A system for compensating for a latency difference in a fronthaul in ring topology is provided, including a centralization node linked to a BBU group, a plurality of distribution nodes linked to a plurality of RRH groups, an optical bi-directional ring network connecting the central node and the distribution nodes and allows a WDM optical signal to be transmitted and received between the central node and the distribution nodes, and a FIFO buffer that stores an electrical signal. Each of the distribution nodes demultiplexes the WDM optical signal, converts each demultiplexed optical signal into an electrical signal, stores the electrical signal in the FIFO buffer, converts the electrical signal stored in the FIFO buffer into an optical signal, and adjusts a size of the FIFO buffer, thus compensating for a difference between latencies before and after an occurrence of a switchover in the optical bi-directional ring network.

An optical communication system includes: a first network-side device and a second network-side device each coupled to a communication network; and a first terminal-side device and a second terminal-side device configured to communicate with the first network-side device and the second network-side device by being coupled to the first network-side device and the second network-side device via a first communication cable and a second communication cable, respectively, wherein the first network-side device is coupled to the first terminal-side device via the communication network, the second network-side device, and a third communication cable for coupling the second network-side device and the first terminal-side device so as to communicate between the first network-side device and the first terminal-side device.

There is described a reconfigurable array for facilitating dynamic combination and distribution of RF signals. The reconfigurable array comprises: (a) a number, N.sub.i, of input devices for generating or supplying RF input signals; (b) a number, N.sub.o, of output devices for analysing or forwarding RF output signals; (c) an optical switch matrix comprising a number, N.sub.p, of ports, wherein each of the ports is an optical input or an optical output, wherein each input device is coupled to a respective port of the optical switch matrix at an optical input, wherein each output device is coupled to a respective port of the optical switch matrix at an optical output, and wherein the optical switch matrix is configurable to enable optical connection of any optical input to any optical output; and (d) a plurality of multi-port devices that each have multiple uncommon ports which couple to a single common port, wherein each port of each multi-port device is coupled to a respective port of the optical switch matrix, and wherein each multi-port device enables either fan-in of optical signals from the uncommon ports to the common port or fan-out of optical signals from the common port to the uncommon ports depending on the configuration of the reconfigurable array. The plurality of multi-port devices include at least one M:1 multi-port device, where M is a predetermined maximum number of RF signals for the reconfigurable array to fan-in or fan-out, where MN.sub.i and MN.sub.o.

A satellite system may have a constellation of communications satellites that provides services to users with electronic devices such as portable electronic devices and home/office equipment. The satellites may support communications between the electronic devices of the users and gateways. Each gateway may have satellite transceiver circuitry that transmits and receives satellite signals. Each gateway may also have an optical add-drop multiplexer coupled to a fiber ring and radio-frequency-over-fiber circuitry coupled between the satellite transceiver circuitry and the optical add-drop multiplexer. A metropolitan point-of-presence may be in communication with the fiber ring and may have modems for centrally processing communications (received and transmitted in an intermediate frequency) in the satellite system.

A method implemented by a node in a network utilizing Multiprotocol Label Switching (MPLS) includes performing a convergence procedure to discover the topology of a network in which multiple nodes are arranged; and upon determining that the topology of the network is a ring topology whereby the node is connected to two neighboring nodes by a respective link, creating a first table for a first link, the first table including labels representing at least a portion of a label stack for allowing the node to transmit packets to another node in the network in a clockwise (CW) direction around the ring; and creating a second table for a second link, the second table including labels representing at least a portion of a label stack for allowing the node to transmit packets to another node in the network in an anti-clockwise (ACW) direction around the ring.

An integrated source generation, transmission, and distribution system based on a photonic loop includes a central station unit and subscriber station units. The central station unit and the subscriber station units are connected to form the photonic loop. The central station unit transmits carrier radio frequency signals respectively into the photonic loop in a clockwise direction and a counterclockwise direction of the photonic loop, and receives the optical carrier radio frequency signals respectively transmitted in the clockwise direction and the counterclockwise direction to form a closed loop after an optical processing and an electrical processing. The central station unit stabilizes transmission delays of the photonic loop in combination with an external reference signal, and locks a frequency or a phase of microwave signals. The subscriber station units receive and process the optical carrier radio frequency signals to obtain first microwave frequency signals.