Increasing capacity demands in emerging wireless technologies are expected to be met by network densification and spectrum bands open multiple technologies. These will, turn, increase the level of interference also result more complex inter-technology interactions, which will need managed through sharing mechanisms. Consequently, novel mechanisms should designed allow access for technologies, while efficiently utilizing resources overall. Importantly, it is not trivial design such efficient...

The recent decisions by regulators in the USA and UK to open up unused portions of UHF spectrum for secondary use have been met with keen interest using these TV white spaces (TVWS) providing broadband services through Wi-Fi-like connectivity. Amid ensuing media hype about "Wi-Fi on steroids", there is a widespread perception that Wi-Fi operating TVWS will provide much longer range, superior speeds, more reliable connections than traditional at 2.4 GHz. In this paper, we present quantitative...

Hybrid beamforming (HBF) multi-user multiple-input multiple-output (MU-MIMO) is a key technology for unlocking the directional millimeter-wave (mm-wave) nature spatial multiplexing beyond current codebook-based 5G-NR networks. In order to suppress co-scheduled users' interference, HBF MU-MIMO predicated on having sufficient radio frequency chains and accurate channel state information (CSI), which can otherwise lead performance losses due imperfect interference cancellation. this work, we...

Spectrum sharing mechanisms need to be carefully designed enable inter-technology coexistence in the unlicensed bands, as these bands are an instance of a spectrum commons where heterogeneous technologies and deployments must coexist. Unlike licensed multiple could coexist only primary-secondary DSA mode, offers competition opportunities between dominant technologies, such Wi-Fi recently proposed LTE 5 GHz band. In this paper we systematically study performance different schemes for commons....

Many satellite operators are currently planning to deploy non-geostationary-satellite orbit (NGSO) systems for broadband communication services in the Ku-, Ka-, and V-band, where some of them have already started launching. Consequently, new challenges expected inter-system coexistence due increase interference level complexity interactions resulting from heterogeneity constellations. This is especially relevant Ku-band, NGSO most diverse existing geostationary-satellite (GSO) systems, which...

This letter characterizes the effect of mutual interference in a planar network pulsed-radar devices. Using stochastic geometry tools and strongest interferer approximation, we derive simple closed-form expressions that pinpoint role played by key system parameters on radar detection range false alarm rate. The fundamental tradeoffs between performance, density, antenna directivity are captured for different path-loss exponents no-fading Rayleigh-fading cases. discussion highlights practical...

Millimeter-wave (mm-wave) wireless local area networks (WLANs) are expected to provide multi-Gbps connectivity by exploiting the large amount of unoccupied spectrum in e.g. unlicensed 60 GHz band. However, overcome high path loss inherent at these frequencies, mm-wave must employ highly directional beamforming antennas, which makes link establishment and maintenance much more challenging than traditional omnidirectional networks. In particular, maintaining under node mobility necessitates...

Due to the high expected increase in mobile data traffic and scarcity of licensed spectrum for cellular networks, 3GPP has started preliminary work standardizing LTE operation 5 GHz unlicensed band (LTE-U). However, LTE-U would interfere with other legacy technologies operating band, most important being contention-based Wi-Fi, which be blocked by conventional LTE, is designed dedicated spectrum. Consequently, some coexistence-enabling mechanisms have been proposed LTE-U, but their...

Energy efficient communication is a key requirement of energy-constrained wireless sensor networks. Cooperative diversity can be applied to networks significantly reduce node energy consumption. However, judicious selection and coordination cooperation partners essential exploiting this saving potential cooperation. In paper we investigate optimal partner choice power allocation for in Our insights lead us formulate heuristics which form simple practical strategy networks, allowing nodes...

An understanding of the underlying spatial structure user-deployed wireless networks is invaluable for design and optimization opportunistic small-cell technologies in emerging multi-tier architectures. IEEE 802.11 Wi-Fi provide a real-world example such large-scale random network structure. In this paper we report on high-resolution measurement survey deployments Germany as step towards deriving more sophisticated models transmitter distributions networks, which are core offloading...

Millimeter-wave (mm-wave) communication technology can provide multi-Gbps connectivity but directional mm-wave links are easily blocked by moving obstacles, e.g. humans, common in indoor environments. Seamless high speed data provisioning thus necessitates timely beamsteering to secondary reflected case of primary link obstruction. Making smart beam-switching decisions requires superior environment awareness, predict and avoid We propose the novel concept radar-enhanced medium access ---...

Future 5G cellular networks are expected to exploit the abundant spectrum resources of millimeter-wave (mm-wave) bands satisfy demand for multi-Gbps mobile links anticipated by exponential data traffic growth. However, given directional nature mm-wave links, feasibility is critically dependent on efficient antenna beamsteering and a rich inventory strong LOS (line-of-sight) NLOS (non line-of-sight) paths from effective reflectors in urban environment. In this paper we report results detailed...

