Search results for " Network"
showing 10 items of 6428 documents
A Survey on LoRa for Smart Agriculture: Current Trends and Future Perspectives
2023
This paper provides a survey on the adoption of LoRa in the agricultural field, and reviews state-of-the-art solutions for Smart Agriculture, analyzing the potential of this technology in different infield applications. In particular, we consider four reference scenarios, namely irrigation systems, plantation and crop monitoring, tree monitoring, and livestock monitoring, which exhibit heterogeneous requirements in terms of network bandwidth, density, sensors’ complexity, and energy demand, as well as latency in the decision process. We discuss how LoRa-based solutions can work in these scenarios, analyzing their scalability, interoperability, network architecture, and energy-efficiency. Fi…
The quest for bandwidth estimation techniques for large-scale distributed systems
2010
In recent years the research community has developed many techniques to estimate the end-to-end available bandwidth of an Internet path. This important metric can be potentially exploited to optimize the performance of several distributed systems and, even, to improve the effectiveness of the congestion control mechanism of TCP. Thus, it has been suggested that some existing estimation techniques could be used for this purpose. However, existing tools were not designed for large-scale deployments and were mostly validated in controlled settings, considering only one measurement running at a time. In this paper, we argue that current tools, while offering good estimates when used alone, migh…
Large-Scale Available Bandwidth Measurements: Interference in Current Techniques
2011
The end-to-end available bandwidth of an Internet path is a desirable information that can be exploited to optimize system performance. Several tools have been proposed in the past to estimate it. However, existing measurement techniques were not designed for large-scale deployments. In this paper we show that current tools do not properly work where multiple probing processes share a portion of a path. We provide experimental evidence to quantify the impact of mutual interference between measurements. We further analyze the characteristics of popular tools, quantifying (i) the impact of mutual interference, (ii) the total overhead imposed to the network and (iii) the intrusiveness of the m…
An energy analysis of IEEE 802.15.6 scheduled access modes
2010
Body Area Networks (BANs) are an emerging area of wireless personal communications. The IEEE 802.15.6 working group aims to develop a communications standard optimised for low power devices operating on, in or around the human body. IEEE 802.15.6 specifically targets low power medical application areas. The IEEE 802.15.6 draft defines two main channel access modes; contention based and contention free. This paper examines the energy lifetime performance of contention free access and in particular of periodic scheduled allocations. This paper presents an overview of the IEEE 802.15.6 and an analytical model for estimating the device lifetime. The analysis determines the maximum device lifeti…
Coexistence between IEEE802.15.4 and IEEE802.11 through cross-technology signaling
2017
When different technologies use the same frequency bands in close proximity, the resulting interference typically results in performance degradation. Coexistence methods exist, but these are often technology specific and requiring technology specific interference detection methods. To remove the root cause of the performance degradation, devices should be able to negotiate medium access even when using different technologies. To this end, this paper proposes an architecture that allows crosstechnology medium access by means of a Time Division Multiple Access (TDMA) scheme. In order to achieve cross-technology synchronization, which is required for the TDMA solution, an energy pattern beacon…
Cross-Technology WiFi/ZigBee Communications: Dealing With Channel Insertions and Deletions
2016
In this letter, we show how cross-technology interference can be exploited to set up a low-rate bidirectional communication channel between heterogeneous WiFi and ZigBee networks. Because of the environment noise and receivers' implementation, the cross-technology channel can be severely affected by insertions and deletions of symbols, whose effects need to be taken into account by the coding scheme and communication protocol.
INDOOR LOCALIZATION USING COGNITIVE RADIOS AND SOFTWARE-DEFINED WIRELESS NETWORKS
Correlation-Based Similarity Metric For Clustering In Multimedia Social Network
2011
Offloading through Opportunistic Networks with Dynamic Content Requests
2014
Offloading is gaining momentum as a technique to overcome the cellular capacity crunch due to the surge of mobile data traffic demand. Multiple offloading techniques are currently under investigation, from modifications inside the cellular network architecture, to integration of multiple wireless broadband infrastructures, to exploiting direct communications between mobile devices. In this paper we focus on the latter type of offloading, and specifically on offloading through opportunistic networks. As opposed to most of the literature looking at this type of offloading, in this paper we consider the case where requests for content are non-synchronised, i.e. users request content at random …
Supporting code mobility and dynamic reconfigurations over Wireless MAC Processor Prototype
2014
Mobile networks for Internet Access are a fundamental segment of Internet access net- works, where resource optimization are really critical because of the limited bandwidth availability. While traditionally resource optimizations have been focused on high effi- cient modulation and coding schemes, to be dynamically tuned according to the wireless channel and interference conditions, it has also been shown how medium access schemes can have a significant impact on the network performance according to the application and networking scenarios. This thesis work proposes an architectural solution for supporting Medium Access Con- trol (MAC) reconfigurations in terms of dynamic programming and c…