Showing papers in "International Journal of Wireless & Mobile Networks in 2012"
TL;DR: An intelligent network selection strategy which combines two multi attribute decision making (MADM) methods such as analytic network process (ANP) and the technique for order preference by similarity to an ideal solution (TOPSIS) method is proposed.
Abstract: Providing service continuity to the end users with best quality is a very important issue in the next generation wireless communications. With the evolution of the mobile devices towards a multimode architecture and the coexistence of multitude of radio access technologies (RAT’s), the users are able to benefit simultaneously from these RAT’s. However, the major issue in heterogeneous wireless communications is how to choose the most suitable access network for mobile’s user which can be used as long as possible for communication. To achieve this issue, this paper proposes an intelligent network selection strategy which combines two multi attribute decision making (MADM) methods such as analytic network process (ANP) and the technique for order preference by similarity to an ideal solution (TOPSIS) method. The ANP method is used to find the differentiate weights of available networks by considering each criterion and the TOPSIS method is applied to rank the alternatives. Our new strategy for network selection can dealing with the limitations of MADM methods which are the ranking abnormality and the ping-ponf effect.
39 citations
TL;DR: This paper proposes a clustering technique which will balance the load among the cluster by using some backup nodes, which will increase the network lifetime and will provide high throughput.
Abstract: In wireless sensor network, clustering is used as an effective technique to achieve scalability, selforganization, power saving, channel access, routing etc.[3]. Lifetime of sensor nodes determines the lifetime of the network and is crucial for the sensing capability.[2]. Clustering is the key technique used to extend the lifetime of a sensor network. Clustering can be used for load balancing to extend the lifetime of a sensor network by reducing energy consumption. Load balancing using clustering can also increase network scalability. Wireless sensor network with the nodes with different energy levels can prolong the network lifetime of the network and also its reliability. In this paper we propose a clustering technique which will balance the load among the cluster by using some backup nodes. The backup high energy and high processing power nodes replace the cluster head after the cluster reaches to its threshold limit. This approach will increase the network lifetime and will provide high throughput.
32 citations
TL;DR: By simulation results, it is shown that the proposed agent based congestion control technique for MANETs attains high delivery ratio and throughput with reduced delay when compared with the different existing technique.
Abstract: In Mobile Ad hoc Networks (MANETs) obstruction occurs due to the packet loss and it can be successfully reduced by involving congestion control scheme which includes routing algorithm and a flow control at the network layer. In this paper, we propose to agent based congestion control technique for MANETs. In our technique, the information about network congestion is collected and distributed by mobile agents (MA) A mobile agent based congestion control AODV routing protocol is proposed to avoid congestion in ad hoc network. Some mobile agents are collected in ad-hoc network, which carry routing information and nodes congestion status. When mobile agent movements through the network, it can select a less-loaded neighbor node as its next hop and update the routing table according to the node’s congestion status. With the support of mobile agents, the nodes can get the dynamic network topology in time. By simulation results, we have shown that our proposed technique attains high delivery ratio and throughput with reduced delay when compared with the different existing technique.
30 citations
TL;DR: Simulation results confirm that AMPDU, and Two level frame aggregation methods improve extensively data throughput, and conclude that overall, the two-level aggregation can improve throughput performance of 802.11n.
Abstract: IEEE 802.11n Draft is next-generation wireless LAN standard. This article gives detailed description and comparative study of A-MPDU and Two level frame aggregation mechanisms proposed in the latest 802.11n draft standard, which improve extensively the channel efficiency and data throughput. Ns 2 simulator is used for simulation of 802.11n WLAN frame aggregation. Simulation results confirm that AMPDU, and Two level frame aggregation methods improve extensively data throughput. It analyse the performance of each frame aggregation scheme in distinct scenarios, and it conclude that overall, the two-level aggregation can improve throughput performance of 802.11n. Two level aggregation can more effectively deliver data from multiple sources, PDR rate is much higher with much lower delay and Two level aggregation consumed less energy as compared with A-MPDU approach..
