Search results for " random access"

showing 4 items of 4 documents

Supporting a Pseudo-TDMA Access Scheme in Mesh Wireless Networks

2013

Wireless mesh networks appear a promising solution for pro- viding ubiquitous low-cost wireless access, but cannot rely on simple CSMA access protocols because of the critical inefficiencies that arise in topologies with hidden nodes. To overcome these limitations, some important protocol extensions based on synchronization and reservation mechanisms have been ratified. In this paper we show that an alternative approach to the standardiza- tion of new features and signaling messages for mesh networks can be the utilization of programmable nodes able to execute different MAC protocols programmed on the fly. Signaling messages are used only for disseminating the new protocol among the nodes. …

Wireless mesh networkHidden node problembusiness.industryComputer scienceWireless networkSettore ING-INF/03 - TelecomunicazioniDistributed computingComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSOrder One Network ProtocolShared meshKey distribution in wireless sensor networkswireless mesh networks synchronization pseudo-TDMA random accessbusinessComputer networkIEEE 802.11sWireless distribution system
researchProduct

Moving RTS/CTS to the frequency domain: an efficient contention scheme for 802.11ax networks

2019

In this paper, we propose a contention mechanism based on the execution of multiple contention rounds in the frequency domain (ReCHo), which is designed to offer high throughput performance and robustness with respect to imperfect carrier sensing. The main idea is using narrow tones as signalling messages for performing channel access contentions and allowing the Access Point (AP) to echo these signals, in order to extend the sensing capabilities to all the stations associated to the AP. In particular, we refer to the emerging IEEE 802.11ax standard, showing how our scheme can boost performance of random access with respect to the current version of IEEE 802.11ax OFDMA Back-Off (OBO), even …

imperfect sensingHidden node problemSettore ING-INF/03 - TelecomunicazioniOrthogonal frequency-division multiplexingComputer sciencebusiness.industryMechanism based020206 networking & telecommunications02 engineering and technologySignallingFrequency-domain signallingRobustness (computer science)020204 information systemsFrequency domainTelecommunications link0202 electrical engineering electronic engineering information engineeringfrequency-domain signalling; IEEE 802.11ax; imperfect sensing; random access contentionrandom access contentionbusinessIEEE 802.11axRandom accessComputer network
researchProduct

'Good to Repeat': Making Random Access Near-Optimal with Repeated Contentions

2020

Recent advances on WLAN technology have been focused mostly on boosting network capacity by means of a more efficient and flexible physical layer. A new concept is required at MAC level to exploit fully the new capabilities of the PHY layer. In this article, we propose a contention mechanism based on Repeated Contentions (ReCo) in frequency domain. It provides a simple-to-configure, robust and short-term fair algorithm for the random contention component of the MAC protocol. The throughput efficiency of ReCo is not sensitive to the number of contending stations, so that ReCo does not require adaptive tuning of the access parameters for performance optimization. Efficiency and robustness is …

imperfect sensingbusiness.industryOrthogonal frequency-division multiplexingComputer scienceSettore ING-INF/03 - TelecomunicazioniApplied MathematicsComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKSPhysical layer020206 networking & telecommunicationsThroughput02 engineering and technologyIEEE 802.11ax; random access contention; frequency-domain signalling; imperfect sensingComputer Science ApplicationsPHYfrequency-domain signalling0202 electrical engineering electronic engineering information engineeringfrequency-domain signalingWirelessrandom access contentionSettore ICAR/19 - RestauroElectrical and Electronic EngineeringbusinessRandom accessIEEE 802.11axComputer network
researchProduct

Resistive switching in memristors based on yttria-stabilized zirconia

2021

yttria-stabilized zirconiaresistive switchingResistive Random Access Memorylight- and noise-induced resistive switchingstochastic resonanceMemristormetal-insulator-metal structuremetal-insulator-semiconductor structurespace-charge-limited current
researchProduct