Game-Theoretic Channel Allocation in Cognitive Radio Networks

Cognitive radio networks provide dynamic spectrum access techniques to support the increase in spectrum demand. In particular, the spectrum sharing among primary and secondary users can improve spectrum utilization in unused spectrum by primary users. In this paper, we propose a novel game theoretic channel allocation framework to maximize channel utilization in cognitive radio networks. We degisn the utility function based on the co-channel interference among primary and secondary users. In addition, we embed the property of the adjacent channel intererence to consider real wireless environment. The results show that the utility function converges quickly to Nash equilibrium and achieves channel gain by up to 25 dB compared to initial assignment

IACR: an interference-aware channel reservation for wireless sensor networks

In battery-based wireless sensor networks, energy-efficient operation is one of the most important factors. Especially, in order to improve energy efficiency in wireless sensor networks, various studies on low power operation have been actively conducted in the MAC layer. In recent years, mutual interference among various radio technologies using the same radio frequency band has become a serious problem. Wi-Fi, ZigBee, and Bluetooth use the same frequency band of 2.4GHz at the same time, which causes various signal interference problems. In this paper, we propose a novel channel reservation scheme, called IACR, to improve the energy efficiency of wireless sensor networks in an environment where interference occurs between various wireless technologies. The proposed scheme inserts a PN code into a long preamble for exchanging transmission status information between a transmitting node and a receiving node, thereby improving the transmission success probability while receiving less influence on transmission of other radio technologies. We performed an event-driven simulation and an experiment to measure the signal detection rate. As a result, it can be seen that the proposed technique reduces the packet drop rate by 15% and increases the discoverable distance of the control packet for channel reservation

Light-weight Routing Protocol in IoT-based Inter-Device Telecommunication Wireless Environment

The primary task for IoT-based hyper-connectivity communications lies in the development of direct communications technique among IoT devices in RPL (Routing Protocol for Low-Power and Lossy Networks) environment without the aid from infras such as access points, base stations etc. In a low-power and lossy wireless network, IoT devices and routers cannot keep the original path toward the destination since they have the limited memory, except for a limited number of the default router information.. Different from the previous light-weight routing protocols focusing on the reduction of the control messages, the proposed scheme provides the light-weight IPv6 address auto-configuration, IPv6 neighbor discovery and routing protocol in a IoT capable infra-less wireless networks with the bloom filer and enhanced rank concepts. And for the first time we evaluate our proposed scheme based on the modeling of various probability distributions in the IoT environments with the lossy wireless link. Specifically, the proposed enhanced RPL based light-weight routing protocol improves the robustness with the multi-paths locally established based on the enhanced rank concepts even though lossy wireless links are existed. We showed the improvements of the proposed scheme up to 40% than the RPL based protocol

Analysis of IEEE 802.15.4 Beacon-Enabled MAC Protocol

This paper aims to develop several mathematical models to study medium access control (MAC) protocol in the IEEE 802.15.4 beacon-enabled mode with star topology. In particular, the MAC protocol which employs a slotted carrier-sense multiple access with collision avoidance (CSMA/CA) algorithm used in the contention access period (CAP) of a superframe is modelled. The analysis studies the effectiveness of the CSMA/CA algorithm and provides explicit mathematical expressions for power consumption, access delay, and data frame drop probability. The proposed models precisely follow CSMA/CA algorithm in MAC protocol of beacon-enabled mode and differ from those previously published in the literature as 1) they are derived based on data frame generation rate of end devices, 2) they provide a completed expression for frame access delay, and 3) lowpower states of end devices are considered for power efficiency evaluations. The paper shows how power consumption of end devices is improved on the balance with data frame delay. The validity of the proposed models is confirmed and complemented by extensive simulations

EETA: An Energy Efficient Transmission Alignment for Wireless Sensor Network Applications

Energy conserving MAC protocols performing adaptive duty-cycling mechanism have been widely studied to improve the energy efficiency in Wireless Sensor Networks (WSNs). In particular, several asynchronous Low Power Listening (LPL) MAC protocols such as B-MAC, X-MAC and ContikiMAC transmit a long preamble or consecutive data packets for an efficient rendezvous between senders and receivers. However, the rendezvous results in the challenging problem of unnecessary channel utilization since the senders occupy a large portion of the medium. Furthermore, when a traffic generation time overlaps with other neighbouring nodes, they frequently encounter spatially-correlated contention incurring excessive channel contention. In this paper, we propose a novel traffic distribution scheme called an Energy Efficient Transmission Alignment (EETA), that shifts a traffic generation time of the application layer. By using a MAC layer feedback including contention information, the cross-layer framework determines whether the node delays its transmission or not. EETA is robust from the heavy contending environment due to its traffic distribution feature. We evaluate the performance of EETA through diverse experiments on the TelosB platform. The results show that EETA improves the overall energy efficiency by up to 35%, and reduces the latency by up to 48% compared to the existing scheme