28 citations
TL;DR: From the simulation it is inferred that tight coupling with gateway relocation is performing better from handover point of view, and two mechanisms such as neighbour bandwidth reservation and gateway relocation are employed.
Abstract: In wireless communication new technologies emerges regularly with faster data rates and larger coverage area. Therefore the forthcoming challenge is to make the best possible use of the available heterogeneous network. For connecting mobile between heterogeneous networks vertical handoff is mandatory. IP Multimedia Subsystem is an emerging architecture for interworking of heterogeneous networks. In this paper we used WLAN/WiMAX/LTE heterogeneous networks. Coupling architectures such as tight coupling and loose coupling are considered. In order to reduce the latency two mechanisms such as neighbour bandwidth reservation and gateway relocation are employed. The parameters such as vertical handoff delay, Mobile scanning interval activity, neighbouring advertisement received are obtained. From the simulation it is inferred that tight coupling with gateway relocation is performing better from handover point of view.
27 citations
TL;DR: This paper introduces an algorithm of multipath OLSR (Optimized Link State Routing) for energy optimization of the nodes in the network and concludes that this solution improves the number of nodes alive by about 10 to 25% by always choosing energy optimized paths in thenetwork with some increase in normalized routing overheads.
Abstract: Mobile Adhoc Network (MANET) eliminates the complexity associated with an infrastructure networks. Wireless devices are allowed to communicate on the fly for applications. It does not rely on base station to coordinate the flow of the nodes in the network. This paper introduces an algorithm of multipath OLSR (Optimized Link State Routing) for energy optimization of the nodes in the network. It is concluded that this solution improves the number of nodes alive by about 10 to 25% by always choosing energy optimized paths in the network with some increase in normalized routing overheads.
25 citations
TL;DR: This article investigates the efficacy of a novel moment generating function (MGF) based analytical framework for calculating the ergodic channel capacities of cooperative dual-hop amplify-and-forward (CAF) relay networks under three distinct source-adaptive transmission policies in Rice and Nakagamim fading environments.
Abstract: This article investigates the efficacy of a novel moment generating function (MGF) based analytical framework for calculating the ergodic channel capacities of cooperative dual-hop amplify-and-forward (CAF) relay networks under three distinct source-adaptive transmission policies in Rice and Nakagamim fading environments. The proposed analytical approach relies on a new exponential-type integral
24 citations
TL;DR: This experiment has provided insight into the performance of vehicular traffic communication for a small realistic scenario and average delivery ratio, packet loss, and router drop as statistical measures for driver route choice with traffic light scenario are evaluated.
24 citations
TL;DR: This paper presents an efficient routing protocol named as “QoS- Cluster Based Routing Protocol” (Q-CBRP) to support QoS in Wireless Mesh Network.
Abstract: The wireless mesh network is a new emerging technology that will change the world of industrial networks connectivity to more efficient and profitable. Mesh networks consist of static wireless nodes and mobile customer; have emerged as a key technology fornew generation networks. The Quality of Service (QOS) is designed to promote and support multimedia applications (audio and video), real time. However guarantee of QoS on wireless networks is a difficult problem by comparison at its deployment in a wired IP network. In this paper, we present an efficient routing protocol named as “QoS- Cluster Based Routing Protocol” (Q-CBRP) to support QoS in Wireless Mesh Network.
22 citations
TL;DR: This paper proposes a multi-hop cluster based routing protocol which is more energy efficient than single hop protocol and shows that the protocol offers a better performance than single-hop clustering routing protocols in terms of network lifetime and energy consumption by improving FND.
Abstract: Wireless sensor networks (WSNs) are composed of many homogeneous or heterogeneous sensor nodes with limited resources. A sensor node is comprised of three components: a sensor, a processor and a wireless communication device. These sensor nodes dispersed throughout it to monitor, collect, and transmit data. The sensors are inexpensive, simple, and their power source is irreplaceable. Knowing the sensors power levels cannot be restored, many protocols have been developed to make collecting, receiving and transferring data more energy efficient. In this paper, we propose a multi-hop cluster based routing protocol which is more energy efficient than single hop protocol. Simulation results show that the protocol offers a better performance than single-hop clustering routing protocols in terms of network lifetime and energy consumption by improving FND.
