10,540 research outputs found
Proposition and validation of an original MAC layer with simultaneous medium accesses for low latency wireless control/command applications
Control/command processes require a transmission system with some
characteristics like high reliability, low latency and strong guarantees on
messages delivery. Concerning wire networks, field buses technologies like FIP
offer this kind of service (periodic tasks, real time constraints...).
Unfortunately, few wireless technologies can propose a communication system
which respects such constraints. Indeed, wireless transmissions must deal with
medium characteristics which make impossible the direct translation of
mechanisms used with wire networks. The purpose of this paper is to present an
original Medium Access Control (MAC) layer for a real time Low Power-Wireless
Personal Area Network (LP-WPAN). The proposed MAC-layer has been validated by
several complementary methods; in this paper, we focus on the specific
Simultaneous Guaranteed Time Slot (SGTS) part
A Survey of Green Networking Research
Reduction of unnecessary energy consumption is becoming a major concern in
wired networking, because of the potential economical benefits and of its
expected environmental impact. These issues, usually referred to as "green
networking", relate to embedding energy-awareness in the design, in the devices
and in the protocols of networks. In this work, we first formulate a more
precise definition of the "green" attribute. We furthermore identify a few
paradigms that are the key enablers of energy-aware networking research. We
then overview the current state of the art and provide a taxonomy of the
relevant work, with a special focus on wired networking. At a high level, we
identify four branches of green networking research that stem from different
observations on the root causes of energy waste, namely (i) Adaptive Link Rate,
(ii) Interface proxying, (iii) Energy-aware infrastructures and (iv)
Energy-aware applications. In this work, we do not only explore specific
proposals pertaining to each of the above branches, but also offer a
perspective for research.Comment: Index Terms: Green Networking; Wired Networks; Adaptive Link Rate;
Interface Proxying; Energy-aware Infrastructures; Energy-aware Applications.
18 pages, 6 figures, 2 table
Nap: Practical Micro-Sleeps for 802.11 WLANs
In this paper, we revisit the idea of putting interfaces to sleep during
'packet overhearing' (i.e., when there are ongoing transmissions addressed to
other stations) from a practical standpoint. To this aim, we perform a robust
experimental characterisation of the timing and consumption behaviour of a
commercial 802.11 card. We design Nap, a local standard-compliant
energy-saving mechanism that leverages micro-sleep opportunities inherent to
the CSMA operation of 802.11 WLANs. This mechanism is backwards compatible and
incrementally deployable, and takes into account the timing limitations of
existing hardware, as well as practical CSMA-related issues (e.g., capture
effect). According to the performance assessment carried out through
trace-based simulation, the use of our scheme would result in a 57% reduction
in the time spent in overhearing, thus leading to an energy saving of 15.8% of
the activity time.Comment: 15 pages, 12 figure
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
H-MAC: A Hybrid MAC Protocol for Wireless Sensor Networks
In this paper, we propose a hybrid medium access control protocol (H-MAC) for
wireless sensor networks. It is based on the IEEE 802.11's power saving
mechanism (PSM) and slotted aloha, and utilizes multiple slots dynamically to
improve performance. Existing MAC protocols for sensor networks reduce energy
consumptions by introducing variation in an active/sleep mechanism. But they
may not provide energy efficiency in varying traffic conditions as well as they
did not address Quality of Service (QoS) issues. H-MAC, the propose MAC
protocol maintains energy efficiency as well as QoS issues like latency,
throughput, and channel utilization. Our numerical results show that H-MAC has
significant improvements in QoS parameters than the existing MAC protocols for
sensor networks while consuming comparable amount of energy.Comment: 10 pages, IJCNC Journal 201
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