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Applications operating over airborne networks are known to perform quite sub-optimally. Transmission control protocol (TCP) based applications often experience very low data throughput, while the user datagram protocol (UDP) based applications suffer high packet loss as well as out-of-order delivery. This is due to the high bit error rate (BER) nature of the wireless links and the high mobility of...
Multiband tactical communication modems must employ different waveforms to meet various demands in quality and nature of data. Range maximization, high data throughput and power conservation requirements are usually not fulfilled by a single waveform. To effectively deliver tactical multimedia data including coded audio, text, video, map and navigation information using radio, multiple choice of frequency...
We propose a game-theoretic framework for quality-of-service (QoS) aware resource competition among coexisting wireless links in mobile wireless networks. The senders of wireless links use the constant transmit power and then the wireless resources of interest is characterized by time-slot length. Multiple wireless links will use the limited wireless resources through a time-slot competition game...
In wireless networks, communication links may be subject to random fatal attacks: for example, sensor networks under sudden power losses or cognitive radio networks with unpredictable primary user spectrum occupancy. Under such circumstances, it is critical to quantify how fast and reliably information can be collected over attacked links. In our previous work, we studied such channels by considering...
Demand Assigned Multiple Access (DAMA) is a technology used to assign link capacity based on user demand. The allocation of capacity is limited by a set of constraints (e.g., priority of the traffic, link condition, RF interference, required bandwidth). Capacity is allocated in the time and frequency domains. An allocation algorithm determines per-user capacity for each assignment epoch. A packing...
The FlexNet-Waveform (FN-WF) is a new, highly-configurable MANET waveform for the international ground-based SDR arena, designed for the new FlexNet-One and FlexNet-Four hardware platforms. To ensure maximum compatibility and interoperability, the FN-WF assumes an IP-based platform with standard COTS protocols on the wired, Ethernet connections, while the wireless links utilize the best practices...
Modern Unmanned Aerial Vehicles (UAVs) have the capability of carrying sensors that produce large amounts of data. A high speed wireless data link is required to transfer this data to other systems for processing. This paper presents an FPGA-based implementation of a high data-rate (350 Mbps) QPSK modulator and demodulator to support a high data rate relay from a UAV to a ground station. By using...
Efficient use of spectrum requires an accurate determination of interference effects. In this paper, we introduce a radio to radio (R2R) factor that quantifies the interference effects of one radio waveform on another based on multiple waveform properties instead of solely on intermediate frequency (IF) signal power. The R2R factor is formulated as a dimensionless correction term in the victims communication...
We consider multi-constrained power, rate and channel allocation crafted for low power consumption, delay tolerant traffic, and under interfering link conditions that may be used in a cognitive radio system. Specifically, an iterative distributed algorithm, based on a sum-power constrained sum-rate maximization with upper (and lower) per user and channel power and rate constraints, as well as upper...
As advanced communications techniques reach capacity, have reduced performance or system availability, or become unusable, the warfighter must have a reliable, high-capacity communications system in place and standing ready to supplant the degrading systems. Events in the recent past have shown satellites vulnerable to a number of ills or potential problems that could be debilitating. This paper addresses...
In an autonomous sensor network without a central fusion center, it is desired that any node has the ability to make the final decision once it has enough information about the phenomenon of interest (PoI) within a certain confidence level. In this paper, we propose a distributed sequential methodology which updates the current node's estimator based on its own observation and noise corrupted decision...
Mobile free space optical (FSO) and directional RF communications links suffer from frequent link blockages due to opaque obstructions that can result in degraded or failed networks. In this paper, a methodology is presented for assuring connectivity in networks with fragile links. The frequency and duration of link blockages are characterized using modeling and emulation tools developed for realistic...
In the tactical Internet, inter-domain links consist mostly of unreliable and low bandwidth wireless links. To enable seamless routing across different Autonomous Systems (ASes), we propose an inter-domain Traffic Engineering (TE) scheme to reroute traffic when congestion occurs. There are two components for the TE scheme. First, a Traffic Splitting (TS) scheme is used for load balancing among parallel...
Carrier sense multiple access (CSMA) is the conventional medium access method used in wireless ad hoc networks. it can be enhanced as a space-division based CSMA (namely, SD-CSMA) by using multi-antenna techniques, which allows concurrent link communications in the network. In this paper, we present a MAC design that can adaptively switch between CSMA and SD-CSMA in multi-antenna based ad hoc networks...
The effects of adaptive-rate transmissions and routing on the total throughput of a slow-frequency-hop packet-radio network are considered. Adaptive rates are achieved through the use of error-control coding with perfect side information. Both fixed-length codes and variable-length codes are considered. Performance results are obtained for direct transmission (i.e., no routing), two-hop limited routing,...
Site multi-homing is an important capability in modern military networks. Resilience of a site is greatly enhanced when it has multiple upstream connections to the global information grid, including the global Internet. Similarly, the ability to provide traffic engineering for a site can be important in reducing delays and packet loss over low-bandwidth and/or high-delay uplinks. Current approaches...
There are three separate power control algorithms utilized in the Mobile User Objective System (MUOS). They are Point-to-Point, Group, and Common-Channel. Although MUOS is largely based on Third Generation Project Partnership (3GPP) standards, a unique non-standard group network capability is provided in the system. This point-to-multipoint capability requires a novel dedicated Group Power Control...
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