Pub Date : 2010-03-14DOI: 10.1109/INFCOM.2010.5461981
C. Feng, Wain Sy Anthea Au, S. Valaee, Z. Tan
The sparse nature of location finding problem makes the theory of compressive sensing desirable for indoor positioning in Wireless Local Area Networks (WLANs). In this paper, we address the received signal strength (RSS)-based localization problem in WLANs using the theory of compressive sensing (CS), which offers accurate recovery of sparse signals from a small number of measurements by solving an $ell_1$-minimization problem. A pre-processing procedure of orthogonalization is used to induce incoherence needed in the CS theory. In order to mitigate the effects of RSS variations due to channel impediments, the proposed positioning system consists of two steps: coarse localization by exploiting affinity propagation, and fine localization by the CS theory. In the fine localization stage, access point selection problem is studied to further increase the accuracy. We implement the positioning system on a WiFi-integrated mobile device (HP iPAQ hx4700 with Windows Mobile 2003 Pocket PC) to evaluate the performance. Experimental results indicate that the proposed system leads to substantial improvements on localization accuracy and complexity over the widely used traditional fingerprinting methods.
定位问题的稀疏性使得压缩感知理论成为无线局域网(wlan)室内定位的理想方法。在本文中，我们使用压缩感知(CS)理论解决了无线局域网中基于接收信号强度(RSS)的定位问题，该理论通过解决$ell_1$-最小化问题，从少量测量中精确恢复稀疏信号。采用正交化的预处理程序来诱导CS理论所需的非相干性。为了减轻由于通道障碍引起的RSS变化的影响，提出的定位系统包括两个步骤:利用亲和传播进行粗定位和利用CS理论进行精细定位。在精细定位阶段，研究了接入点选择问题，进一步提高了定位精度。我们在wifi集成的移动设备(HP iPAQ hx4700和Windows mobile 2003 Pocket PC)上实现了定位系统，以评估其性能。实验结果表明，与传统的指纹识别方法相比，该系统在定位精度和复杂性方面有了很大的提高。
{"title":"Compressive Sensing Based Positioning Using RSS of WLAN Access Points","authors":"C. Feng, Wain Sy Anthea Au, S. Valaee, Z. Tan","doi":"10.1109/INFCOM.2010.5461981","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5461981","url":null,"abstract":"The sparse nature of location finding problem makes the theory of compressive sensing desirable for indoor positioning in Wireless Local Area Networks (WLANs). In this paper, we address the received signal strength (RSS)-based localization problem in WLANs using the theory of compressive sensing (CS), which offers accurate recovery of sparse signals from a small number of measurements by solving an $ell_1$-minimization problem. A pre-processing procedure of orthogonalization is used to induce incoherence needed in the CS theory. In order to mitigate the effects of RSS variations due to channel impediments, the proposed positioning system consists of two steps: coarse localization by exploiting affinity propagation, and fine localization by the CS theory. In the fine localization stage, access point selection problem is studied to further increase the accuracy. We implement the positioning system on a WiFi-integrated mobile device (HP iPAQ hx4700 with Windows Mobile 2003 Pocket PC) to evaluate the performance. Experimental results indicate that the proposed system leads to substantial improvements on localization accuracy and complexity over the widely used traditional fingerprinting methods.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127671148","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462192
Rami Cohen, D. Raz
In recent years, hardware based packet classification has became an essential component in many networking devices. Ternary Content-Addressable Memories (TCAMs) are one of the most popular solutions in this domain, allowing to compare in parallel the packet header against a large set of rules, and to retrieve the first match. However, using TCAM to match a range of values is much more problematic and dramatically reduces the cost effectiveness of the solution. In this paper we study ways to use simple built-in TCAM mechanisms in order to increase the efficiency of range coverage. While current techniques have a worst expansion ratio of 2W-4, we present an efficient algorithm enabling to encode any range with at most W TCAM entries (where W in the number of bits), without using additional processing, extra bits, and without any external encoding. The same paradigm can be applied to multiple raging rules as well, resulting in significant improvement over current known techniques. Moreover, our simulation results indicate that these techniques can be used to reduce the actual TCAM size of hardware networking devices under realistic scenarios.
