Maximal Scheduling in Wireless Ad Hoc Networks With Hypergraph Interference Models

The year 2005 witnesses the third occasion that the Wireless Personal Area and Ad-hoc Networks minitrack is part of the annual HICSS conference. This year there was a substantial increase in submissions (thus a substantial decrease in the acceptance rate), indicating the growing importance of research in this area. The minitrack is also focused on fundamental challenges and issues arising in wireless sensor networks and their applications. Wireless sensor networks differ from other wireless networks in the need for unattended and very low-energy operation, in the possibility of collaboration and distributed sensor calibration, and in the mission oriented nature of most sensor networks. Thus our mini track looks at two very important streams of research. After a strict review process nine papers were selected to be included in the program of the minitrack. The first paper is titled “BT-Crowds: Crowds-style Anonymity with Bluetooth and Java,” presenting an interesting idea on how anonymity can be achieved when sending messages in WPAN environments. Our second paper revisits scatternet formation issues of Bluetooth based ad hoc networks thus the title: “A Dynamic and Distributed Scatternet Formation Protocol for Real-life Bluetooth Scatternets.” The third paper is titled “Secure Dynamic Source Routing” and presents a new variant of the DSR routing protocol with special emphasis on security. In the fourth paper, the discussion concerns “Routing Based Feedback towards Applications in Mobile Ad Hoc Networks,” where routing notifications are relayed via event channels. “A Location Service Mechanism for Position-Based Multicasting in Wireless Mobile Ad hoc Networks” is the title of the fifth paper in the minitrack. It presents some innovative ideas on how location information can be managed for multicast communications in ad-hoc networks. In the sixth paper, “Sliding Window Protocol for Secure Group Communication in Ad Hoc Networks,” the authors propose a sliding window protocol for determining multiple routes in a multi-communications environment. In the seventh paper titled “Ad Hoc Routing Protocol Avoiding Route Breaks Based on AODV,” the authors propose improvements to the well-known AODV ad hoc routing protocol The eight paper, “Joint Scheduling and Routing Algorithm for Ad Hoc Wireless,” presents an innovative and interesting idea wrapped around an iterative algorithm on power control. In the final paper of the minitrack, “Performance Issues of Ad Hoc Routing Protocols in a Network Scenario used for VideoPhone Applications,” the authors present a simulation based performance analysis of different ad hoc routing protocols using the application pointed to in the title. These papers highlight some of the issues and work towards solutions in Personal Area and ad hoc networks which are among the most active research fields in wireless networking. We believe that the papers will provide opportunities for researchers to come together and discuss and debate the results of the interesting experiments that are described in the papers. We are confident that the minitrack will achieve its goal of bringing together leading researchers, to present new results and discuss synergies between the two areas. We also take this opportunity to thank all the reviewers for their valuable and professional work as well as all the authors who submitted papers and thus helped us to create such a strong minitrack. We would also like to express our sincere gratitude to the conference organizers for their hard work and help.

Link scheduling is a fundamental problem in wireless ad hoc and sensor networks. In this paper, we focus on the shortest link scheduling (SLS) under Signal-to-Interference-plus-Noise-Ratio and hypergraph models, and propose an approximation algorithm $$SLS_{pc}$$SLSpc (A link scheduling algorithm with oblivious power assignment for the shortest link scheduling) with oblivious power assignment for better performance than GOW* proposed by Blough et al. [IEEE/ACM Trans Netw 18(6):1701---1712, 2010]. For the average scheduling length of $$SLS_{pc}$$SLSpc is 1 / m of GOW*, where $$m=\lfloor \varDelta _{max}\cdot p \rfloor $$m=źΔmax·pź is the expected number of the links in the set V returned by the algorithm HyperMaxLS (Maximal links schedule under hypergraph model) and $$0

