1,164 research outputs found
Cross-layer Balanced and Reliable Opportunistic Routing Algorithm for Mobile Ad Hoc Networks
For improving the efficiency and the reliability of the opportunistic routing
algorithm, in this paper, we propose the cross-layer and reliable opportunistic
routing algorithm (CBRT) for Mobile Ad Hoc Networks, which introduces the
improved efficiency fuzzy logic and humoral regulation inspired topology
control into the opportunistic routing algorithm. In CBRT, the inputs of the
fuzzy logic system are the relative variance (rv) of the metrics rather than
the values of the metrics, which reduces the number of fuzzy rules
dramatically. Moreover, the number of fuzzy rules does not increase when the
number of inputs increases. For reducing the control cost, in CBRT, the node
degree in the candidate relays set is a range rather than a constant number.
The nodes are divided into different categories based on their node degree in
the candidate relays set. The nodes adjust their transmission range based on
which categories that they belong to. Additionally, for investigating the
effection of the node mobility on routing performance, we propose a link
lifetime prediction algorithm which takes both the moving speed and moving
direction into account. In CBRT, the source node determines the relaying
priorities of the relaying nodes based on their utilities. The relaying node
which the utility is large will have high priority to relay the data packet. By
these innovations, the network performance in CBRT is much better than that in
ExOR, however, the computation complexity is not increased in CBRT.Comment: 14 pages, 17 figures, 31 formulas, IEEE Sensors Journal, 201
Role of Neural Network in Mobile Ad Hoc Networks for Mobility Prediction
The MANETs differ from traditional networks in a lot of aspects, such as high channel error rates, unusual channel features, frequent link breaks, and intense link layer contentions. These characteristics significantly reduce network connectivity, which affects overall network latency, network overhead, network throughput (i.e. the amount of data successfully transferred via a MANETs in a predetermined amount of time), and packet delivery ratio (PDR). For effective network resources preparation and organization in MANETs, the mobility forecast of MN and units is essential. This effectiveness would allow for better planning and higher overall quality - of - service, including reliable facility availability and efficient management of energy. In this research, we suggest to use ELMs, which are renowned for their ability to approximate anything, to model and forecast the mobility of each node in a MANET. Mobility-aware topology control methods and location-assisted routing both leverage mobility prediction in MANETs. It is assumed that each MN taking part in these protocols is aware of its current mobility data, including location, velocity, and movements direction angle. This approach predicts both the locations of future nodes and the distances between subsequent nodes. The interaction or relationship between the Cartesian longitude and latitude of the erratic nodes is better captured by ELMs than by multilayer perceptron’s, resulting in mobility prediction that is based on several conventional mobility models that is more precise and realistic
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Reliable on-demand routing protocols for mobile ad-hoc networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.Mobile Ad-Hoc Network (MANET) facilitates the creation of dynamic reconfigurable networks, without centralized infrastructure. MANET routing protocols have to face high challenges like link instability, node mobility, frequently changing topologies and energy consumption of node, due to these challenges routing becomes one of the core issues in MANETs. This Thesis mainly focuses on the reactive routing protocol such as Ad-Hoc On-Demand Distance Vector (AODV) routing protocol. Reliable and Efficient Reactive Routing Protocol (RERRP) for MANET has been proposed to reduce the link breakages between the moving nodes. This scheme selects a reliable route using Reliability Factor (RF); the RF considers Route Expiration Time and Hop Count to select a routing path with high reliability and have less number of hops. The simulation result shows that RERRP outperforms AODV and enhance the packet delivery fraction (PDF) by around 6% and reduces the network routing load (NRL) by around 30%. Broadcasting in MANET could cause serious redundancy, contention, and collision of the packets. A scheme, Effective Broadcast Control Routing Protocol (EBCRP) has been proposed for the controlling of broadcast storm problem in a MANET. The EBCRP is mainly selects the reliable node while controlling the redundant re-broadcast of the route request