MiWEBA, a pioneer project on 5G mm-wave overlay networks

Presenters: Thomas Haustein, Kei Sakaguchi

Abstract: Due to the popularisation of smart phones and tablets in recent years, the traffic of data on conventional networks is predicted to be increased by 1000 times in the next 10 years. To face the severe issue of system capacity shortage due to the increasing data traffic in cellular networks, standardisation on heterogeneous networks with overlay deployment of low-power base stations in the service area of conventional ones is being done by the 3GPP – an international standardisation body of cellular networks. On the other hand, despite ultra-high-speed systems employing mm-wave such as WiGig and 802.11ad have been standardized, they are not connected to the cellular networks, and their applications are still restricted to only performing data transfer between AV equipment or working as a bridge for Internet connection across buildings.
MiWEBA conducts research and development of mm-wave overlay heterogeneous network (HetNet) in which mm-wave ultra-broadband base stations employing recent state-of-art technologies of mm-wave devices are introduced and integrated into conventional cellular networks. Through system design, international standardisation, and validation experiments of the mm-wave overlay HetNet, MiWEBA aims to extend the network capacity by 1000 times to solve the capacity limitation issue at reasonable cost and without loss of convenience to users. The mm-wave overlay HetNet consists of the backhaul/fronthaul connecting mm-wave ultra-broadband base stations with the cellular network, an access link integrating both conventional cellular access link such as LTE and the novel mm-wave link, and a central controller which is able to realise seamless UE handover as well as dynamically control communication resources of low-power base stations.
Int this talk we will give an overview over the first two years and the impressive results that we have gained so far.


Green Spatial Focusing Techniques for MiWEBA scenarios

Presenters: Nicolas Cassiau, Isabelle Siaud

Abstract: Green oriented spatial focusing techniques are key technical challenges for 5G challenges, with the introduction of massive MIMO antennas, advanced spatial processing as well as innovative beamforming techniques. Transmissions in mm-wave band as addressed in the MiWEBA project are particularly adapted to such massive MIMO antenna deployment leading to interference limitation, capacity increase and link budget evolvements. This presentation exposes research topics addressed in the MiWEBA project with optimized Time reversal performance for Wi-Fi Hotspots (IEEE802.11 ac @5GHz and IEEE802.11 ad @60 Ghz) and moving hotspots requiring novel fast beam tracking and beam switching processing. MiWEBA results are exposed upon these 2 technical scenarios for Mobile Access and backhauling.Link budget assesments are exposed to highlight associated radio coverage extensions.


RAN-level Interworking Architecture for 5G Millimeter-wave Heteregeneous Networks

Presenter: Hailan Peng

Abstract: Recently, the millimeter-wave (mm-wave) based HetNet has been explored to provide multi-gigabits-per-second data rates over short distances in the 60 GHz frequency band for 5G wireless networks. WiGig (Wireless Gigabit Alliance) is one of the available radio access technologies using mm-wave. However, the conventional interworking solutions are not sufficient for the implementation of LTE (Long Term Evolution)/WiGig HetNets. Since the coverage area of WiGig is very small due to the high propagation loss of the mm-wave band signal, it is difficult for UEs to perform cell discovery and handover if using conventional LTE/WLAN (wireless local area networks) interworking solutions approved in 3GPP (3rd Generation Partnership Project) Release 12, which cannot support specific techniques of WiGig well, such as beamforming and new media access methods. To solve these problems and find solutions for LTE/WiGig interworking, RAN (radio access network)-level tightly coupled interworking architecture will be a promising solution. Here, as a RAN-level tightly coupled interworking solution, it proposes to design a LTE/WiGig protocol adaptor above the protocol stacks of WiGig to process and transfer control signaling and user data traffic. Based on the C/U (control/user plane) splitting mechanism discussed in 3GPP Rel-12, extended user/control plane architectures for the interworking of LTE and WiGig in mm-wave HetNets are designed. The proposed extended control plane can assist UEs to discover and access mm-wave BSs successfully and support LTE macro cells to jointly control the radio resources of both LTE and WiGig, so as to improve spectrum efficiency. The extended user plane can serve UEs with multi-gigabits data rate by using both LTE U-plane and WiGig U-plane. The effectiveness of the proposal will be shown. Moreover, large data traffic transfer for mm-wave BSs will result in heavy backhaul overhead on LTE core network (CN). The evaluation of the downlink backhaul throughput and energy efficiency of mm-wave HetNets are also with significant importance, which are compared with that of 3.5GHz LTE HetNets.


