Search results for "Application protocol"
showing 7 items of 17 documents
A Wireless Mesh Network-based System for Hotspots Deployment and Management
2007
In recent years Wireless Local Area Networks (WLANs) or hotspots, as they are commonly known, have emerged as a promising networking platform to extend network connectivity in public venues, providing local coverage for Internet applications on the move in urban areas and rural environments. Wireless hotspots using 802.11-based technology have popped up in corporate offices, coffeehouses, airports, restaurants and bookstores worldwide. For all their utility and ease of use the 802.11 wireless protocol, known as WiFi, has become the mobile connectivity mechanism of choice for business people, travelers, villagers, and everyone else. Unfortunately, even with the protocol's ease of use and its…
Preamble Sampling MAC Protocol for Low Power Wireless Sensor Networks with IEEE 802.15.4 Transceivers
2006
In this paper a preamble sampling MAC protocol for low power wireless sensor networks is proposed. The article describes the implementation of the protocol using network nodes equipped with the Chipcon CC2420 802.15.4 transceiver. The power consumption of the transceiver has been measured and the MAC protocol has been adapted to the transceiver properties. The results show the trade-off between power consumption and transmission delay for this algorithm during the communication process.
A Group-Based Protocol for Large Wireless AD-HOC and Sensor Networks
2008
Many routing protocols for ad-hoc networks and sensor networks have been designed, but none of them is based on groups. It is known that grouping nodes gives better performance to the group and to the whole system, thereby avoiding unnecessary message forwarding and additional overheads. We propose an approach where the network is split into several groups of sensors where connections between groups are established as a function of the proximity and the neighbor's available capacity (based on the sensor's energy). In this paper the network architecture is described with its mathematical description and the messages that are needed to proper operation. It is also simulated how much time is n…
Adoption of Constrained Application Protocol
2016
Among billions of Internet enabled devices that are expected to surround us in the near future, many will be resource constrained, i.e., will have limited power supply, processing power and memory. To cope with these limitations, the Constrained Application Protocol (CoAP) has been recently introduced as a lightweight alternative to HTTP for connecting the resource limited devices to the Web. Although the new protocol offers solid technical advantages, it remains uncertain whether a successful uptake will follow, as it depends also on its economic feasibility for the involved stakeholders. Therefore, this paper studies the techno-economic feasibility of CoAP using a systematic methodologica…
Analysis and Performance Evaluation of the IEEE 802.16 ARQ Mechanism
2008
The IEEE 802.16 standard defines the ARQ mechanismas a part of the MAC layer. The functioning of the ARQmechanism depends on a number of parameters. The IEEE802.16 specification defines them but it does not provide concrete values and solutions. This paper studies the key features and parameters of the 802.16 ARQ mechanism. In particular, we consider a choice for the ARQ feedback type, an algorithm to build block sequences, the ARQ feedback intensity, a scheduling of the ARQ feedbacks and retransmissions, the ARQ block rearrangement, ARQ transmission window and the ARQ block size. We ran simulation scenarios to study these parameters and how they impact the performance of application protoc…
Emergency Treatment of Anaphylactic Reactions in Air Rescue Missions: An Eight-Year Analysis of a German Rescue Helicopter Base.
2021
AbstractIntroduction:Anaphylactic reactions can lead to a life-threatening situation. In the event of anaphylaxis, rapid and targeted emergency treatment is indicated.Study Objective:The study sought to determine the emergency therapy administered for anaphylaxis in children and adults. Focus was placed on therapy with adrenaline. In addition, the study aimed to investigate demographic data, triggers, and hospitalization rates of the different severities of anaphylaxis.Methods:A retrospective analysis of anaphylactic reactions was conducted using data from prehospital emergency missions performed by the Air Rescue Dresden/Germany from 2008 through 2015 using the standardized application pro…
Retrieving Monitoring and Accounting Information from Constrained Devices in Internet-of-Things Applications
2013
Part 6: Monitoring Mechanisms; International audience; Internet-of-Things (IoT) is envisioned to provide connectivity to a vast number of sensing or actuating devices with limited computational and communication capabilities. For the organizations that manage these constrained devices, the monitoring of each device’s operational status and performance level as well as the accounting of their resource usage are of great importance. However, monitoring and accounting support is lacking in today’s IoT platforms. Hence, this paper studies the applicability of the Constrained Application Protocol (CoAP), a lightweight transfer protocol under development by IETF, for efficiently retrieving monito…