Abstract: This invention relates to methods and systems for searching. It is particularly applicable to methods of searching which enable efficient identification of compatible portfolios. Embodiments of the invention propose methods of searching which address the huge search space issue associated with identifying compatible portfolios. In particular, embodiments of the invention start their search operations simultaneously from both sides by both trying to form valid portfolios from candidate products until a valid solution is found and trying to find conflicts from the defined compatibility rules until a conflict is found which leads to the conclusion that no valid solution exists. A conclusion from either process will stop the whole searching process which can significantly reduce blind and unnecessary searching in the whole search space.

Abstract: This invention relates to end-to-end transparent clocks and methods of estimating skew in end-to-end transparent clocks. Embodiments of the invention relate to techniques for estimating clock skew between a free-running clock in a transparent clock and a master clock, in particular by using the timing information embedded in timing messages passing through the transparent clock. Further embodiments of the invention set out uses of these estimates to modify the residence times computed by the transparent clock and a synchronization network including such transparent clocks.

Abstract: This invention relates to peer-to-peer transparent clocks and methods of estimating skew in peer-to-peer transparent clocks. Embodiments of the invention relate to techniques for estimating clock skew between a free-running clock in a transparent clock and a master clock, in particular by using the timing information embedded in timing messages passing through the transparent clock. Further embodiments of the invention set out uses of these estimates to modify the residence times computed by the transparent clock and a synchronization network including such transparent clocks.

Abstract: This invention relates to methods and devices for timing synchronization. The invention has particular application where timing is being carried out over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Embodiments of the invention make use of estimated forward and reverse path delay asymmetries directly in the estimation algorithm (for example a Kalman filter). This can allow the variation in the timestamps which have been compensated for the delay asymmetry to be significantly reduced, which can reduce the complexity of the phase offset estimation algorithm.

Abstract: A method for designating a class of data content for determining how the content will be handled by a content delivery network (CDN) into one of: a transport designation by which content is transported from an entrance node to one or more edge nodes; a caching designation by which the content is stored at one or more edge nodes; and a hybrid designation by which content is stored at a node in the CDN for subsequent transport to one or more edge nodes in the CDN, the method comprising: determining a set of one or more transport designation options; determining a set of one or more caching designation options; determining a set of one or more hybrid designation options; determining a normalised measure resource requirement for each of the transport, caching and hybrid designation options; and selecting one designation option for the class of content from all of the transport, caching and hybrid designation options by an optimisation function for selecting the designation option based on the determined normalise

Abstract: This invention relates to methods and systems for controlling appliances, particularly climate control appliances such as air conditioning units used in buildings. Embodiments of the invention provide methods and systems which provide a framework of semi-autonomous sensors and actuators which can achieve climate control without the need for centralised or explicit coordination. In certain embodiments, the climate control system is capable of identifying suitable pairings of sensors and actuators and taking into account actions of other actuators. The embodiments have particular application in buildings where large numbers of individual sensors and actuators are deployed in an ad-hoc or unplanned manner over time, but can communicate with each other. The embodiments of the invention can provide improved efficiency, reduced infrastructure costs, improved flexibility and can be deployed across multiple sites.

Abstract: This invention relates to methods and systems for estimating offset, skew and drift. Embodiments of the invention relate to methods and systems which allow these relationships between a slave clock and a master clock to be estimated based on the exchange of timestamped messages between the master and the slave. Further embodiments of the invention set out uses of these estimates to synchronize a local clock in a slave to a master and to steer the slave clock to stay aligned to the master clock when the master clock is temporarily unavailable or the communication path between slave and master is temporarily unavailable.

Abstract: This invention relates to methods and systems for optimizing network catchment areas, in particular based on completion times of the customer premises. Embodiments of the invention aggregate different customer premises to form demarcated catchment areas by minimizing the overall weighted cost function comprising the distance and completion time within each catchment area, while also considering practical constraints. Embodiments of the invention allow network planners to specify their preferences of distance against time to produce cost-effective network schemes for very large numbers of customer premises and form network catchment areas without any overlapping.

