This section will contain the Flex5Gware project plan.
The Flex5Gware consortium is formed by 17 European partners belonging to 9 different Member States. Of these 17 partners, 5 are large industries, 3 are SMEs, 6 are research institutions, and 3 are universities. The geographical distribution of the partners is shown in the figure below:
The complete list of Flex5Gware partners is:
The overall objective of Flex5Gware is to deliver highly reconfigurable HW platforms together with HW-agnostic SW platforms targeting both network elements and devices taking into account increased capacity, reduced energy footprint, as well as scalability and modularity, to enable a smooth transition from 4G mobile wireless systems to 5G.
In order to fulfil the above overall objective, Flex5Gware will address the following specific objectives:
- Increasing the HW versatility and reconfigurability
In order to deal with the increasing traffic demand and, especially, with the anticipated heterogeneity of traffic in 5G, future 5G networks will require an increase of HW versatility and reconfigurability and the ability to operate at millimetre wave (mmWave) bands. To that respect, scalable, flexible and integrated (multi-)RAT networks are required. Although the SW defined radio (SDR) paradigm and, in general, the digitally assisted analogue front-end have contributed in this direction, further improvements cannot be made without novel enhancements on the HW itself. Versatile, reconfigurable and flexible HW components and platforms, which are able to cope with all the functionalities needed and invoked by the SW domain, are thus required for delivering innovative cost effective and efficient network elements and devices and achieving a successful commercial exploitation and deployment of 5G.
More specifically, for systems working below 6 GHz, Flex5Gware will deliver new approaches on versatile multi-band transceiver implementations, together with advanced semiconductor technologies and new HW architectures. This will result in RF basestation key elements (e.g., filters, power amplifiers (PA), low-noise amplifiers (LNA), and mixers) enabling the operation at overall bandwidths (BW) of 1 GHz (gain factor of 10 with respect to current technologies) and with massive MIMO support.
In the frequency domain above 6 GHz and including mmWave, Flex5Gware will provide RF front-ends (e.g., PAs, low profile antennas) and a low-noise on-chip local oscillator (LO), which will enable the seamless operation of 5G systems at those frequency bands (the phase noise will be improved by a factor of 10 with respect to current standards like WirelessHD and 802.11ad). Furthermore, regarding mixed-signal technologies, new fibre-to-the antenna transceiver subsystem technology for frequencies up to 10 GHz will be developed, which will increase the versatility of the basestation deployment. Last but not least, Flex5Gware will deal with digital signal processing architectures for flexible and modular operation based on HW/SW partitioning techniques of transceiver functions.
All the above contributions will lead to increased HW versatility not only in current 4G frequency bands, but, more importantly, in foreseen 5G frequency bands (including mmWave and unlicensed spectrum) enabling a fast and strong market penetration of 5G systems.
- Designing and developing HW-agnostic, flexible and cost-effective SW platforms
The control and the management of the heterogeneous HW infrastructure and devices expected in 5G in a way that guarantees an effective (rapid, easy and dependable) service development and deployment, as well as the adaptability to very demanding and changing contexts of operation, guaranteeing Quality of Service (QoS) and Quality of Experience (QoE) are of utmost importance. Thus, scalable, flexible and multi-RAT networks, programmability and dynamic reconfiguration through interface abstractions/uniform Application Programming Interfaces (API) are required, enabling thus a HW-agnostic operation.
Flex5Gware will specify the required HW abstractions and SW building blocks in a generic, HW-agnostic and programmable architecture, so as to enable the orchestration of services and the development of new ones, supporting, among others, real-time re-configuration of the PHY parameters of RATs, MAC protocol extensions and distributed optimization schemes including the orchestration of communication services accross multiple nodes. Moreover, HW abstractions also enable the simplification of the definition of protocol logic and control policies decoupling them from the specific technologies / manufacturer designs.
