To address the scarcity of spectrum, FCC mandated
the dynamic sharing of spectrum among the different tiers of
users. The success of spectrum sharing, however, relies on the
automated enforcement of spectrum policies. We focus on ex
post spectrum enforcement during/after the occurrence of a
potentially harmful event, but before/after an actual harm has
occurred. The major challenges addressed by us are to ensure
maximum channel coverage in a given region of enforcement,
accurate and reliable detection of enforcement, and selection of
an efficient algorithm to select entities for detection of violation.
We adopt a crowdsourced methodology to monitor spectrum
usage. We ensure maximum coverage of the given area by
dividing it into equal-sized regions and solve the enforcement
problem by a divide and conquer mechanism over the entire
region. We use a variant of the Multiple Choice Secretary
algorithm to select volunteers. We finally simulate the
enforcement framework and analyze the results.
more »
« less
Spectrum Misuse Detection in Cooperative Wireless Networks
The success of dynamic spectrum sharing in wireless networks depends on reliable automated enforcement of spectrum access policies. In this paper, a crowdsourced approach is used to select volunteers to detect spectrum misuse. Volunteer selection is based on multiple criteria, including their reputation, likelihood of being in a region and ability to effectively detect channel misuse. We formulate the volunteer selection problem as a stable matching problem, whereby, volunteers' monitoring preferences are matched to channels' attributes. Given a set of volunteers, the objective is to ensure maximum coverage of the spectrum enforcement area and accurate detection of spectrum access violation of all channels in the area. The two matching algorithms, Volunteer Matching (VM) and Reverse Volunteer Matching (RVM) are based on variants of the Gale-Shapley algorithm for stable matching. We also propose two Hybrid algorithms, HYBRID-VM and HYBRID-RVM that augment the matching algorithms with a Secretary-based algorithm to overcome the shortcomings of the individual vanilla algorithms. Simulation results show that volunteer selection by using HYBRID-VM gives better coverage of region (better by 19.2% when compared to threshold-based Secretary algorithm), better accuracy of detection and better volunteer happiness when compared to the other algorithms that are tested.
more »
« less
- Award ID(s):
- 1642949
- NSF-PAR ID:
- 10218691
- Date Published:
- Journal Name:
- GLOBECOM 2020 - 2020 IEEE Global Communications Conference
- Page Range / eLocation ID:
- 1 to 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
null (Ed.)Cooperative wireless networks, enabled by Cognitive Radios, facilitate mobile users to dynamically share access to spectrum. However, spectrum bands can be accessed illegitimately by malicious users. Therefore, the success of dynamic spectrum sharing relies on automated enforcement of spectrum policies. While the focus has been on ex ante spectrum enforcement, this work explores new approaches to address efficient ex post spectrum enforcement. The main objective of this work is to ensure maximum coverage of the area of enforcement and accurate detection of spectrum access violation. The first objective is achieved with the help of Lloyd's algorithm to divide the enforcement area into a set of uniformly sized coverage regions. The interference detection accuracy is achieved through crowdsourcing of the spectrum access monitoring to volunteers, based on their computational capabilities, location attributes and reputation. A simulation framework was developed in CSIM19 (C++ version) to analyze the performance of the proposed system over the entire area of enforcement. The results show that the proposed scheme ensures efficient coverage of all the channels and regions in the area of enforcement and a high average accuracy of detection.more » « less
-
This paper addresses the complete area coverage problem of a known environment by multiple-robots. Complete area coverage is the problem of moving an end-effector over all available space while avoiding existing obstacles. In such tasks, using multiple robots can increase the efficiency of the area coverage in terms of minimizing the operational time and increase the robustness in the face of robot attrition. Unfortunately, the problem of finding an optimal solution for such an area coverage problem with multiple robots is known to be NP-complete. In this paper we present two approximation heuristics for solving the multi-robot coverage problem. The first solution presented is a direct extension of an efficient single robot area coverage algorithm, based on an exact cellular decomposition. The second algorithm is a greedy approach that divides the area into equal regions and applies an efficient single-robot coverage algorithm to each region. We present experimental results for two algorithms. Results indicate that our approaches provide good coverage distribution between robots and minimize the workload per robot, meanwhile ensuring complete coverage of the area.more » « less
-
null (Ed.)The emerging satellite videos provide the opportunity to detect moving objects and track their trajectories, which were not possible for remotely sensed imagery with limited temporal resolution. So far, most studies using satellite video data have been concentrated on traffic monitoring through detecting and tracking moving cars, whereas the studies on other moving objects such as airplanes are limited. In this paper, an integrated method for monitoring moving airplanes from a satellite video is proposed. First, we design a normalized frame difference labeling (NFDL) algorithm to detect moving airplanes, which adopts a non-recursive strategy to deliver stable detection throughout the whole video. Second, the template matching (TM) technique is utilized for tracking the detected moving airplanes in the frame sequence by improved similarity measures (ISMs) with better rotation invariance and model drift suppression ability. Template matching with improved similarity measures (TM-ISMs) is further implemented to handle the leave-the-scene problem. The developed method is tested on a satellite video to detect and track eleven moving airplanes. Our NFDL algorithm successfully detects all the moving airplanes with the highest F1 score of 0.88 among existing algorithms. The performance of TM-ISMs is compared with both its traditional counterparts and other state-of-the-art tracking algorithms. The experimental results show that TM-ISMs can handle both rotation and leave-the-scene problems. Moreover, TM-ISMs achieve a very high tracking accuracy of 0.921 and the highest tracking speed of 470.62 frames per second.more » « less
-
IEEE (Ed.)A hybrid cloud that combines both public and private clouds is becoming more and more popular due to the advantages of improved security, scalability, and guaranteed SLA (Service-Level Agreement) at a lower cost than a separate private or public cloud. The existing studies rarely consider VM migrations in a hybrid cloud environment with dynamically changed VM workloads. From an enterprise’s perspective, these migrations are necessary to minimize the cost of utilizing public clouds and guarantee SLAs of VMs in a hybrid cloud environment. In this paper, we propose an elastic VM allocation and migration algorithm for a hybrid cloud, called E-VM, to fully utilize the resources in a private cloud and to minimize the cost of using a public cloud while guaranteeing the SLAs of all VMs. The E-VM considers the bi-direction migration between private and public clouds. Two components, VM-predictor and VM-selector, are designed and implemented in E-VM to determine if a migration has to be triggered between private and public clouds and which VMs will be migrated to the opposite cloud, respectively. Moreover, E-VM is designed based on the existing public cloud pricing models and can be easily adapted to any cloud service provider. According to simulator results based on a set of captured industrial VM traces/workloads and additional experiments directly on a real-world hybrid cloud, the proposed E-VM can significantly reduce the total cost of using the public cloud compared to the existing VM migration schemes.more » « less