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Selected Areas in Communications, IEEE Journal on

Issue 5 • Date June 2012

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Displaying Results 1 - 23 of 23
  • Table of contents

    Publication Year: 2012 , Page(s): c1 - c4
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  • IEEE Communications Society [staff list]

    Publication Year: 2012 , Page(s): c2
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  • Guest Editorial: Communications Challenges and Dynamics for Unmanned Autonomous Vehicles

    Publication Year: 2012 , Page(s): 849 - 851
    Cited by:  Papers (1)
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  • Requirements, Challenges and Analysis of Alternatives for Wireless Datalinks for Unmanned Aircraft Systems

    Publication Year: 2012 , Page(s): 852 - 860
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (796 KB) |  | HTML iconHTML  

    Two key challenges in the design of datalinks for unmanned aircraft (UAS) systems compared to other wireless links are the long range of distances and speeds that need to be covered. The 960 - 1164 MHz part of the IEEE L band has been identified as a candidate spectrum for future manned and unmanned aircraft datalinks. The amount of spectrum available in the L-Band is not sufficient to support video applications common in UASs and so dual-band designs using both L-Band and C-Band are being considered. For L-Band, two projects funded by EUROCONTROL L-Band Digital Aeronautical Communications Systems 1 and 2 (L-DACS1 and L-DACS2) are often mentioned for use in UAS also. We briefly discuss issues with their use for UAS. We compare the two proposals in terms of their scalability, spectral efficiency, and interference resistance. Then we discuss several issues in UAS datalink design including availability, networking, preemption, and chaining. We also propose ways to mitigate interference with other systems in the L-Band. View full abstract»

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  • Distributed Planning Strategies to Ensure Network Connectivity for Dynamic Heterogeneous Teams

    Publication Year: 2012 , Page(s): 861 - 869
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5871 KB) |  | HTML iconHTML  

    This paper presents a cooperative distributed planning algorithm that ensures network connectivity for a team of heterogeneous agents operating in dynamic and communication-limited environments. The algorithm, named CBBA with Relays, builds on the Consensus-Based Bundle Algorithm (CBBA), a distributed task allocation framework developed previously by the authors and their colleagues. Information available through existing consensus phases of CBBA is leveraged to predict the network topology and to propose relay tasks to repair connectivity violations. The algorithm ensures network connectivity during task execution while preserving the distributed and polynomial-time guarantees of CBBA. By employing under-utilized agents as communication relays, CBBA with Relays improves the range of the team without limiting the scope of the active agents, thus improving mission performance. The algorithm is validated through simulation trials and through experimental indoor and outdoor field tests, demonstrating the real-time applicability of the approach. View full abstract»

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  • Cooperative Unmanned Autonomous Vehicle Control for Spatially Secure Group Communications

    Publication Year: 2012 , Page(s): 870 - 882
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (479 KB) |  | HTML iconHTML  

    Beyond the individual independent unmanned autonomous vehicle (UAV), cooperative control of multiple UAVs has started to receive significant attention from industry, academia and the military. For the sake of UAV cooperation, proper wireless communication is imperative, but incurs several problems. Among them, spatially secure group communication (SSGC), which must maximize spatial UAV group size while minimizing the communication boundary of the group, is a unique problem for multiple UAV control from a security perspective. In particular, the SSGC problem must be considered for military applications such as multiple unmanned aerial or ground vehicle control. In this paper, we investigate the SSGC problem. To provide a solution, an analytical framework is first presented to model the dynamics of multiple UAVs and SSGC. The theoretical analysis and simulation results regarding how communication affects group dynamics and spatial communication security are also discussed. Our contribution is to suggest a new way to view multiple UAV control with spatially secure communication, and to provide a distributed method to address the problem cooperatively. View full abstract»

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  • Optimizing Cascaded Chains of Unmanned Aircraft Acting as Communication Relays

    Publication Year: 2012 , Page(s): 883 - 898
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6625 KB) |  | HTML iconHTML  

