Abstract: This invention relates to methods and devices for time synchronization. The invention has particular application in the alignment of slave clocks to a master clock and in dealing with packet delay variation and dynamic asymmetries in the network links between them. In embodiments of the invention, the slave clock uses the peer link delay and residence times measured by peer-to-peer transparent clocks to compensate for clock synchronization errors that arise due to variability in message transfer delays. Embodiments provide a simple linear approximation technique and a Kalman filter-based technique for estimating offset and skew of the slave clock.

Abstract: This invention relates to methods and systems for controlling consumption, particularly power consumption, more particularly by appliances in a building, and is generally suitable for integration with building management systems. Embodiments of the invention provide methods and systems which probabilistically limit the aggregated power load of a plurality of climate control appliances in a building to a selected value, while seeking to minimize the deviation from target environmental conditions within the building. The embodiments of the invention propose distributed decision-making by individual devices based on projected deviation from the target conditions after a period of activity or inactivity.

Abstract: The invention relates to a method and system that provide a continuous querying mechanism that analyses real-time data streams to generate relevant results. It leverages data grid and event processing technology to provide a high performance and extremely scalable continuous querying solution. An embodiment of the invention provides a flexible querying language and data storage to allow users to register their interest in specific types of data, e.g. processes. The users are notified of matching results using an event-based mechanism. In order to efficiently analyze a large amount of data, the embodiment uses a grid infrastructure that allows storage of the data across many grid nodes and distributes the query execution workload, avoiding the bottleneck represented by constantly querying a database. Continuous queries are stored in a Continuous Query Registry and that Registry is invoked every time an insert or update event occurs on the triple store.

Abstract: The invention relates to a method and system that provide a high performance and extremely scalable triple store within the Resource Description Framework (or alternative data models), with optimized query execution. An embodiment of the invention provides a data storage and analysis system to support scalable monitoring and analysis of business processes along multiple configurable perspectives and levels of granularity. This embodiment analyses data from processes that have been already executed and from ongoing processes, as a continuous flow of information. This embodiment provides defining and monitoring processes based on no initial domain knowledge about the process and such that the process will be built only from the incoming flow of information. Another embodiment of the invention provides a grid infrastructure that allows storage of data across many grid nodes and distribution of the workload, avoiding the bottleneck represented by constantly querying a database.

Abstract: This invention relates to methods and systems for estimating skew based on, for example, the IEEE 1588 Precision Time Protocol (PTP). These methods and systems can allow the clock skew between a master clock (server) and slave clock (client) exchanging PTP messages over a packet network to be estimated. In one embodiment, the slave employs a digital phase-locked loop (DPLL) driven by timestamps supplied from a master clock. The slave is able to process the timestamp information embedded in PTP Sync and Follow_Up messages in order to lock its frequency to that of the master clock. In certain embodiments a frequency locked DPLL and a local free-running counter are used to estimate the skew of the local slave oscillator.

Abstract: This invention relates to methods and devices for time and frequency synchronization, especially over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Timing protocol messages are exposed to artifacts in the network such as packet delay variations (PDV) or packet losses. Embodiments of the invention provide a digital phase locked loop (DPLL) based on direct digital synthesis to provide both time and frequency signals for use at the slave (time client). An example of this DPLL in conjunction with a recursive least squares mechanism for clock offset and skew estimation is also provided.

Abstract: In response to requests for their use of the resources by the applications, resources are first allocated to “inelastic” requests specified for performance at a specific time slot. A baseline allocation of resources is then determined which is the minimum amount of capacity that has to be used for efficient operation of the resources required to meet the requests. This baseline will include some additional capacity as the minimum efficient capacity is less than the maximum capacity. “Elastic” requests, specified for performance within a predetermined time range comprising two or more of the set of time slots, are then allocated so as to prioritize the use of this spare capacity, bringing actual usage up to at least the baseline allocation of resources. If further capacity is required to meet all the inelastic requests, further capacity is allocated and the baseline redefined to include it.

Abstract: This invention relates to assignment of mobile clients (such as mobile telephones or software agents) to mainly stationary servers (such as mobile network base stations or computer servers) with the objective of reducing or minimizing the number of active servers. Once the number of users of a server drops below a specified level, the server may be deactivated resulting in power and efficiency savings. Preferably the method of the invention operates dynamically and during run time. In certain embodiments, the method can accept trade-offs in the quality of service or the number of active servers. In an embodiment of the invention, servers are arranged to “compete” with adjacent servers for their clients. This competition may be in a self-amplifying manner such that with the effect that more “popular” servers are more likely to succeed thus resulting in servers which are below a utilization threshold and can therefore be switched off.

Abstract: This invention relates to packet selection techniques that can be used in conjunction with a clock recovery mechanism to mitigate the effects of packet delay variation on timing messages exchanged over a packet network, particularly when seeking to synchronize the time of a clock in a slave device to that of a master clock. The packet selection techniques can assist in reducing the noise in the recovered clock signal at the slave device, allowing recovery to a higher quality. Embodiments of the invention provide techniques based on extracting timing packets that create a constant interval between the arrival of selected packets at the slave device and on extracting timing packets which are closest to making the interval between arrival of the selected packets equal to the interval between the departure of the packets.

Abstract: This invention relates to methods and devices for channel identification. The invention is particularly concerned with techniques for non-line of sight channel identification. In embodiments of the invention the methods and devices are used for channel identification in wireless geolocation systems. Embodiments of the invention make use of an entropy estimation of the channel to distinguish channel conditions and in particular to identify line-of-sight and non-line-of-sight channels and which can be used to solve the NLOS problem of determining relative distances between transmitter and receiver. In particular embodiments an entropy estimation of the channel impulse response (CIR) is used to construct a robust entropy-based channel identification technique. As a result, more accurate localization in indoor and other multipath environments may be possible.

