Advanced PHY/MAC Design for Infrastructure-less Wireless Networks

Wireless networks play a key role in providing information exchange among distributed mobile devices. Nowadays, Infrastructure-Less Wireless Networks (ILWNs), which include ad hoc and sensor networks, are gaining increasing popularity as they do not need a fixed infrastructure. Simultaneously, multiple research initiatives have led to different findings at the physical (PHY) layer of the wireless communication systems, which can effectively be adopted in ILWNs. However, the distributed nature of ILWNs demand for different network control policies that should have into account the most recent findings to increase the network performance. This thesis investigates the adoption of Multi-Packet Reception (MPR) techniques at the PHY layer of distributed wireless networks, which is itself a challenging task due to the lack of a central coordinator and the spatial distribution of the nodes. The work starts with the derivation of an MPR system performance model that allows to determine optimal points of operation for different radio conditions. The model developed and validated in this thesis is then used to study the performance of ILWNs in high density of transmitters and when the spectrum can be sensed a priori (i.e. before each transmission). Based on the theoretical analysis developed in the thesis, we show that depending on the propagation conditions the spectrum sensing can reduce the network throughput to a level where its use should be avoided. At the final stage, we propose a crosslayered architecture that improves the capacity of an ILWN. Different Medium Access Control (MAC) schemes for ILWNs adopting MPR communications are proposed and their performance is theoretically characterized. We propose a cross-layer optimization methodology that considers the features of the MPR communication scheme together with the MAC performance. The proposed cross-layer optimization methodology improves the throughput of ILWNs, which is validated through theoretical analysis and multiple simulation results

