Mobile device operating systems do not allow users to specify their preferred network(s). Therefore, when there are competing WiFi networks to which a mobile device is authorized to connect, the device may associate itself unpredictably with any one of those networks. This unpredictability results in some network services being unavailable if the device connects to the “wrong” network. The device-AP association problem is a challenging one since the protocol stacks on mobile devices and their innate association behaviors are beyond a network operator's control. This paper discusses a highly memory-efficient and processor-frugal AP-side approach to altering these association behaviors. Our approach makes minor alterations to the transition sequences in the IEEE 802.11 state machine in order to impose the desired device-network association behavior. The changes that we propose are backwards compatible with the IEEE 802.11 standard. Our experiments in the real world demonstrate that our approach is very effective and results in the desired association behavior with complete predictability, regardless of the mobile device, its iOS™1or Android ™2operating system, or the version of that operating system.

For many real time applications, parallel computers offer a natural computing platform. However, very little attention has been paid to software support for real time embedded systems on parallel machines. The paper addresses the problem of formal software specification for parallel real time systems, and presents some features of a formal specification language-PRETSEL (Parallel REal Time SpEcification Language). The syntax of PRETSEL is presented and the formal semantic rules are defined. The effectiveness of PRETSEL is demonstrated through the specification of the functionality and timing requirements of a Sonar system.

The relevance of a form of cut elimination theorem for linear logic tensor theories to the concept of a process on a Petri net is discussed. The discussion is based on two definitions of processes given by E. Best and R. Devillers (1987). Their notions of process correspond to equivalence relations on linear logic proofs. It is noted that the cut reduced proofs form a process under the finer of these definitions. Using a strongly normalizing rewrite system and a weak Church-Rosser theorem, it is shown that each class of the coarser process definition contains exactly one of these finer classes which can therefore be viewed as a canonical or normal process representative. The relevance of these rewrite rules to the categorical approach of P. Degano et al. (1989) is also discussed.>

The digital multiplexed interface (DMI) specifies the interface requirements for multiplexed data communication over digital facilities between a host computer and a PBX. A part of the DMI's packet-mode data-transfer protocol, which is based on the X.25 packet-level protocols, is specified formally using the selection/resolution (S/R) model. A formal verification of the resetting phase of this protocol, using the S/R-model-based software tool SPANNER, is presented. It is shown that the protocol is not fully correct in the sense that some sequence of events may lead it to unsafe states. These states give rise to a livelock situation. A way to rectify this problem is suggested.>

An applicative language based on the LAMBDA-Calculus is presented. The language, SLIPS (Small Language for Instruction Purposes), is described using the LAMBDA-Calculus as a metalanguage. A call-by-need mechanism of function invocation eliminates the drawbacks of both call-by-name and call-by-value. The system has been implemented in PASCAL.