Valerio Frascolla

Performance analysis of LTE protocol processing on an ARM based mobile platform

In this paper we present detailed profiling results and identify the time critical algorithms of the Long Term Evolution (LTE) layer 2 (L2) protocol processing on an ARM based mobile hardware platform. Furthermore, we investigate the applicability of a single ARM processor combined with a traditional hardware acceleration concept for the significantly increased computational demands in LTE and future mobile devices. A virtual prototyping approach is adopted in order to simulate a state-of-the-art mobile phone platform which is based on an ARM1176 core. Moreover a physical layer and base station emulator is implemented that allows for protocol investigations on transport block level at different transmission conditions. By simulating LTE data rates of 100 Mbit/s and beyond, we measure the execution times in a protocol stack model which is compliant to 3GPP Rel.8 specifications and comprises the most processing intensive downlink (DL) part of the LTE L2 data plane. We show that the computing power of a single embedded processor at reasonable clock frequencies is not enough to cope with the L2 requirements of next generation mobile devices. Thereby, Robust Header Compression (ROHC) processing is identified as the major time critical software algorithm, demanding half of the entire L2 DL execution time. Finally, we illustrate that a conventional hardware acceleration approach for the encryption algorithms fails to offer the performance required by LTE and future mobile phones.

Enabling wireless backhauling for next generation mmWave networks

This paper presents some key findings w.r.t. the Radio Resource Management (RRM) in wireless Backhaul (BH) of mmWave networks. First, the envisioned design of mmWave backhaul architecture is outlined highlighting the most important newly needed functional blocks and in what they differ from a non-mmWave architectures. Next, the challenges and functionality of RRM techniques are discussed, focusing on Routing and Link scheduling algorithms in such BH architecture. Furthermore different possible interactions between RRM functions are explored. Finally, preliminary analytical and experimental study on the performance of different link scheduling and routing functions for mmWave backhauling are provided, highlighting in particular the impact of traffic load and dynamic route selection on BH End to End delay.

Energy-efficient interference management in LTE-D2D communication

This paper focuses on one of the key enabling technology that will compose future 5G network, the Direct-LTE communication underlying a cellular infrastructure, also commonly known as Device-to-Device (D2D). Energy efficiency algorithms are proposed for the communication between D2D users and cellular users (CUs) and, following the Lagrangian duality theory, an optimal power and rate control solution is given for D2D users, while satisfying the interference limits related to CUs. Finally, the new algorithm is used to achieve proportional fairness between D2D users and CUs and to show with numerical results that the interference to CUs can be limited to always be under a predefined threshold.

Licensed shared access — State-of-the-art and current challenges

In the context of a wireless communication infrastructure, the Licensed Shared Access (LSA) concept is currently being developed by CEPT regulation and ETSI standardization bodies, with the aim of enabling cellular operators to have access to further spectral resources on a licensed shared basis. Even though spectrum owners, also known as Incumbents, will cooperate with cellular operators in the framework of a Sharing Agreement that is typically set-up for a long-term basis, the LSA concept will in addition, under specific conditions, give Incumbents the opportunity to reclaim spectrum on a per-need basis. Obviously, this new concept for managing spectrum introduces a number of novel challenges, such as vacate in a coordinated manner the LSA bands in case of a corresponding request being triggered by Incumbents, coordinate the LSA spectrum when it is used in proximity to neighbouring countries and/or regulation domains, establish protection zones in which maximum interference levels are guaranteed to Incumbents, etc. This paper gives an overview on the LSA state-of-the-art and elaborates the key challenges to be addressed in the future design of LSA systems.

Power analysis and optimization of the ZUC stream cipher for LTE-Advanced mobile terminals

In this paper we devise and compare several hardware implementations of the confidentiality algorithm that is based on the ZUC stream cipher. First we design and analyze a reference architecture, which reflects a basic implementation of the algorithm, with respect to power and area consumption in order to identify designs bottlenecks. Then different architectures for the most power demanding operations are explored to reduce the power consumption at the register transfer level. These architectures are evaluated at various timing constraints to account for data rates from LTE up to LTE-Advanced. The hardware analysis is done using Faradays 90 nm standard cell library. Our results show that 19% of power savings with 2% of area reduction can be achieved by using a cryptographic substitution box with one-hot encoding. When combining this with parallel LFSR architectures, power savings can be raised up to 37%, but with an area overhead of 10%.

