Radio Communications

The proposed proof-of-concept design described herein demonstrates that minimalist multiagent systems do provide all expected qualities: scalability, dynamic properties, efficiency, simplicity, adaptability and auto-configuration. Moreover, it represents a novel and surprisingly simple solution to resource allocation. It is most obvious with the power allocation scheme which results in drastically lower spatial power distributions when compared with traditional algorithms. The multi agent design approach, based on heuristics appears effective. It requires an understanding of the underlying mechanisms and compromises within the context of the problem at hand, from which insights and intuition can be drawn and used to design the agents. While it is unclear a priori to which end result the system will converge to, it should be noted that it is also unclear a priori to which it should. Indeed, the current context is far different from formal frameworks such as information theory which are often characterized by a single uni-dimension criterion, e.g. the channel capacity. In our multi-dimensional context, information theory remains too limited at the time to model and grasp the many possibilities and compromises facing a multitude of mobiles and DBS with macrodiversity where limited resources lead to interference. And in such a context, the proposed MA approach has the virtue of demonstrating via simulation that some novel allocation solutions (which should be understood as compromises) can lead to much higher efficiency of resource usage (where efficiency is necessarily also a notion of compromise). The design in itself is not so complicated, and one should keep in mind the fuzziness of such an approach. Indeed, the utility functions proposed could have a variety of alternatives. What matters is not their exactness, but that they provide certain properties that will sustain the interactions of agents. These properties remain to be understood and studied to provide insights on the inner workings of the agent system. For example, the shaping function in the utility function of the connection agents uses a logarithm which could be replaced by a first degree approximation (x - 1) and still converge, but a concave function with similar properties (e.g. (x - 1)2, null for x = 1 and strictly increasing for x> 1) would, despite providing some degree of convergence, fall short of a more balanced solution. The shaping function is therefore crucial to converge to certain Pareto solutions, and this remains to be studied in detail. Concerning MA design, we considered more specifically the notion of homeostasis which is not explicitly mentioned in Parunak's methodology. The proposed design shows how the search for such an equilibrium helps in designing and tuning the properties of the agents' behavior to obtain the desired global function. Considering future work, the proposed MA design and DBS architecture offers malleability and vast margins for tuning, enhancing, or providing additional functionality. It was studied in (Leroux et al., 2008) that the reuse of channels could be enhanced by pairing mobiles to cooperate in exploiting a single channel while multiplying their diversity gain. Interesting results have been found in this study. Yet, coupled with power-level control, the management of cooperation between mobiles revealed counter synergistic effects. To date, finding a way to have the cooperation and power-control agents interoperate in a synergetic manner remains an open problem. Another additional functionality to be studied is beamforming. Channel allocation agents would need to be improved to account for dynamically-created directive beams and provide network-wide gains by minimizing interference . Channelization also needs to be further studied, including a model to implement the IEEE 802.11 shared random access mechanism (CSMA/CA on conjunction with the so-called dis- Preface 5 Radio-communications architectures 11 Antoine Diet, Martine Villegas, Geneviève Baudoin and Fabien Robert 11 Analytical SIR for Cross Layer Channel Model 47 Abdurazak Mudesir and Harald Haas 47 The Impact of Fixed and