Abstract: In a mesh connected communications network, nested link protection for a working link between two nodes across the network is provided. In the event of a fault on the working link between the two nodes, traffic on the link may be switched to a single parallel link between the two nodes, thereby restoring traffic on the link. Additionally, a link protection path extending between the two nodes is provisioned by way of at least one intermediate node. In the event the parallel protection link is not available, traffic carried on the working link may be switched to the link protection path, restoring traffic to the second node by way of the intermediate node. Conveniently, link protection path switching may be used in the event the parallel protection link is not available or at the choice of an operator.

Abstract: A detector tube is supplied with air at an adjustable pressure balanced by at least two adjustable leak flow rates in the conduits 4 and 7 in order to adjust the position of ball in the tube. The possible manual inclination of tube between an extreme vertical position and position slightly inclined to the horizontal is a complementary means of adjustment. The detector tube can be used for the detection and measurement of micropressures and micro flow rates.

Abstract: A micro air-wave detection device particularly for breathing monitoring and surveillance, which comprises a tube (2) having a ball (5) disposed therein with minimum clearance. The tube (2) is disposed in a horizontal or slightly inclined position and is connected to a conduit (38) which picks up the pressure variation of a nasal respirator (53). Detection of the to-and-fro movement of the ball at the level of an independent detection unit (10) containing the tube is transmitted by optical fibers (45) to an electronic control and alarm module (22).