While scalable cell-free massive MIMO (CF-mMIMO) shows advantages in static conditions, the impact of its changing serving access point (AP) set a mobile network is not yet addressed. In this paper we first derive CPU cluster and AP handover rates CF-mMIMO as exact numerical results tight closed form approximations. We then use our rate result to analyse mobility-aware throughput. compare spectral efficiency (SE) against distributed with pure network- UE-centric selection, for different...

This paper presents an investigation of the energy-efficiency two major cooperative diversity techniques in short-range wireless sensor networks: virtual-MISO (multiple-input-single-output) and decode-and-forward. The total energy consumption a system consists transmission energy, transceiver circuit local communication cost. In explicit precedes long-haul transmission, whereas decode-and-forward nodes cooperate by overhearing repeating each other's transmissions. Our analysis shows that is...

Digital modulation classification (DMC) can be highly valuable for equipping radios with increased spectrum awareness in complex emerging wireless networks. However, as the existing literature is overwhelmingly based on theoretical or simulation results, it unclear how well DMC performs practice. In this paper we study performance of real-world networks, using an extensive RF signal dataset 250,000 over-the-air transmissions heterogeneous transceiver hardware and co-channel interference. Our...

Wi-Fi is the dominant wireless indoor broadband solution and thus key for meeting exponential traffic growth. The recent IEEE 802.11ac amendment enables PHY data rates exceeding 1 Gbps. However, it not clear how this increased per-link performance, achieved especially via wider channels, translates to network-level performance. latter crucial understanding true potential of emerging Wi-Fi, as massive densification network infrastructure needed keeping up with capacity demands. In paper we...

We demonstrate the first open source toolchain for studying and visualizing coverage of highly directional mm-wave cellular networks. Based on realistic ray tracing simulations, our framework enables user to study expected performance robustness deployments in a near real-time fashion. A modular software architecture makes easily extendible with new statistics visualizations.

We study whether realistic fifth-generation (5G) mm-wave cellular networks would cause harmful out-of-band interference to weather satellites sensing in the 23.8 GHz band. estimate uplink and downlink from a single interferer network of interferers New York City, using real three-dimensional (3D) building data antenna patterns. perform detailed ray-tracing propagation simulations, for locations MetOp-B satellite its scanning orientations ground representative urban cell sites. In addition...

Crowdsourcing is a promising approach to collect the received signal strength (RSS) measurements required construct Wi-Fi radio environment maps (REMs) via spatial interpolation methods. However, crowdsourced RSS are often unreliable and especially in indoor propagation environments they strongly affected by shadowing fading. It thus important understand which method better suited for such REMs. In this paper we present an extensive empirical performance evaluation of four major methods...

We present a spectrum-agile mm-wave packet radio communication system and demonstrate it by using multimedia streaming. The developed platform is based on USRP software defined radios (SDRs) executing open-source GNU Radio code cost-efficient commercial off-the-shelf components. Our able to operate in both the V- E-bands, covering practice 60~GHz, 70~GHz 80~GHz frequency bands. One of main design goals has been provide an SDR that academic groups, particularly protocol designers, could use...

The millimeter-wave (mm-wave) bands are currently being explored for multi-Gbps wireless local area networks (WLANs). Directional antennas required to overcome the high attenuation inherent at mm-wave frequencies. However, directionality makes link maintenance and establishment tasks complex, especially under node mobility, as slight misalignment of antenna beams between nodes leads disruption. Consequently, low latency beamsteering algorithms needed fast re-establishment support seamless...

Exploiting multi-antenna technologies for robust beamsteering to overcome the effects of blockage and beam misalignment is key providing seamless multi-Gbps connectivity in millimeter-wave (mm-wave) networks. In this paper, we present first large-scale outdoor mm-wave measurement study using a phased antenna array typical European town. We systematically collect fine-grained 3D angle-of-arrival (AoA) angle-of-departure (AoD) data, totaling over 50,000 received signal strength measurements....

Recent rulings by US and UK regulators allowing access to unused portions of TV spectrum have elicited high hopes for the practical value these whitespaces (TVWS) secondary exploitation. However, this optimism has been largely fueled rather simple early studies, which do not consider all system aspects in sufficient detail; few experimental works reported are proprietary only a small number nodes, whereas existing more sophisticated theoretical studies focus on singular isolation from...

Proponents of deploying LTE in the 5 GHz band for providing additional cellular network capacity have claimed that would be a better neighbour to Wi-Fi unlicensed band, than is itself. On other side debate, community has objected highly detrimental performance. However, there lack transparent and systematic engineering evidence supporting contradicting claims two camps, which essential ascertaining whether regulatory intervention fact required protect incumbent from new entrant. To this end,...