POPEYE: providing collaborative services for ad hoc and spontaneous communities

Next generation collaborative systems will offer mobile users seamless and natural collaboration amongst a diversity of agents, within distributed, knowledge-rich and virtualized working environments. This ambitious goal faces numerous challenges from the underlying communication infrastructure to the high level application services, with the aim to provide services with the appropriate quality (such as persistence, synchronization, and security). Most currently available tools supporting collaboration address either rather traditional and rigid intra-organizational collaboration scenarios or, at the opposite, completely free and unstructured open communities’s interactions. Emerging dynamic, flexible and ad hoc collaboration schemes are hardly or not supported at all. The POPEYE framework offers collaborative services for applications that aim to enable spontaneous collaboration over P2P wireless ad hoc groups, where fixed infrastructure is not a prerequisite, where virtual communities can emerge spontaneously and share data with the appropriate quality of service for business applications (persistence, synchronization, security, etc.).     

Three-tier neural model for service provisioning over collaborative flying ad hoc networks

Neural Computing and Applications - Collaboration among different ad hoc networks allows the formation of efficient guided networks. One of the such collaborative networks is formed between aerial...     

A new authentication model for ad hoc networks

A new trust model for authentication in ad hoc networks is proposed. The model differentiates between the identity-based and public-key-based trusts for issuing the validity certificates that bind public keys to real-world identifiers. It includes a model for combining these trusts and a technique for computing the public-key-based trust. In this composite trust model, without or with recommendation, a new algorithm for node authentication on the basis of arbitrary graphs of previously issued validity certificates is developed. It is called the validity propagation algorithm and is computationally feasible even for large networks. In general, the proposed method is applicable to any public-key infrastructure, distributed or hierarchical, with or without certification authorities.     

Angle and ranging based localization method for ad hoc network

In ad hoc sensor networks, it is very essential for sensors to know their own positions exactly which provide the context to sensed data. Sensors in ad hoc sensor networks enable to locate their positions from a relatively small number of landmarks that know their coordinates through external means (e.g., GPS). In this paper, we assume that sensor nodes can measure the distances and relative bearings to neighboring nodes within their transmission range. The proposed method will utilize the distances and relative bearings to find the locations of nodes. Firstly, sensors nearest landmarks will locate their position and then in order nodes more hops far from landmark will. We utilize many landmark coordinates and multiple paths to a landmark to improve the accuracy of the position. Simulation results under the various conditions have been obtained and especially compared with the results using DV-hop and DV-distances.     

Ad hoc网络中基于带宽的准入控制研究

在决定无线自组织网服务质量的诸多参数中,可用带宽是至关重要的参数。通过引用泊松分布流量产生器产生数据包的概率和发送数据包的概率,研究由于隐藏节点引起冲突的概率,消除由于节点发生碰撞对可用带宽的消耗。通过分析与推导,建立IIAB算法模型,并将IIAB加载到AODV协议,利用RREQ/RREP对新的业务流进行准许接入和资源预留,在此基础上,提出了新的基于IIAB-AODV协议的准入控制机制。通过NS2网络仿真平台模拟表明：提出的模型提高了估测可用带宽的精度以及基于IIAB-AODV协议的准入控制机制更能够保障和提高网络的服务质量。     

SCPS: A self-configuring power-saving protocol for wireless ad hoc networks

SCPS is a novel self-configuring power-saving protocol for wireless one-hop ad hoc networks. According to IEEE 802.11 WLAN standard, a station may enter a special power-saving (PS) mode. SCPS allows all stations in the PS mode to adjust their wakeup schedules whenever a station enters or exits the PS mode. The adjustment can balance the number of wakeup stations in each beacon interval so that the contention for transmission medium and the collisions in transmission will be ameliorated, which results in more efficient energy usage. Simulation results show that SCPS successfully balances the number of stations that wake up in each beacon interval, increases the sleep ratio, and reduces the collision probability. The combined effect reduces total energy consumption.     

On-siteDriverID: A secure authentication scheme based on Spanish eID cards for vehicular ad hoc networks

Security in Vehicle Ad Hoc Networks (VANETs) has been a topic of interest since the origins of vehicular communications. Different approaches have been followed as new security threats have emerged in the last few years. The approach of conditional privacy has been widely used as it guarantees authentication among vehicles but not revealing their real identities. Although the real identity of a vehicle can be traced by the authorities, the process to do that is time consuming and typically involves several entities (for instance road authorities that request the identification, license plate records bodies, a judge to allow revealing the identity associated to a license plate…). Moreover, this process is always subsequent to the detection of a road situation that requires knowing the real vehicle identities. However, in vehicular scenarios, authorities would beneficiate from knowing the real drivers’ identity in advance. We propose in this paper On-SiteDriverID, a secure protocol and its application which allows authorities’ vehicles to obtain drivers’ real identities rapidly and on demand on VANET scenarios. Thus, authorities would be able to gather information about drivers and vehicles, allowing them to act in a safer and better manner in situations such as traffic control duties or emergencies. The obtained simulation results in real VANET scenarios based on real maps guarantee that in the 60%–70% of cases the proposed On-SiteDriverID successfully obtains the identity of the drivers.     

