In this paper we investigate and characterize user activity in WiFi networks by analyzing and comparing the behavior of users that connect to two public WiFi networks, one of them deployed in a University campus and the other in a major urban area. We characterize WiFi network user activity based on two main features, namely: time users stay connected to Access Points and Access Point load. Overall, the main contributions of our work are as follows: (1) to the best of our knowledge, this is the first study comparing user activity in two different scenarions, i.e., a University campus WiFi network and an urban WiFi network; (2) our results validate previously observed characteristics of user behavior in WiFi networks, as well as unveil new behavior patterns, such as the fact that users on campus tend to stay connected to the network for longer periods of time when compared to users in an urban area; and (3) our work is the first study to formally test and validate the hypothesis that association times in WiFi networks follows a power law and to estimate the power-law's tail index.
{"title":"Characterizing User Activity in WiFi Networks: University Campus and Urban Area Case Studies","authors":"L. Oliveira, K. Obraczka, A. Rodríguez","doi":"10.1145/2988287.2989172","DOIUrl":"https://doi.org/10.1145/2988287.2989172","url":null,"abstract":"In this paper we investigate and characterize user activity in WiFi networks by analyzing and comparing the behavior of users that connect to two public WiFi networks, one of them deployed in a University campus and the other in a major urban area. We characterize WiFi network user activity based on two main features, namely: time users stay connected to Access Points and Access Point load. Overall, the main contributions of our work are as follows: (1) to the best of our knowledge, this is the first study comparing user activity in two different scenarions, i.e., a University campus WiFi network and an urban WiFi network; (2) our results validate previously observed characteristics of user behavior in WiFi networks, as well as unveil new behavior patterns, such as the fact that users on campus tend to stay connected to the network for longer periods of time when compared to users in an urban area; and (3) our work is the first study to formally test and validate the hypothesis that association times in WiFi networks follows a power law and to estimate the power-law's tail index.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116595524","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}
To increase throughput the 802.11n standard introduced several physical layer transmission features including a short guard interval wider channels, and MIMO. Since obtaining peak throughput depends on choosing the combination of physical layer features (configuration) best suited for the channel conditions, the large number of configurations greatly complicates the decision. A deeper understanding of relationships between configurations under a variety of channel conditions should simplify the choices and improve the performance of algorithms selecting configurations. Examples of such algorithms include: rate and channel width adaptation, frame aggregation, and MIMO setting optimization. We propose a methodology for assessing the possibility of accurate estimation of the frame error rate (FER) of one configuration from the FER of another. Using devices that support up to 3 spatial streams (96 configurations), we conduct experiments under a variety of channel conditions to quantify relationships between configurations. We find that interesting relationships exist between many different configurations. Our results show that in 6 of the 7 scenarios studied at most five configurations are required to accurately estimate the error rate of all remaining 91 configurations and in the other scenario at most 15 configurations are required. Although we show that these relationships may change over time, perhaps most surprising is that relationships have been found over periods of up to one hour. These findings suggest optimization algorithms should not need to measure the FER of many configurations, but instead can sample a small subset of configurations to accurately estimate the FER of other configurtions. To demonstrate this possibility, we make simple modifications to the Minstrel HT rate adaptation algorithm to exploit relationships and observe improvements in throughput of up to 28%.
