Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098686
Ahmed Abujoda, Panagiotis Papadimitriou
The deployment of micro-datacenters for network function virtualization (NFV) by Internet Service Providers creates opportunities for flow processing along the traffic path. On-path processing requires the discovery of the middleboxes that will be traversed by each flow and the assignment of network functions (NFs) to middleboxes, while preserving the order of the NFs as specified in the service chain. NF location dependencies may require flow processing establishment across multiple NF Providers (NFPs). This entails additional challenges for middlebox discovery and selection, stemming from the NFPs' restrictions in information disclosure and interoperability. To address these issues, we present MIDAS, an architecture for the coordination of middlebox discovery and selection across multiple NFPs. MIDAS relies on a centralized middlebox controller in each NFP to provide interoperability among NFPs for flow processing setup. MIDAS establishes on-path processing via middlebox signaling, controller chaining, and Multi-Party Computation (MPC) based middlebox selection. We particularly employ MPC to preserve the confidentiality of middlebox utilization across the NFPs. We study the feasibility of MIDAS using a prototype implementation and further present simulation results to assess the efficiency of our middlebox selection approach.
{"title":"MIDAS: Middlebox discovery and selection for on-path flow processing","authors":"Ahmed Abujoda, Panagiotis Papadimitriou","doi":"10.1109/COMSNETS.2015.7098686","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098686","url":null,"abstract":"The deployment of micro-datacenters for network function virtualization (NFV) by Internet Service Providers creates opportunities for flow processing along the traffic path. On-path processing requires the discovery of the middleboxes that will be traversed by each flow and the assignment of network functions (NFs) to middleboxes, while preserving the order of the NFs as specified in the service chain. NF location dependencies may require flow processing establishment across multiple NF Providers (NFPs). This entails additional challenges for middlebox discovery and selection, stemming from the NFPs' restrictions in information disclosure and interoperability. To address these issues, we present MIDAS, an architecture for the coordination of middlebox discovery and selection across multiple NFPs. MIDAS relies on a centralized middlebox controller in each NFP to provide interoperability among NFPs for flow processing setup. MIDAS establishes on-path processing via middlebox signaling, controller chaining, and Multi-Party Computation (MPC) based middlebox selection. We particularly employ MPC to preserve the confidentiality of middlebox utilization across the NFPs. We study the feasibility of MIDAS using a prototype implementation and further present simulation results to assess the efficiency of our middlebox selection approach.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127615384","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098676
Apratim Mukherjee, Souvik Basu, Siuli Roy, S. Bandyopadhyay
Situational awareness is a critical component in a post-disaster recovery operation for assessment of needs and identification of available resources at different parts of a disaster-affected area. This information, in turn, may help the relief agencies to appropriately coordinate, manage and channelize their resources. A major hindrance in developing such global situational awareness is the non-uniform interaction pattern of relief workers. Volunteers in a particular region have much better knowledge of the local situation than those belonging to regions further away. This information asymmetry leads to deviation in perceptions of volunteers working in different regions, thereby affecting the resource distribution process. Thus, a unified global situational view of the entire disaster affected area is essential to bridge the perception gap of volunteers and to help them develop a common understanding of the actual scenario. In this paper, we propose a scheme for developing such a coherent global view of the post-disaster situation using local situational information in a smart-phone based delay tolerant peer-to-peer network environment.We focus on generating a comprehensive view which is consistent for all workers irrespective of their location or mobility. The proposed scheme takes into account the spatial locality and spatial regularity properties of human mobility and uses a concept of “opportunistic knowledge injection” to disseminate local situational knowledge to other remote areas without significant network overhead. The effectiveness of the proposal is evaluated on the ONE simulator.