    This work presents a decentralized mobility control algorithm for an optimal end-to-end communication chain using a team of unmanned aircraft acting solely as communication relays. The chaining controller drives the location of a virtual control point, using estimates of the communication objective function gradient calculated using stochastic approximation techniques, to locations of improved relaying for unmanned aircraft. The gradient estimate is derived from observation data of the communication objective function taken along a path generated by the aircraft orbiting about the control point. Flight experiments show that an unmanned aircraft can measure the signal-to-noise-and-interference ratio fields from IEEE 802.11b/g (WiFi) communication links; generate estimates of the field gradients using the least-squares gradient estimation method; and use the gradient estimates to drive a control point to a location that improves communication capacity. View full abstract»

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  • Underwater Data Collection Using Robotic Sensor Networks

    Publication Year: 2012 , Page(s): 899 - 911
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2862 KB) |  | HTML iconHTML  

    We examine the problem of utilizing an autonomous underwater vehicle (AUV) to collect data from an underwater sensor network. The sensors in the network are equipped with acoustic modems that provide noisy, range-limited communication. The AUV must plan a path that maximizes the information collected while minimizing travel time or fuel expenditure. We propose AUV path planning methods that extend algorithms for variants of the Traveling Salesperson Problem (TSP). While executing a path, the AUV can improve performance by communicating with multiple nodes in the network at once. Such multi-node communication requires a scheduling protocol that is robust to channel variations and interference. To this end, we examine two multiple access protocols for the underwater data collection scenario, one based on deterministic access and another based on random access. We compare the proposed algorithms to baseline strategies through simulated experiments that utilize models derived from experimental test data. Our results demonstrate that properly designed communication models and scheduling protocols are essential for choosing the appropriate path planning algorithms for data collection. View full abstract»

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  • Bridging Cooperative Sensing and Route Planning of Autonomous Vehicles

    Publication Year: 2012 , Page(s): 912 - 922
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (978 KB) |  | HTML iconHTML  

    Autonomous Vehicles (AV) are used to solve the problem of data gathering in large scale sensor deployments with disconnected clusters of sensors networks. Our take is that an efficient strategy for data collection with AVs should leverage i) cooperation amongst sensors in communication range of each other forming a sensor cluster, ii) advanced coding and data storage techniques for easing the cooperation process, and iii) AV route-planning that is both content and cooperation-aware. Our work formulates the problem of efficient data gathering as a cooperative route-optimization problem with communication constraints. We also analyze (network) coded data transmission and storage for simplifying cooperation amongst sensors as well as data collection by the AV. Given the complexity of the problem, we focus on heuristic techniques, such as particle swarm optimization, to calculate the AV's route and the times for communication with each sensor and/or cluster of sensors. We analyze two extreme cases, i.e., networks with and without intra- cluster cooperation, and provide numerical results to illustrate that the performance gap between them increases with the number of nodes. We show that cooperation in a 100 sensor deployment can increase the amount of data collected by up to a factor of 3 with respect to path planning without cooperation. View full abstract»

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  • Adaptive Communication-Constrained Deployment of Unmanned Vehicle Systems

    Publication Year: 2012 , Page(s): 923 - 934
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1047 KB) |  | HTML iconHTML  

    Cooperation between multiple autonomous vehicles requires inter-vehicle communication, which in many scenarios must be established over an ad-hoc wireless network. This paper proposes an optimization-based approach to the deployment of such mobile robotic networks. A primal-dual gradient descent algorithm jointly optimizes the steady-state positions of the robots based on the specification of a high-level task in the form of a potential field, and routes packets through the network to support the communication rates desired for the application. The motion planning and communication objectives are tightly coupled since the link capacities depend heavily on the relative distances between vehicles. The algorithm decomposes naturally into two components, one for position optimization and one for communication optimization, coupled via a set of Lagrange multipliers. Crucially and in contrast to previous work, our method can rely on on-line evaluation of the channel capacities during deployment instead of a prespecified model. In this case, a randomized sampling scheme along the trajectories allows the robots to implement the algorithm with minimal coordination overhead. View full abstract»

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  • Connectivity Maintenance in Mobile Wireless Networks via Constrained Mobility

    Publication Year: 2012 , Page(s): 935 - 950
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2139 KB) |  | HTML iconHTML  

