{"title":"LAMA","authors":"Holger Döbler, Björn Scheuermann","doi":"10.1145/3345768.3355925","DOIUrl":"https://doi.org/10.1145/3345768.3355925","url":null,"abstract":"It is nowadays common in all kinds of traffic-maritime, air, road-that vehicles use beaconing systems to broadcast their position and other navigational data to nearby vehicles to improve situational awareness. MAC protocols for the beaconing use case face special challenges: protocol overhead has a significant performance impact due to small packet size, fair and frequent access to the channel is required, and the broadcast nature limits the applicability of hand shakes. We propose LAMA, a MAC protocol for position awareness beaconing that is based on the locally shared position information. Our contention-free approach uses neither handshakes nor forwarding of state, thereby requiring only small constant protocol overhead per beacon and scaling well with large neighbor counts. Yet, it successfully suppresses interference, including hidden-terminal-type, while maximizing channel utilization through coordinated spatial reuse. In a quantitative evaluation using the ns-3 discrete event simulator we compare LAMA against SO-TDMA, the MAC protocol used in the maritime automatic identification system. We find that LAMA outperforms SO-TDMA with respect to several metrics in synthetic random topologies as well as in scenarios based on real vessel traffic traces.","PeriodicalId":413520,"journal":{"name":"Proceedings of the 22nd International ACM Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems - MSWIM '19","volume":"25 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116832548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raphael Naves, Gentian Jakllari, H. Khalifé, Vania Conan, André-Luc Beylot
{"title":"COLiDeR","authors":"Raphael Naves, Gentian Jakllari, H. Khalifé, Vania Conan, André-Luc Beylot","doi":"10.1145/3345768.3355941","DOIUrl":"https://doi.org/10.1145/3345768.3355941","url":null,"abstract":"In this work, we present COLiDeR, the first practical system for two-path relaying using off-the-shelf half-duplex radios. While two-path relaying has been mostly studied from a theoretical perspective in the literature, our solution addresses the challenges of making it practical by introducing two key contributions. First, using a measurement-driven approach, we identify the best approach for a radio to handle two overlapping signals. Just as important, we carefully quantify its limits and introduce the concept of the decoding areas. Second, we introduce a cross-layer protocol that seamlessly navigates the decoding areas with the objective of maximizing throughput while minimizing decoding failures. Experiments on a 4-USRP testbed show that COLiDeR delivers between 80-95% of the relaying performance of an ideal full-duplex radio while incurring negligible decoding failures.","PeriodicalId":413520,"journal":{"name":"Proceedings of the 22nd International ACM Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems - MSWIM '19","volume":"26 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121004569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}