Adrian Loch, A. Asadi, Gek Hong Sim, J. Widmer, M. Hollick
{"title":"mm-Wave on wheels: Practical 60 GHz vehicular communication without beam training","authors":"Adrian Loch, A. Asadi, Gek Hong Sim, J. Widmer, M. Hollick","doi":"10.1109/COMSNETS.2017.7945351","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945351","url":null,"abstract":"At vehicular speeds, the contact time during which a mobile node is in range of a fixed road side unit (RSU) is short. While this is not an issue if the RSU only needs to deliver textual information such as traffic updates, short contact times become problematic when transmitting a large amount of information. For instance, an RSU may need to deliver high volumes of local navigation data for an augmented reality application, or video material regarding tourist information of a nearby town. Millimeter-wave (mm-Wave) communication is highly promising for such scenarios since it provides order-of-magnitude larger throughput than the existing technologies operating at lower frequencies. However, the contact time in mm-Wave vehicular scenarios becomes even shorter due to the directional nature of the communication. This raises a fundamental question: can the high throughput of mm-Wave make up for the reduction in the contact time? In this paper, we analyze this trade-off and design a first-of-its-kind practical mm-Wave vehicular testbed to evaluate the resulting performance. Specifically, we consider alternative locations for the RSU other than at the side of the road, such as on top of a bridge or inside a roundabout. Moreover, we leverage that the road implicitly determines the direction in which the RSU expects a car to be located. This allows us to use fixed beam-steering at both the car and the RSU, thus avoiding costly beam-training. We validate our approach in real-world vehicular scenarios with actual traffic in a mid-sized town in Spain. The results show that our fixed beam-steering approach enables the RSU to transmit large amounts of data in a very short amount of time for a wide range of speeds. This allows us to provide detailed insights into the aforementioned fundamental question regarding the use of mm-Wave in vehicular scenarios.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128762614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gek Hong Sim, A. Asadi, Adrian Loch, M. Hollick, J. Widmer
{"title":"Opp-relay: Managing directionality and mobility issues of millimeter-wave via D2D communication","authors":"Gek Hong Sim, A. Asadi, Adrian Loch, M. Hollick, J. Widmer","doi":"10.1109/COMSNETS.2017.7945370","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945370","url":null,"abstract":"The directionality of millimeter-Wave (mm-Wave) communication results in challenging network dynamics and thus complex system design. A key problem with such networks is human blockage, which is highly detrimental since absorption at mm-Wave frequencies is extremely high. This poses a significant challenge for the state-of-the-art technologies in 5G networks such as Device-to-Device (D2D) communication. Essentially, the aforementioned dynamics hinder direct communication between devices. Existing protocols in the mm-Wave band such as IEEE 802.11ad address this problem using relays. However, the complexity relay discovery in these protocols grows linearly with the number of users, Hence, these approaches are infeasible for crowded areas such as malls or busy pedestrian streets. In this paper, we present a lightweight relaying mechanism called Opp-Relay that builds on the existing D2D features of the 3GPP standard to opportunistically discover an mm-Wave enabled relay. Specifically, we provide an algorithm to compute the optimal beamwidth for opportunistic discovery of a relay in dense and dynamic network environments. We validate our approach in practice using our experimental testbed operating in the 60 GHz band. Our experiments demonstrate that choosing a suitable beamwidth to discover and communicate with a relay node is crucial. Moreover, we show that our relaying mechanism significantly reduces the complexity of relay discovery.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121210007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Social network visualization: Does partial edges affect user comprehension?","authors":"Mithileysh Sathiyanarayanan, Donato Pirozzi","doi":"10.1109/COMSNETS.2017.7945455","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945455","url":null,"abstract":"In a small-world resolution, Euler diagrams are tangentially augmented with graphs and are realized in social network analysis but one of the main issue is the visual clutter. One interesting way of reducing this clutter is to use partial edges when there are visual elements (edge and curve) crossings. This paper empirically evaluates the use of partial edges for a small-scaled Euler diagrams with graphs and tests whether Euler diagrams with partial edges are readable and interpretable. In this study, twenty participants were presented with eighteen manually drawn diagrams using a software which recorded the answers and the time taken to answer each question. The results indicate that there is no significant difference between diagrams having partial and non-partial edges in terms of accuracy and time (performance analysis) but users preferred partial edges to be aesthetically pleasing in terms of reading graphs in Euler diagrams and layout features (preference analysis), which means partial edges can be used as a strategy to avoid clutter. The results obtained from the task performance and preference will be useful in generating real small-world graphs in an optimal way. The paper concludes that partial edges in a graph does not significantly affect comprehension and as a further direction, our existing Euler diagrams with complete graphs (full edges) tool will be extended to partial edges and evaluated.