Abstract: A video surveillance system wherein a monitoring station collects video data obtained by a monitoring camera is disclosed. The system includes a multihop wireless network formed of a plurality of wireless nodes including a first wireless node having the monitoring camera, and a second wireless node having a gateway connected to the monitoring station. The system also includes a priority control device configured to control the wireless network so that transmission in a link between the first wireless node and the second wireless node is performed at a priority level contained in a priority information message. The transmission including transmitting a video data request from the monitoring station to the monitoring camera, or transmitting video data from the monitoring camera to the monitoring station.

Abstract: A protection path reservation method which reserves protection paths to avoid a node failure for each transmission path on a network formed of a plurality of nodes, comprising assuming the nodes as an imaginary failure node in turn in a condition in which the node failure is not present in the network, and selecting N neighbor nodes connected to the imaginary failure node through N links, wherein the imaginary failure nodes sequentially transmit protection path reservation request messages to neighbor nodes, and the nodes which have received the protection path reservation request messages sequentially, one by one, reserve N?1 protection paths starting from the nodes.

Abstract: A video surveillance system wherein a monitoring station collects video data obtained by a monitoring camera is disclosed. The system includes a multihop wireless network formed of a plurality of wireless nodes including a first wireless node having the monitoring camera, and a second wireless node having a gateway connected to the monitoring station. The system also includes a priority control device configured to control the wireless network so that transmission in a link between the first wireless node and the second wireless node is performed at a priority level contained in a priority information message. The transmission including transmitting a video data request from the monitoring station to the monitoring camera, or transmitting video data from the monitoring camera to the monitoring station.

Abstract: A protection path reservation method which reserves protection paths to avoid a node failure for each transmission path on a network formed of a plurality of nodes, comprising assuming the nodes as an imaginary failure node in turn in a condition in which the node failure is not present in the network, and selecting N neighbor nodes connected to the imaginary failure node through N links, wherein the imaginary failure nodes sequentially transmit protection path reservation request messages to neighbor nodes, and the nodes which have received the protection path reservation request messages sequentially, one by one, reserve N-1 protection paths starting from the nodes.

Abstract: A transmission system which performs protections to node failures by using protection paths equipped by a shared node protection system for each transmission path on a network formed of a plurality of nodes, uniformly moving transmission band setting of all other protection paths which share these transmission bands when the transmission bands on the network are occupied by the protections.

Abstract: Optical signals inputted to input ports are split in half by 1×2 optical splitters respectively and the resulting signals are inputted to the input terminals of an optical matrix switch. The optical matrix switch switches between the routes of the individual optical signals and outputs the signal at any of the output ports. This enables the optical signal from the same input port to be outputted at two different output ports, which makes it possible to effect “bridge” at the time of protection switching.

Abstract: A matrix switch comprises a matrix switch main body (2), a preprocessing block (1) provided on an input side of the matrix switch main body (2), and a postprocessing block (3) provided on an output side of the matrix switch main body (2), wherein each of the preprocessing block (1), the matrix switch main body (2) and the postprocessing block (3) comprises a circuit, which parallel-converts a line input with each setting bit width, performs a bit stream operation in the setting bit width, serially converts it, and performs line output, respectively, and the matrix switch main body (2) is divided into the setting bit width parallel-converted with the preprocessing block (1) and switching-control is performed.

Abstract: Optical signals inputted to input ports are split in half by 1×2 optical splitters respectively and the resulting signals are inputted to the input terminals of an optical matrix switch. The optical matrix switch switches between the routes of the individual optical signals and outputs the signal at any of the output ports. This enables the optical signal from the same input port to be outputted at two different output ports, which makes it possible to effect “bridge” at the time of protection switching.