@inbook {18024, title = {Modeling Responsiveness of Decentralized Service Discovery in Wireless Mesh Networks}, booktitle = {MMB \& DFT}, series = {Lecture Notes in Computer Science}, volume = {8376}, year = {2014}, pages = {88-102}, publisher = {Springer International Publishing Switzerland}, organization = {Springer International Publishing Switzerland}, abstract = {In modern service networks, discovery plays a crucial role as a layer where providing instances of a given service can be published and enumerated. Since successful discovery is mandatory for service usage, comprehensive service dependability assessment needs to incorporate the dependability of the discovery layer. This work focuses on the responsiveness of the discovery layer, the probability to operate successfully within a deadline, even in the presence of faults. It proposes a hierarchy of stochastic models for decentralized discovery and uses it to describe the discovery of a single service using three well-known discovery protocols: domain name system based service discovery (DNS-SD), simple service discovery protocol (SSDP) and service location protocol (SLP). Further, a methodology to use the model hierarchy in wireless mesh networks is introduced. Given a pair service requester and provider, a discovery protocol and a deadline, it estimates packet loss probabilities and transmission time distributions for each link on the communication paths between the pair, generates specific model instances and calculates the expected responsiveness. Finally, the paper introduces a new metric, the expected responsiveness distance d_er to estimate the maximum distance from a provider where requesters are still able to discover it with a required responsiveness. The models and their methodology are demonstrated using monitoring data from the distributed embedded systems (DES) testbed at Freie Universit{\"a}t Berlin. It is shown how the responsiveness and d_er of the protocols change depending on the position of requester and provider and the overall link quality in the network.}, keywords = {fault tolerance, Markov Models, Real time systems, Responsiveness, Service Discovery, Wireless mesh networks}, isbn = {978-3-319-05358-5}, issn = {0302-9743}, doi = {10.1007/978-3-319-05359-2_7}, url = {http://andreas-dittrich.eu/2013/12/modeling-responsiveness-of-decentralized-service-discovery-in-wireless-mesh-networks}, author = {Dittrich, Andreas and Lichtblau, Bj{\"o}rn and Rezende, Rafael and Malek, Miroslaw}, editor = {Fischbach, K. and Krieger, U. R.} } @conference {18232, title = {Responsiveness of Service Discovery in Wireless Mesh Networks}, booktitle = {20th Pacific Rim International Symposium on Dependable Computing (PRDC)}, year = {2014}, month = {11/2014}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Singapore}, abstract = {Service Discovery (SD) is an integral part of service networks. Before a service can be used, it needs to be discovered successfully. Comprehensive service dependability analysis thus needs to include the SD process. As a time-critical operation, an important property of SD is responsiveness: The probability of successful discovery within a deadline, even in the presence of faults. This is especially true for dynamic networks with complex fault behavior such as wireless networks. This work evaluates the responsiveness of decentralized SD in wireless mesh networks. For this reason, the experiment framework ExCovery has been employed, which provides a unified description, execution, measurement and storage of experiments. ExCovery runs on the Distributed Embedded System (DES) wireless testbed at Freie Universit{\"a}t Berlin. We present and discuss the results of the experiments and show how responsiveness is affected by the position and number of requester and providers as well as the load in the network. The results clearly demonstrate that in all but the most favorable conditions, the configurations of current SD protocols struggle to achieve a high responsiveness.}, keywords = {Experiments, Responsiveness, Service Discovery, Wireless mesh networks, Zeroconf}, doi = {10.1109/PRDC.2014.38}, url = {http://andreas-dittrich.eu/2014/06/prdc2014}, author = {Dittrich, Andreas and Herrera, Daniel Solis and Coto, Pablo and Malek, Miroslaw} }