IMDEA Networks Institute Digital Repository
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A PMIPv6-based solution for Distributed Mobility Management
No full textIntended status: Standards Track
Expires: January 12, 2014The number of mobile users and their traffic demand is expected to be ever-increasing in future years, and this growth can represent a limitation for deploying current mobility management schemes that are intrinsically centralized, e.g., Mobile IPv6 and Proxy Mobile IPv6.For this reason it has been waved a need for distributed and dynamic mobility management approaches, with the objective of reducing operators' burdens, evolving to a cheaper and more efficient architecture.
This draft describes multiple solutions for network-based distributed mobility management inspired by the well known Proxy Mobile IPv6.Internet Engineering Task Force (IETF)pu
Network Sharing and its Energy Benefits: a Study of European Mobile Network Operators
No full textIn this paper we investigate the potential energy saving inherent in the network sharing approach, whereby all (or significant parts) of the network infrastructures existing in a country can be shared by different network operators. In our study we consider European mobile network operators, and we use simple analytical models to show that in most European countries the amount of energy necessary to run mobile networks can be reduced by 35 to 60% with respect to the case in which each operator manages a separate network infrastructure.TRUEpu
A Survey on Opportunistic Scheduling in Wireless Communications
Get PDFWireless technology advancements made opportunistic scheduling a popular topic in recent times. However, opportunistic schedulers for wireless systems have been studied since nearly twenty years, but not implemented in real systems due to their high complexity and hardly achievable requirements. In contrast, today's popularity of opportunistic schedulers extends to implementation proposals for next generation cellular technologies. Motivated by such a novel interest towards opportunistic scheduling, we provide a taxonomy for opportunistic schedulers, which is based on scheduling design's objectives; accordingly, we provide an extensive review of opportunistic scheduling proposals which have appeared in the literature during nearly two decades. The huge number of papers available in the literature propose different techniques to perform opportunistic scheduling, ranging from simple heuristic algorithms to complex mathematical models. Some proposals are only designed to increase the total network capacity, while others enhance QoS objectives such as throughput and fairness. Interestingly, our survey helps to unveil two major issues:(i) the research in opportunistic is mature enough to jump from pure theory to implementation, and (ii) there are still under-explored and interesting research areas in opportunistic scheduling, e.g., opportunistic offloading of cellular traffic to 802.11-like networks, or cooperative/distributed opportunistic scheduling.TRUEpu
An SDN-based Network Architecture for Extremely Dense Wireless Networks
Get PDFTelecommunications networks are undergoing ma- jor changes so as to meet the requirements of the next gener- ation of users and services, which create a need for a general revised architectural approach rather than a series of local and incremental technology updates. This is especially manifest in mobile broadband wireless access, where a major traffic increase is expected, mostly because of video transmission and cloud-based applications. The installation of a high number of very small cells is foreseen as the only practical way to achieve the demands. However, this would create a struggle on the mobile network operators because of the limited backhaul capacity, the increased energy consumption, and the explosion of signalling. In the FP7 project CROWD, Software Defined Networking (SDN) has been identified as a solution to tame extreme density of wireless networks. Following this paradigm, a novel network architecture accounting for MAC control and Mobility Management has been proposed, being the subject of this paper.TRUEpu
A Simple Approximate Analysis of Floating Content for Context-Aware Applications
Get PDFContext-awareness is a peculiar characteristic of an ever
expanding set of applications that make use of a combination
of restricted spatio-temporal locality and mobile communications, to deliver a variety of services to the end user. It is expected that by 2014 more than 1:5 billion people would be using applications based on local search(search restricted on the basis of spatio-temporal locality), and that mobile location based services will drive revenues of more than $15 billion worldwide [1]. A common feature of such context-aware applications is the fact that their communication requirements significantly differ from ordinary applications. For most of them, the scope of generated content itself is local. This locally
relevant content may be of little concern to the rest of the
world, therefore moving this content from the user device
to store it in a well-accessible centralized location and/or
making this information available beyond its scope represents a clear waste of resources (connectivity, storage). Due to these specific requirements, opportunistic communication can play a special role when coupled with context-awareness. The benefit of opportunistic communications is that it naturally incorporates context as spatial proximity is closely associated with connectivity.