{"title":"Examining Relationships Between 802.11n Physical Layer Transmission Feature Combinations","authors":"A. Abedi, Tim Brecht","doi":"10.1145/2988287.2989159","DOIUrl":"https://doi.org/10.1145/2988287.2989159","url":null,"abstract":"To increase throughput the 802.11n standard introduced several physical layer transmission features including a short guard interval wider channels, and MIMO. Since obtaining peak throughput depends on choosing the combination of physical layer features (configuration) best suited for the channel conditions, the large number of configurations greatly complicates the decision. A deeper understanding of relationships between configurations under a variety of channel conditions should simplify the choices and improve the performance of algorithms selecting configurations. Examples of such algorithms include: rate and channel width adaptation, frame aggregation, and MIMO setting optimization. We propose a methodology for assessing the possibility of accurate estimation of the frame error rate (FER) of one configuration from the FER of another. Using devices that support up to 3 spatial streams (96 configurations), we conduct experiments under a variety of channel conditions to quantify relationships between configurations. We find that interesting relationships exist between many different configurations. Our results show that in 6 of the 7 scenarios studied at most five configurations are required to accurately estimate the error rate of all remaining 91 configurations and in the other scenario at most 15 configurations are required. Although we show that these relationships may change over time, perhaps most surprising is that relationships have been found over periods of up to one hour. These findings suggest optimization algorithms should not need to measure the FER of many configurations, but instead can sample a small subset of configurations to accurately estimate the FER of other configurtions. To demonstrate this possibility, we make simple modifications to the Minstrel HT rate adaptation algorithm to exploit relationships and observe improvements in throughput of up to 28%.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129703665","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}
The IEEE 802.11 standards define a distributed scheme for Wi-Fi access points and stations to fairly share the wireless medium. Even if fully standard-compliant, Wi-Fi devices from different vendors have implementation differences that lead to disparities in their ability to access the medium. Erratic upper-layer behaviors become manifest when devices that exhibit such disparities inter-operate within one network. In this paper we show examples of those behaviors based on common use cases. We find that a primary cause of performance inconsistency for most network applications is the uneven ability of different IEEE 802.11 devices to access the shared medium for transmission of TCP acknowledgments, further aggravated by the excessive size of the buffers where those packets are queued before transmission. We devise and validate in a real network an effective solution for Linux hosts that is based on the link-layer priorities of IEEE 802.11e. This solution allows researchers conducting Wi-Fi experiments to collect device-independent results, and application providers to guarantee a consistent experience to their users across different devices.
{"title":"Normalization of Application Performance in IEEE 802.11 Networks","authors":"Joseph D. Beshay, R. Prakash, A. Francini","doi":"10.1145/2988287.2989147","DOIUrl":"https://doi.org/10.1145/2988287.2989147","url":null,"abstract":"The IEEE 802.11 standards define a distributed scheme for Wi-Fi access points and stations to fairly share the wireless medium. Even if fully standard-compliant, Wi-Fi devices from different vendors have implementation differences that lead to disparities in their ability to access the medium. Erratic upper-layer behaviors become manifest when devices that exhibit such disparities inter-operate within one network. In this paper we show examples of those behaviors based on common use cases. We find that a primary cause of performance inconsistency for most network applications is the uneven ability of different IEEE 802.11 devices to access the shared medium for transmission of TCP acknowledgments, further aggravated by the excessive size of the buffers where those packets are queued before transmission. We devise and validate in a real network an effective solution for Linux hosts that is based on the link-layer priorities of IEEE 802.11e. This solution allows researchers conducting Wi-Fi experiments to collect device-independent results, and application providers to guarantee a consistent experience to their users across different devices.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"132 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130484902","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}
Time Slotted Channel Hopping (TSCH) is among the proposed Medium Access Control (MAC) layer protocols of the IEEE 802.15.4-2015 standard for low-power wireless communications in Internet of Things (IoT). TSCH aims to guarantee high network reliability by exploiting channel hopping and keeping the nodes time-synchronized at the MAC layer. In this paper, we focus on the traffic isolation issue, where several clients and applications may cohabit under the same wireless infrastructure without impacting each other. To this end, we present an autonomous version of 6TiSCH where each device uses only local information to select their timeslots. Moreover, we exploit 6TiSCH tracks to guarantee flow isolation, defining the concept of shared (best-effort) and dedicated (isolated) tracks. Our thorough experimental performance evaluation campaign, conducted over the open and large scale FIT IoT-LAB testbed (by employing the OpenWSN), highlight the interest of this solution to provide reliability and low delay while not relying on any centralized component.