22 citations
TL;DR: An attempt has been made to compare the performance of on demand reactive routing protocols i.e. Ad hoc On Demand Distance Vector and Dynamic Source Routing and as per the findings the differences in the protocol mechanics lead to significant performance differentials for both of these protocols.
Abstract: A mobile ad hoc network (MANET) is a collection of wireless mobile nodes dynamically forming a network topology without the use of any existing network infrastructure or centralized administration. Routing is the process which transmitting the data packets from a source node to a given destination. The main procedure for evaluating the performance of MANETs is simulation. The on-demand protocol performs better than the table-driven protocol. Different methods and simulation environments give different results. It is not clear how these different protocols perform under different environments. One protocol may be the best in one network configuration but the worst in another. In this paper an attempt has been made to compare the performance of on demand reactive routing protocols i.e. Ad hoc On Demand Distance Vector (AODV) and Dynamic Source Routing (DSR). As per our findings the differences in the protocol mechanics lead to significant performance differentials for both of these protocols. Always the network protocols were simulated as a function of mobility, but not as a function of network density. In our paper the performance of AODV and DSR is evaluated with respect to performance metrics like Packet Delivery Fraction (PDF), Average end-to-end delay, Normalized Routing Load (NRL) and throughput by varying network size up to 50 nodes. These simulations are carried out using the NS-2 which is the main network simulator, NAM (Network Animator), AWK (post processing script). Our results presented in this research work demonstrate the concept AODV and DSR routing protocols w.r.t. MANET size in an Ad hoc environment.
TL;DR: A new approach of cluster head selection by a homogeneous sensor node (having same initial energy) in wireless sensor network, which involves choosing the cluster head which lies closest to the midpoint of the base station and the sensor node is proposed.
Abstract: Wireless sensor networks (WSN) provide the availability of small and low-cost sensor nodes with capability of detecting, observing and monitoring the environment, along with data processing and communication. These sensor nodes have limited transmission range, processing and storage capabilities as well as their energy resources. Routing protocols for wireless sensor networks are responsible for maintaining the energy efficient paths in the network and have to ensure extended network lifetime. In this paper, we propose and analyze a new approach of cluster head selection by a homogeneous sensor node (having same initial energy) in wireless sensor network, which involves choosing the cluster head which lies closest to the midpoint of the base station and the sensor node. Our proposed routing algorithm is related with energy and distance factors of each nodes. This scheme is then compared with the traditional LEACH protocol which involves selecting the cluster head which is nearest to the particular node. We conclude that the proposed protocol effectively extends the network lifetime with less consumption of energy in the network.
TL;DR: This paper is mainly aimed at a review of the security and privacy issues related with context-aware systems and gives a brief introduction regarding the preferred and suitable frameworks required to implement the security requirements.
Abstract: A context aware system is recognized as a “system which uses any context information previous to, or in the duration of, service stipulations”, whereas the main goal of this system is to track and identify the users. The mobility feature of most computing and personal assistance devices have made the ‘context of the user’ an important aspect of the system, affecting its development process in terms of end-user requirements and system behaviour. Context Aware Systems are different from traditional systems as they provide unique features such as heterogeneity, high complexity and artificial intelligence. Since the parameters that constitute a context aware system, such as location and time of the day are rapidly changing. The use and importance of this system is increasing and therefore becoming a major part in prospective wireless systems. However, beside the numerous advantages, context-aware systems have also come up with the numerous issues and challenges related to privacy and security of the user’s information in these systems. Therefore, this paper is mainly aimed at a review of the security and privacy issues related with context-aware systems. It also gives a brief introduction regarding the preferred and suitable frameworks required to implement the security requirements. It further focuses on the main question for most researchers about the frameworks used for context-aware systems.
