http://www.csun.edu/~andrzej/COMP529-S05/papers/Mesh%20Networks%20Survey.pdf

Wireless mesh networks: a survey

A method for providing unequal allocation of rights among agents while operating according to fair principles, comprising assigning a hierarchal rank to each agent; providing a synthetic economic value to a first set of agents at the a high level of the hierarchy; allocating portions of the synthetic economic value by the first set of agents to a second set of agents at respectively different hierarchal rank than the first set of agents; and conducting an auction amongst agents using the synthetic economic value as the currency. A method for allocation among agents, comprising assigning a wealth generation function for generating future wealth to each of a plurality of agents, communicating subjective market information between agents, and transferring wealth generated by the secure wealth generation function between agents in consideration of a market transaction. The method may further comprise the step of transferring at least a portion of the wealth generation function between agents.

Multifactorial optimization system and method

Recent research results have demonstrated the feasibility of full-duplex wireless communication for short-range links. Although the focus of the previous works has been active cancellation of the self-interference signal, a majority of the overall self-interference suppression is often due to passive suppression, i.e., isolation of the transmit and receive antennas. We present a measurement-based study of the capabilities and limitations of three key mechanisms for passive self-interference suppression: directional isolation, absorptive shielding, and cross-polarization. The study demonstrates that more than 70 dB of passive suppression can be achieved in certain environments, but also establishes two results on the limitations of passive suppression: (1) environmental reflections limit the amount of passive suppression that can be achieved, and (2) passive suppression, in general, increases the frequency selectivity of the residual self-interference signal. These results suggest two design implications: (1) deployments of full-duplex infrastructure nodes should minimize near-antenna reflectors, and (2) active cancellation in concatenation with passive suppression should employ higher-order filters or per-subcarrier cancellation.

/pdf/passive-self-interference-suppression-for-full-duplex-4uj3ottjbs.pdf

Passive Self-Interference Suppression for Full-Duplex Infrastructure Nodes

Wormhole attacks enable an attacker with limited resources and no cryptographic material to wreak havoc on wireless networks. To date, no general defenses against wormhole attacks have been proposed. This paper presents an analysis of wormhole attacks and proposes a countermeasure using directional antennas. We present a cooperative protocol whereby nodes share directional information to prevent wormhole endpoints from masquerading as false neighbors. Our defense greatly diminishes the threat of wormhole attacks and requires no location information or clock synchronization.

/pdf/using-directional-antennas-to-prevent-wormhole-attacks-z7i6rx5ym2.pdf

Using Directional Antennas to Prevent Wormhole Attacks.

This paper derives the outage probability and transmission capacity of ad hoc wireless networks with nodes employing multiple antenna diversity techniques, for a general class of signal distributions. This analysis allows system performance to be quantified for fading or non-fading environments. The transmission capacity is given for interference-limited uniformly random networks on the entire plane with path loss exponent alpha > 2 in which nodes use: (1) static beamforming through M sectorized antennas, for which the increase in transmission capacity is shown to be thetas(M2) if the antennas are without sidelobes, but less in the event of a nonzero sidelobe level; (2) dynamic eigenbeamforming (maximal ratio transmission/combining), in which the increase is shown to be thetas(M 2/alpha ); (3) various transmit antenna selection and receive antenna selection combining schemes, which give appreciable but rapidly diminishing gains; and (4) orthogonal space-time block coding, for which there is only a small gain due to channel hardening, equivalent to Nakagami-m fading for increasing m. It is concluded that in ad hoc networks, static and dynamic beamforming perform best, selection combining performs well but with rapidly diminishing returns with added antennas, and that space-time block coding offers only marginal gains.

Transmission capacity of ad hoc networks with spatial diversity

Directional antennas offer tremendous potential for improving the performance of ad hoc networks. Harnessing this potential, however, requires new mechanisms at the medium access and network layers for intelligently and adaptively exploiting the antenna system. While recent years have seen a surge of research into such mechanisms, the problem of developing a complete ad hoc networking system, including the unique challenge of real-life prototype development and experimentation has not been addressed. In this paper, we present utilizing directional antennas for ad hoc networking (UDAAN). UDAAN is an interacting suite of modular network- and medium access control (MAC)-layer mechanisms for adaptive control of steered or switched antenna systems in an ad hoc network. UDAAN consists of several new mechanisms-a directional power-controlled MAC, neighbor discovery with beamforming, link characterization for directional antennas, proactive routing and forwarding-all working cohesively to provide the first complete systems solution. We also describe the development of a real-life ad hoc network testbed using UDAAN with switched directional antennas, and we discuss the lessons learned during field trials. High fidelity simulation results, using the same networking code as in the prototype, are also presented both for a specific scenario and using random mobility models. For the range of parameters studied, our results show that UDAAN can produce a very significant improvement in throughput over omnidirectional communications.