packet. The proposed algorithm EBCRP is an on-demand routing protocol, therefore AODV route discovery mechanism was selected as the base of this scheme. The analysis of the performance of EBCRP has revealed that the EBCRP have controlled the routing overhead significantly, reduces it around 70% and enhance the packet delivery by 13% as compared to AODV. An Energy Sensible and Route Stability Based Routing Protocol (ESRSBR) have also been proposed that mainly focuses on increasing the network lifetime with better packet delivery. The ESRSBR supports those nodes to participate in the data transfer that have more residual energy related to their neighbour nodes. The proposed protocol also keeps track of the stability of the links between the nodes. Finally, the ESRSBR selects those routes which consist of nodes that have more residual energy and have stable links. The comparative analysis of ESRSBR with AODV and recently proposed routing protocol called Link Stability and Energy Aware (LSEA) routing protocol revealed that the proposed protocol ESRSBR has a significantly affect the network lifetime, increases it around 10% and 13% as compared to LSEA and AODV protocols respectively. The ESRSBR also decreases the routing overhead by 22% over LSEA and by 38% over AODV.Higher Education Commission of Pakistan and NED University of Engineering and Technology Karach
Research on Quality of Service Based Routing Protocols for Mobile Ad Hoc Networks
Quality of service (QoS) based routing protocols play a significant role in MANETs to maintain proper flow of data with efficient power consumption and without data loss. However, several network resource based technical challenges or issues are encountered in the design and implementation of QoS routing protocols that perform their routing function by considering the shortest route or the lowest cost. Furthermore, a secondary route is not reserved and alternative routes are not searched unless the established route is broken. The current structures of the state-of-the-art protocols for MANETs are not appropriate for today's high bandwidth and mobility requirements. Therefore, research on new routing protocols is needed, considering energy level, coverage, location, speed, movement, and link stability instead of only shortest path and lowest cost. This paper summarizes the main characteristics of QoS-based routing protocols to facilitate researchers to design and select QoS-based routing protocols. In this study, a wide range of protocols with their characteristics were classified according to QoS routing strategy, routing information update mechanism, interaction between network and MAC layer, QoS constraints, QoS guarantee type and number of discovered routes. In addition, the protocols were compared in terms of properties, design features, challenges and QoS metrics
Role of Deep Learning in Mobile Ad-hoc Networks
The portable capability of MANETs has specially delighted in an unexpected expansion. A massive need for dynamic ad-hoc basis networking continues to be created by advancements in hardware design, high-speed growth in the wireless network communications infrastructure, and increased user requirements for node mobility and regional delivery processes. There are several challenging issues in mobile ad-hoc networks, such as machine learning method cannot analyze features like node mobility, channel variation, channel interference because of the absence of deep neural layers. Due to decentralized nature of mobile ad hoc networks, its necessitate to concentrate over some extremely serious issues like stability, scalability, routing based problems such as network congestion, optimal path selection, etc. and security
Resource-efficient strategies for mobile ad-hoc networking
The ubiquity and widespread availability of wireless mobile devices with ever increasing
inter-connectivity (e. g. by means of Bluetooth, WiFi or UWB) have led to new and emerging
next generation mobile communication paradigms, such as the Mobile Ad-hoc NETworks
(MANETs). MANETs are differentiated from traditional mobile systems by their unique properties,
e. g. unpredictable nodal location, unstable topology and multi-hop packet relay. The
success of on-going research in communications involving MANETs has encouraged their applications
in areas with stringent performance requirements such as the e-healthcare, e. g. to
connect them with existing systems to deliver e-healthcare services anytime anywhere. However,
given that the capacity of mobile devices is restricted by their resource constraints (e. g.
computing power, energy supply and bandwidth), a fundamental challenge in MANETs is how
to realize the crucial performance/Quality of Service (QoS) expectations of communications in
a network of high dynamism without overusing the limited resources.