{"title":"Experimental Validation of a Distributed Self-Configured 6TiSCH with Traffic Isolation in Low Power Lossy Networks","authors":"Fabrice Théoleyre, Georgios Z. Papadopoulos","doi":"10.1145/2988287.2989133","DOIUrl":"https://doi.org/10.1145/2988287.2989133","url":null,"abstract":"Time Slotted Channel Hopping (TSCH) is among the proposed Medium Access Control (MAC) layer protocols of the IEEE 802.15.4-2015 standard for low-power wireless communications in Internet of Things (IoT). TSCH aims to guarantee high network reliability by exploiting channel hopping and keeping the nodes time-synchronized at the MAC layer. In this paper, we focus on the traffic isolation issue, where several clients and applications may cohabit under the same wireless infrastructure without impacting each other. To this end, we present an autonomous version of 6TiSCH where each device uses only local information to select their timeslots. Moreover, we exploit 6TiSCH tracks to guarantee flow isolation, defining the concept of shared (best-effort) and dedicated (isolated) tracks. Our thorough experimental performance evaluation campaign, conducted over the open and large scale FIT IoT-LAB testbed (by employing the OpenWSN), highlight the interest of this solution to provide reliability and low delay while not relying on any centralized component.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128056698","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}
We consider an infrastructure-based wireless network comprising two types of nodes, namely, relays and sinks. The relay nodes are used to extend the network coverage by providing multi-hop paths to the sink nodes that are connected to a wireline infrastructure. Restricting to the one-dimensional case, our objective is to characterize the fraction of covered region for given densities of sink and relay nodes. We first compare and contrast our infrastructure-based model with the traditional setting, where a point is said to be covered if it simply lies within the range of some node. Then, drawing an analogy between the connected components of the network and the busy periods of an M / D /∞ queue, and using renewal theoretic arguments we obtain an explicit expression for the average vacancy (which is the complement of coverage). We also compute an upper bound for vacancy by introducing the notion of left-coverage (i.e., {coverage by a node from the left}). We prove a lower bound by coupling our model with an independent-disk model, where the sinks' coverage regions are independent and identically distributed. Through numerical work, we study the problem of minimizing network deployment cost subject to a constraint on the average vacancy. We also conduct simulations to understand the properties of a general notion of coverage, obtained by introducing hop-counts into the definition.
我们考虑一个基于基础设施的无线网络，包括两种类型的节点，即中继和接收器。中继节点通过向连接到有线基础设施的汇聚节点提供多跳路径来扩展网络覆盖范围。限制在一维情况下，我们的目标是表征给定密度的sink和relay节点的覆盖区域的比例。我们首先将基于基础设施的模型与传统设置进行比较和对比，在传统设置中，如果一个点仅仅位于某个节点的范围内，则认为它被覆盖了。然后，将网络的连通部分类比为M / D /∞队列的繁忙时段，并利用更新理论论证，得到了平均空位(即覆盖的补)的显式表达式。我们还通过引入左覆盖的概念(即{一个节点从左边覆盖})来计算空位的上界。我们通过将模型与独立盘模型耦合证明了一个下界，其中汇的覆盖区域是独立且同分布的。通过数值计算，研究了在平均空位约束下网络部署成本最小化的问题。我们还进行了模拟，以了解通过在定义中引入跳数获得的覆盖的一般概念的属性。
{"title":"Coverage Properties of One-Dimensional Infrastructure-Based Wireless Networks","authors":"K. P. Naveen, Anurag Kumar","doi":"10.1145/2988287.2989135","DOIUrl":"https://doi.org/10.1145/2988287.2989135","url":null,"abstract":"We consider an infrastructure-based wireless network comprising two types of nodes, namely, relays and sinks. The relay nodes are used to extend the network coverage by providing multi-hop paths to the sink nodes that are connected to a wireline infrastructure. Restricting to the one-dimensional case, our objective is to characterize the fraction of covered region for given densities of sink and relay nodes. We first compare and contrast our infrastructure-based model with the traditional setting, where a point is said to be covered if it simply lies within the range of some node. Then, drawing an analogy between the connected components of the network and the busy periods of an M / D /∞ queue, and using renewal theoretic arguments we obtain an explicit expression for the average vacancy (which is the complement of coverage). We also compute an upper bound for vacancy by introducing the notion of left-coverage (i.e., {coverage by a node from the left}). We prove a lower bound by coupling our model with an independent-disk model, where the sinks' coverage regions are independent and identically distributed. Through numerical work, we study the problem of minimizing network deployment cost subject to a constraint on the average vacancy. We also conduct simulations to understand the properties of a general notion of coverage, obtained by introducing hop-counts into the definition.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115790108","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}
Optimization models and techniques are often used to achieve efficient allocation of limited network resources to competing demands in communication networks. In this talk, the speaker will give a brief overview of distributed optimization theory, including convex optimization problems for which iterative solution techniques exist and converge. The well-known Transport Control Protocol (TCP) is shown to be equivalent a distributed solution that achieves the optimal allocation of bandwidth in communication networks. As for wireless ad-hoc and sensor networks, each link capacity depends on the transmission power of other links due to co-channel interference. In addition, the quality of multimedia services supported by these networks cannot be represented by a concave function of the amount of allocated bandwidth. These factors unfortunately make the resource allocation problem for the wireless networks become a non-convex optimization problem. New distributed solution techniques will be presented to solve these problems and numerical examples will also be provided. This talk will also consider the in-network data processing in wireless sensor networks where data are aggregated (fused) along the way they are transferred toward the end user. It will be shown that finding the optimal solution for the distributed processing problem is NP-hard, but for specific parameter settings, the problem can lead to a distributed framework for achieving the optimal tradeoff between communications and computation costs. Future work on integrating data or signal processing techniques with the distributed solution framework will be discussed.