Moving Scatterers on the Statistics of MIMO Vehicle-to-Vehicle Channels 61 Ali Chelli and Matthias Pätzold 61 Planar Antenna Array Hybrid Beamforming for SDMA in Millimeter Wave WPAN 75 Sau-HsuanWu, Lin-Kai Chiu, Ko-Yen Lin and Ming-Chen Chiang 75 A Distributed Multilayer Software Architecture for MIMO Testbeds 87 José A. García-Naya, M. González-López and L. Castedo 87 Recent Developments in Channel Estimation and Detection for MIMO Systems 109 Seyed Mohammad-Sajad Sadough and Mohammad-Ali Khalighi 109 Cooperative MIMO Systems in Wireless Sensor Networks 133 M. Riduan Ahmad, Eryk Dutkiewicz, Xiaojing Huang and M. Kadim Suaidi 133 Optimal Cooperative MIMO Scheme in Wireless Sensor Networks 161 M. Riduan Ahmad, Eryk Dutkiewicz, Xiaojing Huang and M. Kadim Suaidi 161 Single/Multi-User MIMO Differential Capacity 177 Daniel Castanheira and Atílio Gameiro 177 Low Dimensional MIMO Systems with Finite Sized Constellation Inputs 195 Rizwan Ghaffar and Raymond Knopp 195 Advanced Hybrid–ARQ Receivers for Broadband MIMO Communications 221 Tarik Ait-Idir, Houda Chafnaji, Samir Saoudi and Athanasios Vasilakos 221 Cooperative ARQ: A Medium Access Control (MAC) Layer Perspective 237 Jesús Alonso-Zárate, Elli Kartsakli, Luis Alonso and Christos Verikoukis 237 A Hybrid Feedback Mechanism to Exploit Multiuser Diversity in Wireless Networks 257 Yahya S. Al-Harthi 257 Opportunistic Access Schemes for Multiuser OFDM Wireless Networks 275 Cédric Gueguen and Sébastien Baey 275 Bidirectional Cooperative Relaying 291 Prabhat Kumar Upadhyay and Shankar Prakriya 291 A Novel Amplify-and-Forward Relay Channel Model for Mobile-to-Mobile Fading Channels Under Line-of-Sight Conditions 317 Batool Talha and Matthias Pätzold 317 Resource Management with Limited Capability of Fixed Relay Station in Multi-hop Cellular Networks 331 Jemin Lee and Daesik Hong 331 On Cross-layer Routing in Wireless Multi-Hop Networks 349 Golnaz Karbaschi, Anne Fladenmuller and Sébastien Baey 349 Mobile WiMAX Performance Investigation 371 Alessandro Bazzi, Giacomo Leonardi, Gianni Pasolini and Oreste Andrisano 371 Throughput-Enhanced Communication Approach for Subscriber Stations in IEEE 802.16 Point-to-Multipoint Networks 395 Chung-Hsien Hsu and Kai-Ten Feng 395 Holdoff Algorithms for IEEE 802.16 Mesh Mode in Multi-hop Wireless Mesh Networks 409 Bong Chan Kim and Hwang Soo Lee 409 Call Admission Control Algorithms based on Random Waypoint Mobility for IEEE802.16e Networks 429 Khalil Ibrahimi, Rachid El-Azouzi, Thierry Peyre and El Houssine Bouyakhf 429 Queueing-Model-Based Analysis for IEEE802.11 Wireless LANs with Non-Saturated Nodes 451 Shigeo Shioda and Mayumi Komatsu 451 Increasing the Time Connected to Already Deployed 802.11 Wireless Networks while Traveling by Subway 467 Jaeouk Ok, Pedro Morales, Masateru Minami and Hiroyuki Morikawa 467 Asymmetric carrier sense in heterogeneous medical networks environment 483 Bin Zhen, Huan-Bang Li, Shinsuke Hara and Ryuji Kohno 483 Multi-Agent Design for the Physical Layer of a Distributed Base Station Network 503 Philippe Leroux and Sébastien Roy 503 Inter-RAT Handover Between UMTS And WiMAX 533 Bin LIU, Philippe Martins, Philippe Bertin and Abed Ellatif Samhat 533 MHD-CAR: A Distributed Cross-Layer Solution for Augmenting Seamless Mobility Management Protocols 561 Faqir Zarrar Yousaf, Christian Müller and Christian Wietfeld 561 Mobility in IP Networks: From Link Layer to Application Layer Protocols and Architectures 583 Thienne Johnson, Eleri Cardozo, Rodrigo Prado, Eduardo Zagari and Tomas Badan 583 Positioning in Indoor Mobile Systems 607 Miloš Borenović and Aleksandar Nešković 607 Location in Ad Hoc Networks 629 Israel Martin-Escalona, Marc Ciurana and Francisco Barcelo-Arroyo 629 Location Tracking Schemes for Broadband Wireless Networks 649 Po-Hsuan Tseng and Kai-Ten Feng 649 Wireless Multi-hop Localization Games for Entertainment Computing 661 Tomoya Takenaka, Hiroshi Mineno and Tadanori Mizuno 661 Measuring Network Security 683 Emmanouil Serrelis and Nikolaos Alexandris 683 A testing process for Interoperability and Conformance of secure Web Services 699 Spyridon Papastergiou and Despina Polemi 699 In this chapter