ACoRN Early Career Researcher Workshop on Wireless Multihop Networking

Abstracts

Abstracts are available for some of the presentations. For details of all presentations please view the program.

Challenges in MAC layer Design for Multi-hop Wireless Networks
Prof. Sanjay Jha, University of New South Wales		 Recently there has been a rapid increase in research and commercial activities in multi-hop wireless networks (Mesh and Sensor). In the future, high-speed wireless meshes will enable a whole new range of exciting applications to the home, such as TV or local content delivery, community events, streaming of rich sensor feeds (such as security/traffic cameras), and video-on-demand within a local community (perhaps with people sharing rights to movies purchased collectively). This talk will address the challenges involved in designing MAC layer to meet these challenges. Impact of recent developments multiple wireless interface support for systems will also be discussed. View Full Program...
A Review of Multipath Routing Protocols: From Wireless Ad Hoc to Mesh Networks
Jack W. Tsai, Tim Moors, National ICT Australia (NICTA)/ University of New South Wales		 Multipath routing allows building and use of multiple paths for routing between a source-destination pair. It exploits the resource redundancy and diversity in the underlying network to provide benefits such as fault tolerance, load balancing, bandwidth aggregation, and improvement in QoS metrics such as delay. There are three elements to a multipath routing, namely, path discovery, traffic distribution, and path maintenance. Path discovery involves finding available paths using pre-defined criteria. A popular metric is path disjointness, a measure of resource diversity between paths. Traffic distribution strategy defines how concurrently available paths are used, and how data to the same destination is split and distributed over multiple paths. Path maintenance specifies when and how new paths are acquired if the states of currently available paths change. There are numerous multipath routing protocols proposed for wireless ad hoc networks, exploring characteristics in mobility, interference, topology, etc. We present a selection of these protocols and give a discussion on how multipath techniques can be extended to wireless mesh networks. Lastly we briefly describe the path selection framework in the current proposal for IEEE 802.11s mesh standard. We argue that, although the proposal does not define use of multipath routing, its extensible framework for path selection provides provision for such protocols to be implemented. View Full Program...
Hybrid Mesh Ad-hoc On-demand Distance Vector Routing Protocol
Asad Amir Pirzada, National ICT Australia , Marius Portmann and Jadwiga Indulska, University of Queensland		 Wireless Mesh Networks (WMNs) have recently gained increasing attention and have emerged as a technology with great potential for a wide range of applications. WMNs can be considered as a superset of traditional mobile ad-hoc networks (MANETs), where the network is comprised of mobile client devices (MESH CLIENTs). In addition to MESH CLIENTs, a WMN can also contain relatively static devices called mesh routers (MESH ROUTERs). Such hybrid WMNs are characterized by a high level of heterogeneity, since static MESH ROUTERs are typically much less resource constrained than mobile MESH CLIENTs, and are also often equipped with multiple radio interfaces. Traditional ad-hoc routing protocols do not differentiate between these types of nodes and therefore cannot achieve optimal performance in hybrid WMNs. In this paper, we propose simple extensions to AODV which aim to take advantage of the heterogeneity in hybrid WMNs by preferentially routing packets via paths consisting of high capacity MESH ROUTERs. In addition, we implement a simple channel selection scheme that reduces interference and maximizes channel diversity in multi-radio WMNs. Our simulation results show that in hybrid WMNs, our extensions result in significant performance gains over the standard AODV protocol. View Full Program...
Equalising Sensor Energy and Maximizing Sensor Network Lifespan Using RETT
Khaled Matrouk, University of Sydney		 Lately, sensor networks have received much attention in the research community. Sensor networks are wireless multi-hop networks connecting battery operated sensing devices. One of the aims of these networks is to make them self-configuring and self-healing so that they can be easily deployed and self-sufficient. A fundamental limitation with sensor networks is their limited life span because of their battery operation. To that end, much research has been carried out to maximize the life span of sensor networks through energy conservation. In this paper, we investigate energy conservation from a different angle. We introduce RETT, a protocol that aims at equalising energy in such a way that the entire network remains operational at maximal time in case the application would so require. When the entire network is operational, it is certain that events from any sensor in the network will find a delivery path through the network and that actuation of actuators in response to sensed events will be carried out. We focus on the algorithms that enable this and provide experimental results that show how they save on energy compared with the well-known LEACH algorithm. View Full Program...
Internet Extensions of Dynamic Source Routing Protocol for Ad Hoc Networks
