{"title":"Improving TCP reordering robustness in multipath networks","authors":"Changming Ma, Ka-Cheong Leung","doi":"10.1109/LCN.2004.66","DOIUrl":"https://doi.org/10.1109/LCN.2004.66","url":null,"abstract":"The TCP performance can deteriorate substantially in multipath packet-forwarding networks which induce persistent packet reordering. Focusing on these networks, we propose a simple algorithm to adaptively adjust the value of dupthresh, the threshold of duplicate acknowledgement at which the TCP fast retransmission algorithm is triggered, to improve the TCP performance. It uses an exponentially weighted moving average (EWMA) and the mean deviation of the length of reordering events to adjust the value of dupthresh. Our algorithm also computes an upper bound of dupthresh to avoid retransmission timeout events. In addition, it provides a mechanism to decrease dupthresh at the retransmission timeout (RTO) events. The simulation results show that our algorithm improves the protocol performance significantly with very low overhead. It achieves a greater throughput and fewer false fast retransmissions.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126543491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application layer multicasting for mobile ad-hoc networks with network layer support","authors":"J. Biswas, S. Nandy","doi":"10.1109/LCN.2004.22","DOIUrl":"https://doi.org/10.1109/LCN.2004.22","url":null,"abstract":"An ad hoc network is composed of mobile nodes without any infrastructure. Mobile nodes dynamically form a temporary network to communicate with each other Applications of mobile ad hoc networks require group oriented services. Hence multicast support is a critical feature for ad hoc networks. In this paper we present an efficient application layer multicast solution suitable for medium mobility applications in the MANET environment. We use network layer support to build the overlay topology closer to the actual network topology. We try to maximize packet delivery ratio and to minimize control overhead. Through simulations we show that the control overhead for our algorithm is within the acceptable limit and it achieves acceptable packet delivery ratio for medium mobility applications.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124957352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Estimation and removal of clock skew from delay measures","authors":"H. Khlifi, Jean-Charles Grégoire","doi":"10.1109/LCN.2004.54","DOIUrl":"https://doi.org/10.1109/LCN.2004.54","url":null,"abstract":"Packet delay traces are important sources of measurements for analyzing end-to-end performance of computer networks. Due to the lack of tight synchronization between the clocks of end systems, these measurements can be quite inaccurate. Therefore, detection, estimation and removal of clock skew from delay traces is a critical operation to obtain precise measurements of network latencies. In this paper, we propose two new techniques to detect, estimate and remove the clock skew in delay traces. The first technique, named average technique, derives the clock skew estimate by calculating the average of the difference between consecutive packets' delay. The second technique, named direct skew removal technique, proceeds by iteratively evaluating a set of possible skew values until the best value is reached. Compared with existing techniques such as linear programming and convex-hull, the average technique reduces the complexity of the skew estimation operation. The direct skew removal is more accurate and allows us to obtain delay after skew removal with the same precision as the original traces. Clock skew is also present in online delay measurements that are used by real-time endpoints such as audio and video terminals, to determine the buffering delay of received packets and to synchronize streams from different sources. The problem is more obvious when communication sessions last for a long time. Contrary to the offline skew removal, little work has been done on the online skew removal problem. We propose two simple algorithms to remove the clock skew from online delay measurements. The first algorithm, named the sliding window algorithm, tracks the skew by continually evaluating the variation of the minimum measured delay. The second algorithm, named the combined algorithm, is a mixed approach of the sliding window and the convex-hull algorithm proposed elsewhere.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121845495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On available bandwidth measurement implementation and experiment","authors":"Jingsha He","doi":"10.1109/LCN.2004.88","DOIUrl":"https://doi.org/10.1109/LCN.2004.88","url":null,"abstract":"We summarize the implementation and experiment of the available bandwidth measurement algorithm (He et al. (2001)). Our experiment shows that, compared with other measurement techniques, this algorithm can achieve better performance, lower overhead and fast convergence. It can also self-adapt to any bandwidth and respond to resolution requirements. Therefore, no prior knowledge about bottleneck bandwidth is required and measurement resolution can be specified to meet application requirements, which is important for applications and services designed for high speed networks and multimedia applications due to the wide range of bandwidths that may be required.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121266080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A sensor network test-bed for an integrated target surveillance experiment","authors":"P. Biswas, S. Phoha","doi":"10.1109/LCN.2004.9","DOIUrl":"https://doi.org/10.1109/LCN.2004.9","url":null,"abstract":"We describe a distributed sensor network test-bed and a surveillance experiment to demonstrate the integration of distributed tracking algorithms with strategies for location estimation, energy management and mobility management of sensor nodes. The test-bed consists of real sensor nodes augmented with a simulated environment. Data from real world tracking is provided to the simulated environment, where it is used to self-organize the sensor network in an energy-efficient way. Results from the simulation are then fed back to the real world to enable the sensor network to reorganize for reinforced tracking.