TL;DR: Congested environment around a WASN increases the chance of multipath propagation and it in turn introduces multipath fading, and the effects of both of these factors are considered on the performance of I-Min routing protocol designed for WASNs.
Abstract: Energy efficiency is a much talked about thing in the domain of geocast routing protocols for Wireless Ad Hoc and Sensor Networks (WASNs). Fermat point based protocols are capable of reducing the energy consumption of a WASN by reducing the total transmission distance in a multi hop-multi sink scenario. Presently, there are quite a handful of them but many of them have not considered the effect of changing propagation environment around the considered network while measuring the performance of the protocol. Congested environment around a WASN increases the chance of multipath propagation and it in turn introduces multipath fading. In this paper, the effects of both of these factors are considered on the performance of I-Min routing protocol designed for WASNs.
TL;DR: In this paper, the authors present a framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nodes.
Abstract: Mobile ad hoc networks (MANETs) are self-configuring infrastructure-less networks comprised of mobile nodes that communicate over wireless links without any central control on a peer-to-peer basis. These individual nodes act as routers to forward both their own data and also their neighbours’ data by sending and receiving packets to and from other nodes in the network. The relatively easy configuration and the quick deployment make ad hoc networks suitable the emergency situations (such as human or natural disasters) and for military units in enemy territory. Securing data dissemination between these nodes in such networks, however, is a very challenging task. Exposing such information to anyone else other than the intended nodes could cause a privacy and confidentiality breach, particularly in military scenarios. In this paper we present a novel framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nodes. We evaluate our framework using the Network Simulator (NS-2) to check whether the privacy and confidentiality of the originator are met. For this we implemented the Policy Enforcement Points (PEPs), as NS-2 agents that manage and enforce the policies attached to packets at every node in the MANET.
TL;DR: The objective of this paper is to propose a smart-phone/ PDA based disaster management system based on peer to peer communication only and supporting disconnected operation.
Abstract: During any post-disaster period, the availability of the Internet is ruled out in most cases, mobile phones are only partially usable in some selected regions. Candidate devices for maintaining minimal services are mostly expensive satellite phones or specialized point-to-point radio communication systems. As communication systems become crippled, so do the management of the relief operations. One of the common problems during disasters is that the rescue and relief operations are not well-coordinated. For this reason, there is a need for a system that will help in the efficient distribution of rescue and relief to disaster-affected areas. The objective of this paper is to propose a smart-phone/ PDA based disaster management system based on peer to peer communication only and supporting disconnected operation.
TL;DR: The purpose of this paper is to make computer engineer more aware about this specific application domain and the space it offers for applying IT and communication infrastructure, as well as to make horticulture researchers more aware of what wireless technologies have to offer and how to optimize their usage in the greenhouse.
Abstract: In this paper we rethink the application of short-range radio communication technologies to greenhouse management. We briefly survey the application domain, the technological landscape and directions; then review the most interesting properties of existing deployments, and finally define some possible research ideas in the field. This paper neither assumes nor surveys certain WSN technologies, rather than that it attempts to define research problems, identify design space constraints and sketch some possible solutions. The purpose of this paper is twofold: to make computer engineer more aware about this specific application domain and the space it offers for applying IT and communication infrastructure, as well as to make horticulture researchers more aware of what wireless technologies have to offer and how to optimize their usage in the greenhouse.
TL;DR: In this paper, the routing strategy of AODV protocol is changed in order to improve the energy consumption in MANETs by minimizing the regular period of HELLO messages generated by the protocol used for the research, development and maintenance of routes.
