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A MANET or Mobile Ad-Hoc Network is decentralized in nature and it is basically a collection of heterogeneous mobile nodes which are autonomous and can communicate among themselves over the wireless link. In this infrastructure-less network, all the nodes dynamically route the packets by themselves with help of some protocols for sending or receiving the packet information. The ZRP or Zone Routing...
Applying network coding and opportunistic routing can significantly improve the throughput performance of wireless multi-hop networks, but a mismatch problem still exists among the upper flow rate, routing and lower transmission resource scheduling. This paper models the throughput optimization as a network utility function maximization in wireless multi-hop networks. By applying Lagrangian dual decomposition...
To mitigate performance anomalies due to different transmission rates and to improve throughput performance in ad-hoc networks, a previous work has proposed a new method called user cooperative mobility. It also showed that the method achieved good improvement when users appropriately move. However, it only employed theoretical evaluation which does not include detailed behavior such as capture effect...
Demand for ad-hoc networks is increasing so it is expected ad-hoc networks will exist in close proximity in the future. A contention window control method, ACWA, which improves throughput of ad-hoc network against radio interference has been recently proposed. However unfairness of throughput between ACWA and DCF might be caused. We propose a modified ACWA method (GSAR scheme) which drastically improves...
Cognitive radio (CR) is a promising method suitable for solving inefficiency spectrum policy by opportunistically identifying the vacant portions of the spectrum that are used by primary users (PUs). In cognitive radio ad hoc networks (CRAHNs), secondary users (SUs) can opportunistically utilize the spectrum that is available from PUs. In this paper, we propose a neighbor-aware distance estimated...
The connectivity in wireless communication is established based on the receiving signal strength, which is affected by distance, interference, noise, mobility, etc. As a result, a node has a limited coverage area. Therefore, the connectivity becomes one of the significant limitations in multi-hop wireless networks. The relaying concept and transmission power control were introduced to overcome the...
IEEE 802.11 WLANs use carrier sense multiple access with collision avoidance (CSMA/CA) to initiate the Request to Send / Clear to Send (RTS/CTS) handshaking mechanism that solves the hidden node problem. However RTS/CTS also causes the exposed node problem where a node is unnecessarily prevented from accessing the wireless channel even when such access will not disrupt another nodes ongoing transmission...
In this paper the performance analysis of a routing algorithm for MANETs called Service Zone Gateway Prediction (SZGP) is presented. This is a non-cooperative and hybrid type of routing with a hierarchical multilayered structure, incorporating pre-computed multipath hop-by-hop distributed connectivity. The goal is balance of the load among the nodes and reliable and energy efficient communication...
In this paper, we have discussed the experiments performed by us on Bluetooth technology. These experiments are divided into sections that describe the extension of the limitation of Bluetooth range. Section A: Here we are showing a piconet consisting of four slaves and one master in a Bluetooth ad-hoc network ranging 200meters. Section B: Three piconets with four slaves each and slave of one piconet...
Energy is a scarce resource in mobile ad hoc networks (MANETs). Network coding (NC) has been proposed recently as a means to reduce the number of transmissions and energy consumption. In this paper, we introduce energy consumption control into network coding to further enhance its performance. We propose a Sliding Window Network Coding for Energy Efficient in MANETs (SWNC-EE). The performance of the...
Vehicular ad-hoc networks (VANETs) that enable communication among vehicles have recently attracted significant interest from researchers, due to the range of practical applications they can facilitate, particularly related to road safety. Despite the stringent performance requirements for such applications, the IEEE 802.11p standard still uses the carrier sensing medium access/collision avoidance...
One key goal of Vehicular Ad-hoc Networks (VANETs) is to provide sufficient Quality-of-Service (QoS) for real-time safety applications. These applications facilitate wireless broadcast warning messages between neighboring vehicles to inform drivers on time about dangerous situations like accidents. The IEEE 1609.4 standard in DSRC defines a MAC layer implementation for multichannel operations in VANETs...
We consider a collision channel model without feedback based on a time-slotted communication channel shared by K users. In this model, packets transmitted in the same time slot collide with each other and are unrecoverable. Each user accesses the channel according to an internal periodical pattern called protocol sequence. Due to the lack of feedback, users cannot synchronize their protocol sequences,...
The use of small, low-altitude Unmanned Aerial Vehicles (UAVs) have been emerging as suitable solutions in the cellular network context to provide radio coverage in disaster recovery regions as well as in hotspot areas. However, when such hotspot groups are in movement, they create a demand for coverage and capacity at locations of their traversal, congesting the nearby ground base stations. In our...
This paper presents a mobility-aware channel allocation strategy for clustered ad hoc network. Our main novelty is to consider the mobility associated with the number of times that the channel with larger spectral distance is allocated to guide the channel allocation process, while quickly responding to changes in the network topology. In our performance evaluation, we use a realistic mobility model...
Vehicular ad-hoc networks (VANETs), as an important component of intelligent transportation systems (ITS), have been attracting more and more research interests for their various promising applications. Although various MAC protocols have been proposed, efficient medium access remains a significant challenge in VANETs, especially in improving the network throughput in heavy traffic vehicular networks...
In several community scenarios, people share benevolently their spare broadband Internet access connectivity with other people who cannot afford it. Although laudable, this sharing process can negatively affect the service received by the primary users, thus jeopardizing the continuity of this community service. In this paper we propose the use of a gateway that separates the traffic of the primary...
Unmanned aircraft systems are expected to open pathways towards the development of many new services. Owing to their airborne flexible mobility, systems using unmanned aircraft (UA) have a significant potential to change our daily lives. However, several issues with such systems need to be addressed. In particular, wireless transmission of data such as high quality video from a UA to Ground Stations...
In this paper, a cross-layer-based sensor node selection scheme in a cooperative network with equally spatially correlated channels is proposed. The equally correlated model can be used as a worst-case benchmark or as a rough approximation by assuming equal correlation coefficients for all channels. By considering the physical and link layer characteristics, one or multiple sensor nodes are selected...
In this paper, an analytical model is developed to study the performance of distributed and opportunistic multichannel bonding in IEEE 802.11ac WLANs, with co-existing legacy IEEE 802.11a/b/g users. By modeling the transmissions of legacy users and ac users with and without channel bonding in each channel as a two-level renewal process, the channel bonding probability of ac users in each secondary...
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