Green MT Link adaptation techniques for mm-wave MT-HetNets

Presenter: Isabelle Siaud

Abstract: 5G technical requirements within H2020, turned towards capacity increase with constant network power consumption, involve innovative Multi-Techno Heterogeneous Network (MT-HetNet) architectures encompassing advanced link adaptation techniques for air interface switching following green, QoS criteria and radio resource management processing in order to limit multi-user interference and guaranty radio coverage. These research topics are addressed in the MiWEBA project with mm-wave overlay components around the 60 GHz RF band. Wi-Fi based phantom cells integrated in mobile cellular networks as well as mm-wave backhauling transmissions in dense urban areas are evaluated. This presentation exposes novel CQI metrics, their performance and implementation issues for fast link adaptation processing in Wi-Fi Hot spots and MT-HetNets. 2 test cases derived from MiWEBA scenarios are studied, considering single AP and separate APs able to communicate with a user terminal, leading to AP selection. Transmit power gains and radio coverage extensions are given upon MIMO and Time Reversal transmissions. Perspectives conclude this presentation.


Architecture, Algorithm, Protocol for RRM in 5G HetNet

Presenter: Roya Ebrahim Rezagah

Abstract: Future heterogeneous networks (HetNets) are going to consist of cellular macro cell base stations and various types of small cell base stations (SC-BS), each operating in microwave and/or millimeter bands. Efficient radio resource management (RRM) will be a challenge when dealing with various types of base stations with different capabilities and ranges. One of the targets of MiWEBA project is to propose, evaluate and test algorithms and a protocol for RRM in such HetNets. As much as possible, the proposed protocol follows the architecture of control signaling in current 3GPP standard to assure the feasibility of future implementation. However, new requirements of 5G HetNets imposes inevitable amendments to current standardized protocol. Furthermore, the measurements and information collected during RRM are also used to update the traffic map in the macro cell area. Based on this, the proposed protocol is extended to detect and handle long-term network optimization actions, therefore creating a self-organizing-network (SON).


Unified air interface and Multi-Band processing in the METIS project

Presenter: Eeva Lähetkangas

Abstract: 5G radio access technology for mobile broadband targeted to be available beyond 2020 is expected to fulfill the demand of exponentially increasing data traffic and to allow people and machines to enjoy gigabit data rates with virtually zero latency. To realize this vision of ubiquitous mobile broadband, dense deployments with access to very large bandwidths are required. This leads the METIS project to consider a wide range of frequency bands, varying from below 6 GHz up to the millimeter wave (mmW) frequencies. A unified baseband design based on a harmonized PHY layer numerology is proposed to facilitate low-cost implementation of the concept. An Ultra Dense Network optimized TDD frame structure is utilized to enable physical layer flexibility and reduction in latency and to further achieve significant performance improvements, such as reduced battery consumption and improved throughput. Advanced antenna technique with high gain beamforming is utilized to enable transmission at high frequencies. Such system designs in the METIS project are exposed and assessed. Following this concept, Harmonized RF front end schemes allowing fast multi-band processing are presented to facilitateair interface switching between @5GHz IEEE802.11 ac and 60 GHz Very High Data Rate systems encompassing IEEE802.11 ad and Ecma-368 standards operating at 60 GHz. . Link budget are presented to make a Proof of Concept of such Multi-band architectures.


