• Tuesday, 13 June, 11:30-13:00, Radisson Blu Kiikeli
• Session Chair: Markus Dominik Mueck (Intel Deutschland GmbH, Germany)

11:30 5G Trial System Coverage Evaluation Utilizing Multi-Point Transmission in 15 GHz Frequency Band

Kimmo Hiltunen (Ericsson Research, Oy L M Ericsson Ab, Finland); Arne Simonsson and Peter Ökvist (Ericsson Research, Sweden); Björn Halvarsson (Ericsson, Sweden)

The downlink coverage of a 5G trial system operating within the 15 GHz frequency band is evaluated in this paper with the help of drive test measurements. Key 5G features, such as beamforming, beam tracking and multi-point transmission have been utilized during the measurements. The results indicate that multi-point transmission provides a clear improvement to the downlink coverage. Received signal strength is improved due to the macro diversity offered by the utilization of multiple transmission points. Furthermore, distributed MIMO, i.e. the possibility for the user equipment (UE) to simultaneously receive independent data streams from multiple transmission points, results in large improvements in the average rank values. This is the case in particular for the locations in between the transmission points, where the UE has sufficiently good links towards the serving nodes. Finally, as a result of both the improved signal strength and higher rank values, the average downlink throughput is improved by 33-46% (whole area) or 39-42% (busy square). All in all, the trial system is able to maintain a very high downlink throughput, varying from 4 to 13 Gbps, towards a UE moving within the busy square, which demonstrates the benefit of seamless mobility between the different beams and transmission points.

11:48 On LoRaWAN Scalability: Empirical Evaluation of Susceptibility to Inter-Network Interference

Konstantin Mikhaylov, Juha Petäjäjärvi and Janne Janhunen (University of Oulu, Finland)

Appearing on the stage quite recently, the Low Power Wide Area Networks (LPWANs) are currently getting much of attention. In the current paper we study the susceptibility of one LPWAN technology, namely LoRaWAN, to the inter-network interferences. By the means of excessive empirical measurements employing the certified commercial transceivers, we characterize the effect of modulation coding schemes (known for LoRaWAN as data rates (DRs)) of a transmitter and an interferer on probability of successful packet delivery while operating in EU 868 MHz band. We show that in reality the transmissions with different DRs in the same frequency channel can negatively affect each other and that the high DRs are influenced by interferences more severely than the low ones. Also, we show that the LoRa-modulated DRs are affected by the interferences much less than the FSK-modulated one. Importantly, the presented results provide insight into the network-level operation of the LoRa LPWAN technology in general, and its scalability potential in particular. The results can also be used as a reference for simulations and analyses or for defining the communication parameters for real-life applications.

12:06 An SDR-based Prototype of Spectrally Precoded OFDM

Medhat Mohamad (Luleå Technical University, Sweden); Rickard Nilsson and Jaap van de Beek (Luleå University of Technology, Sweden)

Spectrally precoded OFDM is a recent approach that aims for the suppression of the OOB, as well as the in-band gap, emissions in OFDM systems. Theoretically, the technique shows High suppression of the OOB and the in-band gap emissions. Although, practically hardware impairments may limit the precoder's performance. Yet, this demonstration shows that despite the hardware impairments, implemented spectrally precoded OFDM generates emissions tens of decibels less than that of plain OFDM. Therefore, the demonstration proves that communications links are less vulnerable to interference coming from spectrally precoded OFDM signals than to interference coming from plain OFDM signals.

12:24 Experimental Evaluation of Relative Calibration in a MISO-TDD System

Theoni Magounaki (Orange Labs, France); Florian Kaltenberger (Eurecom, France); Xiwen Jiang (EURECOM, France); Cyril Buey (Orange Labs - La Turbie, France); Philippe Ratajczak (Orange Labs, France); Fabien Ferrero (University Nice Sophia Antipolis, CNRS, LEAT & CREMANT, France)

We study the transmit time reversal beamforming in a 8x1 MISO communication system at 2.68GHz. We consider the downlink time reversal transmission where a base station (BS) communicates with one user. A prototype composed by 8 antennas and designed by Orange labs acts as the base station while the user has a single antenna. The reciprocity property is destroyed by the non-symmetric characteristics of the radio frequency (RF) electronic circuitry. We use relative calibration which is based exclusively on signal processing techniques to solve this issue. Utilizing a controlled test setup based on OpenAirInterface (OAI), the ExpressMIMO2 software defined radio boards, as well as a servo controlled rail, we compare the performance of the different prototypes in terms of the received beamforming Signal to Noise Ratio (SNR). We also evaluate the performance of an antenna selection scheme at the transmit side as a low-cost low-complexity alternative to capture many of the advantages of multi-antenna systems. The measurements show that the relative calibration method is performing almost optimal and that the complexity can be significantly reduced by using antenna selection.

12:42 Energy Monitoring and Management in 5G Integrated Fronthaul and Backhaul

Osamah Ibrahiem Abdullaziz (National Chiao Tung University, Taiwan); Marco Capitani (Nextworks, Italy); Claudio E. Casetti and Carla-Fabiana Chiasserini (Politecnico di Torino, Italy); Shahzoob Bilal Chundrigar (ITRI, Taiwan); Giada Landi (Nextworks, Italy); Xi Li (NEC, Germany); F Moscatelli (Nextworks, Italy); Kei Sakaguchi (Fraunhofer Heinrich Hertz Institute, Germany); Samer T. Talat (Industrial Technology Research Institute, Taiwan)

Energy efficiency is likely to be the litmus test for the sustainability of upcoming 5G networks. Before the new generation of cellular networks are ready to roll out, their architecture designers are motivated to leverage the SDN technology for the sake of its offered flexibility, scalability, and programmability to achieve the 5G KPI of 10 times lower energy consumption. In this paper, we present Proofs-of-Concept of Energy Management and Monitoring Applications (EMMAs) in the context of three challenging, realistic case studies, along with a SDN/NFV-based MANO architecture to manage converged fronthaul/backhaul 5G transport networks.