Abstract: The aim of this work is to change the routing strategy of AODV protocol (Ad hoc On Demand Vector) in order to improve the energy consumption in mobile ad hoc networks (MANET). The purpose is to minimize the regular period of HELLO messages generated by the AODV protocol used for the research, development and maintenance of routes. This information is useful to have an idea about battery power levels of different network hosts. After storing this information, the node elect the shortest path following the classical model used this information to elect safest path (make a compromise) in terms of energy. Transmitter node does not select another node as its battery will be exhausted soon. Any node of the network can have the same information’s about the neighborhoods as well as other information about the energy level of the different terminal to avoid routing using a link that will be lost due to an exhausted battery of a node in this link. Analytical study and simulations by Jist/SWANS have been conducted to note that no divergence relatively to the classical AODV, a node can have this type of information that improves the energy efficiency in ad hoc networks.
TL;DR: A classification of cognitive radio proposals based on multi-agent concept is proposed and the pros and cons for each of the described approach are pointed out.
Abstract: In the last decade, cognitive radio technology received a lot of consideration for spectrum optimization. This issue creates huge opportunities for interesting research and development in a wide range of applications. This paper presents a state of the art on cognitive radio researches especially works using multi-agent systems. We propose among others a classification of cognitive radio proposals based on multi-agent concept and point out the pros and cons for each of the described approach.
TL;DR: Experimental results show significant improvement in the accuracy of positioning techniques for VANET that can provide accurate positioning service in the areas where GPS signals are hindered by the obstacles.
Abstract: Vehicular Ad Hoc Networks (VANET) is a very promising research venue that can offers many useful and critical applications including the safety applications. Most of these applications require that each vehicle knows precisely its current position in real time. GPS is the most common positioning technique for VANET. However, it is not accurate. Moreover, the GPS signals cannot be received in the tunnels, undergrounds, or near tall buildings. Thus, no positioning service can be obtained in these locations. Even if the Deferential GPS (DGPS) can provide high accuracy, but still no GPS converge in these locations. In this paper, we provide positioning techniques for VANET that can provide accurate positioning service in the areas where GPS signals are hindered by the obstacles. Experimental results show significant improvement in the accuracy. This allows when combined with DGPS the continuity of a precise positioning service that can be used by most of the VANET applications .
TL;DR: This paper presents a simple yet efficient priority-aware congestion control scheme to support bursty data, and results achieved from extensive simulation experiments corroborate that the proposed scheme operates well in terms of delay, throughput, and packet dropping, for both bursty and ordinary traffic.
Abstract: In the course of last decade, wireless sensor networks (WSNs) have grabbed attention of both academic research community and industrial users. Such networks provide a broad range of applications, making them of great significance. Energy is the greatest concern of such battery-operated networks as it directly influences the lifetime of the network. As packet dropping due to congestion has a dramatically negative impact on energy consumption, congestion control is a vital issue for wireless sensor network, particularly for wireless multimedia sensor networks (WMSNs) in which bursty traffic is prevailing. In this paper, we present a simple yet efficient priority-aware congestion control scheme to support bursty data. Results achieved from our extensive simulation experiments corroborate that the proposed scheme operates well in terms of delay, throughput, and packet dropping, for both bursty and ordinary traffic.
TL;DR: DWT and DCT image compression algorithm is used that allows an efficient tradeoff between energy consumption and image distortion, and these experimental results demonstrated by the performance evaluation are in terms of image quality, execution time and memory space.
Abstract: The recent availability of inexpensive hardware has enabled the new research field of wireless sensor networks. This is a network of interconnected devices, capable of retrieving images from the environment. The nodes, in this type of network, have very limited resources, in terms of processing unit, bandwidth and energy. Efficient coding of the image content is therefore important. In Wireless Sensors Network, many image compression algorithms are used. Indeed, the most popular methods such as JPEG or JPEG2000 can yield higher energy consumption than when transmitting uncompressed images. However, the most of the compression algorithms are inapplicable on sensor nodes because the limitation in terms of memory as well as processor speed. To solve this problem, we use DWT and DCT image compression algorithm that allows an efficient tradeoff between energy consumption and image distortion. These experimental results demonstrated by the performance evaluation are in terms of image quality, execution time and memory space, as shown in this paper.
TL;DR: Simulation results show that proposed algorithm achieves low recovery cost and high recovery probability of failed mobile hosts.
