2,400 research outputs found
Energy-efficient wireless communication
In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters
E2MaC: an energy efficient MAC protocol for multimedia traffic
Energy efficiency is an important issue for mobile computers since they must rely on their batteries. We present a novel MAC protocol that achieves a good energy efficiency of wireless interface of the mobile and provides support for diverse traffic types and QoS. The scheduler of the base station is responsible to provide the required QoS to connections on the wireless link and to minimise the amount of energy spend by the mobile. The main principles of the E2MaC protocol are to avoid unsuccessful actions, minimise the number of transitions, and synchronise the mobile and the base-station. We will show that considerable amounts of energy can be saved using these principles. In the protocol the actions of the mobile are minimised. The base-station with plenty of energy performs actions in courtesy of the mobile. We have paid much attention in reducing the cost of a mobile for just being connected. The protocol is able to provide near-optimal energy efficiency (i.e. energy is only spent for the actual transfer) for a mobile within the constraints of the QoS of all connections in a cell, and only requires a small overhead
Energy-efficient adaptive wireless network design
Energy efficiency is an important issue for mobile computers since they must rely on their batteries. We present an energy-efficient highly adaptive architecture of a network interface and novel data link layer protocol for wireless networks that provides quality of service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations are necessary to achieve energy efficiency and an acceptable quality of service. The paper provides a review of ideas and techniques relevant to the design of an energy efficient adaptive wireless networ
Capacity Analysis of IEEE 802.11ah WLANs for M2M Communications
Focusing on the increasing market of the sensors and actuators networks, the
IEEE 802.11ah Task Group is currently working on the standardization of a new
amendment. This new amendment will operate at the sub-1GHz band, ensure
transmission ranges up to 1 Km, data rates above 100 kbps and very low power
operation. With IEEE 802.11ah, the WLANs will offer a solution for applications
such as smart metering, plan automation, eHealth or surveillance. Moreover,
thanks to a hierarchical signalling, the IEEE 802.11ah will be able to manage a
higher number of stations (STAs) and improve the 802.11 Power Saving
Mechanisms. In order to support a high number of STAs, two different signalling
modes are proposed, TIM and Non-TIM Offset. In this paper we present a
theoretical model to predict the maximum number of STAs supported by both modes
depending on the traffic load and the data rate used. Moreover, the IEEE
802.11ah performance and energy consumption for both signalling modes and for
different traffic patterns and data rates is evaluated. Results show that both
modes achieve similar Packet Delivery Ratio values but the energy consumed with
the TIM Offset is, in average, a 11.7% lower.Comment: Multiple Access Communications 201
Survey on wireless technology trade-offs for the industrial internet of things
Aside from vast deployment cost reduction, Industrial Wireless Sensor and Actuator Networks (IWSAN) introduce a new level of industrial connectivity. Wireless connection of sensors and actuators in industrial environments not only enables wireless monitoring and actuation, it also enables coordination of production stages, connecting mobile robots and autonomous transport vehicles, as well as localization and tracking of assets. All these opportunities already inspired the development of many wireless technologies in an effort to fully enable Industry 4.0. However, different technologies significantly differ in performance and capabilities, none being capable of supporting all industrial use cases. When designing a network solution, one must be aware of the capabilities and the trade-offs that prospective technologies have. This paper evaluates the technologies potentially suitable for IWSAN solutions covering an entire industrial site with limited infrastructure cost and discusses their trade-offs in an effort to provide information for choosing the most suitable technology for the use case of interest. The comparative discussion presented in this paper aims to enable engineers to choose the most suitable wireless technology for their specific IWSAN deployment
A Study of Medium Access Control Protocols for Wireless Body Area Networks
The seamless integration of low-power, miniaturised, invasive/non-invasive
lightweight sensor nodes have contributed to the development of a proactive and
unobtrusive Wireless Body Area Network (WBAN). A WBAN provides long-term health
monitoring of a patient without any constraint on his/her normal dailylife
activities. This monitoring requires low-power operation of
invasive/non-invasive sensor nodes. In other words, a power-efficient Medium
Access Control (MAC) protocol is required to satisfy the stringent WBAN
requirements including low-power consumption. In this paper, we first outline
the WBAN requirements that are important for the design of a low-power MAC
protocol. Then we study low-power MAC protocols proposed/investigated for WBAN
with emphasis on their strengths and weaknesses. We also review different
power-efficient mechanisms for WBAN. In addition, useful suggestions are given
to help the MAC designers to develop a low-power MAC protocol that will satisfy
the stringent WBAN requirements.Comment: 13 pages, 8 figures, 7 table
Energy Efficient and Reliable Wireless Sensor Networks - An Extension to IEEE 802.15.4e
Collecting sensor data in industrial environments from up to some tenth of
battery powered sensor nodes with sampling rates up to 100Hz requires energy
aware protocols, which avoid collisions and long listening phases. The IEEE
802.15.4 standard focuses on energy aware wireless sensor networks (WSNs) and
the Task Group 4e has published an amendment to fulfill up to 100 sensor value
transmissions per second per sensor node (Low Latency Deterministic Network
(LLDN) mode) to satisfy demands of factory automation. To improve the
reliability of the data collection in the star topology of the LLDN mode, we
propose a relay strategy, which can be performed within the LLDN schedule.
Furthermore we propose an extension of the star topology to collect data from
two-hop sensor nodes. The proposed Retransmission Mode enables power savings in
the sensor node of more than 33%, while reducing the packet loss by up to 50%.
To reach this performance, an optimum spatial distribution is necessary, which
is discussed in detail
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