Ad hoc networking with directional antennas: a complete system solution

In this paper, we present UDAAN ("utilizing directional antennas for ad hoc networking"), which is an interacting suite of modular network- and MAC-layer mechanisms for adaptive control of steered or switched antenna systems in an ad hoc network. UDAAN consists of several new mechanisms - a directional power-controlled MAC, neighbor discovery with beamforming, link characterization with directional antennas, proactive routing and forwarding all working cohesively to provide the first complete systems solution. We describe the development of a real-life ad hoc network testbed using UDAAN with switched directional antennas, and we discuss the lessons learned during field trials. High fidelity simulation results, using the same networking code as in the prototype, are also presented. For the range of parameters studied, our results show that UDAAN can produce up to a factor-of-10 improvement in throughput over omni-directional communications.

DARPA's Disruption-Tolerant Networking (DTN) program is developing technologies that enable access to information when stable end-to-end paths do not exist and network infrastructure access cannot be assured. DTN technology makes use of persistence within network nodes, along with the opportunistic use of mobility, to overcome disruptions to connectivity. In this paper, we describe the SPINDLE Disruption-Tolerant Networking system and related technology being developed at BBN under the DTN program. Using an open-source, standards-based core with a plugin architecture and well-specified interfaces, we enable independent development and insertion of innovative DoD-relevant technology while allowing the core system to be refined and engineered within a COTS context. SPINDLE technology innovations include: (i) routing algorithms that work efficiently across a wide range of network disruption, (ii) a name-management architecture for DTNs that supports progressive resolution of intentional name attributes within the network (not at the source), including support for "queries as names" and name-scheme translation, (iii) distributed caching, indexing, and retrieval approaches for disruption-tolerant content-based (rather than locator-based) access to information, and (iv) a declarative knowledge-based approach that integrates routing, intentional naming, policy-based resource management, and content-based access to information. We present preliminary results that show that the DTN approach outperforms traditional end-to-end approaches across a wide range of network disruption.

/pdf/the-spindle-disruption-tolerant-networking-system-4jan3cbqro.pdf

The SPINDLE Disruption-Tolerant Networking System

We consider the concept of opportunistic spectrum access (OSA) -- whereby radios identify unused portions of licensed spectrum, and utilize that spectrum without adverse impact on the primary licensees. OSA allows both dramatically higher spectrum utilization and near-zero deployment time, with an obvious and significant impact on both civilian and military communications. We discuss two broad classes of challenges to OSA: spectrum agility, which involves wideband sensing, opportunity identification, coordination and use; and policy agility, which enables regulatory policies to be applied dynamically using machine understandable policies. Focusing on spectrum agility, we present an architecture based on an OSA adaptation layer. We describe protocols for OSA, including a hole information protocol, idle channel selection and use, and an access protocol for the coordination channel. We present a simulation study, discuss insights, and show that even a simple protocol for opportunistic spectrum allocation can provide an order-of-magnitude performance improvement in throughput over a legacy system.

Opportunistic spectrum access: challenges, architecture, protocols

Systems and methods are disclosed for determining whether a mission has occurred. The disclosed systems and methods utilize event models that represent a sequence of tasks that an entity could or must take in order to successfully complete the mission. As a specific example, an event model may represent the sequence of tasks a malicious insider may complete in order to exfiltrate sensitive information. Most event models include certain tasks that must be accomplished in order for the insider to successfully exfiltrate an organization's sensitive information. Many of the observable tasks in the attack models can be monitored using relatively little information, such as the source, time, and type of the communication. The monitored information is utilized in a traceback search through the event model for occurrences of the tasks of the event model to determine whether the mission that the event model represents occurred.

S. Polit

Papers

Ad hoc networking with directional antennas: a complete system solution

Ad hoc networking with directional antennas: a complete system solution

The SPINDLE Disruption-Tolerant Networking System

Opportunistic spectrum access: challenges, architecture, protocols

Systems and methods for detecting malicious insiders using event models