires an orchestration framework that enables proper instantiation, monitoring and operation of VNFs and Network Functions (NFs) (e.g. modulation, coding, multiple access, ciphering, etc.).

5G Visualization: The METIS-II Project Approach

One of the main objectives of the METIS-II project was to enable 5G concepts to reach and convince a wide audience from technology experts to decision makers from non-ICT industries. To achieve this objective, it was necessary to provide easy-to-understand and insightful visualization of 5G. This paper presents the visualization platform developed in the METIS-II project as a joint work of researchers and artists, which is a 3D visualization tool that allows viewers to interact with 5G-enabled scenarios, while permitting simulation driven data to be intuitively evaluated. The platform is a game-based customizable tool that allows a rapid integration of new concepts, allows real-time interaction with remote 5G simulators, and provides a virtual reality-based immersive user experience. As a result, the METIS-II visualization platform has successfully contributed to the dissemination of 5G in different fora and its use will be continued after METIS-II.