A variety of networking technologies (e. g. routing, mobility estimation and connectivity
prediction) have been developed to overcome the topological instability and unpredictability
and to enable communications in MANETs with satisfactory performance or QoS. However,
these technologies often feature a high consumption of power and/or bandwidth, which makes
them unsuitable for resource constrained handheld or embedded mobile devices. In particular,
existing strategies of routing and mobility characterization are shown to achieve fairly
good performance but at the expense of excessive traffic overhead or energy consumption. For
instance, existing hybrid routing protocols in dense MANETs are based in two-dimensional organizations
that produce heavy proactive traffic. In sparse MANETs, existing packet delivery
strategy often replicates too many copies of a packet for a QoS target. In addition, existing
tools for measuring nodal mobility are based on either the GPS or GPS-free positioning systems,
which incur intensive communications/computations that are costly for battery-powered
terminals. There is a need to develop economical networking strategies (in terms of resource
utilization) in delivering the desired performance/soft QoS targets.
The main goal of this project is to develop new networking strategies (in particular, for
routing and mobility characterization) that are efficient in terms of resource consumptions while
being effective in realizing performance expectations for communication services (e. g. in the
scenario of e-healthcare emergency) with critical QoS requirements in resource-constrained
MANETs.
The main contributions of the thesis are threefold:
(1) In order to tackle the inefficient bandwidth utilization of hybrid service/routing discovery
in dense MANETs, a novel "track-based" scheme is developed. The scheme deploys
a one-dimensional track-like structure for hybrid routing and service discovery. In comparison
with existing hybrid routing/service discovery protocols that are based on two-dimensional
structures, the track-based scheme is more efficient in terms of traffic overhead (e. g. about 60%
less in low mobility scenarios as shown in Fig. 3.4). Due to the way "provocative tracks" are
established, the scheme has also the capability to adapt to the network traffic and mobility for
a better performance.
(2) To minimize the resource utilization of packet delivery in sparse MANETs where wireless
links are intermittently connected, a store-and-forward based scheme, "adaptive multicopy
routing", was developed for packet delivery in sparse mobile ad-hoc networks. Instead
of relying on the source to control the delivery overhead as in the conventional multi-copy
protocols, the scheme allows each intermediate node to independently decide whether to forward
a packet according to the soft QoS target and local network conditions. Therefore, the
scheme can adapt to varying networking situations that cannot be anticipated in conventional
source-defined strategies and deliver packets for a specific QoS targets using minimum traffic
overhead.
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(3) The important issue of mobility measurement that imposes heavy communication/computation
burdens on a mobile is addressed with a set of resource-efficient "GPS-free" soluti ons,
which provide mobility characterization with minimal resource utilization for ranging and signalling
by making use of the information of the time-varying ranges between neighbouring
mobile nodes (or groups of mobile nodes). The range-based solutions for mobility characterization
consist of a new mobility metric for network-wide performance measurement, two
velocity estimators for approximating the inter-node relative speeds, and a new scheme for
characterizing the nodal mobility. The new metric and its variants are capable of capturing the
mobility of a network as well as predicting the performance. The velocity estimators are used to
measure the speed and orientation of a mobile relative to its neighbours, given the presence of a
departing node. Based on the velocity estimators, the new scheme for mobility characterization
is capable of characterizing the mobility of a node that are associated with topological stability,
i. e. the node's speeds, orientations relative to its neighbouring nodes and its past epoch time.
iiiBIOPATTERN EU Network of Excellence (EU Contract 508803
Vehicular ad hoc routing protocol with link expiration time (VARP-LET) information
This thesis presents a vehicular ad hoc routing protocol that uses link expiration time (LET) information in selection of routes. The proposed protocol is named as VARP-LET, which uses LET information to increase reliability and stability of the routes. LET information is used selectively in the route discovery mechanism to reduce the routing control overhead. In addition to LET a Route Break Indicator (RBI) message is introduced. RBI is generated when a link breakage is about to occur. A source node on receiving the RBI signal preemptively stops sending data packets through a route before it breaks. This provision decreases the packet loss. The effectiveness of LET and RBI is tested via network simulations with NS-2. These simulations show that VARP-LET protocol increases packet delivery ratio by 20.7% in street section mobility model and by 30% in highway mobility scenario compared to regular AODV protocol. It is also shown that the protocol significantly reduces frequent route failure and routing overhead
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