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Assigned BGP extended communities
Get PDFBGP Extended Communities:
Within the IDR working group, an IETF working group document ("Assigned BGP extended communities", draft-ietf-idr-reserved-extended-communities-03, and -04 [3]) co-authored with Bruno Decraene, Senior Researcher at France Telecom - Orange, is progressing in its standardization process. This draft is putting a registry into place for "well-known" BGP extended communities. Its goal is to ease the standardization of BGP features relying on BGP extended communities by providing a pool for ISPs and Router Vendors to pick values dedicated to specific BGP features. These documents update a previous version, published in 2011.This document defines an IANA registry in order to assign non-transitive extended communities from. These are similar to the existing well-known BGP communities defined in RFC 1997 but provide a control over inter-AS community advertisement as, per RFC RFC 4360, they are not transitive across Autonomous System boundaries. For that purpose, this document defines the use of the reserved Autonomous System number 0.65535 in the non-transitive generic four-octet AS specific extended community type.Internet Engineering Task Force (IETF)pu
Fair, Real-Time Control of a Traffic Signal
No full textInformation on the vehicles approaching an intersection is used to control the traffic signal in order to reduce delay fairly. Two fairness mechanisms, min-max fairness and proportional fairness, are defined. Min-max fairness minimizes the maximum delay of vehicles, and is fair from the perspective of the vehicles, and proportional fairness minimizes the delays of vehicles controlled by a phase of the traffic signal, and is fair from the perspective of the traffic signal. These fairness mechanisms are compared with an earlier mechanism that minimizes the average delay and with fixed cycle traffic signals. The comparisons for a range of arrival rates, and for both balanced and unbalanced loads on the approaches to the signal, are performed. All of the real-time mechanisms are similar at low to moderate loads, and provide a significant improvement over the fixed traffic signal. This is expected because vehicles don’t wait at a red light when there are no vehicles passing through the intersection. As the load increases: Minimum delay control has a significantly smaller delay than fixed control, but treats some vehicles extremely unfairly; the average delay of min-max fairness may be slightly greater than fixed control, but the individual vehicles are treated much more fairly; and, proportional fairness reduces the average delay close to that of minimum delay control, and treats the individual vehicles almost as fairly as min-max fairness. Based upon this study, proportional fairness is recommended to control traffic signals.TRUEpu
On the Intertwining between Capacity Scaling and TCP Congestion Control
Get PDFRecent works advocate the possibility of improving energy efficiency of network devices by modulating switching and transmission capacity according to traffic load. However, addressing the trade-off between energy saving and Quality of Service (QoS) under these approaches is not a trivial task, specially because most of the traffic in the Internet of today is carried by TCP, and is hence adaptive to the available resources.
In this paper we present a preliminary investigation of the possible intertwining between capacity scaling approaches and TCP congestion control, and we show how this interaction can affect performance in terms of both energy saving and QoS.TRUEpu
Techniques for Sentiment Analysis and Topic Detection of Spanish Tweets: Preliminary Report
Get PDFSEPLN 2012 – XXVIII Congreso de la Sociedad Española para el Procesamiento del Lenguaje Natural), co-located with the Spanish Informatics Conference (CEDI2012 – III Congreso Español de Informática)Sentiment analysis and topic detection are new problems that are at the intersection of natural language processing(NLP) and data mining. Sentiment analysis attempts to determine if a text is positive, negative, or neither, while topic detection attempts to identify the subject of the text. A significant amount of effort has been invested in constructing effective solutions for these problems, mostly for English texts. Using a corpus of Spanish tweets,we present a comparative analysis of different approaches and classification techniques for these problems.The data is preprocessed using techniques and tools proposed in the literature,together with others specifically proposed here that take into account the characteristics of Twitter.Then,popular classifiers have been used.(In particular,all classifiers of WEKA have been evaluated.)Due to its high number not all the results obtained will be presented here.TRUEpu
Opportunistic Information Dissemination in Mobile Ad-hoc Networks. Adaptiveness vs. Obliviousness and Randomization vs. Determinism
No full textFALSEpu
Network based Distributed Mobility Approach
No full textIMDEA Networks researchers have been contributing actively and extensively to this body of work over the last years. This contribution was produced in the following context:
Vice-chairing IEEE 802.21 TGb
Antonio de la Oliva was elected as IEEE 802.21 TGb Vice-chair in July 2011. The main responsibility of the position resides in shepherding the IEEE 802.21b specification until it is finally approved by the IEEE 802 Executive Committee. The specification, which contains significant contributions from on-going (MEDIEVAL) and past (CARMEN) European projects, passed the Sponsor Ballot in November 2011 and is currently awaiting approval-which will hopefully be ratified on the March 2012 plenary meeting.
Leading of the IEEE 802.21 Future Project Planning Ad-hoc group
The IEEE 802.21a and IEEE 802.21b amendments are already completed and waiting for ratification from IEEE 802 EC. This opens the door to new projects within the IEEE 802.21. IMDEA Networks, through one of its collaborators, is currently leading the Ad- Hoc group in charge of defining the new working items. Even more, some of the ideas developed within MEDIEVAL have been proposed and accepted as working items. A new Project Authorization Request (on MIHF_ID Group Management) was prepared through the last months of 2011, and submitted for approval on January 2012. The new project, to be named IEEE 802.21 TGd, will hopefully be approved on the March 2012 meeting.
Contributions to IEEE 802.21a/b/c and IEEE 802.11
Apart from the above activities, several technical contributions to IEEE 802.21a/b/c and IEEE 802.11 were performed during the 2011 period. In IEEE 802.21a several contributions and comments to address the different letters and sponsor ballots were performed. The main technical contributions from MEDIEVAL and CARMEN were introduced in IEEE 802.21b during 2010 and beginning of 2011 (2011 being devoted to defending such contributions during the different ballots). IEEE 802.21c standardizes the mechanisms to enable optimized single radio handover. Some of the technical details of this approach are very similar to the issues analyzed for DMM, hence the solutions designed within MEDIEVAL have been contributed to the task group. Finally, part of the work performed in FLAVIA was presented at the Next Wireless Generation Steering Committee (NWG SC), and was received positively.This document presents an IEEE 802.21 based mechanism to enabled network based distributed mobility management.IEEEpu
Control Theoretic Optimization of 802.11 WLANs: Implementation and Experimental Evaluation
Get PDFM.Sc. Thesis Director: Dr. Albert Banchs Roca
Supervisors: Albert Banchs Roca, Ph.D; Vincenzo Mancuso, Ph.D.In 802.11 WLANs, the dynamic adaptation of the contention parameters along network conditions results in relevant performance improvements. Despite the ability to change these parameters has been available in standard devices for years, no adaptive mechanism using this functionality
has been validated in a realistic deployment so far. In our work, we report our experiences related to the implementation and evaluation of two adaptive algorithms based on control theory, one centralized and one distributed, in a large-scale testbed consisting of eighteen commercial off-the-shelf devices. We conduct extensive measurements under non-ideal channel condition, considering the impact of different network scenarios in
terms of number of active nodes and traffic generated. We show that both algorithms significantly outperform the standard configuration in terms of total throughput. We also expose the limitations inherent to distributed schemes, and demonstrate that the centralized approach substantially
improves performance under a broad variety of scenarios, which confirms its suitability for real deployments.Telematics EngineeringUniversidad Carlos III de Madrid, Spainpu