{"title":"Developing a coherent global view for post disaster situation awareness using opportunistic network","authors":"Apratim Mukherjee, Souvik Basu, Siuli Roy, S. Bandyopadhyay","doi":"10.1109/COMSNETS.2015.7098676","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098676","url":null,"abstract":"Situational awareness is a critical component in a post-disaster recovery operation for assessment of needs and identification of available resources at different parts of a disaster-affected area. This information, in turn, may help the relief agencies to appropriately coordinate, manage and channelize their resources. A major hindrance in developing such global situational awareness is the non-uniform interaction pattern of relief workers. Volunteers in a particular region have much better knowledge of the local situation than those belonging to regions further away. This information asymmetry leads to deviation in perceptions of volunteers working in different regions, thereby affecting the resource distribution process. Thus, a unified global situational view of the entire disaster affected area is essential to bridge the perception gap of volunteers and to help them develop a common understanding of the actual scenario. In this paper, we propose a scheme for developing such a coherent global view of the post-disaster situation using local situational information in a smart-phone based delay tolerant peer-to-peer network environment.We focus on generating a comprehensive view which is consistent for all workers irrespective of their location or mobility. The proposed scheme takes into account the spatial locality and spatial regularity properties of human mobility and uses a concept of “opportunistic knowledge injection” to disseminate local situational knowledge to other remote areas without significant network overhead. The effectiveness of the proposal is evaluated on the ONE simulator.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130942257","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098705
Alvika Gautam, Vinayak Naik, Archie Gupta, S. K. Sharma, K. Sriram
Sleep quantity affects an individual's personal health. The gold standard of measuring sleep and diagnosing sleep disorders is Polysomnography (PSG). Although PSG is accurate, it is expensive and it lacks portability. A number of wearable devices with embedded sensors have emerged in the recent past as an alternative to PSG for regular sleep monitoring directly by the user. These devices are intrusive and cause discomfort besides being expensive. In this work, we present an algorithm to detect sleep using a smartphone with the help of its inbuilt accelerometer sensor. We present three different approaches to classify raw acceleration data into two states - Sleep and Wake. In the first approach, we take an equation from Kushida's algorithm to process accelerometer data. Henceforth, we call it Kushida's equation. While the second is based on statistical functions, the third is based on Hidden Markov Model (HMM) training. Although all the three approaches are suitable for a phone's resources, each approach demands different amount of resources. While Kushida's equation-based approach demands the least, the HMM training-based approach demands the maximum. We collected data from mobile phone's accelerometer for four subjects for twelve days each. We compare accuracy of sleep detection using each of the three approaches with that of Zeo sensor, which is based on Electroencephalogram (EEG) sensor to detect sleep. EEG is an important modality in PSG. We find that HMM training-based approach is as much as 84% accurate. It is 15% more accurate as compared to Kushida's equation-based approach and 10% more accurate as compared to statistical method-based approach. In order to concisely represent the sleep quality of people, we model their sleep data using HMM. We present an analysis to find out a tradeoff between the amount of training data and the accuracy provided in the modeling of sleep. We find that six days of sleep data is sufficient for accurate modeling. We compare accuracy of our HMM training-based algorithm with a representative third party app SleepTime available from Google Play Store for Android. We find that the detection done using HMM approach is closer to that done by Zeo by 13% as compared to the third party Android application SleepTime. We show that our HMM training-based approach is efficient as it takes less than ten seconds to get executed on Moto G Android phone.
睡眠量影响个人健康。测量睡眠和诊断睡眠障碍的金标准是多导睡眠图(PSG)。虽然PSG很精确，但价格昂贵且缺乏便携性。最近出现了许多带有嵌入式传感器的可穿戴设备，作为用户直接定期监测睡眠的PSG的替代品。这些设备除了价格昂贵外，还会造成侵入性和不适。在这项工作中，我们提出了一种使用智能手机在其内置加速度计传感器的帮助下检测睡眠的算法。我们提出了三种不同的方法将原始加速度数据分为两种状态-睡眠和唤醒。在第一种方法中，我们采用Kushida算法中的方程来处理加速度计数据。从此，我们称它为Kushida方程。第二种是基于统计函数，第三种是基于隐马尔可夫模型(HMM)训练。虽然这三种方法都适用于手机的资源，但每种方法需要不同数量的资源。Kushida的基于方程的方法要求最少，而基于HMM训练的方法要求最多。我们从手机的加速度计中收集了四个受试者的数据，每个受试者12天。我们将三种方法的睡眠检测精度与基于脑电图(EEG)传感器的Zeo传感器的睡眠检测精度进行了比较。脑电图是PSG的一种重要方式。我们发现基于HMM训练的方法准确率高达84%。与Kushida的基于方程的方法相比，它的准确性提高了15%，与基于统计方法的方法相比，它的准确性提高了10%。为了简洁地表示人们的睡眠质量，我们使用HMM对他们的睡眠数据进行建模。我们提出了一项分析，以找出训练数据量和睡眠建模提供的准确性之间的权衡。我们发现六天的睡眠数据足以进行准确的建模。我们将基于HMM训练的算法的准确性与Google Play Store中提供的具有代表性的第三方应用SleepTime进行比较。我们发现，与第三方Android应用程序SleepTime相比，使用HMM方法完成的检测与Zeo的检测结果接近13%。我们证明了基于HMM训练的方法是有效的，因为在Moto G Android手机上执行不到10秒。
