doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Experimental evaluation of Moderated EDCA over WMP Date: November 11, 2015 Authors: NameCompanyAddressPhone Ilenia Tinnirello University of Palermo / CNIT Research Team Italy nipa.it Domenico Garlisi University of Palermo / CNIT Research Team Italy dieet.unipa.it Fabrizio Giuliao University of Palermo / CNIT Research Team Italy dieet.unipa.it Giuseppe Bianchi University of Rome / CNIT Research Team Itlay uniroma2.it Slide 1

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Experiment Setup 6 contending nodes under saturated greedy traffic two groups of stations: legacy EDCA and moderated EDCA (M-EDCA) AP EDCA Moderated EDCA Slide 2

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team How to implemented M-EDCA? In principle a very ‘small’modification of the protocol, but working on lower-mac parameters.. –How to measure backoff freezing occurrences, being backoff process hard-coded into the card? Feasible thanks to the Wireless MAC Processor (WMP) architecture! –Developed by the CNIT research team within the European research project FLAVIA Slide 3

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team WMP Architecture In one slide… –Set of radio tasks pre-implemented in the NIC actions, events, conditions In practice, a MAC-specific «instruction set» –MAC programs: eXtended Finite State Machines Suitably byte-coded for injection in the NIC –NIC: no more a protocol, but an XFSM executor Called «wireless MAC processor» MAC design: XFSM bytecode MAC Engine: XFSM executor MAC Bytecode load Slide 4

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team From EDCA to M-EDCA (basically, adding a transition for counting IPT!) RX PHASE TX PHASE BACKOFF Slide 5

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team CW Updates –Periodic CW updates in Userspace (for using floating-point arithmetic): Sample IPT at regular time intervals and update CW CW update acts directly on NIC registers. –State machine at firmware level: Measure IPTm Filter IPT = IPT + 1/8 * (IPTm -IPT); T WMP REGISTER USERSPACE SCRIPT FIRMWARE DATA REQUEST CW update Slide 6

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Results Reference experiment: 6 EDCA legacy nodes Throughput variability from 0.6 to 1.6 Mbps due to real position- dependent interference Average CW from to EDCA EDCA CW Slide 7

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Results 3 EDCA legacy nodes vs. 3 Moderated EDCA Throughput results comparable with previous ones! –lower variability for M-EDCA stations Average CW for Moderated EDCA equal to 22 (vs. 24 obtained in simulation) Damping factor selected 0.7 and 0.1 Moderated CWs updated every 100ms See plots on next slides Slide 8

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Throughput 9 (damping 0.7)

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Throughput 10 (damping 0.1)

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team EDCA CW 11 (damping 0.7)

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team EDCA CW 12 (damping 0.1)

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Moderated EDCA CW 13 (damping 0.7)

doc.: IEEE /1437r0 Submission November 2015 Ilenia Tinnirello, CNIT Research Team Moderated EDCA CW 14 (damping 0.1)

References 000m-moderated-backoff.ppt 15