@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 {18043,
	title = {Probabilistic Breadth-First Search {\textendash} A Method for Evaluation of Network-Wide Broadcast Protocols},
	booktitle = {6th IEEE/ACM/IFIP International Conference on New Technologies, Mobility and Security (NTMS)},
	year = {2014},
	month = {03/2014},
	publisher = {IEEE Computer Society},
	organization = {IEEE Computer Society},
	address = {Dubai, UAE},
	abstract = {In wireless mesh networks (WMNs), network-wide broadcasts (NWBs) are a fundamental operation, required by routing and other mechanisms that distribute information to all nodes in the network. However, due to the characteristics of wireless communication, NWBs are generally problematic. Optimizing them is thus a prime target when improving the overall performance and dependability of WMNs. Most of the existing optimizations neglect the real nature of WMNs and are based on simple graph models, which provide optimistic assumptions of NWB dissemination. On the other hand, models that fully consider the complex propagation characteristics of NWBs quickly become unsolvable due to their complexity. In this paper, we present the Monte Carlo method probabilistic breadth-first search (PBFS) to approximate the reachability of NWB protocols. PBFS simulates individual NWBs on graphs with probabilistic edge weights, which reflect link qualities of individual wireless links in the WMN, and estimates reachability over a configurable number of simulated runs. This approach is not only more efficient than existing ones, but further provides additional information such as the distribution of path lengths. Furthermore, it is easily extensible to NWB schemes other than flooding. The applicability of PBFS is validated both theoretically and empirically, in the latter by comparing reachability as calculated by PBFS and measured in a real-world WMN. Validation shows that PBFS quickly converges to the theoretically correct value and approximates the behaviour of real-life testbeds very well. The feasibility of PBFS to support research on NWB optimizations or higher level protocols that employ NWBs is demonstrated in two use cases.},
	keywords = {Monte Carlo methods, Network-wide broadcasts, Probabilistic network graphs, Wireless mesh networks},
	isbn = {9781479932238},
	doi = {10.1109/NTMS.2014.6814046},
	url = {http://andreas-dittrich.eu/2014/01/pbfs},
	author = {Lichtblau, Bj{\"o}rn and Dittrich, Andreas}
}