Abstract: Proposed work is a mobility based checkpointing and trust based rollback recovery algorithm to provide fault tolerance in Mobile Ad hoc Network (MANET). Here each mobile host maintains a count of number of clusters a mobile host traverses through, during a single checkpoint interval. A mobile host increments ‘cluster-change-count’ by 1, each time it leaves a cluster and joins another. Each mobile host saves a checkpoint independently if its ‘cluster-change-count’ exceeds a predefined threshold. This measure is important because each mobile host leaves its last checkpoint and logs at different clusters that it has visited earlier. If the mobile host fails, the time to search and collect its last checkpoint and logs gets added to the recovery time of the mobile host. In MANET, retrieval of checkpoint and logs has to be done through a number of intermediate mobile hosts because each mobile host has short area coverage, hence direct communication among distant mobile hosts is not possible. Now if any of these mobile hosts fail, depending on the nature of failure, the checkpoint or log may be lost or forwarding of them to the failed host may be delayed causing unsuccessful or delayed recovery of the failed host respectively. This can be avoided if it is ensured that the checkpoints and logs are forwarded only through trusted nodes. Trust model proposed here computes trust value of a mobile host based on four factors: failure rate, availability in network, unused energy and recommendations from neighbour mobile hosts. Simulation results show that proposed algorithm achieves low recovery cost and high recovery probability of failed mobile hosts.
TL;DR: AntMesh as mentioned in this paper is a distributed interference-aware data forwarding algorithm which enables the use of smart ants to probabilistically and concurrently perform the routing and data forwarding in order to stochastically solve a dynamic network routing problem.
Abstract: Routing in wireless mesh networks (WMNs) has been an active area of research for the last several years. In this paper, we address the problem of packet routing for efficient data forwarding in wireless mesh networks (WMNs) with the help of smart ants acting as intelligent agents. The aim of this paper is to study the use of such biologically inspired agents to effectively route the packets in WMNs. In particular, we propose AntMesh, a distributed interference-aware data forwarding algorithm which enables the use of smart ants to probabilistically and concurrently perform the routing and data forwarding in order to stochastically solve a dynamic network routing problem. AntMesh belongs to the class of routing algorithms inspired by the behaviour of real ants which are known to find a shortest path between their nest and a food source. In addition, AntMesh has the capability to effectively utilize the space/channel diversity typically common in multi radio WMNs and to discover high throughput paths with less interflow and intra-flow interference while conventional wireless network routing protocols fail to do so. We implement our smart ant-based routing algorithm in ns-2 and carry out extensive evaluation. We demonstrate the stability of AntMesh in terms of how quickly it adapts itself to the changing dynamics or load on the network. We tune the parameters of AntMesh algorithm to study the effect on its performance in terms of the routing load and end-to-end delay and have tested its performance under various network scenarios particularly fixed nodes mesh networks and also on mobile WMN scenarios. The results obtained show AntMesh's advantages that make it a valuable candidate to operate in mesh networks.
TL;DR: A trust framework for opportunistic network where the nodes in the network follow the trace based mobility model and the message is encrypted to secure both the data and path information is presented.
Abstract: Opportunistic networks are usually formed spontaneously by mobile devices equipped with short range wireless communication interfaces. The idea is that an end-to-end connection may never be present. Designing and implementing a routing protocol to support both service discovery and delivery in such kinds of networks is a challenging problem on account of frequent disconnections and topology changes. In this network one of the most important issues relies on the selection of the best intermediate node to forward the messages towards the destination. This paper presents a trust framework for opportunistic network where the nodes in the network follow the trace based mobility model. The selection of next hop to forward the data packets is based on the trust value as well as the direction of movement of node towards the destination. The trust value is obtained from the trust framework of the data forwarding node. The direction of destination is obtained from the movement trace file that is maintained by the nodes in the network. In this proposed framework, the message is encrypted to secure both the data and path information. The effectiveness of this proposed framework is shown using simulation.