Point-to-point voice over ad hoc networks: A survey

The dynamic topologies of mobile and wireless ad hoc networks affect voice communication applications. Difficult issues are wireless links with time-varying capacity and large loss rates, available bandwidth undergoing fast time-scale variations due to channel fading and physical obstacles, absence of centralized components assisting session set up and management, and instability of routes. The purpose of this paper is to survey research works that have been conducted to address these difficulties with an emphasis on the support of point-to-point voice sessions. The survey covers six complementary aspects: voice over ad hoc network architecture, route selection, bandwidth reservation and admission control, adaptive applications and security.     

A multi-timescale cross-layer approach for wireless ad hoc networks

Conventionally, cross-layer designs with same timescale updates can work well; however, there is a difference in layers’ timescales and each layer normally operates at its corresponding timescale when implemented in real systems. To respect this issue, in this article, we introduce a multi-timescale cross-layer design along with three sets of constraints: congestion control, link delay, and power control and with the objective of maximizing the overall utility and minimizing the total link delay and power consumption. The proposed procedure can be implemented in a distributed fashion, which not only guarantees truly optimal solutions to the underlying problem, but also adheres to the natural timescale difference among layers. Finally, the numerical results further solidify the efficacies of our proposal compared to the current frameworks.     

A scalable multimedia QoS architecture for ad hoc networks

Communication demands have grown from separate data and voice to integrated multimedia, paving the way to converging fixed, mobile and IP networks. Supporting Multimedia is a challenging task for wireless ad hoc network designers. Multimedia forms high data rate traffic with stringent Quality of Service (QoS) requirements. Wireless ad hoc networks are characterized by frequent topology changes, unreliable wireless channel, network congestion and resource contention. Providing scalable QoS is the most important challenge for multimedia delivery over ad hoc networks. We introduce here a provisioning and routing architecture for ad hoc networks which scales well while provisioning QoS. The proposed architecture is analysed using a mix of HTTP, voice and video streaming applications over 54 Mbps 802.11 g-based ad hoc networks. The architecture is simulated and compared to well-known routing protocols using the OPNET Modeller. The results show that our architecture scales well with increase in the network size, and outperforms well-known routing protocols.     

A context-aware cross-layer broadcast model for ad hoc networks

The standard 802.11 medium access control (MAC) performs poorly for heavy broadcast traffic. We present our context-aware cross-layer (CACL) broadcast model as an alternative. The basic CACL model uses only contextual data available to the 802.11 MAC and so is usable by any routing protocol that uses the 802.11 MAC. CACL fits the total broadcasts in any two-hop neighborhood to wireless channel capacity. We compare collision rates for CACL and the 802.11 MAC and conclude that, for a wide range of network conditions, CACL offers superior single-hop transmission rates. We also present a geographically constrained extension to CACL, CACL-G and compare it against CACL in vehicular scenarios of varying node density. Our results show that CACL-G offers increasingly superior performance over the basic CACL model as node density increases.     

A fuzzy-based Power-aware management for mobile ad hoc networks

In recent years, people have become more dependent on wireless network services to obtain the latest information at any time anywhere. Wireless networks must effectively allow several types of mobile devices send data to one another. The Mobile Ad Hoc Network (MANET) is one important type of non-infrastructure mobile network that consists of many mobile hosts, usually cellular phones. The power consumption rate and bandwidth of each mobile host device becomes an important issue and needs to be addressed. For increasing the reliability of the manager in Hierarchical Cellular Based Management (HCBM), this paper proposed a Power-aware protocol to select a stable manager from mobile hosts by fuzzy based inference systems based on the factors of speed, battery power, and location. Further, our protocol can trigger a mobile agent to distribute the managerial workload.     

