Abstract: Embodiments of the invention proxy control the establishment or continued existence of a WLAN connection by using the back end authentication mechanism to authenticate/de-authenticate a WLAN session in dependence on the experienced quality of the connection during the set-up phase or session itself. This has the effect of preventing a bad quality connection from being established or from continuing, and hence should improve the user experience, and help a WLAN network operator maintain a service with high Quality of Service (QoS).

Abstract: Embodiments of the invention provide the ability to use policy defined by the operator to control the interfaces on which data is sent and received by a device. The policy can be dynamically updated by the operator, by pushing new policy to the device for implementation. The policy can define that the device should switch certain data between two or more available interfaces at certain times, or may define when certain data may be sent or received over a particular interface. Advantageously, the device may receive new policy from the operator in order to help with the operator's own operational objectives. For example, the operator may be engaging in traffic shaping or other traffic limitation, for example to ease congestion or enforce service agreements.

Abstract: A buried object detector comprising: a loop antenna and an RF source, the RF source coupled to the loop antenna and arranged to feed the loop antenna with an RF signal, the detector further comprising a detector circuit coupled to the loop antenna and arranged to detect changes in the quality factor of a resonant circuit formed by the loop antenna, wherein the loop antenna is arranged to magnetically couple with a buried object, thereby reducing the quality factor of the resonant circuit.

Abstract: An apparatus for radio communication using surface waves, the apparatus comprising: a guiding medium having a first surface suitable for the propagation of surface waves, the first surface having a reactive impedance; at least one communication node, the node having a transmitter and/or receiver coupled to a transducer, the transducer positioned on or adjacent the first surface of said guiding medium; wherein the at least one communication node is arranged to launch and/or receive surface waves, over the first surface of said guiding medium.

Abstract: A method for detecting signals using an adaptive transducer arrangement, the arrangement including a transducer array having a plurality of transducers, a beamformer, and an energy detector, the method comprising: determining weights to be applied by the beamformer to signals emitted from each transducer in order to maximise a performance metric; applying the determined weights to the signals emitted from each transducer; measuring the energy received at the energy detector; comparing the measured energy with a predetermined value and based on said comparison determining whether or not one or more signals are present.

Abstract: A method of filtering sections of a data stream involves determining a set of characters of interest, testing each section of the data stream for the presence of one or more of the set of characters of interest and extracting sections in which at least one of the characters is present.

Abstract: A power manager for a mobile device comprises a traffic shaping unit (30) and a management unit (26). The traffic shaping unit is incorporated into a networking layer (8) of a mobile device architecture. The traffic management unit spans application layer (7) and networking layer (8) of the mobile device architecture. The traffic shaping unit and management unit are connected via a feed path (73). The management unit (26) is provided with inputs (74) to receive measurements of external parameters (65 to 69). The management unit further comprises a processor (20) to process the received measurements and a traffic shaping function generator (21) to receive the processed measurements and generate a traffic shaping function. The management unit (26) inputs the generated traffic shaping function to the traffic shaping unit (30) via the feed path (73), whereby the traffic management unit controls transmissions from the mobile device.

Abstract: A rod antenna and antenna circuit are described which make use of negative feedback to reduce the Q of the antenna, but which also makes use of a different coil tapping arrangement to significantly reduce electric field susceptibility on the detected signal from the main coil as well as different biasing arrangements to reduce noise. More particularly, in some embodiments of the invention the main detector coil of the antenna has a centre tap that is AC grounded with signal taps then being taken from the opposite ends of the main coil, and being respectively fed to the inputs of a differential amplifier. The output of the differential amplifier is then fed to the magnetic circuit of the rod antenna via a second inductor winding that is magnetically coupled to the resonance circuit of the main antenna coil.

Abstract: A method of grouping communication sessions, the method comprising: selecting a plurality of communications sessions from a data stream; determining which data structures, of said communication sessions, occur more frequently than chance; and sorting the communication sessions into groups, wherein communication sessions which have similar data structures, determined to occur more frequently than chance, are sorted into the same group.

Abstract: A method of identifier correlation in a communications network, the network comprising: an identifier translator, for translating at least one identifier of a communications packet, wherein a packet which has passed through the identifier translator comprises translated and untranslated identifiers; the method comprising: selecting a first packet prior to transmission through the identifier translator; selecting a second packet after transmission through the identifier translator which has at least one identifier which is the same as a corresponding identifier of the first packet; and correlating at least one identifier from the first packet which is different to a corresponding identifier of the second packet.

Abstract: A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Abstract: A networked probe system for a communications network (28) comprising at least one user device and at least one network device, comprises a plurality of probes (25). A probe (25) is provided in each path between the or each user device and the or each network device. Each probe (25) stores one or more parameters of interest. The probes (25) monitor communication from the user device for a subset of the communication satisfying the one or more parameters. On determining the presence of the one or more parameters in the subset of the communication, the probe (25) provides a notification to all other probes in the network (28).

Abstract: A power supply and communication system comprising a single-wire data bus, itself having comprising a source end and a termination end, the termination end being connected to ground through a resistance of less than 10?. A circuit is connected at the termination end, between the single-wire data bus and ground, and the circuit comprises means for deriving its supply voltage and receiving input data from a time-variant signal applied to the single-wire data bus.

Abstract: A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Abstract: In a multilateration apparatus a correlator is provided with a time of arrival correlation window which is set to cater for the path lengths that may be experienced before a signal from an object to be located is received by receivers in the system. This may be on the basis of the largest possible path length in the system or on a receiver by receiver basis.

Abstract: A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Abstract: Systems, methods and a mobile device for using policy defined by the operator to control the interfaces on which data is sent and received by the device are provided. The policy can be dynamically updated by the operator, by pushing new policy to the device for implementation. The policy can define that the device should switch certain data between two or more available interfaces at certain times, or when certain data may be sent or received over a particular interface. The device may receive new policy from the operator in order to help with the operator's own operational objectives, such as traffic shaping or other traffic limitation to ease congestion or enforce service agreements. A policy implementing corresponding traffic limitation or shaping on the air interface between the mobile device and network base stations can be sent to the mobile device so as to reduce signaling congestion on the air-interface.

Abstract: A network resilient to at least two points of failure comprises a plurality of nodes. A first path between a source node and a destination node is determined and a second path between a source node and a destination node is determined. The first and second paths are node-disjoint.

Abstract: A method and apparatus are described for the unwrapping of a set of phase values observed for an incoming signal on a phased array antenna. The difference between values observed on adjacent elements in the array forms a first data set. The differences between adjacent ordinates in the first data set forms a second data set. The values in the second data set are rounded to the nearest whole multiple of one complete cycle before the differencing process is reversed to provide the values (representing a whole number of complete cycles) which are added to the observed phase values to provide the unwrapped phase values.

Abstract: There is described a method of communicating over a public data network, for example the Internet. A user of a public PC, for example one located in an Internet café, uses the Internet browser provided on the public PC to downloaded from a remote trusted web site a secure Internet browser that then runs within the browser provided on the public PC. The user uses the secure Internet browser to browse the Internet. The secure browser has been configured so that no copy of information transmitted into the network or downloaded from the network is cached or otherwise recorded on the hard disc of the terminal. The user may thus browse the Internet without leaving a record of sensitive information (e.g. credit card details) used in the browsing session at the public terminal.