{"title":"Use of Optimization Models for Resource Allocation in Wireless Ad-Hoc and Sensor Networks","authors":"K. Leung","doi":"10.1145/2988287.2998440","DOIUrl":"https://doi.org/10.1145/2988287.2998440","url":null,"abstract":"Optimization models and techniques are often used to achieve efficient allocation of limited network resources to competing demands in communication networks. In this talk, the speaker will give a brief overview of distributed optimization theory, including convex optimization problems for which iterative solution techniques exist and converge. The well-known Transport Control Protocol (TCP) is shown to be equivalent a distributed solution that achieves the optimal allocation of bandwidth in communication networks. As for wireless ad-hoc and sensor networks, each link capacity depends on the transmission power of other links due to co-channel interference. In addition, the quality of multimedia services supported by these networks cannot be represented by a concave function of the amount of allocated bandwidth. These factors unfortunately make the resource allocation problem for the wireless networks become a non-convex optimization problem. New distributed solution techniques will be presented to solve these problems and numerical examples will also be provided. This talk will also consider the in-network data processing in wireless sensor networks where data are aggregated (fused) along the way they are transferred toward the end user. It will be shown that finding the optimal solution for the distributed processing problem is NP-hard, but for specific parameter settings, the problem can lead to a distributed framework for achieving the optimal tradeoff between communications and computation costs. Future work on integrating data or signal processing techniques with the distributed solution framework will be discussed.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114901963","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}
This work presents a control-theoretic scalable device-to-device offloading system that provides seamless video streaming services to clients by effectively offloading parts of the video traffic to D2D networks in order to alleviate the cellular network traffic load. In the proposed system, the main functionalities of the content centric networking (CCN) technology are employed to simultaneously download the video content from multiple wireless networks. A two-stage PID-based LTE traffic controller is proposed to determine the amount of traffic to be offloaded to the D2D network among the cellular operator, the D2D servers, and the D2D clients. The proposed system is fully implemented using a CCNx open source and C/C++. Experimental results are provided to demonstrate the performance improvement of the proposed system.
{"title":"Control-theoretic Scalable Device-to-Device Offloading System for Video Streaming Services","authors":"Gi Seok Park, Wan Kim, Hwangjun Song","doi":"10.1145/2988287.2989145","DOIUrl":"https://doi.org/10.1145/2988287.2989145","url":null,"abstract":"This work presents a control-theoretic scalable device-to-device offloading system that provides seamless video streaming services to clients by effectively offloading parts of the video traffic to D2D networks in order to alleviate the cellular network traffic load. In the proposed system, the main functionalities of the content centric networking (CCN) technology are employed to simultaneously download the video content from multiple wireless networks. A two-stage PID-based LTE traffic controller is proposed to determine the amount of traffic to be offloaded to the D2D network among the cellular operator, the D2D servers, and the D2D clients. The proposed system is fully implemented using a CCNx open source and C/C++. Experimental results are provided to demonstrate the performance improvement of the proposed system.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"89 14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129764771","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}
In a wireless system, a signal map shows the signal strength at different locations termed reference points (RPs). As access points (APs) and their transmission power may change over time, keeping an updated signal map is important for applications such as Wi-Fi optimization and indoor localization. Traditionally, the signal map is obtained by a full site survey, which is time-consuming and costly. We address in this paper how to efficiently update a signal map given sparse samples randomly crowdsourced in the space (e.g., by signal monitors, explicit human input, or implicit user participation). We propose Compressive Signal Reconstruction (CSR), a novel learning system employing Bayesian compressive sensing (BCS) for online signal map update. CSR does not rely on any path loss model or line of sight, and is generic enough to serve as a plug-in of any wireless system. Besides signal map update, CSR also computes the estimation error of signals in terms of confidence interval. CSR models the signal correlation with a kernel function. Using it, CSR constructs a sensing matrix based on the newly sampled signals. The sensing matrix is then used to compute the signal change at all the RPs with any BCS algorithm. We have conducted extensive experiments on CSR in our university campus. Our results show that CSR outperforms other state-of-the-art algorithms by a wide margin (reducing signal error by about 30% and sampling points by 20%).