Shuo Ding, Arek Dadej, Steven Gordon, University of South Australia 		The on-demand routing protocols are specially designed for mobile ad hoc networks that generally work in stand-alone mode. However it’s promising to integrate the ad hoc network with IP-based infrastructure to extend the limited services to a wider area. In this paper, a novel Internet routing extension for Dynamic Source Routing protocol is developed, with expectation to achieve an efficient Internet routing scheme for ad hoc networks. We specify a thorough design including Route Cache enquiry, external route discovery, Route Cache update, external route construction, route error, and route salvage. View Full Program...
Energy Minimisation of CDMA Based MANETs Through Spreading Gain Optimisation
Shamim Joarder, Sylvie Perreau, Aruna Jayasuriya, University of South Australia		 Our research proposes an algorithm that combines the qualities of code division multiple access (CDMA) and time division multiple access (TDMA) to minimise the total network energy. Energy in CDMA system depends on transmission power and transmission time. It can be shown that transmission time directly proportional to processing gain of the transmitter-receiver pair. As a result minimisation of total network energy depends on the processing gain and transmission time. The choice of processing gain depends on the interference level that a receiver needs to overcome to receive its intended signal. On the other hand the interference level at each receiver depends on the distance between the receiver and all other transmitters around it, apart from its intended transmitter. In this research, we investigate the impact on network energy by forming subsets of transmitter/receiver pairs. Formation of these subsets depends on the maximum processing gain that can be used for transmission as well as having maximum number of transmitter-receiver pair at each subset. TDMA is used to schedule the subsets and the communication channel employs CDMA. The results show that the proposed algorithm decreases total network energy by significant amount. In this work we also address the impact of the total network energy by applying priory to individual nodes, which ensures fair scheduling among all intended transmitters in the network. This approach has been extended for multihop network, where route depends on minimum energy consumption and the initial guess of maximum transmission distance. The result heavily depends on the initial transmission radius chosen for each transmitter and in our case it is the distance between a transmitter and its closest neighbour. The result has been compared with all possible transmission distance and it is observed that our approach is close to the optimal in terms of total energy consumption of the network. View Full Program...
Applying Relay Balance and Active Queue Management to Multihop Wireless Networks
Binh Ngo , Steven Gordon , University of South Australia		 In wireless environment such as mesh or sensor networks, increasing the number of nodes and traffic load would quickly overload the network as nodes must share the scarce wireless bandwidth. In such condition, delay can be very high due to the packet queuing time. In the case nodes share the channel using the IEEE 802.11 MAC protocol, the delay could be several seconds even with a single session in a chain topology and could be as high as tens of seconds in other situations. In this paper, we propose to apply the relay balance scheme and a new queue management scheme that can reduce the delay while still providing high throughput. We then evaluate our new scheme by simulations and the results show that it could reduce the delay by about 20 times in selected scenarios. View Full Program...
Link Dynamics in Mobile Ad-hoc Networks
Quang-My Tran, Arek Dadej , Sylvie Perreau , University of South Australia 		In this paper, we propose a link property that reflects the network dynamics in generalized manner as it is independent of the mobility model assumed and the number of nodes in the network. We develop an analytical framework for calculating the probability of link change, including link creation and link breakage, for random walk mobility model. There are many applications of the probability of link change in MANETs, such as network design, routing protocol optimization and network performance evaluation. As an illustration, we have proposed an application of the probability of link change in the previous paper as a generalized mobility metric for MANETs. View Full Program...
Balancing GoS in Cellular Mobile Telephone Networks using Static Channel Relaying Strategy with Adaptive threshold
The Anh Ngo, Sylvie Perreau , Arek Dadej , University of South Australia		 During recent decades, cellular telephone networks have grown rapidly in both technology and commerce. The numbers of mobile users increase every single day, while the frequency resources keep remaining. Solutions for best channel utilisation are an interesting target for researchers. Channel Relaying Strategy (CRS) is one of potential schemes that have studied recently. This scheme has achieved the good results in releasing congestion as well as enhancing Grade of Service (GoS). However, the GoS is generally not balanced between hot and cold cells in a hot region after CRS applied. In this paper, the algorithm to control threshold adapting with different load conditions is presented to solve that problem. The simulation results show that the GoS of hot and cold cells now is balanced by using Static Channel Relaying Strategy with Adaptive Threshold (SCRS-AT). View Full Program...