we have provided operational and functional details of a proposed protocol called MHD-CAR that has been designed in view of the stringent performance requirements imposed by fast moving MNs in terms of seamless and fast handovers in a heterogeneous wireless network environment. MHD-CAR optimises the standard CARD protocol in enabling a MN to discover on the fly the identity and capabilities of not only the neighbouring CARs but also CARs that may be located multiple hops away, and all this is achieved with minimum reliance on the network. This is expected to augment the performance of seamless handover protocols like FMIPv6 by ensuring accurate selection of NAR with minimum discovery latency. The MHD-CAR is a distributed mechanism in which the ARs are able to inter-communicate their identities and capabilities information to neighbouring ARs and to ARs that are located multiple wireless-hops away without relying on maintaining and managing a central CARD server. Each AR stores this information in their local CAR Tables which are then communicated to the MN upon request. Due to the distributed mechanism, MHD-CAR is more efficient, reliable, survivable and scalable protocol than the CARD protocol. Since the MHD-CAR does not introduce any new protocol messages it can therefore be easily integrated into the present deployment infrastructure. It exhibits far better performance over the IETF's CARD protocol in terms of the substantial reduction of signalling load over both the inter-AR links (by 17.5%) and crucially over the error prone wireless link (by 48%), while utilizing the CARD protocol messages. This reduction in signalling load is achieved because the MN is able to perform RAT and DCC functions locally, based on the information content of the NAN cache, and without relying on the network. Another very important aspect of the MHD-CAR scheme is that it provides cross-layer liaison between L2 and L3 mobility function. This is achieved by having a NAN cache in the MN, which provides the MN with a topological snapshot of the identity and capabilities of the access networks that may be multiple hops away from its present point of attachment. This enables a MN to perform target scanning on selected channels greatly reducing the CAP discovery latency and enhancing the accuracy of the TAR selection process. This alone will have a direct impact on the overall handover latency and fast moving MNs will greatly benefit from it. In contrast to the IEEE 802.21 standard, it is observed that the MHD-CAR is a light weight and much simpler alternative solution that provides the main functional services of the 802.21 MIHS. Although MHD-CAR has not been designed as an alternative to 802.21 but it does share its motivational, operational and functional scope. The IEEE 802.21 WG was developed to provide a unified global mechanism by defining a common MIH layer sandwiched between the Network Layer and the Data Link Layer and defined common triggers that would be generated independent of the underlying access technology. The motivation was to enable the MN to make accurate selection of the network and to provide triggers that would aid the IP mobility protocols like FMIPv6. However all this is being introduced at the cost of high complexity while deviating from the base ISO/OSI prescribed layered approach by introducing a new layer between the L2 and L3. Also it would mandate changes to the existing access technologies to confirm to the MIHS scheme of signalling. For example different SAPs are required to be defined for each of the access technology. It The performance of IEEE8021.16e WirelessMAN-OFDMA depends on a large number of system parameters and implementation choices, such as, among the others, the available bandwidth, the frame duration, the uplink/downlink traffic asymmetry and the fragmentation policy. In the previous sections we provided an analytical framework that allows to evaluate the throughput achievable with TCP/IP connections as well as the amount of supported VoIP users as a function of the most significant parameters characterizing this technology. Beside the analytical model derivation, here we provided