{"title":"Simple Efficient TCAM Based Range Classification","authors":"Rami Cohen, D. Raz","doi":"10.1109/INFCOM.2010.5462192","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462192","url":null,"abstract":"In recent years, hardware based packet classification has became an essential component in many networking devices. Ternary Content-Addressable Memories (TCAMs) are one of the most popular solutions in this domain, allowing to compare in parallel the packet header against a large set of rules, and to retrieve the first match. However, using TCAM to match a range of values is much more problematic and dramatically reduces the cost effectiveness of the solution. In this paper we study ways to use simple built-in TCAM mechanisms in order to increase the efficiency of range coverage. While current techniques have a worst expansion ratio of 2W-4, we present an efficient algorithm enabling to encode any range with at most W TCAM entries (where W in the number of bits), without using additional processing, extra bits, and without any external encoding. The same paradigm can be applied to multiple raging rules as well, resulting in significant improvement over current known techniques. Moreover, our simulation results indicate that these techniques can be used to reduce the actual TCAM size of hardware networking devices under realistic scenarios.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126494346","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5461989
H. Tan, M. Chan, Wendong Xiao, P. Kong, C. Tham
Upon the occurrence of a phenomenon of interest in a wireless sensor network, multiple sensors may be activated, leading to data implosion and redundancy. Data aggregation and/or fusion techniques exploit spatio-temporal correlation among sensory data to reduce traffic load and mitigate congestion. However, this is often at the expense of loss in Information Quality (IQ) of data that is collected at the fusion center. In this work, we address the problem of finding the least-cost routing tree that satisfies a given IQ constraint. We note that the optimal least-cost routing solution is a variation of the classical NP-hard Steiner tree problem in graphs, which incurs high overheads as it requires knowledge of the entire network topology and individual IQ contributions of each activated sensor node. We tackle these issues by proposing: (i) a topology-aware histogram-based aggregation structure that encapsulates the cost of including the IQ contribution of each activated node in a compact and efficient way; and (ii) a greedy heuristic to approximate and prune a least-cost aggregation routing path. We show that the performance of our IQ-aware routing protocol is: (i) bounded by a distance-based aggregation tree that collects data from all the activated nodes; and (ii) comparable to another IQ-aware routing protocol that uses an exhaustive brute-force search to approximate and prune the least-cost aggregation tree.
{"title":"Information Quality Aware Routing in Event-Driven Sensor Networks","authors":"H. Tan, M. Chan, Wendong Xiao, P. Kong, C. Tham","doi":"10.1109/INFCOM.2010.5461989","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5461989","url":null,"abstract":"Upon the occurrence of a phenomenon of interest in a wireless sensor network, multiple sensors may be activated, leading to data implosion and redundancy. Data aggregation and/or fusion techniques exploit spatio-temporal correlation among sensory data to reduce traffic load and mitigate congestion. However, this is often at the expense of loss in Information Quality (IQ) of data that is collected at the fusion center. In this work, we address the problem of finding the least-cost routing tree that satisfies a given IQ constraint. We note that the optimal least-cost routing solution is a variation of the classical NP-hard Steiner tree problem in graphs, which incurs high overheads as it requires knowledge of the entire network topology and individual IQ contributions of each activated sensor node. We tackle these issues by proposing: (i) a topology-aware histogram-based aggregation structure that encapsulates the cost of including the IQ contribution of each activated node in a compact and efficient way; and (ii) a greedy heuristic to approximate and prune a least-cost aggregation routing path. We show that the performance of our IQ-aware routing protocol is: (i) bounded by a distance-based aggregation tree that collects data from all the activated nodes; and (ii) comparable to another IQ-aware routing protocol that uses an exhaustive brute-force search to approximate and prune the least-cost aggregation tree.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125451372","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462200
Mingui Zhang, B. Liu, Beichuan Zhang
False routing announcements are a serious security problem, which can lead to widespread service disruptions in the Internet. A number of detection systems have been proposed and implemented recently, however, it takes time to detect attacks, notify operators, and stop false announcements. Thus detection systems should be complemented by a mitigation scheme that can protect data delivery before the attack is resolved. We propose such a mitigation scheme, QBGP, which decouples the propagation of a path and the adoption of a path for data forwarding. QBGP does not use suspicious paths to forward data traffic, but still propagates them in the routing system to facilitate attack detection. It can protect data delivery from routing announcements of false sub-prefixes, false origins, false nodes and false links. QBGP incurs overhead only when there are suspicious paths, which happen infrequently in real BGP traces. Results from large scale simulations and BGP trace analysis show that QBGP is light-weight yet effective, and it converges faster and incurs less overhead than Pretty Good BGP.