    We explore distributed mechanisms for maintaining the physical layer connectivity of a mobile wireless network while still permitting significant area coverage. Moreover, we require that these mechanisms maintain connectivity despite the unpredictable wireless propagation behavior found in complex real-world environments. To this end, we propose the Spreadable Connected Autonomic Network (SCAN) algorithm, a fully distributed, on-line, low overhead mechanism for maintaining the connectivity of a mobile wireless network. SCAN leverages knowledge of the local (2-hop) network topology to enable each node to intelligently halt its own movement and thereby avoid network partitioning events. By relying on topology data instead of locality information and deterministic connectivity models, SCAN can be applied in a wide range of realistic operational environments. We believe it is for precisely this reason that, to our best knowledge, SCAN was the first such approach to be implemented in hardware. Here, we present results from our implementation of SCAN, finding that our mobile robotic testbed maintains full connectivity over 99% of the time. Moreover, SCAN achieves this in a complex indoor environment, while still allowing testbed nodes to cover a significant area. View full abstract»

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  • Role-Based Connectivity Management with Realistic Air-to-Ground Channels for Cooperative UAVs

    Publication Year: 2012 , Page(s): 951 - 963
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1603 KB) |  | HTML iconHTML  

    Ad-hoc aerial sensor networks leveraging MUAVs (Micro Unmanned Aerial Vehicles) are ideally suited to cost-efficiently explore unknown or hostile environments for example in case of incidents producing harmful gases or radiation. In this manuscript we present results on the investigations of communication-aware steering algorithms for cooperative MUAV swarms. The mission objective is to achieve a maximum spatial exploration efficiency with the simultaneous ability to self-optimize the communication links by exploiting controlled mobility. While our previous work has mainly considered the performance of the Air-to-Air mesh network, in this paper we focus on the Air-to-Ground-link connectivity control. To achieve appropriate communication links to a central sensor data sink even while exploring larger search areas, an agent-based role management strategy is used to provide suitable multi-hop connectivity. The novel algorithms are investigated for static as well as dynamically changing environments. Key results include a detailed realistic aerial channel characterization and network dimensioning analysis considering numbers of MUAVs and density of ground stations vs. exploration speed and sensor data latency. View full abstract»

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  • Smart Transmitters and Receivers for Underwater Free-Space Optical Communication

    Publication Year: 2012 , Page(s): 964 - 974
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (8945 KB) |  | HTML iconHTML  

    The number of unmanned vehicles and devices deployed underwater is increasing. New communication systems and networking protocols are required to handle this growth. Underwater free-space optical communication is poised to augment acoustic communication underwater, especially for short-range, mobile, multi-user environments in future underwater systems. Existing systems are typically point-to-point links with strict pointing and tracking requirements. In this paper we demonstrate compact smart transmitters and receivers for underwater free-space optical communications. The receivers have segmented wide field of view and are capable of estimating angle of arrival of signals. The transmitters are highly directional with individually addressable LEDs for electronic switched beamsteering, and are capable of estimating water quality from its backscattered light collected by its co-located receiver. Together they form enabling technologies for non-traditional networking schemes in swarms of unmanned vehicles underwater. View full abstract»

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  • Joint Node Placement and Assignment for Throughput Optimization in Mobile Backbone Networks

    Publication Year: 2012 , Page(s): 975 - 985
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1140 KB) |  | HTML iconHTML  

    We study the novel hierarchical architecture of Mobile Backbone Networks. In such networks, a set of Mobile Backbone Nodes (MBNs), which are envisioned to be airborne, are deployed to provide an end-to-end communications capability for the terrestrial Regular Nodes (RNs). We address the joint problem of placing a fixed number K MBNs, and assigning each RN to exactly one MBN, using two optimization objectives. The first is the Maximum Fair Placement and Assignment (MFPA) problem in which the objective is to maximize the minimum throughput obtained by any RN. The second is the Maximum Throughput Placement and Assignment (MTPA) problem, in which the objective is to maximize the aggregate throughput of the RNs. We develop an optimal polynomial time algorithm for the MFPA problem for any K, and an optimal polynomial time algorithm for the MTPA problem for K≤ 2. We also develop lower complexity approximation algorithms and present simulation results comparing the performance of the various algorithms. View full abstract»