{"title":"An smartphone-based algorithm to measure and model quantity of sleep","authors":"Alvika Gautam, Vinayak Naik, Archie Gupta, S. K. Sharma, K. Sriram","doi":"10.1109/COMSNETS.2015.7098705","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098705","url":null,"abstract":"Sleep quantity affects an individual's personal health. The gold standard of measuring sleep and diagnosing sleep disorders is Polysomnography (PSG). Although PSG is accurate, it is expensive and it lacks portability. A number of wearable devices with embedded sensors have emerged in the recent past as an alternative to PSG for regular sleep monitoring directly by the user. These devices are intrusive and cause discomfort besides being expensive. In this work, we present an algorithm to detect sleep using a smartphone with the help of its inbuilt accelerometer sensor. We present three different approaches to classify raw acceleration data into two states - Sleep and Wake. In the first approach, we take an equation from Kushida's algorithm to process accelerometer data. Henceforth, we call it Kushida's equation. While the second is based on statistical functions, the third is based on Hidden Markov Model (HMM) training. Although all the three approaches are suitable for a phone's resources, each approach demands different amount of resources. While Kushida's equation-based approach demands the least, the HMM training-based approach demands the maximum. We collected data from mobile phone's accelerometer for four subjects for twelve days each. We compare accuracy of sleep detection using each of the three approaches with that of Zeo sensor, which is based on Electroencephalogram (EEG) sensor to detect sleep. EEG is an important modality in PSG. We find that HMM training-based approach is as much as 84% accurate. It is 15% more accurate as compared to Kushida's equation-based approach and 10% more accurate as compared to statistical method-based approach. In order to concisely represent the sleep quality of people, we model their sleep data using HMM. We present an analysis to find out a tradeoff between the amount of training data and the accuracy provided in the modeling of sleep. We find that six days of sleep data is sufficient for accurate modeling. We compare accuracy of our HMM training-based algorithm with a representative third party app SleepTime available from Google Play Store for Android. We find that the detection done using HMM approach is closer to that done by Zeo by 13% as compared to the third party Android application SleepTime. We show that our HMM training-based approach is efficient as it takes less than ten seconds to get executed on Moto G Android phone.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127431013","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098713
Kundan Kandhway, J. Kuri
We study the problem of optimal seed selection to maximize the fraction of individuals which has received a message in a social network. We have used the Susceptible-Infected (SI) process to model information epidemics. We formulate an optimization problem under a fixed budget constraint on the resource available to recruit individuals in the network to act as seeds, to achieve the above objective. The seeds are decided based on node degrees. This approach will work even when the exact adjacency matrix of the network is unknown and only degrees of the individuals in the network have been estimated. We study effect of the degree distribution of the network on the optimal seed selection strategy and present results for synthetic scale free and Erdös-Rényi networks, and a real scientific collaboration social network. The optimal strategy is compared with two heuristic strategies that (i) selects seeds uniformly among all degrees and (ii) selects highest degree nodes as seeds. Our results show that for a wide range of model parameters, targeting only the highest degree nodes is not optimal for various networks. This work may be of interest to advertisers and campaigners who are interested in spreading a message in a population connected via social networks.
{"title":"Degree based seed optimization to maximize information dissemination in social networks","authors":"Kundan Kandhway, J. Kuri","doi":"10.1109/COMSNETS.2015.7098713","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098713","url":null,"abstract":"We study the problem of optimal seed selection to maximize the fraction of individuals which has received a message in a social network. We have used the Susceptible-Infected (SI) process to model information epidemics. We formulate an optimization problem under a fixed budget constraint on the resource available to recruit individuals in the network to act as seeds, to achieve the above objective. The seeds are decided based on node degrees. This approach will work even when the exact adjacency matrix of the network is unknown and only degrees of the individuals in the network have been estimated. We study effect of the degree distribution of the network on the optimal seed selection strategy and present results for synthetic scale free and Erdös-Rényi networks, and a real scientific collaboration social network. The optimal strategy is compared with two heuristic strategies that (i) selects seeds uniformly among all degrees and (ii) selects highest degree nodes as seeds. Our results show that for a wide range of model parameters, targeting only the highest degree nodes is not optimal for various networks. This work may be of interest to advertisers and campaigners who are interested in spreading a message in a population connected via social networks.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133799970","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098674
Rahul Majethia, Varun Mishra, P. Pathak, Divya Lohani, D. Acharya, Seema Sehrawat
Environmental monitoring using external and Smartphone-interfaced wireless sensors has been widely used in the past. The roadblocks start emerging when we use on-board sensors in off-the-shelf Smartphones to estimate context aware environmental parameters like ambient temperature, humidity and atmospheric pressure. In this work, we evaluate the sensitivity and accuracy of the on-board ambient temperature sensor under various circumstances and measure its performance against standardized weather monitoring equipment. Additionally, we identify the roles of several internal and external factors that affect the temperature data. Such an investigation is motivated by the need of pervasive temperature sensing to power Smart HVAC environments and for weather crowdsourcing. Our experiments reveal that while the on-board temperature sensors have great potential, using them for large scale data collection still requires significant work.