Abstract: This invention relates to methods and systems for monitoring mobile service quality in a mobile network and also for determining parts of a mobile network which need expansion or upgrade. Embodiments of the invention monitor the market impact and/or service quality, and determine an expansion ranking. The market impact, service quality and/or expansion ranking may view the network from a plurality of perspectives, including a location perspective, an historical time perspective, a future time perspective and/or a network element type perspective. The results of the monitoring and determining can be acted on by predetermined rules and/or actions to derive a list of prioritized expansion tasks for the network.

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 more rapidly than conventional estimation techniques and thereby improve the convergence of standard estimation algorithms. In one embodiment, the skew estimation is derived from a set of timestamps from a message exchange between the master and slave using a non-linear least square-fitting algorithm. An example of the fitting algorithm is the Levenberg-Marquardt algorithm.

Abstract: This invention relates to methods and systems for localization. It is particularly concerned with localization techniques based on time difference of arrival for wireless devices. Embodiments of the invention relate to techniques in which a transmitter transmits periodic distinguishable signals which are relayed upon receipt by the client whose location is sought in a form distinguishable from that of the transmitter. Signals from both the transmitter and the client are received by at least three signal receivers which generate a time difference of arrival based on the difference taken for a signal to reach the receiver directly and via the client. Further embodiments of the invention provide a phase detector in the receivers to determine the time difference of arrival between the signals.

Abstract: This invention relates to methods and systems for estimating offset and skew using linear programming. Embodiments of the invention relate to methods and systems which apply linear programming principles to links with asymmetric transmission rates which are estimated from an exchange of timing messages (for example under IEEE 1588 PTP). Further embodiments provide for the estimation of clock offsets using linear programming techniques when the skew is known or estimated.

Abstract: This invention relates to methods and devices for bias estimation and correction, particularly for time-of-arrival (TOA) based wireless geolocation systems. Multipath and non-line-of-sight (NLOS) biases can cause distance estimation errors in the range of tens-hundreds of meters and is particularly problematic in urban and indoor environments. The behavior of the biases dynamically changes depending on the clutter and/or obstructions between the base station and the mobile device. Aspects of the present invention provide practical real-time bias estimation and correction techniques for TOA-based systems and are based on inferring and estimating the biases from dynamic time differential measurements. The techniques can operate in real-time and involve simple calculations.

Abstract: This invention relates to methods and systems for workload distribution, particularly in data centers, more particularly data centers which use fresh air cooling. Embodiments of the invention provide methods and systems which calculate a load value for each server which takes account of both the temperature of the server and its current job queue, and determine the server to which an incoming job should be allocated on the basis of the load values of the available servers.

Abstract: This invention relates to the use of frequency synchronization accuracy as an additional quality metric for mobile call handover between base stations. Call handover is of major importance within any mobile network; without checking frequency synchronization before handover dropped calls and interrupted communication can result.

Abstract: This invention relates to methods and devices for clock synchronization. The invention has particular application in the alignment of slave clocks to a master clock and in dealing with transmission delay asymmetries where the forward and reverse communication paths between the master and slave clocks have asymmetric transmission rates. Such methods and devices have particular application in small cell backhaul solutions for 4G/LTE deployments. In embodiments of the invention, the slave clock uses link rate information to estimate the transmission delay asymmetry and thus estimate the offset and skew of the slave clock. 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 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) while 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 for storing and searching data. Embodiments of the invention make use of suffix trees to support binary pattern matching. Embodiments of the invention can be shown to have comparable search speeds to searches of known suffix trees, but are advantageous in that they have lower memory usage requirements which is important in large data environments.

Abstract: This invention relates to methods and systems for estimating and checking synchronization accuracy, in particular frequency synchronization accuracy. It is particularly applicable to synchronization methods and systems which involve a digital phase-locked loop (DPLL) and embodiments provide methods and systems for estimating and tracking how well the DPLL is frequency synchronized to a source frequency. In one embodiment, frequency synchronization accuracy is used as an additional quality metric for mobile call handover between base stations. Call handover is of major importance within any mobile network; without checking frequency synchronization before handover dropped calls and interrupted communication can result.

Abstract: This invention relates to methods and devices for time transfer. The invention has particular application in the alignment of slave clocks to a master clock and dealing with packet delay variations. In embodiments of the invention, the slave clock uses the residence times measured by end-to-end 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.