Energy-efficient cooperative resource allocation for OFDMA

Energy is increasingly becoming an exclusive commodity in next generation wireless communication systems, where even in legacy systems, the mobile operators operational expenditure is largely attributed to the energy bill. However, as the amount of mobile traffic is expected to double over the next decade as we enter the Next Generation communications era, the need to address energy efficient protocols will be a priority. Therefore, we will need to revisit the design of the mobile network in order to adopt a proactive stance towards reducing the energy consumption of the network. Future emerging communication paradigms will evolve towards Next Generation mobile networks, that will not only consider a new air interface for high broadband connectivity, but will also integrate legacy communications (LTE/LTE-A, IEEE 802.11x, among others) networks to provide a ubiquitous communication platform, and one that can host a multitude of rich services and applications. In this context, one can say that the radio access network will predominantly be OFDMA based, providing the impetus for further research studies on how this technology can be further optimized towards energy efficiency. In fact, advanced approaches towards both energy and spectral efficient design will still dominate the research agenda. Taking a step towards this direction, LTE/LTE-A (Long Term Evolution-Advanced) have already investigated cooperative paradigms such as SON (self-Organizing Networks), Network Sharing, and CoMP (Coordinated Multipoint) transmission. Although these technologies have provided promising results, some are still in their infancy and lack an interdisciplinary design approach limiting their potential gain. In this thesis, we aim to advance these future emerging paradigms from a resource allocation perspective on two accounts. In the first scenario, we address the challenge of load balancing (LB) in OFDMA networks, that is employed to redistribute the traffic load in the network to effectively use spectral resources throughout the day. We aim to reengineer the load-balancing (LB) approach through interdisciplinary design to develop an integrated energy efficient solution based on SON and network sharing, what we refer to as SO-LB (Self-Organizing Load balancing). Obtained simulation results show that by employing SO-LB algorithm in a shared network, it is possible to achieve up to 15-20% savings in energy consumption when compared to LTE-A non-shared networks. The second approach considers CoMP transmission, that is currently used to enhance cell coverage and capacity at cell edge. Legacy approaches mainly consider fundamental scheduling policies towards assigning users for CoMP transmission. We build on these scheduling approaches towards a cross-layer design that provide enhanced resource utilization, fairness, and energy saving whilst maintaining low complexity, in particular for broadband applications

Packet scheduling in satellite HSDPA networks.

Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.The continuous growth in wireless networks is not showing any sign of slowing down as new services, new technologies and new mobile users continue to emerge. Satellite networks are expected to complement the terrestrial network and be a valid option to provide broadband communications services to both fixed and mobile users in scenarios where terrestrial networks cannot be used due to technical and economical viability. In the current emerging satellite networks, where different users with varying traffic demands ranging from multimedia, voice to data and with limited capacity, Radio Resource Management (RRM) is considered as one of the most significant and challenging aspect needed to provide acceptable quality of service that will meet the requirements of the different mobile users. This dissertation considers Packet Scheduling in the Satellite High Speed Downlink Packet Access (S-HSDPA) network. The main focus of this dissertation is to propose a new cross-layer designed packet scheduling scheme, which is one of the functions of RRM, called Queue Aware Channel Based (QACB) Scheduler. The proposed scheduler, which, attempts to sustain the quality of service requirements of different traffic requests, improves the system performance compared to the existing schedulers. The performance analysis comparison of the throughput, delay and fairness is determined through simulations. These metrics have been chosen they are three major performance indices used in wireless communications. Due to long propagation delay in HSDPA via GEO satellite, there is misalignment between the instantaneous channel condition of the mobile user and the one reported to the base station (Node B) in S-HSDPA. This affects effectiveness of the channel based packet schedulers and leads to either under utilization of resource or loss of packets. Hence, this dissertation investigates the effect of the introduction of a Signal-to-Noise (SNR) Margin which is used to mitigate the effect of the long propagation delay on performance of S-HSDPA, and the appropriate SNR margin to be used to achieve the best performance is determined. This is determined using both a semi-analytical and a simulation approach. The results show that the SNR margin of 1.5 dB produces the best performance. Finally, the dissertation investigates the effect of the different Radio Link Control (RLC) Transmission modes which are Acknowledged Mode (AM) and Unacknowledged Mode (UM) as it affects different traffic types and schedulers in S-HSDPA. Proportional fair (PF) scheduler and our proposed, QACB, scheduler have been considered as the schedulers for this investigation. The results show that traffic types are sensitive to the transmitting RLC modes and that the QACB scheduler provides better performance compared to PF scheduler in the two RLC modes considered

Radio Communications

In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

The Synchronized Peer-to-Peer Framework and Distributed Contention-Free Medium Access for Multihop Wireless Sensor Networks

IEEE 802.15.4 is a low-power, low-rate MAC/PHY standard that meets most of the stringent requirements of singlehop wireless sensor networks. Sensor networks with nodal populations composed of thousands of devices have been envisioned in conjunction with environmental, vehicular, military applications, and many others. However, such large sensor network deployments necessitate multihop support as well as low power consumption. In the light of the standard's extremely limited joint support of the two aforementioned attributes, this paper presents two essential contributions. First, a framework is proposed to implement a new IEEE 802.15.4 operating mode, namely, the synchronized peer-to-peer mode. This mode is designed to enable the standard's low-power features in peer-to-peer multihop-ready topologies. The second contribution is a distributed GTS (dGTS) management scheme designed to function in the newly devised network mode. This protocol provides reliable contention-free access in peer-to-peer topologies in a completely distributed manner. Assuming optimal routing, our simulation experiments reveal perfect delivery ratios as long as the traffic load does not reach or surpass its saturation threshold. dGTS sustains at least twice the delivery ratio of contention-based access under suboptimal dynamic routing. Moreover, the dGTS scheme exhibits minimum power consumption by eliminating the retransmissions attributed to contention, which, in turn, reduces the number of transmissions to a minimum

Final report on the evaluation of RRM/CRRM algorithms

Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

Shortest Route at Dynamic Location with Node Combination-Dijkstra Algorithm

Abstract— Online transportation has become a basic requirement of the general public in support of all activities to go to work, school or vacation to the sights. Public transportation services compete to provide the best service so that consumers feel comfortable using the services offered, so that all activities are noticed, one of them is the search for the shortest route in picking the buyer or delivering to the destination. Node Combination method can minimize memory usage and this methode is more optimal when compared to A* and Ant Colony in the shortest route search like Dijkstra algorithm, but can’t store the history node that has been passed. Therefore, using node combination algorithm is very good in searching the shortest distance is not the shortest route. This paper is structured to modify the node combination algorithm to solve the problem of finding the shortest route at the dynamic location obtained from the transport fleet by displaying the nodes that have the shortest distance and will be implemented in the geographic information system in the form of map to facilitate the use of the system. Keywords— Shortest Path, Algorithm Dijkstra, Node Combination, Dynamic Location (key words

Federal Register

Daily publication of the U.S. Office of the Federal Register contains rules and regulations, proposed legislation and rule changes, and other notices, including "Presidential proclamations and Executive Orders, Federal agency documents having general applicability and legal effect, documents required to be published by act of Congress, and other Federal agency documents of public interest" (p. ii). Table of Contents starts on page iii