Abstract: A functional architecture is provided for decentralizing the authorization function of an access control system that incorporates user carried access devices, such as smart cards, and door controllers that interact so as to make access decisions. Access to individual rooms is guarded by parameters partially carried by the user carried access devices and partially included in the door controllers.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. The wireless sensor network is queried by specifying a set of events of interest. For each event of interest included in the set of events of interest, a producer node included in the plurality of nodes identifies when that event of interest occurs and, when that event of interest occurs, transmits event data related to that event of interest to a consumer node included in the plurality of nodes. The wireless sensor network further comprises a data management stack that comprises a plurality of layers. The plurality of layers comprises an execution layer that executes on each producer node included in the plurality of nodes. For each event of interest included in the set of events of interest, the execution layer executing on the producer node for that event of interest identifies when that event of interest occurs.

Abstract: An automaton capable of providing an access control decision upon receiving an access control request is produced by processing context based access control policies specified in a formal descriptive language, and by converting the context based access control policies to the automaton.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. The wireless sensor network is queried by specifying a set of events of interest. For each event of interest included in the set of events of interest, a producer node included in the plurality of nodes identifies when that event of interest occurs and, when that event of interest occurs, transmits event data related to that event of interest to a consumer node included in the plurality of nodes. The query is expressed in a discrete event process algebra that is used to manage processing performed to implement the query.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. At least one of the plurality of nodes determines when a discrete event occurs. When the discrete event occurs, transmits data related to the discrete event over at least one of the wireless communication links. The discrete event is a function of the sensor data.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. A subscription for an event of interest occurring in the wireless sensor network is installed in the wireless sensor network. A publisher node included in the plurality of nodes determines when the event of interest occurs and, when the event of interest occurs, publishes data related to the event of interest for a subscriber node included in the plurality of nodes.

Abstract: A wireless sensor node comprises a wireless transceiver to communicate over a wireless communication link with at least one other node in a wireless sensor network, a sensor interface to receive sensor data from a sensor, and a programmable processor coupled to the sensor interface and the wireless transceiver. The programmable processor executes program instructions that implement a virtual machine for executing an event program that is generated from a query. The event program comprises a plurality of instructions, each instruction being associated with an event. The virtual machine allocates a token data structure for each of event and manages the execution of the plurality of instructions using the token data structures.

Abstract: A small intelligent device has a memory that stores a finite state automaton, an input/output interface that receives an input and provides an output, and a processor. The processor is arranged to receive the input and to traverse the finite state automaton stored in the memory in order to supply the output to the input/output interface. The automaton may be an embodiment of context sensitive and context independent rules that are enforced by the automaton execution logic.

Abstract: A functional architecture is provided for decentralizing the authorization function of an access control system that incorporates user carried access devices, such as smart cards, and door controllers that interact so as to make access decisions. Access to individual rooms is guarded by parameters partially carried by the user carried access devices and partially included in the door controllers.

Abstract: An automaton capable of providing an access control decision upon receiving an access control request is produced by processing context based access control policies specified in a formal descriptive language, and by converting the context based access control policies to the automaton.

Abstract: A wireless sensor node comprises a wireless transceiver to communicate over a wireless communication link with at least one other node in a wireless sensor network, a sensor interface to receive sensor data from a sensor, and a programmable processor coupled to the sensor interface and the wireless transceiver. The programmable processor executes program instructions that implement a virtual machine for executing an event program that is generated from a query. The event program comprises a plurality of instructions, each instruction being associated with an event. The virtual machine allocates a token data structure for each of event and manages the execution of the plurality of instructions using the token data structures.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. A subscription for an event of interest occurring in the wireless sensor network is installed in the wireless sensor network. A publisher node included in the plurality of nodes determines when the event of interest occurs and, when the event of interest occurs, publishes data related to the event of interest for a subscriber node included in the plurality of nodes.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. At least one of the plurality of nodes determines when a discrete event occurs. When the discrete event occurs, transmits data related to the discrete event over at least one of the wireless communication links. The discrete event is a function of the sensor data.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. The wireless sensor network is queried by specifying a set of events of interest. For each event of interest included in the set of events of interest, a producer node included in the plurality of nodes identifies when that event of interest occurs and, when that event of interest occurs, transmits event data related to that event of interest to a consumer node included in the plurality of nodes. The wireless sensor network further comprises a data management stack that comprises a plurality of layers. The plurality of layers comprises an execution layer that executes on each producer node included in the plurality of nodes. For each event of interest included in the set of events of interest, the execution layer executing on the producer node for that event of interest identifies when that event of interest occurs.

Abstract: A wireless sensor network comprises a plurality of nodes that communicate over wireless communication links. At least one of the plurality of nodes receives sensor data from a sensor. The wireless sensor network is queried by specifying a set of events of interest. For each event of interest included in the set of events of interest, a producer node included in the plurality of nodes identifies when that event of interest occurs and, when that event of interest occurs, transmits event data related to that event of interest to a consumer node included in the plurality of nodes. The query is expressed in a discrete event process algebra that is used to manage processing performed to implement the query.