Abstract: An accelerometer device (100) comprises a former (118) and an optical fiber (120) wound around the former. The winding of optical fiber (120) has a sensing portion (126) that is free to move in relation to a direction of desired sensitivity (128). A movable element (106) is disposed opposite the sensing portion (126) of the optical fiber (120), the movable element (106) being translatable so as to urge against the sensing portion (126) of the optical fiber (120) from a position external to the winding of the optical fiber (120) in order to vary a length of the optical fiber (120). The variation in the length of the optical fiber (120) caused by the moveable element (106) is indicative of an acceleration in the direction of desired sensitivity (128).

Abstract: Processing strain measurement signals from a first measured signal representing a first received backscattered optical signal for a first sensor—the first measured signal associated with a first phase signal—and a second measured signal representing a second received backscattered optical signal for a second sensor. The second measured signal is associated with a second phase signal constituting a consolidation of the first phase signal and an additional phase signal—where the additional phase signal is unrecoverable from the first measured signal. The first phase signal is determined from the first measured signal and processed. The second phase signal is determined from the second measured signal, where the first phase signal and additional phase signal are indistinguishable in the phase domain. The second phase signal is processed to obtain the additional phase signal and a strain measurement signal is constructed using the processed first phase signal and additional phase signal.

Abstract: An optical sensor apparatus (102) comprises a length of optical fibre (302) capable of supporting forward direction propagation and reverse direction propagation. The length of optical fibre is interrupted by a plurality of longitudinally spaced shunt devices (220, 306, 308) disposed along the length of optical fibre (302). A plurality of return optical fibres (222, 318, 324) are respectively coupled to the plurality of shunt devices (220, 306, 308) and each of the shunt devices (220, 306, 308) is propagation direction selective.

Abstract: Processing strain measurement signals from a first measured signal representing a first received backscattered optical signal for a first sensor—the first measured signal associated with a first phase signal—and a second measured signal representing a second received backscattered optical signal for a second sensor. The second measured signal is associated with a second phase signal constituting a consolidation of the first phase signal and an additional phase signal—where the additional phase signal is unrecoverable from the first measured signal. The first phase signal is determined from the first measured signal and processed. The second phase signal is determined from the second measured signal, where the first phase signal and additional phase signal are indistinguishable in the phase domain. The second phase signal is processed to obtain the additional phase signal and a strain measurement signal is constructed using the processed first phase signal and additional phase signal.

Abstract: An accelerometer device (100) comprises a former (118) and an optical fiber (120) wound around the former. The winding of optical fiber (120) has a sensing portion (126) that is free to move in relation to a direction of desired sensitivity (128). A movable element (106) is disposed opposite the sensing portion (126) of the optical fiber (120), the movable element (106) being translatable so as to urge against the sensing portion (126) of the optical fiber (120) from a position external to the winding of the optical fiber (120) in order to vary a length of the optical fiber (120). The variation in the length of the optical fiber (120) caused by the moveable element (106) is indicative of an acceleration in the direction of desired sensitivity (128).

Abstract: Apparatus and method for communication are provided. The apparatus means for communicating with a number of user equipment using Orthogonal Frequency-Division Multiple Access connections on given data regions; means for selecting one or more data regions for each connection; and means for selecting the transmission power to be used on each connection, wherein the selection of data regions and powers is performed by minimising the total transmission power used on all connections while fulfilling the performance criteria of each connection.