Capacity Gain through Power Enhancement in Multi-Radio Multi-Channel Wireless Networks

Abstract-The main focus of this paper is to show theoretically that power is a crucial factor in multi-radio multi-channel (MR-MC) wireless networks and hence by judiciously leveraging the power, one can realize a considerable gain on the capacity for MR-MC wireless networks. Such a capacity gain through power enhancement is revealed by our new insights of a co-channel enlarging effect. In particular, when the number of available channels ( ) in a network is larger than that necessary for enabling the maximum set of simultaneous transmissions (˜ ), allocating transmissions to those additional −˜ channels could enlarge the distance between the co-channel transmissions; the larger co-channel distance then allows a higher transmission power for higher link capacity. The finding of this paper specifically indicate that by exploiting the co-channel enlarging effect with power, one can realize the following gain on the capacity for MR-MC wireless networks: (i) In the channelconstraint region (˜ < < 2 ), if each node augments its power from the minimum to ˜ 2 , then a gain of Θ(log( ˜ ) 2 ) is achieved; (ii) In the power-constraint region ( ≥ 2 ), if each node sends at the maximum power level, = . or .2 2 , depending on the power availability at a node, then a gain of Θ(log ) or Θ( ) is achieved, respectively

FIDES: Enhancing Trust in Reconfigurable Based Hardware Systems

Extensive use of third party IP cores (e.g., HDL, netlist) and open source tools in the FPGA application design and development process in conjunction with the inadequate bitstream protection measures have raised crucial security concerns in the past for reconfigurable hardware systems. Designing high fidelity and secure methodologies for FPGAs are still infancy and in particular, there are almost no concrete methods/techniques that can ensure trust in FPGA applications not entirely designed and/or developed in a trusted environment. This work strongly suggests the need for an anomaly detection capability within the FPGAs that can continuously monitor the behavior of the underlying FPGA IP cores and the communication activities of IP cores with other IP cores or peripherals for any abnormalities. To capture this need, we propose a technique called FIDelity Enhancing Security (FIDES) methodology for FPGAs that uses a combination of access control policies and behavior learning techniques for anomaly detection. FIDES essentially comprises of two components: (i) {\em Trusted Wrappers}, a layer of monitors with sensing capabilities distributed across the FPGA fabric; these wrappers embed the output of each IP core $i$ with a tag $\tau_i$ according to the pre-defined security policy $\Pi$ and also verifies the embeddings of each input to the IP core to detect any violation of policies. The use of tagging and tracking enables us to capture the normal interactions of each IP core with its environment (e.g., other IP cores, memory, OS or I/O ports). {\em Trusted Wrappers} also monitors the statistical properties exhibited by each IP core module on execution such as power consumption, number of clock cycles and timing variations to detect any anomalous operations; (ii) a {\em Trusted Anchor} that monitors the communication between the IP cores and the peripherals with regard to the centralized security policies $\Psi$ as well as the statistical properties produced by the peripherals. We target FIDES architecture on a Xilinx Zynq 7020 device implemented with a red-black system comprising of sensitive and non-sensitive IP cores. Our results show that FIDES implementation leads to only 1-2\% overhead in terms of the logic resources per wrapper and incurs minimal latency per wrapper for tag verification and embedding. On the other hand, as compared to the baseline implementation, when all the communications within the system are routed to the Trusted Anchor for centralized policy checking and verification, a latency of 1.5X clock cycles is observed; this clearly manifests the advantage of using distributed wrappers as opposed to centralized policy checking

Advancing the State-of-the-Art in Hardware Trojans Detection

Over the past decade, Hardware Trojans (HTs) research community has made significant progress towards developing effective countermeasures for various types of HTs, yet these countermeasures are shown to be circumvented by sophisticated HTs designed subsequently. Therefore, instead of guaranteeing a certain (low) false negative rate for a small \textit{constant} set of publicly known HTs, a rigorous security framework of HTs should provide an effective algorithm to detect any HT from an \textit{exponentially large} class (exponential in number of wires in IP core) of HTs with negligible false negative rate. In this work, we present HaTCh, the first rigorous algorithm of HT detection within the paradigm of pre-silicon logic testing based tools. HaTCh detects any HT from $H_D$, a huge class of deterministic HTs which is orders of magnitude larger than the small subclass (e.g. TrustHub) considered in the current literature. We prove that HaTCh offers negligible false negative rate and controllable false positive rate for the class $H_D$. Given certain global characteristics regarding the stealthiness of the HT within $H_D$, the computational complexity of HaTCh for practical HTs scales polynomially with the number of wires in the IP core. We implement and test HaTCh on TrustHub and other sophisticated HTs

DESIGN AND OPTIMIZATION OF NEXT GENERATION WIRELESS NETWORKS

A novel paradigm of communication, multi-hop wireless networks, have recently emerged both as a promising and cost-effective architecture to meet the evergrowing demands and expectations of the users. In these class of networks, a collection of wireless nodes dynamically establish and maintain connectivity among themselves, thus, enabling users and nodes to seamlessly internetwork in areas with a little or no communication infrastructure. Due to the self-organizing and self-configuring nature, these networks make a suitable choice for variety of applications ranging from broadband home networking, intelligent transport system (ITS) to smart grid networking. In spite of the multiple aspects of advantages, however, research efforts have shown that when nodes are randomly or arbitrarily placed in a two-dimensional region, the amount of information that can be transmitted by each source-destination pair in a multi-hop fashion becomes vanishingly small, as number of nodes grows to a large level. Although, in the past, we have designed and developed several solutions to improve the efficiency of protocols for multi-hop wireless networks, the overall information-carrying capacity of these networks is still a critical issue to meet the increasing user requirements. Motivated by such an issue, in this dissertation we are concerned with the problem of optimizing the capacity of multi-hop wireless networks. First, we propose to use a combination of cooperative communications and multiple channels, which together has great potential to evade various issues that limits the capacity of wireless networks. Further, using the insights of the proposed approach, we design a channel allocation protocol at the MAC layer for wireless networks employing cooperative communications. We also construct an analytical model to optimize the parameters used in the MAC protocol design. Second, we study the performance improvement in a multi-hop wireless network by coupling it with the coverage and capacity of infrastructure networks, referred to as hybrid wireless networks. In doing so, we point out severe flaws in the existing research efforts and design a simple and practical power-aware routing policy, that can adapt to the operating environment, for hybrid wireless networks. In comparison to existing works, we clearly show the gain one could obtain on delay as well as on capacity in executing our design. Lastly, we propose to use transmission power of nodes to increase the amount of information sent across each wireless link. While prior solutions rely on minimum transmission power to improve spatial reuse or lifetime of nodes, we look at the power problem from a different perspective and show that one can obtain a significant gain in capacity by judiciously enhancing the power in a multi-channel multi-hop wireless network. To prove this interesting result, we essentially introduce the novel concept of a co-channel enlarging effect and then quantify the maximum power at which nodes can communicate on a given channel, without causing harmful interference to other simultaneously communicating pairs. We conclude this dissertation by identifying open issues that need further investigation.Ph.D. in Computer Engineering, May 201