@article {43040,
	title = {Sectors, Beams and Environmental Impact on the Performance of Commercial 5G mmWave Cells: An Empirical Study},
	journal = {IEEE Access},
	volume = {10},
	year = {2022},
	month = {12/2022},
	pages = {133309-133323},
	publisher = { IEEE},
	abstract = {millimeter wave (mmWave) communication is one of the cornerstones of future generations of mobile networks. While the performance of mmWave links has been thoroughly investigated by simulations and testbeds, the behavior of this technology in real-world commercial setups has not yet been thoroughly documented. In this paper, we address this gap and present the results of an empirical study to determine the actual performance of a commercial 5G mmWave cell through on-field measurements. We evaluate the signal and beam coverage map of an operational network as well as the end-to-end communication performance of a 5G mmWave connection, considering various scenarios, including human body blockage effects, foliage-caused and rain-induced attenuation, and water surface effects. To the best of our knowledge, this paper is the first to report on a commercial deployment while not treating the radio as a black box. Measurement results are compared with 3GPP{\textquoteright}s statistical channel models for mmWave to check the possible gaps between simulated and actual\&nbsp;performance. This measurement analysis provides valuable information for researchers and 5G verticals to fully understand how a 5G mmWave commercial access network operates in the real-world.},
	keywords = {5G, commercial 5G networks, coverage analysis, millimeter-wave, mmWave},
	issn = {2169-3536},
	doi = {10.1109/ACCESS.2022.3229588},
	url = {https://ieeexplore.ieee.org/document/9987496},
	author = {Moheb, Salman and Foivos Ioannis {Michelinakis} and Elmokashfi, Ahmed and Gr{\o}ndalen, Ole and Mahmood, Kashif and Zanella, Andrea}
}
@article {gronsund-et-al-JTPO-2012,
	title = {Business Case Evaluations for LTE Network Offloading With Cognitive Femtocells},
	journal = {Telecommunications Policy Journal},
	volume = {37},
	number = {2-3},
	year = {2013},
	month = {March-April},
	pages = {140-153},
	publisher = {Elsevier},
	abstract = {Mobile networks are increasingly becoming capacity limited such that more base stations and smaller cells or more spectrum are required to serve the subscribers\&$\#$39; increasing data usage. Among several challenges, the establishment of new base station sites becomes challenging and expensive. This study proposes and analyzes critical aspects of a business case where a mobile operator offloads its mobile LTE network by deploying cognitive femtocells. When aided by a sensor network the cognitive femtocell will be able to use frequencies other than the mobile network and hence increase its power to cover outdoor areas and neighbour buildings. This cognitive femtocell strategy will be compared with an alternative strategy where an operator deploys conventional femtocells and has to build additional base stations to meet the traffic demands. The business case analysis illustrates that there is a potential for cost savings when offloading the mobile network with cognitive femtocells when compared to the alternative strategy. It must be emphasized that the studied concept is innovative and that the business case period starts in 2017, hence parameter assumptions are uncertain. Therefore, as the most important message of this work, sensitivity analysis are used to reveal the most critical aspects of the cognitive femtocell business case. It is found that that the most critical parameters regarding the cognitive femtocell are the price for backhauling, the number of users supported and the coverage. Furthermore, an optimal coverage radius for the cognitive femtocell for lowest possible costs is found. Costs related to the fixed sensor network are found to be less critical since sensors are embedded in the cognitive femtocells. Sensitivity analysis is also presented for spectral efficiency, cognitive and conventional femtocell offloading gain, sensor density and price, customer density and price for base station site establishment.},
	doi = {10.1016/j.telpol.2012.07.006},
	author = {P{\r a}l Rolfsen {Gr{\o}nsund} and Gr{\o}ndalen, Ole and L{\"a}hteenoja, Markku}
}
@article {gronsundvlsi2012,
	title = {Comparison of Cell Sizes for Cost Efficient Deployment of a Sensor Network Aided Cognitive Radio System, Journal of Signal Processing Systems},
	journal = {Journal of Signal Processing Systems},
	volume = {69},
	number = {1},
	year = {2012},
	pages = {95-104},
	publisher = {Springer},
	abstract = {To exploit spectrum resources on a secondary basis, a Sensor Network Aided Cognitive Radio Network uses a wireless sensor network that assists a secondary cognitive radio network by providing information about the current primary spectrum occupancy. In this paper we determine the performance for different cell sizes when considering the costs for deployment of base stations in a secondary network that exploits spectrum holes identified by the wireless sensor network. The secondary base station is deployed co-located with a mobile primary network that uses a cellular reuse pattern with seven frequencies. Performance of the secondary system and impact on the primary system are mainly studied in terms of throughput, packet loss and coverage when using spectrum holes in the space, time and frequency domains. Especially, we find that the cell size and configured transmit powers for the secondary system are important for optimal system performance, and that smaller cell sizes and less expensive base stations for the secondary system are beneficial. The impact on primary system performance was found to be low, but that optimal tuning of the sensor network is important.},
	doi = {10.1007/s11265-011-0636-4},
	author = {P{\r a}l Rolfsen {Gr{\o}nsund} and Gr{\o}ndalen, Ole}
}
@inproceedings {gronsund-et-al-globecom-2011,
	title = {Evaluation of Interference Requirements in a Sensor Aided Cognitive Radio System},
	journal = {54th IEEE Global Communications Conference (GLOBECOM)},
	year = {2011},
	month = {December},
	publisher = {IEEE},
	type = {Conference},
	abstract = {To better exploit the spectrum resources a wireless sensor network can be used to assists a secondary cognitive radio network by providing information about the current primary spectrum occupancy. In this paper we study the performance of the secondary network when it is co-located with and having similar cell size as a mobile primary network that uses a cellular reuse pattern with seven frequencies. Especially we study how relaxed requirements for the maximum interference generated by the cognitive radios affect the performance of the secondary and primary network in terms of throughput, packet loss, delay, coverage and connectivity. We show that it is possible to find interference limits for the cognitive radio that allow full throughput and coverage for the secondary system at the cost of a slight reduction in throughput and an increase in packet loss per user of 2\% on average for the primary system.},
	author = {P{\r a}l Rolfsen {Gr{\o}nsund} and Gr{\o}ndalen, Ole},
	editor = {IEEE, }
}
@inproceedings {gronsund-et-al-pimrc-2011,
	title = {Performance of a Sensor Network Aided Cognitive Radio System},
	journal = {22th International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
	year = {2011},
	month = {September},
	publisher = {IEEE},
	type = {Conference},
	abstract = {A Sensor Network Aided Cognitive Radio Network uses the concept of a wireless sensor network that assists a cognitive radio network by providing information about the current primary spectrum occupancy. In this paper we study the performance of the cognitive network for various cell sizes and transmit power levels when deployed co-located with a mobile primary system that uses a cellular reuse pattern with seven frequencies. Co-location of secondary and primary base stations has been found to be very important in order to reduce network costs. An expression for the degree of co-location of secondary and primary base stations is derived and used for identifying optimal secondary cell sizes. For these optimal secondary cell sizes, we determine the performance in terms of throughput, packet loss, delay, coverage and connectivity when using spectrum holes in the space, time and frequency domains. Especially, we {fi}nd that cell size and transmit power levels are crucial for secondary system performance, and that smaller cell sizes and less expensive base stations for the secondary system such as WiFi access points and femto-cells is beneficial.},
	author = {P{\r a}l Rolfsen {Gr{\o}nsund} and Gr{\o}ndalen, Ole},
	editor = {IEEE, }
}
