E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080151

A. Jardosh, K. Ramachandran, K. Almeroth, E. Belding-Royer

{"title":"Understanding link-layer behavior in highly congested IEEE 802.11b wireless networks","authors":"A. Jardosh, K. Ramachandran, K. Almeroth, E. Belding-Royer","doi":"10.1145/1080148.1080151","DOIUrl":"https://doi.org/10.1145/1080148.1080151","url":null,"abstract":"The growing deployment and concomitant rise in wireless network usage necessitates the comprehensive understanding of its behavior. More importantly, as networks grow in size and number of users, congestion in the wireless portion of the network is likely to increase. We believe there is a strong need to understand the intricacies of the wireless portion of a congested network by interpreting information collected from the network. Congestion in a wireless network can be best analyzed by studying the transmission of frames at the link layer. To this end, we use vicinity sniffing techniques to analyze the link layer in an operational IEEE 802.11b wireless network. In this paper, we discuss how congestion in a network can be estimated using point-to-point link reliability. We then show how link reliability is correlated with the behavior of link-layer properties such as frame retransmissions, frame sizes, and data rates. Based on the results from these correlations, our hypothesis is that the performance of the link layer in congested networks can be improved by (1) sending smaller frames, and/or (2) using higher data rates with a fewer number of frames sent.","PeriodicalId":351562,"journal":{"name":"E-WIND '05","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122671726","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}

引用次数: 120

Cooperative packet scheduling via pipelining in 802.11 wireless networks 802.11无线网络中通过流水线的协作分组调度

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080156

R. Kompella, Sriram Ramabhadran, I. Ramani, A. Snoeren

{"title":"Cooperative packet scheduling via pipelining in 802.11 wireless networks","authors":"R. Kompella, Sriram Ramabhadran, I. Ramani, A. Snoeren","doi":"10.1145/1080148.1080156","DOIUrl":"https://doi.org/10.1145/1080148.1080156","url":null,"abstract":"The proliferation of 802.11a/b/g based wireless devices has fueled their adoption in many domains -- some of which are unforseen. Yet, these devices lack native support for some of the advanced features (such as service differentiation, etc.) required in specific application domains. A subset of these features relies on cooperative scheduling whereby nodes cooperate among each other to effectively manage resources such as power, throughput and interference in wireless networks. The trajectory of evolution in these devices has been primarily through new extension standards (such as 802.11e/s etc.) that offer support for these features. Plagued with long design cycles and cost overhead to upgrade, this process of upgrading creates an uphill task to users who want to use their wireless devices for different applications. In this paper, we argue that such cooperative scheduling extensions can be supported using a new layer on top of the existing MAC layer. We propose a 2½- pipeline architecture as a generic mechanism to create such domain specific extensions and propose two such protocols, SPARTA (power conservation) and ARGOS (throughput guarantees) over the native 802.11/b/g MAC layer.","PeriodicalId":351562,"journal":{"name":"E-WIND '05","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130615232","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}

引用次数: 15

Towards large-scale mobile network emulation through spatial switching on a wireless grid 通过无线网格的空间交换实现大规模移动网络仿真

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080158

Kishore Ramachandran, S. Kaul, Suhas Mathur, M. Gruteser, I. Seskar

引用次数: 27

Experimental comparison of routing and middleware solutions for mobile ad hoc networks: legacy vs cross-layer approach 移动自组织网络的路由和中间件解决方案的实验比较:遗留与跨层方法

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080166

E. Borgia, M. Conti, Franca Delmastro, E. Gregori

引用次数: 34

Experimental evaluation of TCP performance and fairness in an 802.11e test-bed 802.11e测试平台中TCP性能和公平性的实验评估

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080152

Anthony C. H. Ng, D. Malone, D. Leith

引用次数: 67

Understanding the real-world performance of carrier sense 了解载波感知的实际性能

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080160

K. Jamieson, Bret Hull, Allen K. L. Miu, H. Balakrishnan

引用次数: 167

Explorebots: a mobile network experimentation testbed explorbots:移动网络实验测试平台

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080165

T. Dahlberg, A. Nasipuri, Craig Taylor

引用次数: 47

Experimental investigations into TCP performance over wireless multihop networks 无线多跳网络中TCP性能的实验研究

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080155

Vikas Kawadia, P. Kumar

引用次数: 112

Experimental evaluation of the TCP simultaneous-send problem in 802.11 wireless local area networks 802.11无线局域网中TCP同步发送问题的实验评估

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080153

S. Gopal, D. Raychaudhuri

{"title":"Experimental evaluation of the TCP simultaneous-send problem in 802.11 wireless local area networks","authors":"S. Gopal, D. Raychaudhuri","doi":"10.1145/1080148.1080153","DOIUrl":"https://doi.org/10.1145/1080148.1080153","url":null,"abstract":"This paper is an experimental follow up to our earlier paper [1] that investigated the TCP simultaneous-send problem which arises in infrastructure mode 802.11 wireless local area networks. In particular it was observed that for file transfer traffic, 802.11 wireless nodes have a sustained supply of packets to send and hence experience a relatively high rate of MAC contention. We showed that for TCP, this resulted in competition among data and ACK packets for channel access which caused considerable deterioration in flow throughput. Simulations of TCP ACK skipping as an alleviation to the problem, showed improvements as high as 100% when MAC retries were disabled. There were gains in other scenarios too albeit more moderate.We evaluate the same TCP simultaneous-send problem with real world experiments on a wireless-cum-wired network testbed called ORBIT [2] at WINLAB, Rutgers University. ORBIT makes it feasible to conduct controlled and reproducible experiments in a wireless network scenario. The same network setup scenarios evaluated in simulations were considered here., particularly - scenarios with and without MAC retries, multiple TCP flows and multiple skipped ACKs. However not all scenarios could be reproduced in experiments for logistical reasons. In all, the experimental results confirm the original hypothesis on the detrimental effects of simultaneous-send and corroborate the advantages of ACK skipping, However the percentage gains in TCP throughput are far more moderate as compared to those observed in NS simulations. A reason could be differing TCP implementations, particularly with not all TCP optimizations implemented in NS. We share the experiences and challenges faced, particularly given that this work is among the first of its kind for testbed evaluation of transport protocols over wireless networks.","PeriodicalId":351562,"journal":{"name":"E-WIND '05","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121735150","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}

引用次数: 29

A simple mechanism for capturing and replaying wireless channels 捕获和重放无线信道的简单机制

E-WIND '05 Pub Date : 2005-08-22 DOI: 10.1145/1080148.1080161

Glenn Judd, P. Steenkiste

引用次数: 25

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