{"title":"Contextual sensitivity of the ambient temperature sensor in Smartphones","authors":"Rahul Majethia, Varun Mishra, P. Pathak, Divya Lohani, D. Acharya, Seema Sehrawat","doi":"10.1109/COMSNETS.2015.7098674","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098674","url":null,"abstract":"Environmental monitoring using external and Smartphone-interfaced wireless sensors has been widely used in the past. The roadblocks start emerging when we use on-board sensors in off-the-shelf Smartphones to estimate context aware environmental parameters like ambient temperature, humidity and atmospheric pressure. In this work, we evaluate the sensitivity and accuracy of the on-board ambient temperature sensor under various circumstances and measure its performance against standardized weather monitoring equipment. Additionally, we identify the roles of several internal and external factors that affect the temperature data. Such an investigation is motivated by the need of pervasive temperature sensing to power Smart HVAC environments and for weather crowdsourcing. Our experiments reveal that while the on-board temperature sensors have great potential, using them for large scale data collection still requires significant work.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114496760","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098728
G. Mandyam, Mike Milikich
Identify and authentication in the mobile web are important for many types of applications that benefit users, including payments. The mobile web today has several traditional approaches to authentication that allow for sensitive applications to take place. However, moving forward the use of contextual data can have a place in the area of authentication, Use of sensor information available on smartphones can provide information about user context that can serve either to augment existing authentication techniques or even provide additional authentication factors in their own right.
{"title":"Leveraging contextual data for multifactor authentication in the mobile web","authors":"G. Mandyam, Mike Milikich","doi":"10.1109/COMSNETS.2015.7098728","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098728","url":null,"abstract":"Identify and authentication in the mobile web are important for many types of applications that benefit users, including payments. The mobile web today has several traditional approaches to authentication that allow for sensitive applications to take place. However, moving forward the use of contextual data can have a place in the area of authentication, Use of sensor information available on smartphones can provide information about user context that can serve either to augment existing authentication techniques or even provide additional authentication factors in their own right.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114515394","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098688
A. Vashistha, Shubha Sharma, V. Bohara
In this paper, we analyze a two-phase hierarchical spectrum sharing protocol based on cooperative decode and forward relay transmission wherein it is assumed that the cognitive (i.e secondary) system is equipped with multiple antennas. The performance of the licensed (i.e. primary) as well as cognitive system is quantified by deriving the closed form expressions for outage probability. The theoretical and simulation results show that by exploiting multiple antennas at secondary transmitter (ST), we can drastically improve the performance of both primary and secondary systems as compared to conventional spectrum sharing schemes.
{"title":"Outage & diversity analysis of cooperative spectrum sharing protocol with decode-and-forward relaying","authors":"A. Vashistha, Shubha Sharma, V. Bohara","doi":"10.1109/COMSNETS.2015.7098688","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098688","url":null,"abstract":"In this paper, we analyze a two-phase hierarchical spectrum sharing protocol based on cooperative decode and forward relay transmission wherein it is assumed that the cognitive (i.e secondary) system is equipped with multiple antennas. The performance of the licensed (i.e. primary) as well as cognitive system is quantified by deriving the closed form expressions for outage probability. The theoretical and simulation results show that by exploiting multiple antennas at secondary transmitter (ST), we can drastically improve the performance of both primary and secondary systems as compared to conventional spectrum sharing schemes.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132451984","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098735
Gitakrishnan Ramadurai
Most Indian cities face oversaturated flow conditions during peak periods. In this paper we revisit the traffic signal control to improve urban network performance. Three novel strategies that address congested heterogeneous traffic flow are presented. The first two strategies - keeping intersection signal cycle times shorter and bottleneck metering - are derived from field observed data while the third - exclusive lanes and storage area near intersections for two wheelers - is supported based on a micro-simulation model. Potential improvements are presented based on the strategies. While most recent studies have focused on area wide / network signal control improvements our study shows potential for significant improvement even at the level of an isolated signal.
