Testbed based throughput analysis in a Wireless Sensor Network
03 Apr 2012-pp 1-5
TL;DR: The experimental results show that delivery ratio reduces with increase in data rate due to collisions and help characterise the network capacity limits.
Abstract: This paper presents the throughput results obtained from a Wireless Sensor Network testbed, with single and multiple sources in different network deployments and routing architectures. The experimental testbed deployed at IIT Madras consisted of commercially available Crossbow TelosB and MicaZ nodes and a custom-built sensor node based on the DigiNet Xbee chip, with all nodes implementing the Zigbee standard. The networks were deployed in uniform grid topologies in three different deployments with up to 228 nodes. The main aim of the experiments is to analyze the throughput and packet delivery ratio observed with single and multiple sources. The experimental results show that delivery ratio reduces with increase in data rate due to collisions and help characterise the network capacity limits.
Citations
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01 Nov 2015
TL;DR: Experimental results indicate that the proposed approach can be effectively used for transferring high bandwidth data to the base station.
Abstract: Streaming multimedia data in WSN is a challenge due to constraints such as bandwidth, energy and delay. Moreover, it is not economical to have multimedia sensors integrated with static nodes in the field. In this paper, we propose the use of mobile sensor nodes, which are equipped with multimedia sensors for event monitoring. These mobile entities are capable of streaming high bandwidth data by splitting it and routing the packet to the base station using Frequency Division Multiplexer (FDM) modules. This is done with the support of multi-channel disjoint path routing aided with the static WSN deployed. Experiments were done using MicaZ and TelosB motes to evaluate the performance with the help of our custom designed robotic vehicle. The paper adopts a node disjoint multi-path routing protocol for establishing parallel paths between the sender and the receiver. Experimental results indicate that the proposed approach can be effectively used for transferring high bandwidth data to the base station. Multimedia Streaming, Multichannel MAC, Mobile WSN
Additional excerpts
...The low data-rate of Zigbee protocol makes it challenging to stream multimedia data....
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Journal Article•
TL;DR: This paper presents an implementation of the IEEE 802.15.4 unslotted CSMA/CA protocol on Contiki OS and shows that this implementation is compliant and achieves a better packet delivery rate and better throughput compared to the provided CSma/CA version oncontiki OS.
Abstract: IEEE 802.15.4 is a standard designed for low rate wireless personal area network. This standard uses the Carrier Sensing Multiple Access/Collision Avoidance (CSMA/CA) algorithm to manage the medium access process. CSMA/CA is a random wireless access algorithm that allows each node with equal probability to access the channel. Having a compliant implementation of CSMA/CA algorithm which follows the IEEE 802.15.4 specifications is very important in order to obtain realistic results. Some of the well-known Wireless Sensor Networks (WSNs) operating systems such as Contiki OS do not provide a compliant version. In this paper, we present an implementation of the IEEE 802.15.4 unslotted CSMA/CA protocol on Contiki OS. Simulation results using Contiki OS Cooja simulator showed that our implementation is compliant and achieves a better packet delivery rate and better throughput compared to the provided CSMA/CA version on Contiki OS. Keywords—IEEE 802.15.4, CSMA/CA, Contiki, performance evaluation, throughput.
01 Jan 2013
TL;DR: In this research work an integrated hardware platform for the implementation of the HTN protocol is designed and implemented and the test results using the hardware show that it provides inter-operability with available sensor platforms, can interface with other sensing hardware using standard protocols and provides communication capabilities exceeding that needed by HTN.