Design and implementation of heterogeneous surface gateway for underwater acoustic sensor network

Underwater Acoustic Sensor Networks (UASNs) are used for diverse purposes such as pollution monitoring, disaster prevention and industrial sensing in the oceans. Especially, UASNs are mainly focusing on monitoring various underwater environmental data and delivering the data to a monitoring center where nearby or far from the deployed area. To reliably deliver the data, a surface gateway should convert acoustic signal to RF (Radio Frequency) signal. In this paper, we devise a multiple interfaces-based surface gateway that can connect both a cellular network and a Zigbee network. Depends on the service requirement, the surface gateway can easily adopt each wireless interface and relay the data to a low power ZigBee network or a long range CDMA network

Performance Evaluations for IEEE 802.15.4-based IoT Smart Home Solution

The Internet of Things (IoT) is going to be a market-changing force for a variety of real-time applications such as e-healthcare, home automation, environmental monitoring, and industrial automation. Low power wireless communication protocols offering long lifetime and high reliability such as the IEEE 802.15.4 standard have been a key enabling technology for IoT deployments and are deployed for home automation recently. The issues of the IEEE 802.15.4 networks have moved from theory to real world deployments. The work presented herein intends to demonstrate the use of the IEEE 802.15.4 standard in recent IoT commercial products for smart home applications: the Smart Home Starter Kit. The contributions of the paper are twofold. First, the paper presents how the IEEE 802.15.4 standard is employed in Smart Home Starter Kit. In particular, network topology, network operations, and data transfer mode are investigated. Second, network performance metrics such as end-to-end (E2E) delay and frame reception ratio (FRR) are evaluated by experiments. In addition, the paper discusses several directions for future improvements of home automation commercial products

An energy-efficient cluster head selection in wireless sensor network using grey wolf optimization algorithm

Clustering is considered as one of the most prominent solutions to preserve theenergy in the wireless sensor networks. However, for optimal clustering, anenergy efficient cluster head selection is quite important. Improper selectionofcluster heads(CHs) consumes high energy compared to other sensor nodesdue to the transmission of data packets between the cluster members and thesink node. Thereby, it reduces the network lifetime and performance of thenetwork. In order to overcome the issues, we propose a novelcluster headselection approach usinggrey wolf optimization algorithm(GWO) namelyGWO-CH which considers the residual energy, intra-cluster and sink distance.In addition to that, we formulated an objective function and weight parametersfor anefficient cluster head selection and cluster formation. The proposedalgorithm is tested in different wireless sensor network scenarios by varyingthe number of sensor nodes and cluster heads. The observed results conveythat the proposed algorithm outperforms in terms of achieving better networkperformance compare to other algorithms

Dual Wake-up Low Power Listening for Duty Cycled Wireless Sensor Networks

<p>Abstract</p> <p>Energy management is an interesting research area for wireless sensor networks. Relevant dutycycling (or sleep scheduling) algorithm has been actively studied at MAC, routing, and application levels. Low power listening (LPL) MAC is one of effective dutycycling techniques. This paper proposes a novel approach called dual wake-up LPL (DW-LPL). Existing LPL scheme uses a preamble detection method for both broadcast and unicast, thus suffers from severe overhearing problem at unicast transmission. DW-LPL uses a different wake-up method for unicast while using LPL-like method for broadcast; DW-LPL introduces a receiver-initiated method in which a sender waits a signal from receiver to start unicast transmission, which incurs some signaling overhead but supports flexible adaptive listening as well as overhearing removal effect. Through analysis and Mote (Telosb) experiment, we show that DW-LPL provides more energy saving than LPL and our adaptive listening scheme is effective for energy conservation in practical network topologies and traffic patterns.</p

S.: Medium access control with an energy-efficient algorithm for wireless sensor networks

Abstract. This paper proposes an enhanced B-MAC (ENBMAC), a carrier sense Medium Access Control (MAC) protocol with ultra low power operations for wireless sensor networks. Due to battery-operated computing and sensing devices in wireless sensor networks, the development of MAC protocols that efficiently reduce power consumption is an important issue. B-MAC provides bidirectional interfaces such as Clear Channel Assessment (CCA), Low Power Listening (LPL) and uses an adaptive preamble sampling scheme to optimize performance and conserve energy. This reduces the amount of energy by comparing to other MAC protocols in WSNs. However, B-MAC can not achieve the overhearing avoidance. To solve this problem, we propose Node Recognition (NR) algorithm using the next hop address in MAC layer. Because this mechanism tries to handle the overhearing avoidance, ENBMAC makes it possible to extend the lifetime of the wireless sensor networks that contain a large number of nodes. The experiment results show that ENBMAC protocol reduces the energy consumed by receiving up to 90 percent comparing to B-MAC