An altruistic cross-layer recovering mechanism for ad hoc wireless networks

Video streaming services have restrictive delay and bandwidth constraints. Ad hoc networks represent a hostile environment for this kind of real-time data transmission. Emerging mesh networks, where a backbone provides more topological stability, do not even assure a high quality of experience. In such scenario, mobility of terminal nodes causes link breakages until a new route is calculated. In the meanwhile, lost packets cause annoying video interruptions to the receiver. This paper proposes a new mechanism of recovering lost packets by means of caching overheard packets in neighbor nodes and retransmit them to destination. Moreover, an optimization is shown, which involves a video-aware cache in order to recover full frames and prioritize more significant frames. Results show the improvement in reception, increasing the throughput as well as video quality, whereas larger video interruptions are considerably reduced. Copyright © 2014 John Wiley & Sons, Ltd.Arce Vila, P.; Guerri Cebollada, JC. (2015). An altruistic cross-layer recovering mechanism for ad hoc wireless networks. Wireless Communications and Mobile Computing. 15(13):1744-1758. doi:10.1002/wcm.2459S174417581513Li J Blake C De Couto DSJ Lee HI Morris R Capacity of ad hoc wireless networks Proceedings of the 7th Annual International Conference on Mobile Computing and Networks (MobiCom) 2001 61 69Akyildiz, I. F., & Xudong Wang. (2005). A survey on wireless mesh networks. IEEE Communications Magazine, 43(9), S23-S30. doi:10.1109/mcom.2005.1509968Hsu, C.-J., Liu, H.-I., & Seah, W. K. G. (2011). Opportunistic routing – A review and the challenges ahead. Computer Networks, 55(15), 3592-3603. doi:10.1016/j.comnet.2011.06.021Huang, X., Zhai, H., & Fang, Y. (2008). Robust cooperative routing protocol in mobile wireless sensor networks. IEEE Transactions on Wireless Communications, 7(12), 5278-5285. doi:10.1109/t-wc.2008.060680Wieselthier, J. E., Nguyen, G. D., & Ephremides, A. (2001). Mobile Networks and Applications, 6(3), 251-263. doi:10.1023/a:1011478717164Clausen T Jacquet P Optimized Link State Routing Protocol (OLSR), IETF RFC 3626 2003 http://www.rfc-editor.org/rfc/rfc3626.txtMarina, M. K., & Das, S. R. (2006). Ad hoc on-demand multipath distance vector routing. Wireless Communications and Mobile Computing, 6(7), 969-988. doi:10.1002/wcm.432Zhou X Lu Y Ma HG Routing improvement using multiple disjoint paths for ad hoc networks International Conference on Wireless and Optical Communications Networks (IFIP) 2006 1 5Fujisawa H Minami H Yamamoto M Izumi Y Fujita Y Route selection using retransmission packets for video streaming on ad hoc networks IEEE Conference on Radio and Wireless Symposium (RWS) 2006 607 610Badis H Agha KA QOLSR multi-path routing for mobile ad hoc networks based on multiple metrics: bandwidth and delay IEEE 59th Vehicular Technology Conference (VTC) 2004 2181 2184Wu Z Wu J Cross-layer routing optimization for video transmission over wireless ad hoc networks 6th International Conference on Wireless Communications Networks and Mobile Computing (WiCOM) 2010 1 6Schier, M., & Welzl, M. (2012). Optimizing Selective ARQ for H.264 Live Streaming: A Novel Method for Predicting Loss-Impact in Real Time. IEEE Transactions on Multimedia, 14(2), 415-430. doi:10.1109/tmm.2011.2178235Nikoupour M Nikoupour A Dehghan M A cross-layer framework for video streaming over wireless ad-hoc networks 3rd International Conference on Digital Information Management (ICDIM) 2008 340 345Yamamoto R Miyoshi T Distributed retransmission method using neighbor terminals for ad hoc networks Proceedings of the 14th Asia-Pacific Conference on Communications (APCC) 2008 1 5Gravalos I Kokkinos P Varvarigos EA Multi-criteria cooperative energy-aware routing in wireless ad-hoc networks Proceedings of the 9th International Wireless Communications and Mobile Computing Conference (IWCMC) 2013 387 393Abid, R. M., Benbrahim, T., & Biaz, S. (2010). IEEE 802.11s Wireless Mesh Networks for Last-Mile Internet Access: An Open-Source Real-World Indoor Testbed Implementation. Wireless Sensor Network, 02(10), 725-738. doi:10.4236/wsn.2010.210088Yen, Y.-S., Chang, R.-S., & Wu, C.-Y. (2011). A seamless handoff scheme for IEEE 802.11 wireless networks. Wireless Communications and Mobile Computing, 13(2), 157-169. doi:10.1002/wcm.1102Liangzhong Yin, & Guohong Cao. (2006). Supporting cooperative caching in ad hoc networks. IEEE Transactions on Mobile Computing, 5(1), 77-89. doi:10.1109/tmc.2006.15Biswas S Morris R ExOR: opportunistic multi-hop routing for wireless networks Proceedings of ACM SIGCOMM 2005 133 144Chachulski S Jennings M Katti S Katabi D Trading structure for randomness in wireless opportunistic routing Proceedings of ACM SIGCOMM 2007 169 180Kohler E Handley M Floyd S Datagram Congestion Control Protocol (DCCP), IETF RFC 4340 2006 http://www.rfc-editor.org/rfc/rfc4340.txtSchierl, T., Ganger, K., Hellge, C., Wiegand, T., & Stockhammer, T. (2006). SVC-based multisource streaming for robust video transmission in mobile ad hoc networks. IEEE Wireless Communications, 13(5), 96-103. doi:10.1109/wc-m.2006.250365Iera, A., Molinaro, A., Paratore, S. Y., Ruggeri, G., & Zurzolo, A. (2011). Making a mesh router/gateway from a smartphone: Is that a practical solution? Ad Hoc Networks, 9(8), 1414-1429. doi:10.1016/j.adhoc.2011.03.00

A survey of performance enhancement of transmission control protocol (TCP) in wireless ad hoc networks