Enhanced C-RAN Using D2D Network

With the surge in smartphone sensing, wireless networking, and mobile social networking techniques, mobile crowdsensing (MCS) has become a promising paradigm for 5G networks. An MCS systems service quality heavily depends on the platform, which brings the users under a common cloud with very low delay. Therefore, MCS needs a new platform that brings the best not only from the users perspective, but also from the operators perspective. In this article, we propose a novel architecture for MCS by combining two technologies, those being C-RAN and D2D. C-RAN is a promising enabling technology that can at the same time cope with the ever increasing mobile traffic demand and reduce the surging costs experienced by service operators. In spite of the many advantages offered by C-RAN, one of the main concerns for operators is its associated fronthaul delay. To handle such delay, we come across this D2D solution in C-RAN networks. D2D is adopted as an effective candidate for very low delay between links and has already provided evidence of its potential for novel business opportunities. This article shows, together with standardization aspects, how combining C-RAN and D2D technologies can help to solve the delay issue and fulfill most of the targets specified for 5G networks in terms of delay, capacity, energy efficiency, mobility, and cost.

Joint Uplink and Downlink Performance Profiling of LTE Protocol Processing on a Mobile Platform

This article provides a detailed profiling of the layer 2 L2 protocol processing for 3G successor Long Term Evolution LTE. For this purpose, the most processing intensive part of the LTE L2 data plane is executed on top of a virtual ARM based mobile phone platform. The authors measure the execution times as well as the maximum data rates at different system setups. The profiling is done for uplink UL and downlink DL directions separately as well as in a joint UL and DL scenario. As a result, the authors identify time critical algorithms in the protocol stack and check to what extent state-of-the-art hardware platforms with a single-core processor and traditional hardware acceleration concepts are still applicable for protocol processing in LTE and beyond LTE mobile devices.

Dynamic Licensed Shared Access - A New Architecture and Spectrum Allocation Techniques

This paper proposes a new system architecture for Licensed Shared Access (LSA) wireless networks, as well as novel band management techniques for fair and ranking-based spectrum allocation. The proposed architecture builds upon recently standardized and regulatory-accepted LSA systems and stems from the work done in the EU-funded project ADEL. Two new resource allocation algorithms are introduced and their behaviour is validated via system-level simulations.

5G CHAMPION - Rolling out 5G in 2018

The 5G CHAMPION Consortium will provide the first fully integrated and operational 5G prototype in 2018 - this effort is a major leap ahead compared to existing punctual technology trials, such as, e.g., Proof-of-Concept platforms focusing on mmWave communication in specific bands, etc. This paper describes the overall set-up including a synergetic combination of technologies such as beamforming based mmWave & Satellite service provisioning, virtualized infrastructure, software reconfiguration across the entire stack, accurate positioning and high-speed solutions. The key enablers are described in detail and related efforts in standards and regulation organizations are discussed.

Dynamic LSA for 5G networks the ADEL perspective

Exploiting additional radio spectrum is key to respond to the unprecedented capacity demands of mobile broadband communication systems in recent years. In fact, most of the frequency bands suitable for mobile communications are already in use by other radio services, and spectrum refarming is usually not possible or constitutes a highly time-consuming procedure. At the same time, several field measurement campaigns have shown that the occupied spectrum below 6GHz is severely underutilized, i.e. there exist “spectrum holes” in the time, frequency, and space dimensions, pointing to the possibility of using spectrum sharing as a mean to better exploit additional spectral resources. Licensed shared access (LSA) is a recent spectrum licensing paradigm that allows licensees to share the licensed spectrum of incumbents without causing harmful interference and ensuring a certain quality-of-service (QoS) for both types of players. The EU-funded project ADEL aims to enhance the current LSA paradigm by introducing 1) dynamic radio resource management (RRM), 2) sensing reasoning, based on database-assisted collaborative sensor networking, and 3) an extension to the LSA architecture that allows a more effective RRM, increasing QoS satisfaction and policy enforcement for all players, finally leading to an overall improved spectrum utilization. The key features of ADELs enhanced LSA paradigm are outlined throughout the remainder of this paper.