Abstract: This invention relates to methods and devices for time and frequency synchronization. The invention has particular application where time and frequency synchronization over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP) is being carried out. The primary challenge in clock distribution over packet networks is the variable transit delays experienced by timing packets, packet delay variations (PDVs). Embodiments of the invention provide a method for time offset alignment with PDV compensation where a synchronized frequency signal is available at a slave device via Synchronous Ethernet and is used to determine the compensation parameters for the PDV.

Abstract: This invention relates to methods and devices for synchronization using linear programming, especially over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Timing protocol messages are exposed to artifacts in the network such as packet delay variations (PDV) or packet losses. Embodiments of the invention provide a two-dimensional linear programming technique for estimating clock offset and skew, particularly from two-way exchange of timing messages between a master and a slave device. Some embodiments include a skew and offset adjustable free-running counter for regenerating the master time and frequency at the slave device.

Abstract: This invention relates to methods and devices for motor speed control. The invention has particular application in the control of motors over packet networks. In embodiments of the invention, phase-locked loop principles are used to remotely control the speed of an electric motor over a packet network. The setpoint for the motor is supplied by arriving timestamps from a speed-mapped variable frequency source. The shaft speed of the motor is measured with a tachometer with its output proportional to the motor speed. Any deviation of the actual speed from the setpoint is amplified by the power amplifier whose output drives the motor. Speed control over packet networks allow smoother operation of a process, acceleration control, different operating speeds for each process recipe, compensation for changing process variables, slow operation for setup purposes, adjustments to the rate of production, accurate positioning, and control torque or tension of a system.

Abstract: This invention relates to methods and devices for compensating for path asymmetry, particularly with reference to time and frequency synchronization. The invention has particular application where time and frequency synchronization over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP) is being carried out. Typically communication path delays between a time server (master) and a client (slave) are estimated using the assumption that the forward delay on the path is the same as the reverse delay. As a result, differences between these delays (delay asymmetries) can cause errors in the estimation of the offset of the slave clock from that of the master. Embodiments of the invention provide techniques and devices for compensating for path delay asymmetries that arise when timing protocol messages experience dissimilar queuing delays in the forward and reverse paths.

Abstract: This invention relates to methods and systems for limiting consumption, particularly power consumption, more particularly by appliances in a building, and is generally suitable for integration with building management systems. Embodiments of the invention provide arrangements in which the aggregated power load of a plurality of appliances is capped to a selected value (which may be arbitrary, or may be dictated by conditions) whilst seeking to minimize the deviation from target environmental conditions within the building through a combination of distributed decision making by the appliances themselves and centralized orchestration, which may be informed by real-time sensor readings and/or known properties of the building. The distributed decision-making by individual devices may be based on projected deviation from the target conditions after a period of activity or inactivity but with a central controller which determines which devices should be switched on.

Abstract: This invention relates to methods and systems for controlling consumption, particularly power consumption, more particularly by appliances in a building, and is generally suitable for integration with building management systems. Embodiments of the invention provide methods and systems which probabilistically limit the aggregated power load of a plurality of climate control appliances in a building to a selected value, whilst seeking to minimize the deviation from target environmental conditions within the building. The embodiments of the invention propose distributed decision-making by individual devices based on projected deviation from the target conditions after a period of activity or inactivity.

Abstract: The invention relates to a method and system which provides access control and access control enforcement particularly in relation to business process data streams. Embodiments of the invention provide a method and a set of components (referred to as: Policy Administration Point, Policy Enforcement Point, Filter Updater, Log De-Multiplexer) for fast online filtering of process logs based on access rights. In one embodiment the method comprises a series of steps to (i) encode each user's access rights to the process log in a machine readable format (ii) use such encoding together with incoming process events to compute a custom online filter to be applied to the process log as it is being recorded (iii) execute logical log de-multiplexing, enabling each user to query, inspect and monitor a separate event flow.

Abstract: This invention relates to packet selection techniques that can be used in conjunction with a clock recovery mechanism to mitigate the effects of packet delay variation on timing messages exchanged over a packet network, particularly when seeking to synchronize the time of a clock in a slave device to that of a master clock. The packet selection techniques can assist in reducing the noise in the recovered clock signal at the slave device, allowing recovery to a higher quality. Embodiments of the invention provide techniques based on extracting timing packets that create a constant interval between the arrival of selected packets at the slave device and on extracting timing packets which are closest to making the interval between arrival of the selected packets equal to the interval between the departure of the packets.

Abstract: This invention relates to methods and devices for synchronization using linear programming, especially over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Timing protocol messages are exposed to artifacts in the network such as packet delay variations (PDV) or packet losses. Embodiments of the invention provide a two-dimensional linear programming technique for estimating clock offset and skew, particularly from two-way exchange of timing messages between a master and a slave device. Some embodiments include a skew and offset adjustable free-running counter for regenerating the master time and frequency at the slave device.

Abstract: This invention relates to methods and devices for time and frequency synchronization. The invention has particular application where time and frequency synchronization over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP) is being carried out. The primary challenge in clock distribution over packet networks is the variable transit delays experienced by timing packets, packet delay variations (PDVs). Embodiments of the invention provide a method for time offset alignment with PDV compensation where a synchronized frequency signal is available at a slave device via Synchronous Ethernet and is used to determine the compensation parameters for the PDV.