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131870673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bringing efficient advanced queries to distributed hash tables","authors":"D. Bauer, P. Hurley, R. Pletka, M. Waldvogel","doi":"10.1109/LCN.2004.32","DOIUrl":"https://doi.org/10.1109/LCN.2004.32","url":null,"abstract":"Interest in distributed storage is fueled by demand for reliability and resilience combined with ubiquitous availability. Peer-to-peer (P2P) storage networks are known for their decentralized control, self-organization, and adaptation. Advanced searching for documents and resources remains an open problem. The flooding approach favored by some P2P networks is inefficient in resource usage, but more scalable and resource-efficient solutions based on distributed hash tables (DHT) lack in query expressiveness and flexibility. In this paper, we address this issue and introduce new efficient, scalable, and completely distributed methods that strive to keep resource consumption by queries and index information as low as possible. We describe how to improve the handling of multiple subqueries combined through Boolean set operators. The need for these operators is intensified by applications to go beyond simple exact keyword matches. We discuss, optimize, and analyze appropriate extensions to support range and prefix matching in DHT.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114299257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Avoiding head of line blocking in directional antenna [MAC protocol]","authors":"Vinay Kolar, S. Tilak, N. Abu-Ghazaleh","doi":"10.1109/LCN.2004.30","DOIUrl":"https://doi.org/10.1109/LCN.2004.30","url":null,"abstract":"In existing directional MAC protocols a single queue is used at the MAC layer; this is inherited from omnidirectional implementations. However, while there is a single channel state in omnidirectional transmission (either the channel is busy or not), the state of the channel varies with the desired direction of transmission in directional antennas. Thus, existing implementations which use a single FIFO queue potentially lead to head of line blocking if the medium is busy in the direction of the packet at the top of the queue but is available in other directions. We propose a new queuing organization which could take advantage of the channel more effectively using the underlying antenna system by eliminating head of line blocking. We also identify a problem with the directional virtual carrier sense implementation due to side-lobes and provide a solution to it. Our results indicate that by using a greedy approach, to schedule the packet which has the least wait time, increases the overall throughput and reduces end-to-end delay considerably, especially under heavy loads.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115823307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Link characteristics estimation for IEEE 802.11 DCF based WLAN","authors":"Xiuchao Wu, A. Ananda","doi":"10.1109/LCN.2004.73","DOIUrl":"https://doi.org/10.1109/LCN.2004.73","url":null,"abstract":"Knowledge of network path characteristics enables upper layers to improve performance through adaptation protocols which adjust behaviors according to current network path characteristics. For a mobile node of a wireless network, this knowledge is especially valuable because the characteristics of the wireless link, which often dominate network path characteristics, change frequently and abruptly due to mobility, fading, and contention among nodes. Due to the dynamics and precious bandwidth of the wireless link, the commonly used probing packet methods are not appropriate for estimating the characteristics of a network path with a wireless link. We propose a new mechanism to estimate link characteristics of IEEE 802.11 DCF (distributed coordination function) based wireless LAN (WLAN), one of the most popular wireless access networks. Instead of sending probing-packets, a mobile node estimates its link characteristics based on wireless link quality and the contention status of the whole WLAN. We implement this mechanism and test its accuracy in NS2.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116262949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"New operating modes for Bluetooth networks in distributed process control systems","authors":"L. L. Bello, N. Torrisi, O. Mirabella","doi":"10.1109/LCN.2004.87","DOIUrl":"https://doi.org/10.1109/LCN.2004.87","url":null,"abstract":"The master/slave time division duplex approach implemented in the Bluetooth MAC sublayer simplifies management of the physical communication channel, but suffers from some limitations which prevent efficient bandwidth exploitation and may affect the overall throughput and message delays. These limitation have up to now prevented Bluetooth being extensively and successfully used in areas which differ from the traditional target applications this protocol has been developed for. We address these limitations and propose alternative slave/slave operating modes which enable Bluetooth to support new kinds of applications, such as the ones typical of distributed process control systems.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122131469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Gateway placement for latency and energy efficient data aggregation [wireless sensor networks]","authors":"J. Wong, R. Jafari, M. Potkonjak","doi":"10.1109/LCN.2004.60","DOIUrl":"https://doi.org/10.1109/LCN.2004.60","url":null,"abstract":"We propose the use of multiple gateways to significantly reduce latency and energy consumption in multi-hop wireless sensor networks during data aggregation. We have derived efficient integer linear programming formulations as well as a novel negative selection statistically-tuned heuristics. The heuristics are based on newly developed relaxation based lower bounds that are also used to quantify the effectiveness of the proposed heuristics. Our simulation study indicates that the use of gateways can often reduce latency and energy consumption by several times.","PeriodicalId":366183,"journal":{"name":"29th Annual IEEE International Conference on Local Computer Networks","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122737816","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}