错误路由通知是一个严重的安全问题，它可能导致互联网上广泛的服务中断。最近已经提出并实施了许多检测系统，然而，检测攻击、通知运营商和停止虚假通知需要时间。因此，检测系统应辅以缓解方案，在攻击解决之前保护数据传输。我们提出了这样一种缓解方案，QBGP，它将路径的传播和采用路径进行数据转发解耦。QBGP不使用可疑路径转发数据流量，而是在路由系统中进行传播，方便检测攻击。它可以保护数据传输免受虚假子前缀、虚假起源、虚假节点和虚假链接的路由通知。QBGP只在有可疑路径的情况下才会产生开销，而在实际的BGP路径中，这种情况很少发生。大规模仿真和BGP跟踪分析结果表明，与Pretty Good BGP相比，QBGP具有轻量级、高效、收敛速度快、开销小等优点。
{"title":"Safeguarding Data Delivery by Decoupling Path Propagation and Adoption","authors":"Mingui Zhang, B. Liu, Beichuan Zhang","doi":"10.1109/INFCOM.2010.5462200","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462200","url":null,"abstract":"False routing announcements are a serious security problem, which can lead to widespread service disruptions in the Internet. A number of detection systems have been proposed and implemented recently, however, it takes time to detect attacks, notify operators, and stop false announcements. Thus detection systems should be complemented by a mitigation scheme that can protect data delivery before the attack is resolved. We propose such a mitigation scheme, QBGP, which decouples the propagation of a path and the adoption of a path for data forwarding. QBGP does not use suspicious paths to forward data traffic, but still propagates them in the routing system to facilitate attack detection. It can protect data delivery from routing announcements of false sub-prefixes, false origins, false nodes and false links. QBGP incurs overhead only when there are suspicious paths, which happen infrequently in real BGP traces. Results from large scale simulations and BGP trace analysis show that QBGP is light-weight yet effective, and it converges faster and incurs less overhead than Pretty Good BGP.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128200641","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462160
A. Bremler-Barr, David Hay, Yaron Koral
Pattern matching algorithms lie at the core of all contemporary Intrusion Detection Systems (IDS), making it intrinsic to reduce their speed and memory requirements. This paper focuses on the most popular class of pattern-matching algorithms, the Aho-Corasick--like algorithms, which are based on constructing and traversing a Deterministic Finite Automaton (DFA), representing the patterns. While this approach ensures deterministic time guarantees, modern IDSs need to deal with hundreds of patterns, thus requiring to store very large DFAs which usually do not fit in fast memory. This results in a major bottleneck on the throughput of the IDS, as well as its power consumption and cost. We propose a novel method to compress DFAs by observing that the name of the states is meaningless. While regular DFAs store separately each transition between two states, we use this degree of freedom and encode states in such a way that all transitions to a specific state can be represented by a single prefix that defines a set of current states. Our technique applies to a large class of automata, which can be categorized by simple properties. Then, the problem of pattern matching is reduced to the well-studied problem of Longest Prefix Matching (LPM) that can be solved either in TCAM, in commercially available IP-lookup chips, or in software. Specifically, we show that with a TCAM our scheme can reach a throughput of 10 Gbps with low power consumption.
{"title":"CompactDFA: Generic State Machine Compression for Scalable Pattern Matching","authors":"A. Bremler-Barr, David Hay, Yaron Koral","doi":"10.1109/INFCOM.2010.5462160","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462160","url":null,"abstract":"Pattern matching algorithms lie at the core of all contemporary Intrusion Detection Systems (IDS), making it intrinsic to reduce their speed and memory requirements. This paper focuses on the most popular class of pattern-matching algorithms, the Aho-Corasick--like algorithms, which are based on constructing and traversing a Deterministic Finite Automaton (DFA), representing the patterns. While this approach ensures deterministic time guarantees, modern IDSs need to deal with hundreds of patterns, thus requiring to store very large DFAs which usually do not fit in fast memory. This results in a major bottleneck on the throughput of the IDS, as well as its power consumption and cost. We propose a novel method to compress DFAs by observing that the name of the states is meaningless. While regular DFAs store separately each transition between two states, we use this degree of freedom and encode states in such a way that all transitions to a specific state can be represented by a single prefix that defines a set of current states. Our technique applies to a large class of automata, which can be categorized by simple properties. Then, the problem of pattern matching is reduced to the well-studied problem of Longest Prefix Matching (LPM) that can be solved either in TCAM, in commercially available IP-lookup chips, or in software. Specifically, we show that with a TCAM our scheme can reach a throughput of 10 Gbps with low power consumption.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121735025","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462244
Aiyou Chen, Yu Jin, Jin Cao
We propose the tracking of long duration flows as a new network measurement primitive. Long-duration flows are characterized by their long lived nature in time, and may not have high traffic volumes. We propose an efficient data streaming algorithm to effectively track long duration flows. Our basic technique is to maintain only two Bloom filters at any given time. In each time duration, only old flows that appear in the current time duration get copied to the current Bloom filter. Our basic algorithm is further enhanced by sampling. Using real network traces, we show that our tracking algorithm is very accurate with low false positive and false negative probabilities. Using multi-faceted analysis, we show that more than 50% of hosts participating in long duration flows (duration no less than 30 minutes) are blacklisted by various public sources.
