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Emergency nodes, i.e, nodes with priority 7 as per 802.15.6 standard play a very important role in facilitating the immediate transfer of information during life threatening situations. These nodes should relay critical information with utmost reliability and in the shortest possible time. IEEE 802.15.6 provides the necessary functionality to these nodes by adapting the contention window sizes as...
Wireless Body Area Network (WBAN) is an excellent technology for chronic healthcare monitoring applications. In which, sensor nodes are connected wirelessly in, on or near the human body and also responsible for Data Collection, Data Processing and Data Transmission. Sensor nodes are generally powered by small batteries with sturdily restricted energy resources, so minimizing the energy consumption...
In wireless adhoc network, important issue is connectivity between nodes & establishment of link. There are many parameters which influences packet delivery ratio, throughput & energy of a node but it has strong dependency on distance between the nodes & their placement. For commercial wireless network uniform distribution of nodes are impractical but implementing connectivity of non-uniform...
Wimax is an broadband wireless technology based on IEEE 802.16. It is very helpful and cheaper than other possible solutions. It is purely based on the 4G technology for the upcoming generation. In wireless technology the major problem is speed, Quality of Service, data rates in order to overcome that they going for some valuable technology. In this paper we consider WIMAX and WLAN for controlling...
The current Medium Access Control (MAC) protocol of the Wireless Access in Vehicular Environments (WAVE) system does not consider time utilization of CCH and SCH. In this paper, we present a novel mechanism to extend MAC protocol, which dynamically adjusts the length of Control Channel (CCH) and Service Channel (SCH) intervals according to vehicle density and load conditions of network. In the proposed...
This paper introduces a novel Medium Access Control (MAC) strategy for energy efficient wireless data transmissions which reduces energy consumption while minimizing the negative impact on network Quality of Service (QoS). This strategy adaptively adjusts the sleeping window of the mobile devices' wireless transceiver. The proposed mechanism - the Slow sTart Exponential and Linear Algorithm (STELA)...
As a conventional MAC control protocol for wireless networks, IEEE 802.11 DCF hasn't taken account into the requirement, which TCP/UDP hybrid stream access needs for MAC frame length. The TCP/UDP hybrid stream's transmission delay would increase significantly, that always generate failure of TCP stream transmitting. This paper proposes an improved IEEE 802.11 DCF protocol and theory model based on...
With the development of wireless sensor networks in industry, it is difficult for MAC protocol with single channel to meet the demands of combating interference, high reliability and low delay. The multichannel MAC protocol is a promising approach to meet these challenges. IEEE 802.15.4 standard is the foundation of ZigBee, WirelessHART and ISA100. This article proposes a multi-channel MAC protocol...
In order to access to the time-Delay Performance of the Wireless Sensor Network, respectively preformed the time-delay experiment, simulation and theoretical analysis from the following aspects: the hops and hop spacing, MAC dormancy mechanism, back-off time and transmitted power, etc. Obtained the relations between the time-delay and the above factors. Systematically summed up the time-delay rules...
Platooning of vehicles allows to saving energy and increasing safety provided that there are reliable wireless communication protocols. In this paper, the optimization of the medium access control (MAC) protocol based on IEEE 802.11e for the platoon joining is investigated. The exchange of prosperous dynamic information among vehicules through certain bounded and closed-fitting timeout windows is...
As an inexpensive and scalable Internet access network, we have studied the architecture, protocols, and design optimizations of the Wireless Internet access Mesh Network (WIMNET). WIMNET is composed of multiple access points (APs) that are connected through wireless links. Previously, we have proposed the concept of the CSMA-based Fixed Back off-time Switching (CSMA-FBS) method for WIMNET to improve...
An adaptive medium access control (MAC) retransmission limit selection scheme is proposed to improve the performance of IEEE 802.11p standard MAC protocol for video streaming applications over vehicular ad-hoc networks (VANETs). A multi-objective optimization framework, which jointly minimizes the probability of playback freezes and start-up delay of the streamed video at the destination vehicle by...
Wireless sensor networks are widely used for healthcare applications. A new field known as wireless body area networks (WBAN) has emerged to support this area. An energy efficient medium access control (MAC) protocol can increase the performance of such a network. The major requirements for a WBAN MAC protocol are energy efficiency and low delay. In this paper, we propose a MAC protocol for WBAN using...
The advanced heterogeneous vehicular network (AHVN) is a new paradigm for future vehicular networks. AHVN is an integrated architecture between the VANET and the existing cellular wireless networks. This paper introduces a vehicular communications framework for efficient Multihop connectivity in AHVN. The vehicular communication in VANET is based on the failure probability of vehicular connectivity...
The employment of wireless mesh networking in real- life scenarios has attracted substantial research interest in recent years and in this context VoIP has become a ubiquitous application. However, it has been demonstrated that VoIP transmissions over a multihop network may still remain inadequate in terms of their high packet-loss ratio and network- induced delays. To alleviate these limitations,...
This paper proposes a prioritized access opportunity exchange protocol for enhancing medium access control (MAC) efficiency in short-range one-to-one wireless communications on 60 GHz millimeter wave. A random back-off access protocol is widely spread for distributed wireless networks and is adopted in IEEE 802.11 WLAN standard. When many terminals try to access a wireless medium, the protocol works...
In recent years, Wireless Sensor Networks (WSNs) have drawn broad attention in scientific research, social services, military applications, which can be widely applied in tracking, environment monitoring, but offer interesting challenges to device and protocol designers due to WSNs, which is characterized by high propagation delay and low data rate. For instant and efficient data transmission, medium...
Most of the current wireless sensor networks operate on crowded unlicensed frequency bands. Especially in industrial wireless sensor applications this causes problems because of the received interference from other systems and coexistence problems with other wireless sensor networks. Multi-channel communications can be utilized to improve the performance under interference and enable coexistence of...
This paper proposes a cross-layer design (CLD) framework called channel-aware buffer unit multiple access (C-BUMA) for improving wireless local area network (WLAN) performance. In the framework, the radio propagation (i.e. PHY layer) is combined with the medium access control (MAC) protocol for packet transmissions. By sharing channel information with the MAC protocol, the approach reduced unnecessary...
The paper analysed MAC protocol based on multiple-channel RMA by dividing transmission time of information packet into 1 & a. The paper adopts a joint-control strategy that detect with probability p1 in time 1, detect with probability p2 in time a. On this basis the paper brought forward a new RMA and wireless sensor networks MAC protocol. The paper resolves the throughput of the system, of the...
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