Recently an opportunistic communication paradigm, known
as floating content (FC) [2], conceived to support server-less distributed content sharing was proposed. It aims at ensuring the availability of data within a certain geographic area called anchor zone (AZ). Within the AZ, any time a user who is unaware of the content enters the transmission range of another user possessing it, the content is shared opportunistically. Nodes delete content once they go out of AZ. In recent literature([1], [2]), authors derived an asymptotic condition called criticality condition under which content floats asymptotically.TRUEpu
Towards zero grid electricity networking: Powering BSs with renewable energy sources
Get PDFDigital Object Identifier: 10.1109/ICCW.2013.6649303In this paper we study cellular access networks which solely rely on renewable energy. We consider a cellular network in which a mesh of base stations (BSs) that are powered with renewable sources, and interconnected with wireless backhaul links, cover the service area, and provide connection to few, typically remote, wired network accesses to the national and international backbone. In particular, we study how to dimension BS power generators and energy storage. We start by discussing the BS energy need, that depends on both the BS consumption model and the BS traffic profiles. Focusing then on some specific locations, we consider the use of photovoltaic (PV) panels, and dimension them based on the daily energy need of the BS and on typical radiative power of sun in the considered locations. Once the PV system has been dimensioned, we also evaluate the energy storage capacity that is needed to absorb energy production variability due to both daily and seasonal radiative power variations. Finally, we investigate the effectiveness of integrating the PV system with wind turbines, as well as the benefit induced on the system by base station sleep modes.TRUEpu
Recouping Opportunistic Gain in Dense Base Station Layouts Through Energy-Aware User Cooperation
Get PDFTo meet the increasing demand for wireless capacity, future networks are likely to consist of dense layouts of small cells. Thus, the number of concurrent users served by each base station (BS) is likely to be small which results in diminished gains from opportunistic scheduling, particularly under dynamic traffic loads. We propose user-initiated BS-transparent traffic spreading that leverages user-to-user communication to increase BS scheduling flexibility. The proposed scheme is able to increase opportunistic gains and improve user performance. For a specified tradeoff between performance and power expenditure, we characterize the optimal policy by modeling the system as a Markov decision process and also present a heuristic algorithm that yields significant performance gains. Our simulations show that, in the performance-centric case, average file transfer delays are lowered by up to 20% even in homogeneous scenarios, and up to 50% with heterogeneous users. Further, we show that the bulk of the performance improvement can be achieved with a small increase in power expenditure, e.g., in an energy-sensitive case, up to 78% of the performance improvement can be typically achieved at only 20% of the power expenditure of the performance-centric case.TRUEpu
E-mac: An elastic mac layer for ieee 802.11 networks
Get PDFWe present a system for real-time traffic support in infrastructure and ad hoc IEEE 802.11 networks. The proposed elastic MAC (E-MAC) protocol provides a distributed transmission schedule for stations with real-time traffic requirements, while allowing a seamless coexistence with standard IEEE 802.11 clients, protecting best-effort 802.11 traffic from starvation by means of admission control policies. Our scheduling decisions are based on an ‘elastic’ transmission opportunity (TXOP) assignment which allows for efficient wireless resource usage: whenever a real-time station does not use the assigned TXOP, the other real-time stations can take over the unused access opportunity, thus preventing the well-known inefficiencies of static time division multiple access (TDMA) schemes. Unlike other TDMA-based solutions for 802.11, E-MAC does not require a tight synchronization among the participating clients, thus allowing its implementation on commodity WLAN hardware via minor software changes at the client side, and no changes at the access points (APs). We studied the performance of our mechanism via ns-2 simulations and a mathematical model, showing that it outperforms IEEE 802.11e in terms of throughput, delay, and jitter. We finally provide a proof of concept through the results obtained in a real testbed where we implemented the E-MAC protocol.TRUEpu
Enhancements to Google Course Builder: Assessments Visualisation, YouTube Events Collector and Dummy Data Generator
Get PDFThis paper presents some extensions to the functionality of Google Course Builder (GCB) for improving its learning analytics support. The contributions of our work are the following: we add the functionality of detecting and storing YouTube events, visualise complex data related to the performance of the students, and provide automatic suggestions to the teachers regarding which specific parts of material need revision. Finally, we test our approach by implementing a dummy data generating program, which creates a big number of fictitious students who can interact with the platform in a fashion identical to real students.TRUEpu