More specifically, at the intra-node level, the project will define interface abstractions enhanced by energy awareness offered to the upper layers (e.g., control and management), as well as a generic architecture supporting emerging 5G PHY capabilities (e.g., multiple antennas, dynamic bandwidth, sensing/monitoring operations) and parallel execution of MAC protocols. At the inter-node level, Flex5Gware will design and implement the required control and management plane tools including context extraction and awareness, in order to enable the real-time technology-agnostic deployment, composition and reconfiguration of network protocol stacks and SW modules available across multiple nodes through node sub-ms level synchronization schemes. Intelligent, node-level and network-wide decisions on radio and network operation, through a clean separation between data plane, control plane and management plane, will be provided in alignment with the software defined networks (SDN) paradigm and the reconfiguration impact will be investigated through a feedback loop between network and terminal (or device).
- Increasing the overall achievable capacity provided by 5G communication platforms
The anticipated 1000 fold increase in mobile data traffic over the next decade, the massive amount of new applications (and associated diverse requirements) that networks will have to support, from internet of things (IoT) to Ultra High Definition-TV (UHDTV), as well as the effective service development and deployment tailored to users’ preferences (enhanced QoE), impose the increase of the overall achievable capacity provided by 5G communication platforms.
Flex5Gware will provide a holistic approach for contributing to this specific objective, exploiting - as anticipated - general purpose, programmable and highly reconfigurable HW platforms able to support HW-agnostic SW platforms targeting both network elements and devices. More specifically, in the analogue domain, novel HW solutions designed to support the additional bands in the mmWave range, will enable the provision of higher mobile data volume per geographical area and higher typical user data rate. In terms of mixed-signal technologies, the following Flex5Gware contributions will increase the achievable capacity: full duplex operation (increase of a factor of 2 in the achievable capacity), optical RF to the antenna (that could significantly ease the deployment of interference cancellation schemes such as Coordinated Multi-Point (CoMP) transmission) and high speed converters with support for massive MIMO. In the digital domain, Flex5Gware will provide capacity and user data rate enhancements thanks to the HW support of filterbank multicarrier (FBMC) transceivers (capacity gain by a factor of 2 for signaling and 10 % increase for data traffic) and faster LDPC decoding (throughput increase by a factor of 5 for mmWave applications). Last, but not least, in the SW domain, the control and management plane tools including context extraction and awareness, together with intelligent, node-level and network-wide decisions on radio and network operation based on SDN and virtualization, can help to increase the overall achievable capacity.
- Decreasing the overall energy consumed by 5G communication platforms
Communication systems and, more specifically, Radio Access Networks (RAN) are consuming a significant share of the overall energy consumption. The situation is going to worsen because of the anticipated mobile data traffic increase. The impact will be high in terms of both the environment (due to CO2 emissions) and operational expenditures (OPEX) as reflected in the cost per delivered bit. To that respect, there is a strong need to increase energy efficiency of communication networks. In Flex5Gware, this will be addressed by a holistic design of network components and operation and its deployment strategies.
In terms of mixed-signal technologies, Flex5Gware will demonstrate Peak to Average Power Ratio (PAPR) reduction, predistortion and envelope tracking techniques that can improve the energy efficiency at the PA of basestations by up to 50 % (and up to 30 % at the device level). In addition, power consumption reduction techniques based on joint analogue and digital processing will be provided with efficiency gains of up to a factor of 10 (for specific processing blocks).
In the digital domain, Flex5Gware will study the following HW architectures aimed at decreasing the overall energy consumption: efficient MIMO decoders for user devices (with 20 % energy effiency gains), high speed LDPC implementations (energy savings by a factor of 2), and FBMC transceivers (energy efficiency gain by a factor of 2).
