Probabilistic Model Checking of Contention Resolution in the IEEE 802.15.4 Low-Rate Wireless Personal Area Network Protocol

Abstract—The international standard IEEE 802.15.4 defines low-rate wireless personal area networks, a central communi-cation infrastructure of pervasive computing. In order to avoid conflicts caused by multiple devices transmitting at the same time, it uses a contention resolution algorithm based on randomised exponential backoff that is similar to the ones used in IEEE 802.3 for Ethernet and IEEE 802.11 for Wireless LAN. We model the protocol using probabilistic timed automata, a formalism in which both nondeterministic and probabilistic choice can be represented. The probabilistic timed automaton is transformed into a finite-state Markov decision process via a property-preserving integral-time semantics. Using the proba-bilistic model checker PRISM, we verify correctness properties, compare different operation modes of the protocol, and analyse performance and accuracy of different model abstractions. I

TRAFFIC DEDUCTION SCHEME WITH MANIPULATING ISSUES IN WSNS

Contextual info may be disclosed by eavesdropping on over-the-air communications and acquiring automatic transmission attributes, for instance inter-wrapper occasions, wrapper authority and haven IDs, and product and sizes of transmitted bags. Leakage of environmental info poses an appreciable risk for the WSN quest and action. We refined two methods for separating the WSN to MCDSs and SS-MCDSs and evaluated their show via simulations. When come forward methods in a reputation to surviving off your comprehensive snoop, we proven that restricting the oaf trade automatic transmissions to MCDS nodes, cuts pare over the link upward in consequence of movement normalization. Within the army control plot, the foe can link the occasions detected moment practicing the WSN to compromised worth. We feature our goal isn't to assemble presumably intelligent presumably compelling doubtless gorgeous delicate raid. This somewhat raid is extremely-time employing invulnerability agency and could call for further a pasta perceptive. First, auditors are laid-back devices whichever are demanding to diagnose. Second, the transfer of economical stock wireless plumbing causes it impending sane to open torrent of snoops. Third, even when file encryption allows you to comprise the carton weight, some fields not beyond the wrapper headers be transmitted not over the overt for respectable contract trip. We notify an interested form that computes an estimation of V’s dissolution by balancing in remembrances to the arrival prevalence, in the interest of MCDSs that span V, united with MCDS size

Modelling and verifying IEEE Std 11073-20601 session setup using mCRL2

In this paper we advocate that formal verification should bea part of the development of a communication standard;in a short period of time issues areuncovered that have been in the standard for a number of years, and allsubtleties in the correctness of the protocol are understood.We model and verify the session setup protocolthat is part of the IEEE 11073-20601:2008 standard for communication betweenpersonal health devices.We identify a number of issues present in the standards document.Discussion with a member of the standards committee unveiled that most, but notall, of the identified issues are fixed in the IEEE 11073-20601:2010 version ofthe standard.In addition, the correctness of the protocol, including the fixes, is assessed.For this, properties of the session setup protocol are formulated, and usingthe model checker mCRL2 it is verified whether the model satisfies theseproperties.We show that the session setup protocol is flawed, and propose a straightforwardway to fix this issue

Application and Control Aware Communication Strategies for Transportation and Energy Cyber-Physical Systems

Cyber--Physical Systems (CPSs) are a generation of engineered systems in which computing, communication, and control components are tightly integrated. Some important application domains of CPS are transportation, energy, and medical systems. The dynamics of CPSs are complex, involving the stochastic nature of communication systems, discrete dynamics of computing systems, and continuous dynamics of control systems. The existence of communication between and among controllers of physical processes is one of the basic characteristics of CPSs. Under this situation, some fundamental questions are: 1) How does the network behavior (communication delay, packet loss, etc.) affect the stability of the system? 2) Under what conditions is a complex system stabilizable?;In cases where communication is a component of a control system, scalability of the system becomes a concern. Therefore, one of the first issues to consider is how information about a physical process should be communicated. For example, the timing for sampling and communication is one issue. The traditional approach is to sample the physical process periodically or at predetermined times. An alternative is to sample it when specific events occur. Event-based sampling requires continuous monitoring of the system to decide a sample needs to be communicated. The main contributions of this dissertation in energy cyber-physical system domain are designing and modeling of event-based (on-demand) communication mechanisms. We show that in the problem of tracking a dynamical system over a network, if message generation and communication have correlation with estimation error, the same performance as the periodic sampling and communication method can be reached using a significantly lower rate of data.;For more complex CPSs such as vehicle safety systems, additional considerations for the communication component are needed. Communication strategies that enable robust situational awareness are critical for the design of CPSs, in particular for transportation systems. In this dissertation, we utilize the recently introduced concept of model-based communication and propose a new communication strategy to address this need. Our approach to model behavior of remote vehicles mathematically is to describe the small-scale structure of the remote vehicle movement (e.g. braking, accelerating) by a set of dynamic models and represent the large-scale structure (e.g. free following, turning) by coupling these dynamic models together into a Markov chain. Assuming model-based communication approach, a novel stochastic model predictive method is proposed to achieve cruise control goals and investigate the effect of new methodology.;To evaluate the accuracy and robustness of a situational awareness methodology, it is essential to study the mutual effect of the components of a situational awareness subsystem, and their impact on the accuracy of situational awareness. The main components are estimation and networking processes. One possible approach in this task is to produce models that provide a clear view into the dynamics of these two components. These models should integrate continuous physical dynamics, expressed with ordinary differential equations, with the discrete behaviors of communication, expressed with finite automata or Markov chain. In this dissertation, a hybrid automata model is proposed to combine and model both networking and estimation components in a single framework and investigate their interactions.;In summary, contributions of this dissertation lie in designing and evaluating methods that utilize knowledge of the physical element of CPSs to optimize the behavior of communication subsystems. Employment of such methods yields significant overall system performance improvement without incurring additional communication deployment costs

UML-Based co-design framework for body sensor network applications

Ph.DDOCTOR OF PHILOSOPH