title: Analytical model of large data transactions in CoAP networks.
abstract: We propose a novel analytical model to study fragmentation methods in wireless sensor networks adopting the Constrained Application Protocol (CoAP) and the IEEE 802.15.4 standard for medium access control (MAC). The blockwise transfer technique proposed in CoAP and the 6LoWPAN fragmentation are included in the analysis. The two techniques are compared in terms of reliability and delay, depending on the traffic, the number of nodes and the parameters of the IEEE 802.15.4 MAC. The results are validated trough Monte Carlo simulations. To the best of our knowledge this is the first study that evaluates and compares analytically the performance of CoAP blockwise transfer and 6LoWPAN fragmentation. A major contribution is the possibility to understand the behavior of both techniques with different network conditions. Our results show that 6LoWPAN fragmentation is preferable for delay-constrained applications. For highly congested networks, the blockwise transfer slightly outperforms 6LoWPAN fragmentation in terms of reliability.
authors.affiliation: Wireless Network Group (WNG), Department of Telematics Engineering, Universitat Politècnica de Catalunya, C/Jordi Girona 1-3, Mòdul C3, 08034 Barcelona, Spain. alessandro.ludovici@antel.upc.edu.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Ludovici
authors.affiliation: School of Electrical Engineering, Royal Institute of Technology, 100 44 Stockholm, Sweden. pidm@kth.se.
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Di Marco
authors.affiliation: Wireless Network Group (WNG), Department of Telematics Engineering, Universitat Politècnica de Catalunya, C/Jordi Girona 1-3, Mòdul C3, 08034 Barcelona, Spain. anna.calveras@antel.upc.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Calveras
authors.affiliation: School of Electrical Engineering, Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Karl H
authors.initials: KH
authors.lastname: Johansson
mesh_terms: D008962:Models, Theoretical; D009010:Monte Carlo Method; D058998:Remote Sensing Technology; D013686:Telemetry; D059015:Wireless Technology