criteria, equations and algorithms to make the best choices from the viewpoint of system efficiency. Furthermore, some numerical results were given, showing the impact of some specific parameters on the system performance. With reference to TCP/IP connections, for instance, the troublesome choice of the maximum size of ARQ blocks has been discussed as well as the potential resource wastage entailed by a wrong choice of the asymmetry factor between the downlink and uplink subframes. The main outcome of this analysis is given by a set of criteria to be followed in order to maximize the throughput provided to the final user. As far as VoIP connections are concerned, here we assessed the maximum number of users that can be supported, carefully considering the voice codec characteristics and the adopted scheduling service. The outcomes of this investigation provide an indication about the capacity of this technology to be alternative to other technologies such as UMTS and LTE for the provision of the voice service. As a final remark, let us observe that the analytical framework proposed in this chapter provides a tool to evaluate the upper limits of the throughput and the maximum amount of VoIP users that can be supported by IEEE802.16e WirelessMAN-OFDMA. However, in order to investigate the actual performance of such a complex technology in a given scenario considering the degradation due, for instance, to fading, shadowing, noise and interference, the only feasible way is to adopt a simulation tool able to carefully reproduce all aspects of communications, with particular reference to the physical layer behavior. This kind of investigation has been carried out at WiLab (Italy) by means of the simulation platform SHINE, that has been developed in the last years to assess the performance of wireless networks in realistic scenarios. The interested reader may refer to (Andrisano et al., 2007; 2009; Bazzi et al., 2006) Preface......Page 5 Antoine Diet, Martine Villegas, Geneviève Baudoin and Fabien Robert......Page 11 Abdurazak Mudesir and Harald Haas......Page 47 Ali Chelli and Matthias Pätzold......Page 61 Sau-HsuanWu, Lin-Kai Chiu, Ko-Yen Lin and Ming-Chen Chiang......Page 75 José A. García-Naya, M. González-López and L. Castedo......Page 87 Seyed Mohammad-Sajad Sadough and Mohammad-Ali Khalighi......Page 109 M. Riduan Ahmad, Eryk Dutkiewicz, Xiaojing Huang and M. Kadim Suaidi......Page 133 M. Riduan Ahmad, Eryk Dutkiewicz, Xiaojing Huang and M. Kadim Suaidi......Page 161 Daniel Castanheira and Atílio Gameiro......Page 177 Rizwan Ghaffar and Raymond Knopp......Page 195 Tarik Ait-Idir, Houda Chafnaji, Samir Saoudi and Athanasios Vasilakos......Page 221 Jesús Alonso-Zárate, Elli Kartsakli, Luis Alonso and Christos Verikoukis......Page 237 Yahya S. Al-Harthi......Page 257 Cédric Gueguen and Sébastien Baey......Page 275 Prabhat Kumar Upadhyay and Shankar Prakriya......Page 291 Batool Talha and Matthias Pätzold......Page 317 Jemin Lee and Daesik Hong......Page 331 Golnaz Karbaschi, Anne Fladenmuller and Sébastien Baey......Page 349 Alessandro Bazzi, Giacomo Leonardi, Gianni Pasolini and Oreste Andrisano......Page 371 Chung-Hsien Hsu and Kai-Ten Feng......Page 395 Bong Chan Kim and Hwang Soo Lee......Page 409 Khalil Ibrahimi, Rachid El-Azouzi, Thierry Peyre and El Houssine Bouyakhf......Page 429 Shigeo Shioda and Mayumi Komatsu......Page 451 Jaeouk Ok, Pedro Morales, Masateru Minami and Hiroyuki Morikawa......Page 467 Bin Zhen, Huan-Bang Li, Shinsuke Hara and Ryuji Kohno......Page 483 Philippe Leroux and Sébastien Roy......Page 503 Bin LIU, Philippe Martins, Philippe Bertin and Abed Ellatif Samhat......Page 533 Faqir Zarrar Yousaf, Christian Müller and Christian Wietfeld......Page 561 Thienne Johnson, Eleri Cardozo, Rodrigo Prado, Eduardo Zagari and Tomas Badan......Page 583 Miloš Borenović and Aleksandar Nešković......Page 607 Israel Martin-Escalona, Marc Ciurana and Francisco Barcelo-Arroyo......Page 629 Po-Hsuan Tseng and Kai-Ten Feng......Page 649 Tomoya Takenaka, Hiroshi Mineno and Tadanori Mizuno......Page 661 Emmanouil Serrelis and Nikolaos Alexandris......Page 683 Spyridon Papastergiou and Despina Polemi......Page 699