TL;DR: Rayleigh distribution is the best model to be adopted by communication systems engineers because of the unpredictable nature of the time-varying channel at different mobile speeds in sub-urban environment and as a result it will be very difficult to select the appropriate model in the system design for proper implementation.
Abstract: This paper compares the performance of Rayleigh, Rician and Log-normal distributions in mobile wireless transmission system. In these distributions link quality cannot be predicted accurately enough to achieve reliable performance because of the unpredictable nature of the time-varying channel at different mobile speeds in sub-urban environment and as a result it will be very difficult to select the appropriate model in the system design for proper implementation. Binary Phase Shift Keying signaling scheme is used to modulate the data to be analyzed for efficient transmission over the three different distributions at mobile speeds of 30 km/h, 60 km/h and 90 km/h at carrier frequency of 900 MHz. Square root raised cosine filter is used to convert the modulated signal to analog signal suitable for transmission. The received bits through the channel without mitigating technique over the three scenarios are analyzed and Bit Error Rate (BER) computed for comparison. The results obtained showed that Rayleigh distribution has the highest BER, while Rician distribution has the BER between the Rayleigh and log-normal at the different speeds considered. This implies that Rayleigh distribution is the best model to be adopted by communication systems engineers.
TL;DR: In this paper, an enhancement of a blind channel estimator based on a subspace approach in a MIMO OFDM context (Multi Input Multi Output Orthogonal Frequency Division Multiplexing) in high mobility scenario is proposed.
Abstract: In this paper, we propose an enhancement of a blind channel estimator based on a subspace approach in a MIMO OFDM context (Multi Input Multi Output Orthogonal Frequency Division Multiplexing) in high mobility scenario. As known, the combination between the MIMO context and the OFDM system has stimulated mainly the evolution of the fourth generation broadband wireless communications. The simulations results have demonstrated the effectiveness of the approach for a 16 QAM modulation scheme and had been evaluated in term of bit error rate BER and mean square error MSE versus the signal to noise ratio SNR.
TL;DR: In this paper, CLD based architecture is proposed, where the objective is to provide a solution for power conservation, congestion control, and link failure management.
Abstract: The protocols used in mobile ad-hoc networks are based on the layered architecture. The layered approach is highly rigid and strict since each layer of the architecture is only concerned about the layers immediately above it or below it. Recent wireless protocols rely on significant interactions among various layers of the network stack. A cross-layer design (CLD) introduces stack wide layer interdependencies to optimize network performance. The CLD use the state information flowing throughout the network stack to adapt their behavior accordingly. In this paper, CLD based architecture is proposed, where the objective is to provide a solution for power conservation, congestion control, and link failure management. The link quality is determined by the received signal strength at the physical layer. The channel interference, contention and RTS/CTS packets of the MAC layer are used to determine the transmitting power and ensure the Quality of Service at the application layer.
TL;DR: In this article, a new infrastructure independent handoff approach combining multihoming and intelligent make-before-break handoff is proposed, based on required Handoff time estimation, L2 and L3 handoffs are initiated using effective and timely MIH triggers, reducing so the anticipation time and increasing the probability of prediction.
Abstract: Handoff performance of NEMO BS protocol with existent improvement proposals is still not sufficient for real time and QoS-sensitive applications and further optimizations are needed. When dealing with single homed NEMO, handoff latency and packet loss become irreducible all optimizations included, so that it is impossible to meet requirements of the above applications. Then, How to combine the different Fast handoff approaches remains an open research issue and needs more investigation. In this paper, we propose a new Infrastructure independent handoff approach combining multihoming and intelligent Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3 handoffs are initiated using effective and timely MIH triggers, reducing so the anticipation time and increasing the probability of prediction. We extend MIH services to provide tunnel establishment and switching before link break. Thus, the handoff is performed in background with no latency and no packet loss while pingpong scenario is almost avoided. In addition, our proposal saves cost and power consumption by optimizing the time of simultaneous use of multiple interfaces. We provide also NS2 simulation experiments identifying suitable parameter values used for estimation and validating the proposed model.