{"title":"Tracking Long Duration Flows in Network Traffic","authors":"Aiyou Chen, Yu Jin, Jin Cao","doi":"10.1109/INFCOM.2010.5462244","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462244","url":null,"abstract":"We propose the tracking of long duration flows as a new network measurement primitive. Long-duration flows are characterized by their long lived nature in time, and may not have high traffic volumes. We propose an efficient data streaming algorithm to effectively track long duration flows. Our basic technique is to maintain only two Bloom filters at any given time. In each time duration, only old flows that appear in the current time duration get copied to the current Bloom filter. Our basic algorithm is further enhanced by sampling. Using real network traces, we show that our tracking algorithm is very accurate with low false positive and false negative probabilities. Using multi-faceted analysis, we show that more than 50% of hosts participating in long duration flows (duration no less than 30 minutes) are blacklisted by various public sources.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130002286","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462000
Chenhui Hu, Xinbing Wang, D. Nie, Jun Zhao
A new class of scheduling policies for multicast traffic are proposed in this paper. By utilizing hierarchical cooperative MIMO transmission, our new policies can obtain an aggregate throughput of $Omegabig((frac{n}{k})^{1-epsilon}big)$ for any $epsilon>0$. This achieves a gain of nearly $sqrt{frac{n}{k}}$ compared with non-cooperative scheme in cite{paper:MulticastCapacityXYLi}. Between the two cooperative strategies in our paper, the converge-based one is superior to the other on delay, while the throughput and energy consumption performances are nearly the same. Moreover, to schedule the traffic in a converge multicast manner instead of the simple multicast, we can dramatically reduce the delay by a factor nearly $(frac{n}{k})^frac{h}{2}$, where $h>1$ is the number of the hierarchical layers. Our optimal cooperative strategy achieves an approximate delay-throughput tradeoff $D(n,k)/T(n,k)=Theta(k)$ when $hrightarrowinfty$. This tradeoff ratio is identical to that of non-cooperative scheme, while the throughput performance is greatly improved. Besides, for certain $k$ and $h$, the tradeoff ratio is even better than that of unicast.
{"title":"Multicast Scaling Laws with Hierarchical Cooperation","authors":"Chenhui Hu, Xinbing Wang, D. Nie, Jun Zhao","doi":"10.1109/INFCOM.2010.5462000","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462000","url":null,"abstract":"A new class of scheduling policies for multicast traffic are proposed in this paper. By utilizing hierarchical cooperative MIMO transmission, our new policies can obtain an aggregate throughput of $Omegabig((frac{n}{k})^{1-epsilon}big)$ for any $epsilon>0$. This achieves a gain of nearly $sqrt{frac{n}{k}}$ compared with non-cooperative scheme in cite{paper:MulticastCapacityXYLi}. Between the two cooperative strategies in our paper, the converge-based one is superior to the other on delay, while the throughput and energy consumption performances are nearly the same. Moreover, to schedule the traffic in a converge multicast manner instead of the simple multicast, we can dramatically reduce the delay by a factor nearly $(frac{n}{k})^frac{h}{2}$, where $h>1$ is the number of the hierarchical layers. Our optimal cooperative strategy achieves an approximate delay-throughput tradeoff $D(n,k)/T(n,k)=Theta(k)$ when $hrightarrowinfty$. This tradeoff ratio is identical to that of non-cooperative scheme, while the throughput performance is greatly improved. Besides, for certain $k$ and $h$, the tradeoff ratio is even better than that of unicast.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133993094","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462099
Ching-Ming Lien, Cheng-Shang Chang, Jay Cheng, D. Lee, Jou-Ting Liao
Inspired by the recent development of optical queueing theory, in this paper we study a class of multistage interconnection networks (MINs), called {em twister networks}. Unlike the usual recursive constructions of MINs (either by two-stage expansion or by three-stage expansion), twister networks are constructed {em directly} by a concatenation of bipartite networks. Moreover, the biadjacency matrices of these bipartite networks are sums of subsets of the powers of the circular shift matrix. Though MINs have been studied extensively in the literature, we show there are several {em distinct} properties for twister networks, including routability and conditionally nonblocking properties. In particular, we show that a twister network satisfying (A1) in the paper is routable, and packets can be self-routed through the twister network by using the $cal C$-transform developed in optical queueing theory. Moreover, we define an $N$-modulo distance and use it to show that a twister network satisfying (A2) in the paper is conditionally nonblocking if the $N$-modulo distance between any two outputs is not greater than two times of the $N$-modulo distance between the corresponding two inputs. Such a conditionally nonblocking property allows us to show that a twister network with $N$ inputs/outputs can be used as a $p times p$ rotator and a $p times p$ symmetric TDM switch for any $2 le p le N$. As such, one can use a twister network as the switch fabric for a two-stage load balanced switch that is capable of providing incremental update of the number of linecards.