{"title":"Updating Wireless Signal Map with Bayesian Compressive Sensing","authors":"Bo Yang, Suining He, S. Chan","doi":"10.1145/2988287.2989132","DOIUrl":"https://doi.org/10.1145/2988287.2989132","url":null,"abstract":"In a wireless system, a signal map shows the signal strength at different locations termed reference points (RPs). As access points (APs) and their transmission power may change over time, keeping an updated signal map is important for applications such as Wi-Fi optimization and indoor localization. Traditionally, the signal map is obtained by a full site survey, which is time-consuming and costly. We address in this paper how to efficiently update a signal map given sparse samples randomly crowdsourced in the space (e.g., by signal monitors, explicit human input, or implicit user participation). We propose Compressive Signal Reconstruction (CSR), a novel learning system employing Bayesian compressive sensing (BCS) for online signal map update. CSR does not rely on any path loss model or line of sight, and is generic enough to serve as a plug-in of any wireless system. Besides signal map update, CSR also computes the estimation error of signals in terms of confidence interval. CSR models the signal correlation with a kernel function. Using it, CSR constructs a sensing matrix based on the newly sampled signals. The sensing matrix is then used to compute the signal change at all the RPs with any BCS algorithm. We have conducted extensive experiments on CSR in our university campus. Our results show that CSR outperforms other state-of-the-art algorithms by a wide margin (reducing signal error by about 30% and sampling points by 20%).","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129155434","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}
B. Peres, O. A. D. O. Souza, B. P. Santos, Edson Roteia Araujo Junior, Olga Goussevskaia, M. Vieira, L. Vieira, A. Loureiro
Standard routing protocols for IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) are mainly designed for data collection applications and work by establishing a tree-based network topology, which enables packets to be sent upwards, from the leaves to the root, adapting to dynamics of low-power communication links. The routing tables in such unidirectional networks are very simple and small since each node just needs to maintain the address of its parent in the tree, providing the best-quality route at every moment. In this work, we propose Matrix, a platform-independent routing protocol that utilizes the existing tree structure of the network to enable reliable and efficient any-to-any data traffic. Matrix uses hierarchical IPv6 address assignment in order to optimize routing table size, while preserving bidirectional routing. Moreover, it uses a local broadcast mechanism to forward messages to the right subtree when persistent node or link failures occur. We implemented Matrix on TinyOS and evaluated its performance both analytically and through simulations on TOSSIM. Our results show that the proposed protocol is superior to available protocols for 6LoWPAN, when it comes to any-to-any data communication, in terms of reliability, message efficiency, and memory footprint.