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  • Modulating Retro-Reflector Lasercom Systems for Small Unmanned Vehicles

    Publication Year: 2012 , Page(s): 986 - 992
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    Lasercom, also known as free space optical (FSO) communication, has enjoyed a renewal of interest driven by increasing data rate requirements and the crowding of the RF spectrum, affecting both commercial and military sectors. Military communications must also deal with intentional or unintentional jamming, as well as frequency allocation restrictions, neither of which affects lasercom. The U.S. Naval Research Laboratory (NRL) has been conducting research on lasercom since 1998 with an emphasis on tactical applications. NRL's lasercom research has covered propagation studies in the maritime domain, component development, and systems demonstrations. NRL has developed both conventional lasercom systems and retro-reflecting systems for small platforms. This paper reviews some of the retro-reflecting work, discusses applications of lasercom in the areas of explosive ordnance disposal (EOD) unmanned ground vehicles (UGVs), and unmanned aerial vehicles (UAVs), and describes future directions. View full abstract»

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  • Optimization of UAV Heading for the Ground-to-Air Uplink

    Publication Year: 2012 , Page(s): 993 - 1005
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (515 KB) |  | HTML iconHTML  

    We consider a collection of single-antenna ground nodes communicating with a multi-antenna unmanned aerial vehicle (UAV) over a multiple-access ground-to-air communications link. The UAV uses beamforming to mitigate inter-user interference and achieve spatial division multiple access (SDMA). First, we consider a simple scenario with two static ground nodes and analytically investigate the effect of the UAV's heading on the system sum rate. We then study a more general setting with multiple mobile ground-based terminals, and develop an algorithm for dynamically adjusting the UAV heading to maximize the approximate ergodic sum rate of the uplink channel, using a prediction filter to track the positions of the mobile ground nodes. For the common scenario where a strong line-of-sight (LOS) channel exists between the ground nodes and UAV, we use an asymptotic analysis to find simplified versions of the algorithm for low and high SNR. We present simulation results that demonstrate the benefits of adapting the UAV heading in order to optimize the uplink communications performance. The simulation results also show that the simplified algorithms provide near-optimal performance. View full abstract»

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  • Throughput Analysis for Shallow Water Communication Utilizing Directional Antennas

    Publication Year: 2012 , Page(s): 1006 - 1018
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1012 KB) |  | HTML iconHTML  

    Underwater communication relies on acoustic links due to its long propagation and low attenuation properties. Despite the advantages of using acoustic links over radio frequency (RF), the major drawback is the limited bandwidth of the acoustic spectrum. To circumvent this, we advocate the use of directional antennas rather than the traditional omni-directional antennas to boost the network throughput by taking advantage of the spatial spectrum. In this paper, we analyze the network throughput for shallow water communication with directional antennas. Unlike traditional line-of-sight (LOS) directional communication, our analysis will aim to factor in non-line-of-sight (NLOS) links in the throughput analysis. We will be focusing on two NLOS links; namely refracted-surface-reflected (RSR) and refracted-bottom-reflected (RBR) to study the multipath effects on the network throughput. Simulation experiments are also provided to validate the analytical results. View full abstract»

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  • Information for Authors: IEEE Journal on Selected Areas in Communication (J-SAC)

    Publication Year: 2012 , Page(s): 1019
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  • Reprint Order Form

    Publication Year: 2012 , Page(s): 1020
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  • Call for papers

    Publication Year: 2012 , Page(s): 1021
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  • Call for papers

    Publication Year: 2012 , Page(s): 1022
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  • [Advertisement]

    Publication Year: 2012 , Page(s): 1024
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  • Staff List

    Publication Year: 2012 , Page(s): c3
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Aims & Scope

IEEE Journal on Selected Areas in Communications focuses on all telecommunications, including telephone, telegraphy, facsimile, and point-to-point television, by electromagnetic propagation.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Muriel Médard
MIT