受光排队理论最新发展的启发，本文研究了一类多级互连网络(MINs)，称为{em绕线网络}。与通常的MINs递归构造(通过两阶段展开或三阶段展开)不同，绕线网络是通过二部网络的连接直接构造的。此外，这些二部网络的双邻接矩阵是圆移位矩阵幂的子集的和。虽然文献中对绕线网络进行了广泛的研究，但我们发现绕线网络有几个不同的特性，包括可达性和条件非阻塞特性。特别地，我们证明了满足(A1)的绕线网络是可路由的，并且利用光排队理论中的$cal $ C$-变换，数据包可以在绕线网络中自路由。此外，我们定义了一个$N$模距离，并利用它证明了当任意两个输出之间的$N$模距离不大于对应两个输入之间的$N$模距离的两倍时，满足(A2)的绕线网络是条件非阻塞的。这种条件非阻塞特性使我们能够证明具有$N$输入/输出的绕线网络可以用作$p 乘以p$旋转器和$p 乘以p$对称TDM开关，用于任意$2 le p le N$。因此，可以使用绕线网络作为两级负载平衡交换机的交换结构，该交换机能够提供线卡数量的增量更新。
{"title":"Twister Networks and Their Applications to Load-Balanced Switches","authors":"Ching-Ming Lien, Cheng-Shang Chang, Jay Cheng, D. Lee, Jou-Ting Liao","doi":"10.1109/INFCOM.2010.5462099","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462099","url":null,"abstract":"Inspired by the recent development of optical queueing theory, in this paper we study a class of multistage interconnection networks (MINs), called {em twister networks}. Unlike the usual recursive constructions of MINs (either by two-stage expansion or by three-stage expansion), twister networks are constructed {em directly} by a concatenation of bipartite networks. Moreover, the biadjacency matrices of these bipartite networks are sums of subsets of the powers of the circular shift matrix. Though MINs have been studied extensively in the literature, we show there are several {em distinct} properties for twister networks, including routability and conditionally nonblocking properties. In particular, we show that a twister network satisfying (A1) in the paper is routable, and packets can be self-routed through the twister network by using the $cal C$-transform developed in optical queueing theory. Moreover, we define an $N$-modulo distance and use it to show that a twister network satisfying (A2) in the paper is conditionally nonblocking if the $N$-modulo distance between any two outputs is not greater than two times of the $N$-modulo distance between the corresponding two inputs. Such a conditionally nonblocking property allows us to show that a twister network with $N$ inputs/outputs can be used as a $p times p$ rotator and a $p times p$ symmetric TDM switch for any $2 le p le N$. As such, one can use a twister network as the switch fabric for a two-stage load balanced switch that is capable of providing incremental update of the number of linecards.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133921917","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5461904
P. Wan, Lixin Wang, Ai Huang, Minming Li, F. Yao
The capacity region of multihop wireless network is involved in many capacity optimization problems. However, the membership of the capacity region is NP-complete in general, and hence the direct application of capacity region is quite limited. As a compromise, we often substitute the capacity region with a polynomial approximate capacity subregion. In this paper, we construct polynomial μ-approximate capacity subregions of multihop wireless network under either 802.11 interference model or protocol interference model in which all nodes have uniform communication radii normalized to one and uniform interference radii ρ≥1. The approximation factor μ decreases with ρ in general and is smaller than the best-known ones in the literature. For example, μ=3 when ρ≥2.2907 under the 802.11 interference model or when ρ≥4.2462 under the protocol interference model. Our construction exploits a nature of the wireless interference called strip-wise transitivity of independence discovered in this paper and utilize the independence polytopes of cocomparability graphs in a spatial-divide-conquer manner. We also apply these polynomial μ-approximate capacity subregions to compute μ-approximate solutions for maximum (concurrent) multiflows.