 

Security Vulnerabilities in Channel Assignment of Multi-Radio Multi-Channel Wireless Mesh Networks
Anjum Naveed, Salil S. Kanhere, University of New South Wales 		In order to fully exploit the aggregate bandwidth available in the radio spectrum, future Wireless Mesh Networks (WMN) are expected to take advantage of multiple orthogonal channels, with nodes having the ability to communicate with multiple neighbours simultaneously using multiple radios (NICs) over orthogonal channels. Dynamic channel assignment is critical for ensuring effective utilization of the non-overlapping channels. Several algorithms have been proposed in recent years, which aim at achieving this. However, all these schemes inherently assume that the mesh nodes are well-behaved without any malicious intentions. In this paper, we expose the vulnerabilities in channel assignment algorithms and unveil three new security attacks: Network Endo-Parasite Attack (NEPA), Channel Ecto-Parasite Attack (CEPA) and low-cost ripple effect attack (LORA). These attacks can be launched with relative ease by a malicious node and can cause significant degradation in the network performance. We also evaluate the effectiveness of these attacks through simulation based experiments and briefly discuss possible solutions to counter these new threats. View Full Program...
Defending Multi-hop Ad Hoc Networks Against Distributed Flooding Attacks That Use Address Spoofing
Yinghua Guo, Steven Gordon, University of South Australia 		The broadcasting mechanism used by various routing protocols in Mobile Ad hoc Networks can be exploited by a malicious node to launch flooding, or Denial of Service, attacks. In order to evade being identified by statistics based detection schemes, attackers usually recruit multiple accomplice to dilute attacking traffic density from each attacking source. In addition, they also use the address spoofing technique to challenge attack tracing. In this paper, we investigate the complex flooding attack: multiple-source, distributed, and address spoofing. Further, we propose a detection feature --- the percentage of RREQ addresses that are “new” to a node received in the sampling period, RREQNew --- that behaves differently in normal network senarios and attacking scenario. Applying cumulative sum algorithm on the detection feature, we can effectively identifying this type of attack by observing a significant increase on RREQNew. View Full Program...
Minimum Latency Broadcasting in Multi-rate Wireless Mesh Networks
Junaid Qadir, Chun Tung Chou, Archan Misra, University of New South Wales		 In a multi-rate wireless network, a node can dynamically adjust its link transmission rate by switching between different modulation schemes. For the current IEEE802.11a/b/g standards, this rate adjustment is limited to unicast traffic. In this paper, we describe the solutions to the problem of efficient routing and packet distribution for multicast traffic flows in a multi-rate wireless mesh networks (WMN).We assume that the media access control (MAC) layer of future WMNs will provide some form of multicast support, where the transmitter may be able to specify the transmission rate of the MAC-layer multicast, and, either explicitly or implicitly, the recipients of the multicast. Assuming such MAC layer multi-rate multicast capability, our goal is to study how low-latency (and possibly high throughput) network layer multicast of data traffic can be realized. View Full Program...
Channel MAC : A Novel Medium Access Control Paradigm for Wireless Ad Hoc Networks
Manzur Ashraf, Aruna Jayasuriya, Sylvie Perreau, Lars Rasmussen
University of South Australia 		The IEEE 802.11 has been the dominant MAC protocols used in wireless ad hoc networks. It has been shown theoretically that significant performance improvements as compared to 802.11 can be achieved in random access wireless networks. In this paper we propose a new paradigm of medium access control, based on principles of opportunistic transmission, to improve the performance of wireless ad hoc networks. Simulation results obtained shows a significant improvement of throughput compared to 802.11 MAC layer. View Full Program...