We present the first unified modeling framework for the computation of the throughput capacity of random wireless ad hoc networks in which information is disseminated by means of unicast routing, multicast routing, broadcasting, or different forms of anycasting. We introduce (n,m, k)-casting as a generalization of all forms of one-to-one, one-to-many and many-to-many information dissemination in wireless networks. In this context, n, m, and k denote the total number of nodes in the network, the number of destinations for each communication group, and the actual number of communication-group members that receive information (i.e., k lesm), respectively. We compute upper and lower bounds for the (n, m, k)- cast throughput capacity in random wireless networks. When m = k = ominus(1), the resulting capacity equals the well-known capacity result for multi-pair unicasting by Gupta and Kumar. We demonstrate that ominus(1/radic(mnlogn)) bits per second constitutes a tight bound for the capacity of multicasting (i.e., m = k < n) when m les ominus (n/(log n)). We show that the multicast capacity of a wireless network equals its capacity for multi-pair unicasting when the number of destinations per multicast source is not a function of n. We also show that the multicast capacity of a random wireless ad hoc network is ominus (1/n), which is the broadcast capacity of the network, when m ges ominus(n/ log n). Furthermore, we show that ominus (radicm/(kradic(n log n))),ominus(1/(k log n)) and ominus(1/n) bits per second constitutes a tight bound for the throughput capacity of multicasting (i.e., k < m < n) when ominus(1) les m les ominus (n/ log n), k les ominus(n / log n) les m les n and ominus (n/ log n) les k les m les n respectively.

In wireless mobile ad-hoc networks, data packets have to be relayed hop by hop from a given source node to a destination node. This means that some or all of the mobile nodes must accept to forward information for the benefit of other nodes. It has been shown by F. Nait-Abdesselam, et al., (2003) that this ability of forwarding packets leads to a new unfairness problem in wireless ad-hoc networks, where a node which is forwarding other node's packets gets less bandwidth, for its own use, than a node which is not participating to the routing service. The proposed RAMAC scheme by F. Nait-Abdesselam, et al., (2003), has shown all its effectiveness to cope with this unfairness problem. However, an extra bandwidth is sometimes allowed to the routing node's own traffic comparing to other nonrouting node's own traffics, and the routing node's routed traffic gets much less bandwidth. This is explained by the fact that at the upper layer (for instance the IP layer) does not differentiate between the routing and the own traffics, and that the multiplicative factor used to compute the new contention window is too aggressive. In this paper, an enhanced RAMAC scheme is proposed, by taking into account the differentiation on top of the MAC layer, between the and routed traffics within a routing node, and by smoothing the multiplicative factor used to compute the new contention window. The simulation results obtained showed a good improvement of the original RAMAC scheme, leading to better approximate equal bandwidth share among all the mobile nodes in the wireless ad-hoc network.

2008 14th IEEE International Conference on Parallel and Distributed Systems, ICPADS'08, Melbourne, VIC, 8-10 December 2008

Recent development has a tremendous growth in the ad-hoc wireless networks. Ad-hoc wireless networks are dynamic topology networks organized by a collection of mobile nodes that utilize multi-hop radio relaying and are capable of operating without the support of any fixed infrastructure. Ad-hoc wireless networks are very useful in emergency operations, collaborative and distributed computing and military applications. Multicasting plays an important role in the ad-hoc wireless networks, where nodes form groups to carry out certain tasks that require point-to-multipoint and multipoint-to-multipoint voice and data communication. The biggest challenge in the ad-hoc wireless networks is to find an optimized path between the two nodes. In this paper, we present an ant colony based metaheuristic multicast routing protocol for ad-hoc wireless networks, in that we analyzed the performance of dynamic core based multicast routing protocol (DCMP). This approach maps the solution capability of swarm intelligence to mathematical and engineering problems. The DCMP is highly adaptive, efficient and scalable. The performance of these protocols has been examined under realistic scenarios using NS 2, the network simulator tool. Performance has been analyzed for the metrics packet delivery ratio and control overheads with the multicast routing protocol. The proposed ant colony based routing protocol reduce the overheads in routing.