{"title":"Approximate Capacity Subregions of Uniform Multihop Wireless Networks","authors":"P. Wan, Lixin Wang, Ai Huang, Minming Li, F. Yao","doi":"10.1109/INFCOM.2010.5461904","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5461904","url":null,"abstract":"The capacity region of multihop wireless network is involved in many capacity optimization problems. However, the membership of the capacity region is NP-complete in general, and hence the direct application of capacity region is quite limited. As a compromise, we often substitute the capacity region with a polynomial approximate capacity subregion. In this paper, we construct polynomial μ-approximate capacity subregions of multihop wireless network under either 802.11 interference model or protocol interference model in which all nodes have uniform communication radii normalized to one and uniform interference radii ρ≥1. The approximation factor μ decreases with ρ in general and is smaller than the best-known ones in the literature. For example, μ=3 when ρ≥2.2907 under the 802.11 interference model or when ρ≥4.2462 under the protocol interference model. Our construction exploits a nature of the wireless interference called strip-wise transitivity of independence discovered in this paper and utilize the independence polytopes of cocomparability graphs in a spatial-divide-conquer manner. We also apply these polynomial μ-approximate capacity subregions to compute μ-approximate solutions for maximum (concurrent) multiflows.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"34 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131590220","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 : 2010-03-14DOI: 10.1109/INFCOM.2010.5462060
Zheng Yang, Yunhao Liu
Location awareness is highly critical for wireless ad-hoc and sensor networks. Many efforts have been made to solve the problem of whether or not a network can be localized. Nevertheless, based on the data collected from a working sensor network, it is observed that the network is NOT always entirely localizable. Theoretical analyses also suggest that, in most cases, it is unlikely that all nodes in a network are localizable, although a (large) portion of the nodes can be uniquely located. Existing studies merely examine whether or not a network is localizable as a whole; yet two fundamental questions remain unaddressed: First, given a network configuration, whether or not a specific node is localizable? Second, how many nodes in a network can be located and which are them? In this study, we analyze the limitation of previous works and propose a novel concept of node localizability. By deriving the necessary and sufficient conditions for node localizability, for the first time, it is possible to analyze how many nodes one can expect to locate in sparsely or moderately connected networks. To validate this design, we implement our solution on a real-world sys-tem and the experimental results show that node localizabil-ity provides useful guidelines for network deployment and other location-based services.
{"title":"Understanding Node Localizability of Wireless Ad-hoc Networks","authors":"Zheng Yang, Yunhao Liu","doi":"10.1109/INFCOM.2010.5462060","DOIUrl":"https://doi.org/10.1109/INFCOM.2010.5462060","url":null,"abstract":"Location awareness is highly critical for wireless ad-hoc and sensor networks. Many efforts have been made to solve the problem of whether or not a network can be localized. Nevertheless, based on the data collected from a working sensor network, it is observed that the network is NOT always entirely localizable. Theoretical analyses also suggest that, in most cases, it is unlikely that all nodes in a network are localizable, although a (large) portion of the nodes can be uniquely located. Existing studies merely examine whether or not a network is localizable as a whole; yet two fundamental questions remain unaddressed: First, given a network configuration, whether or not a specific node is localizable? Second, how many nodes in a network can be located and which are them? In this study, we analyze the limitation of previous works and propose a novel concept of node localizability. By deriving the necessary and sufficient conditions for node localizability, for the first time, it is possible to analyze how many nodes one can expect to locate in sparsely or moderately connected networks. To validate this design, we implement our solution on a real-world sys-tem and the experimental results show that node localizabil-ity provides useful guidelines for network deployment and other location-based services.","PeriodicalId":259639,"journal":{"name":"2010 Proceedings IEEE INFOCOM","volume":"512 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131606518","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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