RIVER: A reliable inter-vehicular routing protocol for vehicular ad hoc networks

Vehicular Ad hoc NETworks (VANETs), an emerging technology, would allow vehicles on roads to form a self-organized network without the aid of a permanent infrastructure. As a prerequisite to communication in VANETs, an efficient route between communicating nodes in the network must be established, and the routing protocol must adapt to the rapidly changing topology of vehicles in motion. This is one of the goals of VANET routing protocols. In this paper, we present an efficient routing protocol for VANETs, called the Reliable Inter-VEhicular Routing (RIVER) protocol. RIVER utilizes an undirected graph that represents the surrounding street layout where the vertices of the graph are points at which streets curve or intersect, and the graph edges represent the street segments between those vertices. Unlike existing protocols, RIVER performs real-time, active traffic monitoring and uses these data and other data gathered through passive mechanisms to assign a reliability rating to each street edge. The protocol then uses these reliability ratings to select the most reliable route. Control messages are used to identify a node’s neighbors, determine the reliability of street edges, and to share street edge reliability information with other nodes.     

GRAP: Grey risk assessment based on projection in ad hoc networks

In this paper, we discuss the risk assessment of ad hoc networks, which have highly dynamic topology, open access of wireless channels, and vulnerable data communication. Conventional risk assessment methods are subjective and unreliable as some nodes reveal little information, and the quantity of samples is limited in ad hoc networks. To solve this problem, we propose a GRAP method, which includes grey relational projection (GRP), grey prediction, and grey decision making. Our scheme is designed to assess nodes’ risk under limited circumstances such as small number of samples, incomplete information and lack of experience. Compared with principal component analysis, GRAP has demonstrated better performance and more flexible characteristics. To further the practicability of this method, we utilize a dynamic grey prediction, which shows high accuracy for decision making. In our scheme, four major nodes’ attributes are selected, and the experiment results suggest that our model is more effective and efficient for risk assessment than principal component analysis in ad hoc networks.     

A two-zone hybrid routing protocol for mobile ad hoc networks

Recently, an elegant routing protocol, the zone routing protocol (ZRP), was proposed to provide a hybrid routing framework that is locally proactive and globally reactive, with the goal of minimizing the sum of the proactive and reactive control overhead. The key idea of ZRP is that each node proactively advertises its link state over a fixed number of hops, called the zone radius. These local advertisements provide each node with an updated view of its routing zone - the collection of all nodes and links that are reachable within the zone radius. The nodes on the boundary of the routing zone are called peripheral nodes and play an important role in the reactive zone-based route discovery. The main contribution of this work is to propose a novel hybrid routing protocol - the two-zone routing protocol (TZRP) - as a nontrivial extension of ZRP. In contrast with the original ZRP where a single zone serves a dual purpose, TZRP aims to decouple the protocol's ability to adapt to traffic characteristics from its ability to adapt to mobility. In support of this goal, in TZRP each node maintains two zones: a crisp zone and a fuzzy zone. By adjusting the sizes of these two zones independently, a lower total routing control overhead can be achieved. Extensive simulation results show that TZRP is a general MANET routing framework that can balance the trade offs between various routing control overheads more effectively than ZRP in a wide range of network conditions.     

Securing one-way hash chain based incentive mechanism for vehicular ad hoc networks

One of the most promising applications of yet to come vehicular ad hoc networks (VANETs) is commercial advertising. However, in order to realize commercial advertising over VANET, proper incentives and security mechanisms must be taken into consideration due to the existence of selfish and/or malicious users in the real-world scenario. In this paper, we propose a secure incentive scheme for VANET advertising systems based on one-way hash chains. We also analyze the advertisement propagation behavior in our VANET advertising system using a mathematical model.     

Incentive-based control of ad hoc networks: A performance study

Ad hoc networks are self-configuring networks of mobile nodes, connected by wireless links. If a destination node is beyond the transmission range of an origin node, then the nodes must cooperate to provide a multi-hop route. Any node can act as a sender, receiver or transit node. It is clear that it is in a node’s interest to be a sender or receiver, but it is less clear what the value is of forwarding traffic on behalf of other nodes. The nodes should therefore be given incentives to act as transit nodes, otherwise the network would fail to function. A way to do so is by introducing for each node a credit balance, where nodes use credits to pay for the costs of sending their own traffic, and earn credits by forwarding traffic from other nodes.However, nodes that are located near the edge of the network will attract little transit traffic and earn few credits. In contrast, nodes located near the centroid of the network will attract transit traffic and earn credits. We investigate various ways of providing nodes near the edge of the network with preferential treatment in order to improve their credit balance and their throughputs.We next focus on the situation where each node can move to improve its utility expressed in terms of either credit balance or throughput. Here radio interference plays an important role, as it defines an interesting trade-off: nodes may prefer to be close together in order to reduce the power needed to transmit data, but on the other hand proximity increases radio interference, and has therefore a negative effect on connectivity. Simulation experiments reveal that the positions of the nodes converge to non-trivial optimal positions on 2D and 3D surfaces.