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131538443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficient Twitter sentiment classification using subjective distant supervision","authors":"Tapan Sahni, Chinmay Chandak, Naveen Reddy Chedeti, Manish Singh","doi":"10.1109/COMSNETS.2017.7945451","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945451","url":null,"abstract":"As microblogging services like Twitter are becoming more and more influential in today's globalized world, its facets like sentiment analysis are being extensively studied. We are no longer constrained by our own opinion. Others' opinions and sentiments play a huge role in shaping our perspective. In this paper, we build on previous works on Twitter sentiment analysis using Distant Supervision. The existing approach requires huge computation resource for analyzing large number of tweets. In this paper, we propose techniques to speed up the computation process for sentiment analysis. We use tweet subjectivity to select the right training samples. We also introduce the concept of EFWS (Effective Word Score) of a tweet that is derived from polarity scores of frequently used words, which is an additional heuristic that can be used to speed up the sentiment classification with standard machine learning algorithms. We performed our experiments using 1.6 million tweets. Experimental evaluations show that our proposed technique is more efficient and has higher accuracy compared to previously proposed methods. We achieve overall accuracies of around 80% (EFWS heuristic gives an accuracy around 85%) on a training dataset of 100K tweets, which is half the size of the dataset used for the baseline model. The accuracy of our proposed model is 2–3% higher than the baseline model, and the model effectively trains at twice the speed of the baseline model.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132689172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiyang Chang, Ashkan Rezaei, Balajee Vamanan, Jahangir Hasan, Sanjay G. Rao, T. N. Vijaykumar
{"title":"Hydra: Leveraging functional slicing for efficient distributed SDN controllers","authors":"Yiyang Chang, Ashkan Rezaei, Balajee Vamanan, Jahangir Hasan, Sanjay G. Rao, T. N. Vijaykumar","doi":"10.1109/COMSNETS.2017.7945384","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945384","url":null,"abstract":"The conventional approach to scaling Software-Defined Networking (SDN) controllers today is to partition switches based on network topology, with each partition being controlled by a single physical controller, running all SDN applications. However, topological partitioning is limited by the fact that (i) performance of latency-sensitive (e.g., monitoring) SDN applications associated with a given partition may be impacted by co-located compute-intensive (e.g., route computation) applications; (ii) simultaneously achieving low convergence time and response times might be challenging; and (iii) communication between instances of an application across partitions may increase latencies. To tackle these issues, in this paper, we explore functional slicing, a complementary approach to scaling, where multiple SDN applications belonging to the same topological partition may be placed in physically distinct servers. We present Hydra, a framework for distributed SDN controllers based on functional slicing. Hydra chooses partitions based on convergence time as the primary metric, but places application instances across partitions in a manner that keeps response times low while considering communication between applications of a partition, and instances of an application across partitions. Evaluations using the Floodlight controller show the importance and effectiveness of Hydra in simultaneously keeping convergence times on failures small, while sustaining higher throughput per partition and ensuring responsiveness to latency sensitive applications.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114443772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Request patterns and caching for VoD services with recommendation systems","authors":"Samarth Gupta, Sharayu Moharir","doi":"10.1109/COMSNETS.2017.7945355","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945355","url":null,"abstract":"Video on Demand (VoD) services like Netflix and YouTube account for ever increasing fractions of Internet traffic. It is estimated that this fraction will cross 80% in the next three years. Most popular VoD services have recommendation engines which recommend videos to users based on their viewing history, thus introducing time-correlation in user requests. Understanding and modeling this time-correlation in user requests is critical for network traffic engineering. The primary goal of this work is to use empirically observed properties of user requests to model the effect of recommendation engines on request patterns in VoD services. We propose a Markovian request model to capture the time-correlation in user requests and show that our model is consistent with the observations of existing empirical studies. Most large-scale VoD services deliver content to users via a distributed network of servers as serving users requests via geographically co-located servers reduces latency and network bandwidth consumption. The content replication policy, i.e., determining which contents to cache on the servers is a key resource allocation problem for VoD services. Recent studies show that low start-up delay is a key Quality of Service (QoS) requirement of users of VoD services. This motivates the need to pre-fetch (fetch before contents are requested) and cache content likely to be requested in the near future. Since pre-fetching leads to an increase in the network bandwidth usage, we use our Markovian model to explore the trade-offs and feasibility of implementing recommendation based pre-fetching.