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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...
The law of the time to transmit a packet from a node to its intended receiver, in a wireless network with randomly deployed, multiple-antennas equipped nodes, whose communication is impaired by fading and interference, is investigated. SINR-based coverage at the physical layer is assumed, and the useful signal strength is shaped through either cooperative or non-cooperative beamforming. In particular,...
An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. A number of routing protocols such as Dynamic Source Routing (DSR), Ad Hoc on-Demand Distance Vector Routing (AODV) and Destination-Sequenced Distance-Vector (DSDV) have been implemented. In this paper, an attempt has...
One of the main challenges in wireless industrial networks is the delay caused by shared, error-prone and non-deterministic behavior of wireless communication medium. In this paper, delay statistics of IEEE 802.11e prioritized MAC layer and the improvement caused by using a Spatial Multiplexing (SM) scheme for the IEEE 802.11e-based Soft-Real-Time Wireless Industrial Networks has been analyzed. Using...
We analyze TCP-controlled bulk file transfers in a single station WLAN with nonzero propagation delay between the file server and the WLAN. Our approach is to model the flow of packets as a closed queueing network (BCMP network) with 3 service centres, one each for the Access Point and the STA, and the third for the propagation delay. The service rates of the first two are obtained by analyzing the...
Analytical studies of Medium Access Control (MAC) layer protocols can be used to improve the performance of multi-hop Wireless Sensor Networks (WSNs) in the presence of hidden stations. The selected MAC layer protocol should conform to the distributed nature of the WSNs. The IEEE 802.11 MAC layer with Distributed Coordination Function (DCF) is well suited to WSNs. Analytical studies of IEEE 802.11...
According to multimedia service distribution such as High-Definition Television (HDTV), Internet Protocol Television (IPTV) and Voice Over Internet Protocol (VoIP), the networks are required to guarantee Quality of Service (QoS) and real-time performance. Power Line Communication Technology is used for data transfer as well as the transfer of electric power. However, power line communication has some...
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...
Host identification, today, can be done at many layers of the network protocol stack depending on the identifiable parameter used for classification. But, these generally include fields from TCP/IP/MAC packets; that can be spoofed or manipulated very easily to misguide the identification process or include intolerable error into. Identification on wireless networks can be done with better precision...
Wireless communication in a car has several advantages, given that demanded safety and real-time requirements are fulfilled. This paper presents a wireless MAC protocol designed for the needs of automotive and industrial applications. The proposed MAC protocol provides special support for network traffic prioritization in order to guarantee worst-case message delays for a set of high-prioritized nodes...
The increasing use of wireless networks and the constant minituarization of electrical devices has empowered the development of body area networks (BAN). The BAN for medical applications cover continuous waveform sampling of biomedical signals, monitoring of vital signal information. In order to fulfill the diverse medical applications, these networks have to follow stringent technical requirements...
Multimedia services over resource constrained Wireless Sensor Networks (WSNs) face a performance bottleneck issue from the gateway node to the sink node. Therefore, the queue management at the gateway node is crucial for diversified messages conveyed from the front nodes to the sink node. In this study, we focus on the performance improvement upon different traffic loads over WSNs. A dynamic adaptation...
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...
In heterogeneous wireless networks, multi-interfaced mobile terminals may be connected to links with rapidly varying MAC and physical characteristics. On the other hand, current deployment of communication protocols rely on the information available at associated layer only. In order to improve transport layer performance for multi-homed mobile terminals, we propose a cross-layer approach to schedule...
Supporting QoS for safety-critical applications for intelligent transportation systems accentuates the analytical modeling of delays in vehicular networks. Such analysis is, however, challenging due to the dynamics of such a network. We make progress by deriving lower- and upper-bounds for information dissemination delays in multi-hop vehicular networks using two different routing schemes. In particular,...
We propose an efficient MAC protocol for OFDMA PONs that eliminates the synchronization requirement of ONUs and also exploits the statistical multiplexing gain among traffic of all ONUs for high performances in throughput and delay.
The main goal of the IEEE 802.11n standard is to achieve more than 100Mbps of throughput at the MAC service access point. This high throughput has been achieved via many enhancements in both the physical and MAC layers. A key enhancement is frame aggregation which reduces the overheads and increases the channel utilization efficiency. The MAC layer defines A-MSDU and A-MPDU frame aggregations in which...
The IEEE 802.11 MAC layer protocol is designed for single channel. The improvement of network throughput can be done through the enhancement of spatial reuse and the reduction of transmission collusions by the utilization of multiple channels is important. Channel allocation can exploit the multi-channel missing receiver problem besides there are other problems such as the primordial hidden terminal...
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...
Recent advances in high-speed wireless LANs with physical layer (PHY) rates reaching 600Mbps make them ideal for multimedia applications. It has been shown that efficiency at medium access control (MAC) layer decreases with increasing the PHY rate. To achieve high efficiency, few researches have tried to use aggregation in which few packets are concatenated into a larger frame. The resultant frame...
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