Using ad hoc networks as alternative means of communication in disaster situations is a salutary solution. However, analysing application performance is mandatory for evaluating such a possibility. In this paper we present the two aspects of our approach to application performance assessment on wireless ad hoc networks. The first aspect refers to real-world tests in which we quantify objectively the relationship between network conditions and application performance. The second aspect is represented by the wireless network (WLAN) emulator that we design to run on StarBED, the large-scale network experiment environment of the Hokuriku Research Centre in Ishikawa, Japan. By combining these two aspects we perform experiments with real applications, while having full control of the network conditions in which the application is tested (when using emulation).

In this paper we study connectivity in wireless ad-hoc networks by modeling the network as an undirected geometric random graph. The novel aspect in our study is that for finding the link probability between nodes we use a radio model that takes into account statistical variations of the radio signal power around its mean value. We show that these variations, that are unavoidably caused by the obstructions and irregularities in the surroundings of the transmitting and the receiving antennas, have two distinct effects on the network. Firstly, they reduce the amount of correlation between links causing the geometric random graph tend to behave like a random graph with uncorrelated links. Secondly, these variations increase the probability of long links, which enhances the probability of connectivity for the network.Another new result in our paper is an equation found for the calculation of the giant component size in wireless ad-hoc networks, that takes into account the level of radio signal power variations. With simulations we show that for the planning and design of wireless ad-hoc networks or sensor networks the giant component size is a good measure for "connectivity".

In wireless network, fault tolerant topology control is an important and a challenging task. The wireless nodes and links could experience frequent failures since Wireless networks are usually deployed under extreme environments. Therefore, fault tolerance must be considered for many applications. In wireless network Topology control has been proved effective in saving node power. The main idea of topology control is that instead of using its maximal transmission power, each node sets its power to a certain level such that the global topology satisfies a certain constraint. To increase fault tolerance, nodes in the network will consume more power. Here we need to give the optimum distance between the nodes of the wireless network in order to reduce the consumption of the power of each node.

In this paper, we present a methodology employing statistical analysis and stochastic geometry to study geometric routing schemes in wireless ad hoc networks. In particular, we analyze the network-layer performance of one such scheme, the random [ 1/ 2]disk routing scheme, which is a localized geometric routing scheme in which each node chooses the next relay randomly among the nodes within its transmission range and in the general direction of the destination. The techniques developed in this paper enable us to establish the asymptotic connectivity and the convergence results for the mean and variance of the routing path lengths generated by geometric routing schemes in random wireless networks. In particular, we approximate the progress of the routing path toward the destination by a Markov process and determine the sufficient conditions that ensure the asymptotic connectivity for both dense and large-scale ad hoc networks deploying the random [ 1/ 2]disk routing scheme. Furthermore, using this Markov characterization, we show that the expected length (hop count) of the path generated by the random [ 1/ 2]disk routing scheme normalized by the length of the path generated by the ideal direct-line routing, converges to 3π/4 asymptotically. Moreover, we show that the variance-to-mean ratio of the routing path length converges to 9π <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /64-1 asymptotically. Through simulation, we show that the aforementioned asymptotic statistics are in fact quite accurate even for finite granularity and size of the network.

Wireless Ad-hoc networks have lack of mass deployment. An Ad hoc wireless network has a dynamic nature that leads to constant changes in its network topology. There is an infrastructure less and decentralized network which need a robust dynamic routing protocol. This article presents performance comparison of wireless Ad-hoc network on different routing protocols. Network simulator QualNet 5.0.2 has been used to evaluate the performance of wireless networks with various routing protocols.