Abstract: The safety of rail transport has always been the top priority for the Federal Railroad Administration (FRA). Legacy technology, like wayside monitoring, is still in place and is largely relied upon for detection of faults. Modern technology like Radio Frequency Identification (RFID) has been introduced recently. However, this is largely used to detect a particular railcar rather than to monitor it for problems. Wireless Sensor Network (WSN) technology is being evaluated by the railroads for real-time or near real-time monitoring of the status of railcars for timely response to problems and also for trend analysis. ZigBee has been the networking protocol of choice for the railroads for its low power consumption and cost of implementation. The railroad scenario presents a long linear-chain like network topology which ZigBee was not designed to handle. It has been found that a ZigBee-only network in the railroad environment suffers from drawbacks like long synchronization delays, severe problems with route discovery and maintenance, aggregation of data errors leading to unacceptable packet loss rates, lack of a mechanism to decide traffic priority for critical packets, like alarm, so that they can reliably traverse the network to the collecting node in the locomotive etc. Hybrid Technology Networking (HTN) protocol has been suggested which addresses the shortcomings of ZigBee in the railroad scenario. It proposes a standards-based multi-protocol approach that is well-suited for the railroad scenario. The current crop of sensor platforms does not provide an integrated environment for the implementation of HTN. In this research work an integrated hardware platform for the implementation of the HTN protocol is designed and implemented. The guiding principle has been the adherence to standards. The test results using the hardware show that it provides inter-operability with available sensor platforms, can interface with other sensing hardware using standard protocols and provides communication capabilities exceeding that needed by HTN. v Dedicated to the countless thinkers and innovators who push the boundaries of knowledge today, for a better tomorrow. vi Acknowledgments I would, first and foremost, like to thank my advisor Dr. Sharif for his invaluable guidance and support during the course of my research work. I would also like to thank Dr. Michael Hempel for his timely inputs and new perspectives on the work that I was doing. I am also thankful to my colleagues Fahimeh, Pradhumna and Tao for their help and support during the time I was working on this research. …
References
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17 Nov 2002
TL;DR: It is shown that in some situations, the interference range is much larger than transmission range, where RTS/CTS cannot function well, and a simple MAC layer scheme is proposed to solve this problem.
Abstract: IEEE 802.11 MAC mainly relies on two techniques to combat interference: physical carrier sensing and RTS/CTS handshake (also known as "virtual carrier sensing"). Ideally, the RTS/CTS handshake can eliminate most interference. However, the effectiveness of RTS/CTS handshake is based on the assumption that hidden nodes are within transmission range of receivers. In this paper, we prove using analytic models that in ad hoc networks, such an assumption cannot hold due to the fact that power needed for interrupting a packet reception is much lower than that of delivering a packet successfully. Thus, the "virtual carrier sensing" implemented by RTS/CTS handshake cannot prevent all interference. Physical carrier sensing can complement this in some degree. However, since interference happens at receivers, while physical carrier sensing is detecting transmitters (the same problem causing the hidden terminal situation), physical carrier sensing cannot help much, unless a very large carrier sensing range is adopted, which is limited by the antenna sensitivity. We investigate how effective is the RTS/CTS handshake in terms of reducing interference. We show that in some situations, the interference range is much larger than transmission range, where RTS/CTS cannot function well. Then, a simple MAC layer scheme is proposed to solve this problem. Simulation results verify that our scheme can help IEEE 802.11 resolve most interference caused by large interference range.
701 citations
01 Jul 2003
TL;DR: It is shown that in some situations, the interference range is much larger than transmission range, where RTS/CTS cannot function well, and two independent solutions are proposed that can help IEEE 802.11 resolve most interference caused by large interference range.