In the SW domain, Flex5Gware will provide novel interfaces informing the upper layers about the energy/performance trade-offs so as to choose or devise the best scheme. The goals are energy efficiency improvements of 15 % (total energy consumed). Finally, Flex5Gware will provide control and management plane tools and flexible SW solutions for centralized RAN environments that offer energy efficiency through coordination and dynamic reconfiguration, which are clear enablers towards an energy efficient network operation and service deployment (with goals of energy savings about 25 – 30 % of the energy consumed by remote radio heads (RRH) and overall energy savings ranging from 40 to 60 % thanks to the activation/deactivation of RRH.
- Identifying and prototyping key HW and SW building blocks and providing a proof of concept for all developments in Flex5Gware
Performance evaluation activities are essential together with research and development for providing efficient HW and SW solutions and associated platforms for 5G network elements and devices. A fair evaluation can allow the appropriate final system definition and optimisation by means of prototypes, demonstrations and early trials.
Flex5Gware will evaluate and demonstrate the developed 5G technologies and services, in terms of proofs-of-concept (PoC), both in standalone (single technology) and in integrated (multi-technology) ways. As an important added value, Flex5Gware partner TI will host the Flex5Gware demonstration activities, thanks to the presence of TILAB facilities and TI Test Plant, as already done in the past for the EARTH project demonstrator.
The overall targeted concept in Flex5Gware is that of performing research on and demonstrating key building blocks to enable reconfigurable HW platforms and HW-agnostic SW platforms taking into account increased capacity, reduced energy footprint, as well as scalability and modularity.
The development of this proposed concept entails many system design challenges that will be solved through disruptive technologies. Each technology proposed in Flex5Gware is contributing, at least, to one of the following goals with respect to 5G communication platforms:
- To improve the energy and spectrum efficiency.
- To improve the modularity and flexibility (which implies increased reconfigurability and scalability).
The Flex5Gware consortium has identified four groups of technologies that are necessary to reach these goals (each one of these groups will correspond to a different work package, as detailed in Section 3):
- RF front-ends and antennas
a. RF subsystems for multiband and reconfigurable operation and maximized total bandwidth (PAs, LNAs, frequency converters, filters, mixers) operating at bands below 6 GHz. Advanced semiconductor materials GaN-on-Si and GaN-on-SiC
b. Active low-cost antennas (compact, conformable both for NE and UE) operating below 6 GHz. Based on SIW technology
c. Chip frequency generation in 28 nm CMOS for mmWave bands
d. Joint antenna-power amplifier for mmWave
e. RF impairment analysis for mmWave
- Mixed-signal technologies
a. Broadband A/D and D/A converters for multiple band operation and large bandwidth
b. Power consumption reduction and linearization techniques based on joint analogue and digital processing (e.g., envelope tracking, predistortion)
c. High-bandwidth antenna links based on new fibre-to-the antenna transceiver subsystem technology
d. Full duplex operation
- Digital front-end and HW/SW function split
a. Digital HW architectures for the processing of new 5G waveforms.
b. Advanced receiver architectures (encompassing flexible and efficient MIMO decoders for user equipments and multi-objective optimized FEC decoders).
c. Flexible HW/SW partitioning and other architectures for modularity
d. Abstraction of transceiver HW to be supported in 5G programmable terminals (this includes sensor and location awareness integration in the HW)
- SW modules and functions
a. Reconfigurable, reprogrammable SW architecture with appropriate interface abstractions for flexible control and management mechanisms across heterogeneous wireless devices and access networks.
b. Feedback-loop analysis/muti-node coordination for “over the air” real-time operation and update of nodes, targeting reliability, delay, and “safe fail” operation.
c. New sets of SW tools consisting of libraries and modules in order to support new SW functions, e.g. virtualized base band units (BBU) and reconfigurable layers, offering greater degree of flexibility in terms of configurability.
d. Flexible, effective and efficient resource allocation mechanisms in a centralized RAN environment, that allow an operator to enhance performance and save energy.
Some of these technologies will be directly demonstrated as stand-alone PoCs, while some others will be combined/integrated to create integrated PoCs. The following figure provides a graphical (and intuitive) representation of the Flex5Gware concept.