Cognitive Radio For Green Radio Communications: The Cognitive Green Radio Concept

Presenter: Jacques Palicot

Abstract: Cognitive Green Radio (CGR) integrates sustainable development (SD) for energy efficiency and takes it as an additional crucial constraint in the decision making process of the holistic cognitive cycle. The Brundtland Commission of the United Nations (UN) defined SD as the development that "meets the needs of the present without compromising the ability of future generations to meet their own needs. Green Radio is closely related to reducing energy consumption and also covers more widespread sense, such as spectrum usage optimization (Green spectrum), to decrease spectrum pollution, to reduce electromagnetic radiation/interference levels leading to harmonized coexistence of multiple wireless communications systems as well as a reduced human exposure to harmful radiations, to recycle and reuse ICT equipment. The radio spectrum is considered as a natural and public resource, to be shared world-widely and economized efficiently. Therefore, in our point of view, what is classically meant for Green Communications should be fundamentally extended and even reformed. We propose an intelligent solution based on CR approach, keeping in mind the following key objective: "We would like to decrease the electromagnetic level by sending the right signal in the right direction with the right power, only when it is necessary, for achieving the same QoS by taking advantage of advanced intelligence". This is the essential concept of Useful Radio Waves exposed in this presentation.


ETSI Radio Reconfigurable Systems

Presenter: Ingolf Karls

Abstract: This presentation gives an overview on the ETSI RRS (Reconfigurable Radio Systems) Technical Committee (TC), related standards activities and their relevance to the future 5G framework. In particular, most recent progress on Spectrum Sharing technology is discussed (Licensed Shared Access (LSA) for the European 2.3 GHz context and Spectrum Access System (SAS) for the US 3.5 GHz case), activities on the assembly of Radio Environment Maps (REM), TV White Space and related database solutions as well as progress in the field of software reconfiguration for Mobile Devices. In the latter context, new architectural approaches and related interfaces are detailed and moreover regulation challenges are addressed with a focus on how to define suitable Declaration of Conformity mechanisms. Those solutions are expected to fit into a 5G spectrum toolbox which will help to improve the overall system capacity and efficiency towards to overall objective of achieving a factor 1000x improvement over 4G.


Energy Efficient Massive MIMO in 5GrEEn

Presenter: Cicek Cavdar

Abstract: This study takes into consideration the non-ideal efficiency characteristics of realistic power amplifiers (PAs) along with the daily traffic profile in order to investigate the impact of PA dimensioning on the energy efficiency (EE) of load adaptive massive MIMO system. A multicellular system has been considered where each base station (BS) is equipped with large number of antennas to serve many single antenna users. For a given number of users in a cell, the optimum number of active antennas maximizing EE has been derived where total BS downlink power is assumed to be fixed. Under the same assumption, the PAs have been dimensioned in a way that maximizes network EE not only for a single time snapshot but over twenty four hours of operation while considering dynamic efficiency characteristics of the PAs. In order to incorporate this daily load profile, each BS has been modelled as an M/G/m/m state dependent queue under the assumption that the network is dimensioned to serve a maximum number of users at a time corresponding to 100% cell traffic load. This load adaptive system along with the optimized PA dimensioning achives 30% higher energy efficiency compared to a base system where the BSs always run with a fixed number of active antennas which are most energy efficient while serving 100% traffic load.


mmWave Channel modelling and highly-directional steerable antenna development

Presenter: Alexander Maltsev, Richard Weiler

Abstract: The MiWEBA project addresses in the work package WP5, mm-wave propagation characteristics and models for outdoor channel scenarios. Experimental measurement data in street canyons scenario with omnidirectional antennas and in campus scenarios with directional antennas have been carried out and analyzed, proving the feasibility of millimeter wave phantom cells. Novel quasi-deterministic (QD) models are developed for millimeter access and backhaul scenarios at 60 GHz. The first QD approach exploits a multi-clustering ray tracing modeling. This model generates quasi-deterministic strong rays (D-rays) and a number of relatively weak random rays (R-rays) or flashing rays (F-rays). Rays are calculated based on the geometry of the deployment and signal power conveyed over each of the rays using theoretical formulas (free space losses reflections, polarization and receiver mobility effects like Doppler shift). The second approach based on the multi-rate filter theory generates the equivalent filter of the measured propagation channel adapted to the waveform of the PHY system. The ray tracing QD model is developped and validated with experimental measurements.