This Article is provided by the Brunel Open Access Publishing Fund - Copyright @ 2011 Springer OpenTransmission control protocol (TCP), which provides reliable end-to-end data delivery, performs well in traditional wired network environments, while in wireless ad hoc networks, it does not perform well. Compared to wired networks, wireless ad hoc networks have some specific characteristics such as node mobility and a shared medium. Owing to these specific characteristics of wireless ad hoc networks, TCP faces particular problems with, for example, route failure, channel contention and high bit error rates. These factors are responsible for the performance degradation of TCP in wireless ad hoc networks. The research community has produced a wide range of proposals to improve the performance of TCP in wireless ad hoc networks. This article presents a survey of these proposals (approaches). A classification of TCP improvement proposals for wireless ad hoc networks is presented, which makes it easy to compare the proposals falling under the same category. Tables which summarize the approaches for quick overview are provided. Possible directions for further improvements in this area are suggested in the conclusions. The aim of the article is to enable the reader to quickly acquire an overview of the state of TCP in wireless ad hoc networks.This study is partly funded by Kohat University of Science & Technology (KUST), Pakistan, and the Higher Education Commission, Pakistan

E2XLRADR (Energy Efficient Cross Layer Routing Algorithm with Dynamic Retransmission for Wireless Sensor Networks)

The main focus of this article is to achieve prolonged network lifetime with overall energy efficiency in wireless sensor networks through controlled utilization of limited energy. Major percentage of energy in wireless sensor network is consumed during routing from source to destination, retransmission of data on packet loss. For improvement, cross layered algorithm is proposed for routing and retransmission scheme. Simulation and results shows that this approach can save the overall energy consumptio

RECOMAC: a cross-layer cooperative network protocol for wireless ad hoc networks

A novel decentralized cross-layer multi-hop cooperative protocol, namely, Routing Enabled Cooperative Medium Access Control (RECOMAC) is proposed for wireless ad hoc networks. The protocol architecture makes use of cooperative forwarding methods, in which coded packets are forwarded via opportunistically formed cooperative sets within a region, as RECOMAC spans the physical, medium access control (MAC) and routing layers. Randomized coding is exploited at the physical layer to realize cooperative transmissions, and cooperative forwarding is implemented for routing functionality, which is submerged into the MAC layer, while the overhead for MAC and route set up is minimized. RECOMAC is shown to provide dramatic performance improvements of eight times higher throughput and one tenth of end-to-end delay than that of the conventional architecture in practical wireless mesh networks

Cross-layer design of multi-hop wireless networks

MULTI -hop wireless networks are usually defined as a collection of nodes equipped with radio transmitters, which not only have the capability to communicate each other in a multi-hop fashion, but also to route each others’ data packets. The distributed nature of such networks makes them suitable for a variety of applications where there are no assumed reliable central entities, or controllers, and may significantly improve the scalability issues of conventional single-hop wireless networks. This Ph.D. dissertation mainly investigates two aspects of the research issues related to the efficient multi-hop wireless networks design, namely: (a) network protocols and (b) network management, both in cross-layer design paradigms to ensure the notion of service quality, such as quality of service (QoS) in wireless mesh networks (WMNs) for backhaul applications and quality of information (QoI) in wireless sensor networks (WSNs) for sensing tasks. Throughout the presentation of this Ph.D. dissertation, different network settings are used as illustrative examples, however the proposed algorithms, methodologies, protocols, and models are not restricted in the considered networks, but rather have wide applicability. First, this dissertation proposes a cross-layer design framework integrating a distributed proportional-fair scheduler and a QoS routing algorithm, while using WMNs as an illustrative example. The proposed approach has significant performance gain compared with other network protocols. Second, this dissertation proposes a generic admission control methodology for any packet network, wired and wireless, by modeling the network as a black box, and using a generic mathematical 0. Abstract 3 function and Taylor expansion to capture the admission impact. Third, this dissertation further enhances the previous designs by proposing a negotiation process, to bridge the applications’ service quality demands and the resource management, while using WSNs as an illustrative example. This approach allows the negotiation among different service classes and WSN resource allocations to reach the optimal operational status. Finally, the guarantees of the service quality are extended to the environment of multiple, disconnected, mobile subnetworks, where the question of how to maintain communications using dynamically controlled, unmanned data ferries is investigated