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In this paper, novel simultaneous query techniques are proposed for wireless networks, which allow the access point (AP) of the network to gather key control information from active nodes in the network at low overhead. The query techniques are based on OFDM, and include the analog bloom filter (ABF), with which active nodes send signals simultaneously on randomly selected subcarriers to inform the...
In this paper we treat the problem of identification of a subset of active users in a set of a large number of potentially active users. The users from the subset are activated randomly, such that the access point (AP) does not know the subset or its size a priori. The active users are contending to report their activity to the AP over a multiple access channel. We devise a contention algorithm that...
Wireless sensor network is one of the most promising technology in wireless network. To design a sensor network, improving the lifetime of sensor node is critical issue. For these reason researchers in these field pay great attention to Medium Access Control (MAC) protocol. As most of the nodes are placed in remote and hazardous area, so when the power is down it is difficult to recharge them or it...
We propose a device discovery approach and connection establishment scheme for opportunistic networks using Ad-Hoc Wi-Fi as the underlying communication technology. We employ beacon stuffing method for a device to announce its existence in its neighborhood by broadcasting beacons stuffed with useful information in the field of SSID to remote devices. This method can allow a device to discover multiple...
Underwater acoustic networks (UWANs) have emerged as the primary tool to monitor and act upon the well-being of marine environment. However, the significantly slower propagation speed of acoustic signals, in contrast to RF signals, introduces the spatio-temporal uncertainty, which makes existing medium access control (MAC) solutions for terrestrial RF wireless networks unsuitable for UWANs. In this...
The acoustic propagation speed under water poses significant challenges to the design of underwater sensor networks and their medium access control protocols. Similar to the air, scheduling transmissions under water have significant impacts on throughput, energy consumption, and reliability. Although the conflict scenarios and required scheduling constraints for deriving a collision-free schedule...
WLAN systems based on the IEEE 802.11 could contain hundreds even up to thousands of wireless access points nowadays. However, IEEE 802.11 MAC protocols, including DCF, PCF and EDCA mechanisms, are unable to meet the challenges to provide collision freedom, especially in distributed large scale WLAN systems. We propose a channel access scheduling protocol based on Latin squares, called DCLASS (Distributed...
The MAC protocol is important, especially for wireless LAN because of limited bandwidth. A great deal of research has been carried out and some of proposed schemes are effective. Specifically, considerable effort has been devoted to improving the IEEE 802.11 standard which is utilized widely. Previous theoretical analysis gave the upper bound of IEEE 802.11 DCF throughput which is far below the channel...
Limited bandwidth remains a pressing issue for wireless sensor networks (WSNs) due to the half-duplex property of the sensor radio and the broadcast nature of wireless medium. Designing multi-channel MAC protocol attracts the interest of many researchers as a cost effective solution to meet the higher bandwidth demand for the limited bandwidth in WSN. In this paper, we present a scheduled-based multi-channel...
WSNs are inherently power constrained and are often deployed in harsh environments. As such, node death is a possibility that must be considered while designing protocols for such networks. Rerouting of data is generally necessary so that data from the descendant nodes of the dead node can reach the sink. Since slot allocation in TDMA MAC protocols is generally done based on the routing tree, all...
Airborne backbone networks are useful in tactical applications to interconnect sub-networks. A major challenge in such networks, normally comprising large numbers of highly mobile nodes, is the design of the medium access control (MAC) and routing protocols. We propose integration of MAC and routing functions, which use the attributes of a clustering scheme that addresses scalability. The reactive...
In this paper, we explore the idea of using traffic forecasting to improve the delay performance of a schedule-based medium access control protocol. Schedule-based channel access has been shown to utilize network and energy resources efficiently but is often hindered by the extra delay that scheduling introduces. We explore the use of traffic forecasting to anticipate transmission schedules instead...
Wireless sensor networks (WSN) are being widely deployed and used in sensing, collecting, and disseminating data for various applications in the environmental, industrial, and military sectors. The primary concern in WSNs lies in minimizing the communication between sensor nodes while achieving the desired network operation; thus extending the life time of sensor nodes. In this paper we present an...
This paper focuses on the design of communication strategies between vehicle to roadside unit (RSU). For reducing the contention probability and increasing the probability of uploading high-priority data to the RSU, the IEEE 802.11 PCF MAC protocol is used within the signal coverage rage of RSU. Based on the PCF MAC, a priority-based bandwidth request scheme is applied to increase the probability...
Several underwater network characteristics, including long propagation delays and a bandwidth dependent on distance, provide unique challenges to protocol designers. In this paper we present STUMP-WR, a distributed routing and channel scheduling protocol, designed for heavily loaded underwater networks. STUMP-WR selects and schedules links using a distributed algorithm to overlap communications by...
We consider the problem of selfish misbehavior in scheduling algorithms of wireless networks. All wireless scheduling algorithms are designed under the assumption that network users will follow the algorithm specifications. In this paper, we study two scheduling algorithms in which a selfish user might misbehave in order to achieve better performance. In the first case, we consider a network that...
This paper introduces a light-weight mobility-aware medium access control protocol for wireless sensor networks (MA-MAC). In many respects, the protocol is similar to preamble based, low power listening MAC protocols. It defines a duty-cycle to let nodes sleep when they have no packets to transmit. During active communication, the protocol estimates mobility by evaluating the received signal strength...
Wireless sensor networks typically conserve energy by following a periodic wakeup-sleep schedule: nodes minimize idle time and spend most of their time in a low power sleep state. In order to communicate and exchange data in such a network, the current duty-cycling MAC protocols either require tight synchronization between the neighbor wakeup schedules or spend a significant amount of energy in signaling...
The Mesh Coordinated Channel Access (MCCA) defined by the IEEE 802.11s draft standard implements a TDMA-based Medium Access Control (MAC) protocol by allowing mesh routers to negotiate collision-free transmission opportunities, called MCCAOPs, in a hop-by-hop manner. The procedure to determine the duration, in time slots, and the periodic schedule of MCCAOPs is however left unspecified by the standard...
In wireless sensor networks, centralized data collection at sink leads to funneling effect which causes traffic intensity. This phenomenon results in significant packet collision, congestion, and loss. Researcher has proposed a localized, sink-oriented funneling-MAC to mitigate this funneling effect. Actually, this MAC protocol contributes to reduce this problem. However, funneling-MAC is difficult...
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