Geographic routing protocols establish scalable and robust routes for multi-hop trsdansmission in wireless mobile ad-hoc networks, where accurate location information of the mobile nodes is needed. Aiming to alleviate the influence of location errors, existing works focus on modifying routing protocols through modeling the error sources and mobility prediction. In this paper, we propose a cooperative cluster based geographic routing (CCGR) protocol, which views the cooperative cluster as one virtual relay node, and lessens the impact of location errors through opportunistic receiving and cooperative radio range extension. Opportunistic receiving achieves the link diversity and radio range extension enlarges the transmission distance of one hop. The performance of CCGR is analyzed under scenarios of both static and mobility location errors in terms of reliability index, which is defined to represent the link stability. Further more, numerical results demonstrate that our proposed transmission scheme CCGR outperforms non-cooperative routing schemes in terms of link error probability with location errors.

In wireless ad hoc networks, mobile peers communicate with other peers over wireless links, without the support of preexisting infrastructures, which is an attractive form of peer communications for certain applications. Although many enabling technologies have progressed significantly in recent years, the highly-anticipated deployment of large-scale, heterogeneous wireless ad hoc networks still faces considerable technical challenges, among which achieving secure, trustworthy and dependable peer communications is a major one. In this chapter, we promote identity-based key management, which serves as a prerequisite for various security procedures. We first identify that peer identity plays an irreplaceable role in wireless ad hoc networks, where autonomous peers can join or leave such systems and change their location in these systems at any time. Next, we show that identity-based key management schemes are effective and efficient for bootstrapping any chosen security procedures, especially in wireless ad hoc networks where both over-the-air communication and on-board computing resources can be severely constrained. Finally, we illustrate identity-based secure communication schemes with a security enhancement to the Dynamic Source Routing protocol. We find that identity-based schemes are intrinsically suitable for and practically capable of securing wireless ad hoc networks and may have great impact on dealing with other network security issues.

The wireless ad hoc networks (WANETs) provide a flexible and adaptable infrastructure for transferring data in different environments. It supports multiple description (MD) video transfers, addressing error-prone WANETs, which are becoming increasingly critical as their usage grows. Previous approaches to multicasting MD video in WANETs had significant challenges. Ensuring multimedia streaming quality over WANETs while reducing buffering and traffic are crucial challenges. To overcome the problems, this work proposes a cluster-to-cluster source route cooperative data transmission (C2C-SRCDT) method for packet communication in WANETs. Initially, nodes in cluster formation will be created, and each node’s weights will be evaluated for cluster head (CH) selection. Then, Dijkstra’s transmission routing aware-multiple description video (DTRA-MDV) method estimates the cluster node to select the shortest distance routes between each cluster to send the multiple (image/videos) data. Finally, the time-slot multiple route selection (TSMRS) technique improves throughput and reduces breakage links. C2C-SRCDT reduces buffering and transfers data quality (image/videos) based on network lifetime, bandwidth and transmission time. The proposed simulation is evaluated using various parameters: data delivery ratio, loss, delay, throughput and energy consumption. The proposed system achieves a data delivery ratio of 92%, a delay of 40 sec and a throughput of 91%. These metrics analysed the improvement in video or image quality and traffic to avoid data transfer and transmit the wireless network better than previous approaches.

We consider a general class of low complexity distributed scheduling algorithms in wireless networks, prioritized maximal scheduling, which compute a maximal set of transmitting links in each time slot according to certain pre-specified static priorities. The proposed scheduling scheme has low complexity, and is easily amendable for distributed implementation, such as adjusting inter-frame space (IFS) parameters under the ubiquitous 802.11 protocols. We provide throughput guarantees on the proposed scheduling scheme, by proving tight lower bound on the stability region and scheduling efficiency associated with a fixed priority vector. We next propose an online low complexity priority assignment algorithm, which can stabilize any arrival rate that is in the union of the lower bound regions of all priorities. The throughput guarantees are proved by fluid limits, and therefore can be applied to very general stochastic arrival processes. Finally, the performance of the proposed prioritized maximal scheduling scheme is verified by simulation results.