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134501576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Content replication in large distributed caches","authors":"Sharayu Moharir, N. Karamchandani","doi":"10.1109/COMSNETS.2017.7945368","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945368","url":null,"abstract":"In this paper, we consider the algorithmic task of content replication and request routing in a distributed caching system consisting of a central server and a large number of caches, each with limited storage and service capabilities. We study a time-slotted system where in each time-slot, a large batch of requests has to be matched to a large number of caches, where each request can be served by any cache which stores the requested content. All requests which cannot be served by the caches are served by fetching the requested content from the central server. The goal is to minimize the transmission rate from the central server. We use a novel mapping between our content replication problem and the Knapsack problem to prove a lower bound on the transmission rate for any content replication policy. Using insights obtained from the mapping, we propose a content replication policy — Knapsack Storage — which achieves this lower bound. While it intuitively makes sense to replicate the more popular contents on a larger number of caches, surprisingly, in certain cases, the Knapsack Storage policy chooses not to replicate the most popular contents on the caches at all.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124981832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Energy-based Bayesian spectrum sensing over α-κ-μ fading channels","authors":"Sanjeev Gurugopinath, S. Shobitha","doi":"10.1109/CONECCT.2015.7383881","DOIUrl":"https://doi.org/10.1109/CONECCT.2015.7383881","url":null,"abstract":"In this paper, we consider the problem of energy detection for spectrum sensing over the α-κ-μ fading channel, in a Bayesian framework. The α-κ-μ fading distribution includes popular models such as Rayleigh, Rice, Nakagami-m, Weibull, one-sided Gaussian, α-μ, κ-μ and κ-μ extreme distributions as special cases. We present a fast-converging infinite series expression for the probability of overall error, i.e., the convex combination of probability of false-alarm and probability of signal detection. We also present an analysis on optimal detection threshold that minimizes the probability of error. We discuss the performance of our detector for various values of the fading parameters through numerical techniques and validate our analysis through Monte Carlo simulations.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121938156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Performance comparison of dual connectivity with CoMP in heterogeneous cellular networks","authors":"Yoghitha Ramamoorthi, Abhinav Kumar","doi":"10.1109/COMSNETS.2017.7945382","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945382","url":null,"abstract":"The dual connectivity (DC) can increase the users' throughput in heterogeneous cellular networks (HCNs). Additionally, the coordinated multi-point (CoMP) based transmission/reception can provide higher coverage and throughput in HCNs, specially to edge users in the cell. In this paper, we frame the resource allocation problem for DC as an optimization problem and present the optimal user scheduling for a time based scheduler. We compare the throughput and coverage performance of DC with respect to CoMP in a HCN. Further, extensive simulation results are presented for various user densities and number of small cells in diverse physical scenarios. The results are highly relevant for selection of appropriate technology in HCNs by cellular network operators.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126680116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Emotion-aware computing using smartphone","authors":"Surjya Ghosh","doi":"10.1109/COMSNETS.2017.7945464","DOIUrl":"https://doi.org/10.1109/COMSNETS.2017.7945464","url":null,"abstract":"In this project, we address the problem to determine human emotion states automatically using modern day smartphones. Sensor-rich smartphones have opened up the opportunity to unobtrusively collect user behaviour patterns, activity details and infer information about emotion states. Determining human emotion accurately and efficiently to build a scalable system is the major objective of the project. Towards that goal, we plan to develop an emotion detection model leveraging on different information sources present on smartphone.","PeriodicalId":168357,"journal":{"name":"2017 9th International Conference on Communication Systems and Networks (COMSNETS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123988859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}