{"title":"Strategies for traffic signal control in Indian cities","authors":"Gitakrishnan Ramadurai","doi":"10.1109/COMSNETS.2015.7098735","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098735","url":null,"abstract":"Most Indian cities face oversaturated flow conditions during peak periods. In this paper we revisit the traffic signal control to improve urban network performance. Three novel strategies that address congested heterogeneous traffic flow are presented. The first two strategies - keeping intersection signal cycle times shorter and bottleneck metering - are derived from field observed data while the third - exclusive lanes and storage area near intersections for two wheelers - is supported based on a micro-simulation model. Potential improvements are presented based on the strategies. While most recent studies have focused on area wide / network signal control improvements our study shows potential for significant improvement even at the level of an isolated signal.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115317435","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098700
Naman Mishra, A. Chaurasia, Arun Kallavi, B. Raman, Purushottam Kulkarni
IEEE 802.11n offers several throughput enhancing features over its predecessor 802.11a/g. The two main features at the PHY layer are: MIMO and channel bonding, while the main throughput enhancing feature at the MAC/link layer is Frame Aggregation. While in theory, as well as in controlled experimental conditions, these features achieve throughput enhancements, the extent to which they are useful for in-the-wild deployments has not been studied thus far. This paper presents measurements from three sets of traces: one from a research conference, one from a busy airport, and the third from a dense classroom setting with extensive WiFi usage for classroom activities. Our findings are as follows: (a) the high data rates of 802.11n are not used substantially, although the presence of moderate rates is significant, (b) the use of the channel bonding feature is minimal in dense deployments, and (c) the percentage of bytes undergoing frame aggregation is considerable but the levels of aggregation are not very high. We also undertake controlled experiments which shed light on non-wireless, system bottlenecks. Specifically, we find that many clients are not equipped to handle high levels of frame aggregation. Worse, this interacts badly with the rate adaptation algorithm, significantly lowering the data rates being used. These issues need careful addressing before 802.11n features are used effectively.
{"title":"Usage of 802.11n in practice: A measurement study","authors":"Naman Mishra, A. Chaurasia, Arun Kallavi, B. Raman, Purushottam Kulkarni","doi":"10.1109/COMSNETS.2015.7098700","DOIUrl":"https://doi.org/10.1109/COMSNETS.2015.7098700","url":null,"abstract":"IEEE 802.11n offers several throughput enhancing features over its predecessor 802.11a/g. The two main features at the PHY layer are: MIMO and channel bonding, while the main throughput enhancing feature at the MAC/link layer is Frame Aggregation. While in theory, as well as in controlled experimental conditions, these features achieve throughput enhancements, the extent to which they are useful for in-the-wild deployments has not been studied thus far. This paper presents measurements from three sets of traces: one from a research conference, one from a busy airport, and the third from a dense classroom setting with extensive WiFi usage for classroom activities. Our findings are as follows: (a) the high data rates of 802.11n are not used substantially, although the presence of moderate rates is significant, (b) the use of the channel bonding feature is minimal in dense deployments, and (c) the percentage of bytes undergoing frame aggregation is considerable but the levels of aggregation are not very high. We also undertake controlled experiments which shed light on non-wireless, system bottlenecks. Specifically, we find that many clients are not equipped to handle high levels of frame aggregation. Worse, this interacts badly with the rate adaptation algorithm, significantly lowering the data rates being used. These issues need careful addressing before 802.11n features are used effectively.","PeriodicalId":277593,"journal":{"name":"2015 7th International Conference on Communication Systems and Networks (COMSNETS)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115622618","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}
Pub Date : 2015-05-04DOI: 10.1109/COMSNETS.2015.7098737
P. Paul, Vickey Kumar, Prasenjit Choudhury, S. Nandi
Automated author ranking mechanism in a given research domain has key applications like automatic faculty selection in an institution, selection of outstanding researcher in a particular research domain, selection of domain experts for reviewing articles or project proposals, etc. The advantage of automated mechanism is that it is transparent and free from personal intervention. On the other hand, temporal analysis of author ranking has importance in the issues like selection of candidates for project grants, selection for life-time achievement awards, etc. This being an era of shared authorship in scientific articles, finding exact contribution of an author in a field is always a challenge. In our present work, we propose a modified pagerank-based author ranking algorithm that may identify the exact contribution of a researcher in terms coauthorship scores and paper citation scores in the research field he/she is working, and validate them using H-index, an already well accepted author ranking strategy, with the help of DBLP data set. In addition, we perform a comparative analysis of the change in author ranking for different part of author spectrum over time.
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