Adversarial Detection: Attacking Object Detection in Real Time

Intelligent robots rely on object detection models to perceive the environment. Following advances in deep learning security it has been revealed that object detection models are vulnerable to adversarial attacks. However, prior research primarily focuses on attacking static images or offline videos. Therefore, it is still unclear if such attacks could jeopardize real-world robotic applications in dynamic environments. This paper bridges this gap by presenting the first real-time online attack against object detection models. We devise three attacks that fabricate bounding boxes for nonexistent objects at desired locations. The attacks achieve a success rate of about 90% within about 20 iterations. The demo video is available at: https://youtu.be/zJZ1aNlXsMU.Comment: 7 pages, 10 figure

Capacity, Energy-Efficiency and Cost-Efficiency Aspects of Future Mobile Network Deployment Solutions

Recent data analytics from the mobile broadband networks have revealed an exponentially rising trend of mobile data traffic for the past five years. It is predicted that by 2020 the overall data traffic will increase by a factor of 1000x. This traffic growth is caused both by the increased adoption of smartphones and tablets, and by the increased usage of multimedia rich services, such as video streaming. Furthermore, most of this demand is likely to come from indoor users. In order to be able to meet the increased capacity needs, network densification has been identified as a viable pathway for mobile operators to evolve their networks. Network densification can be achieved by either densifying the existing legacy deployments, e.g. by deploying more macrocell sites or street-level microcells, or by deploying new indoor low-power sites, or both. Furthermore, different distributed antenna solutions offer an additional interesting aspect in network densification and deployments.This doctoral dissertation addresses network densification from alternative deployment strategies’ perspective, in particular, when individual densification solutions are pushed to their capacity limits, such that all the network elements operate at full load. It evaluates and compares the performance of different deployment strategies in terms of capacity-, energy- and cost- efficiency. The performance evaluations are carried out using propagation modeling based analysis and are based on a system-independent approach, integrating not only the classical capacity and spectral efficiency aspects, but also energy- and cost-efficiency perspectives, through realistic power consumption and investment cost models. The energy-efficiency aspects are seen particularly important when moving towards the era of green communications, under clear trends and incentives to save energy at all levels of society. Furthermore, the analysis integrates some of the recent findings related to substantially increased building penetration losses, through the use of more energy-efficient building materials.The obtained results indicate that the indoor femtocell-based solutions with densely deployed femto-cells are much more spectrally-, energy- and cost efficient approach to address the enormous indoor capacity demands of the 5G era and beyond, compared to densifying the outdoor legacy deployment solutions, when the network is pushed to the extreme limit. This is particularly so when the building penetration losses are high, as has been recently observed in actual field measurements. Furthermore, the dynamic outdoor DAS concept, studied also in this thesis, offers an efficient and capacity-adaptive solution to provide outdoor capacity, on-demand, in urban areas. In general, this thesis work provides tools, results, understanding, and insight of both technical and techno-economical aspects of long-term evolutionary perspectives of different mobile network deployment and densification solutions, which can be used by network vendors, operators, and device manufacturers

Coverage Aspects of Temporary LAP Network

This paper studies the coverage aspects of a low altitude platform (LAP) system that can form a temporary communication network. The system consists of multiple autonomous drones equipped with dual-band Wi-Fi access points (APs) with ad hoc capabilities to form a mesh network. The suitability of the LAP system is evaluated from the coverage point of view with calculations and simulations. The results show that more drones are needed to cover (dense) urban than rural environment and the drone altitude should also be higher in urban areas compared with the rural areas.acceptedVersionPeer reviewe

Technoeconomical Analysis of Macrocell and Femtocell Based HetNet under Different Deployment Constraints

Ultradense deployment of small cells is being considered as one of the key flavors of the emerging 5G cellular networks to address the future data capacity challenges. A large share of these deployments will be indoor, as this is the arena where the majority of the data traffic is believed to originate from in the future. Indoor small cell solutions (e.g., femtocell or WiFi) are well positioned for delivering superior indoor coverage and capacity. However, due to relatively smaller coverage footprint compared to traditional macrocells, a very dense deployment of small cells will be needed in order to have a ubiquitous indoor coverage. Such dense deployment triggers cost and energy efficiency concerns for mobile operators. In this paper, we analyze and compare the technoeconomic performance of two deployment strategies: homogeneous macrocellular densification and heterogeneous macro-femto deployment strategy, from an indoor service provisioning perspective. Particularly, we analyze and contrast the performance of macro-femto based deployment, with varying femtocell market penetration rate and under different femtocell backhaul connectivity constraints, with that of homogeneous macrocellular densification. The results indicate superior performance of indoor femtocell based deployment as compared to macrocellular-only densification, due to better indoor coverage, radio channel conditions, and high degree of spatial reuse.publishedVersionPeer reviewe