IPv6 over Low power Wireless Personal Area Networks (6LoWPAN)的标准路由协议主要是为数据采集应用而设计的，它通过建立基于树的网络拓扑来工作，使数据包能够从叶子向上发送到根，以适应低功耗通信链路的动态变化。这种单向网络中的路由表非常简单和小，因为每个节点只需要在树中维护其父节点的地址，随时提供最佳质量的路由。在这项工作中，我们提出了Matrix，这是一种独立于平台的路由协议，它利用现有的网络树结构来实现可靠和高效的任意对任意数据流量。矩阵使用分层IPv6地址分配，以优化路由表的大小，同时保持双向路由。此外，当发生持久节点或链路故障时，它使用本地广播机制将消息转发到正确的子树。我们在TinyOS上实现了Matrix，并在TOSSIM上通过分析和仿真对其性能进行了评估。我们的结果表明，当涉及到任意对任意数据通信时，在可靠性、消息效率和内存占用方面，所提出的协议优于6LoWPAN的可用协议。
{"title":"Matrix: Multihop Address Allocation and Dynamic Any-to-Any Routing for 6LoWPAN","authors":"B. Peres, O. A. D. O. Souza, B. P. Santos, Edson Roteia Araujo Junior, Olga Goussevskaia, M. Vieira, L. Vieira, A. Loureiro","doi":"10.1145/2988287.2989139","DOIUrl":"https://doi.org/10.1145/2988287.2989139","url":null,"abstract":"Standard routing protocols for IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) are mainly designed for data collection applications and work by establishing a tree-based network topology, which enables packets to be sent upwards, from the leaves to the root, adapting to dynamics of low-power communication links. The routing tables in such unidirectional networks are very simple and small since each node just needs to maintain the address of its parent in the tree, providing the best-quality route at every moment. In this work, we propose Matrix, a platform-independent routing protocol that utilizes the existing tree structure of the network to enable reliable and efficient any-to-any data traffic. Matrix uses hierarchical IPv6 address assignment in order to optimize routing table size, while preserving bidirectional routing. Moreover, it uses a local broadcast mechanism to forward messages to the right subtree when persistent node or link failures occur. We implemented Matrix on TinyOS and evaluated its performance both analytically and through simulations on TOSSIM. Our results show that the proposed protocol is superior to available protocols for 6LoWPAN, when it comes to any-to-any data communication, in terms of reliability, message efficiency, and memory footprint.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131013531","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}
Interference problems caused by congestion of vehicles at intersections or on highways may significantly affect vehicle-to-vehicle (V2V) communications, especially for active-safety assistance systems due to the importance of emergency information. In this paper, we propose a theoretical interference model of V2V communications at an intersection that uses transmission power control method. To evaluate and address the interference problem at an intersection, we derived an analytical expression of the outage probability of a typical vehicle at an intersection and provide guidelines for an optimal power control method, which cannot be obtained through simulations. We model the location of vehicles in queueing segments and running segments separately and analyze their interference based on a stochastic geometry approach. In our model, a simple power control method is used: the transmission power of each vehicle is determined by the status of the vehicle, i.e., stopping or running. By changing the transmission power of vehicles in queueing segments, we can mitigate the interference received at vehicles running closer to an intersection. By using the theoretical results, we obtain an optimal power control method, which can balance the trade-off between the outage probabilities of vehicles in queueing segments and running segments. We validated our analytical results and the effect of the power control on V2V communications through numerical experiments.
{"title":"Theoretical Interference Analysis of Inter-vehicular Communication at Intersection with Power Control","authors":"Tatsuaki Kimura, H. Saito","doi":"10.1145/2988287.2989156","DOIUrl":"https://doi.org/10.1145/2988287.2989156","url":null,"abstract":"Interference problems caused by congestion of vehicles at intersections or on highways may significantly affect vehicle-to-vehicle (V2V) communications, especially for active-safety assistance systems due to the importance of emergency information. In this paper, we propose a theoretical interference model of V2V communications at an intersection that uses transmission power control method. To evaluate and address the interference problem at an intersection, we derived an analytical expression of the outage probability of a typical vehicle at an intersection and provide guidelines for an optimal power control method, which cannot be obtained through simulations. We model the location of vehicles in queueing segments and running segments separately and analyze their interference based on a stochastic geometry approach. In our model, a simple power control method is used: the transmission power of each vehicle is determined by the status of the vehicle, i.e., stopping or running. By changing the transmission power of vehicles in queueing segments, we can mitigate the interference received at vehicles running closer to an intersection. By using the theoretical results, we obtain an optimal power control method, which can balance the trade-off between the outage probabilities of vehicles in queueing segments and running segments. We validated our analytical results and the effect of the power control on V2V communications through numerical experiments.","PeriodicalId":158785,"journal":{"name":"Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122162106","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}
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