Abstract: IEEE 802.11 MAC mainly relies on two techniques to combat interference: physical carrier sensing and RTS/CTS handshake (also known as “virtual carrier sensing”). Ideally, the RTS/CTS handshake can eliminate most interference. However, the effectiveness of RTS/CTS handshake is based on the assumption that hidden nodes are within transmission range of receivers. In this paper, we prove using analytic models that in ad hoc networks, such an assumption cannot hold due to the fact that power needed for interrupting a packet reception is much lower than that of delivering a packet successfully. Thus, the “virtual carrier sensing” implemented by RTS/CTS handshake cannot prevent all interference as we expect in theory. Physical carrier sensing can complement this in some degree. However, since interference happens at receivers, while physical carrier sensing is detecting transmitters (the same problem causing the hidden terminal situation), physical carrier sensing cannot help much, unless a very large carrier sensing range is adopted, which is limited by the antenna sensitivity. In this paper, we investigate how effective is the RTS/CTS handshake in terms of reducing interference. We show that in some situations, the interference range is much larger than transmission range, where RTS/CTS cannot function well. Two independent solutions are proposed in this paper. One is a simple enhancement to the IEEE 802.11 MAC protocol. The other is to utilize directional antennas. Simulation results verify that the proposed schemes indeed can help IEEE 802.11 resolve most interference caused by large interference range.
456 citations
01 Oct 2007
TL;DR: This work combines realistic radio consumption models, signal strength estimation and that reception cost may be more than the transmission cost into a single model for estimating radio power costs.
Abstract: Research in the wireless sensor network field has been plagued by difficulties in realistic simulations. These difficulties are often the result of non-realistic assumptions which need to be removed from the equation. Recent work in the field has identified realistic radio consumption models, signal strength estimation and that reception cost may be more than the transmission cost. In our work we combine these techniques into a single model for estimating radio power costs. We also investigate the effects of discrete power levels on transmission cost and show that transmission costs do not always increase as the transmission distance increases.
47 citations
"Testbed based throughput analysis i..." refers background in this paper
...CC2420 provides 32 different power levels (0-31) at which a packet can be transmitted [5], where the highest level 31 corresponds to 0 dB (1 mW)....
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10 Oct 2010
TL;DR: This work presents a generic channel allocation scheme based on k-distance coloring problem, for multiple channel networks, designed keeping in mind the real time deployment issues in wireless networks.
Abstract: Designing a multi-hop wireless network is a challenge mainly because of high bit error rates and the inherent broadcast nature of the medium creating interference. To improve the capacity, protocols based on spatial reuse of frequencies with multiple orthogonal channels have been introduced. This is particularly useful in complete wireless environments such as wireless mesh networks and wireless sensor networks (WSN). Based on initial testbed experiments on WSN testbeds, we show that there is a gap between reality and simulation models due to overheads in implementing these protocols. In order to support QoS guarantees in critical paths for such networks, we present a generic channel allocation scheme based on k-distance coloring problem, for multiple channel networks. The scheme is designed keeping in mind the real time deployment issues in wireless networks. We report the results from experiments conducted using a IEEE 802.15.4 based testbed consisting of Xbow MicaZ nodes and results obtained using the OMNET4 simulation environment.
11 citations
"Testbed based throughput analysis i..." refers background in this paper
...Previously conducted research work [6], [8] shows that throughput depends on several parameters including the number of active sources, wireless link quality, interference and number of hops....
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18 Dec 2009
TL;DR: The throughput results show the per-node throughput does not decline as significantly with increasing number of senders, with the proposed multi-channel protocol.
Abstract: This paper presents an implementation based study of multi-channel medium access control protocols in hardware constrained wireless sensor network(WSN) nodes with 802.15.4 radio. In the network architecture presented, each sensor node has a single radio transceiver that can be tuned to any of the available sixteen non-overlapping channels. The simplest way to select data channel is to use a common channel signaling between the nodes. We have conducted experiments to verify whether control channel congestion can occur in case of 802.15.4 radios using MicaZ and TelosB motes. The throughput results show the per-node throughput does not decline as significantly with increasing number of senders, with the proposed multi-channel protocol.
9 citations
"Testbed based throughput analysis i..." refers background in this paper
...However, we chose the distance to be 10 m such that 99% delivery ratio was consistently achieved on a single link based on repeated experiments [6]....
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...Previously conducted research work [6], [8] shows that throughput depends on several parameters including the number of active sources, wireless link quality, interference and number of hops....
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