摘要:
A communications station (4-i) for a WDM ring network is adapted to insert into an optical fiber (2) packets of optical signals carried by at least one wavelength and having a propagation direction in common with at least one other communications station. The station (4-i) comprises, firstly, optical detection means (17) adapted to observe the traffic in said optical fiber (2) associated with said common wavelength and to deliver detection signals representative of the absence of packets in the optical fiber (2) at the detected wavelength for a duration exceeding a duration threshold and ii) control means (11) adapted, in the event of reception of a detection signal associated with the detected wavelength to determine the remaining time before the end of the current session, and then to instruct the insertion into the optical fiber (2) of a packet awaiting transmission, at the detected wavelength, if the remaining time before the end of the current session is greater than the time necessary for inserting the packet awaiting transmission into the fiber.
摘要:
A communications station (4-i) for a WDM ring network is adapted to insert into an optical fiber (2) packets of optical signals carried by at least one wavelength and having a propagation direction in common with at least one other communications station. The station (4-i) comprises, firstly, optical detection means (17) adapted to observe the traffic in said optical fiber (2) associated with said common wavelength and to deliver detection signals representative of the absence of packets in the optical fiber (2) at the detected wavelength for a duration exceeding a duration threshold and ii) control means (11) adapted, in the event of reception of a detection signal associated with the detected wavelength to determine the remaining time before the end of the current session, and then to instruct the insertion into the optical fiber (2) of a packet awaiting transmission, at the detected wavelength, if the remaining time before the end of the current session is greater than the time necessary for inserting the packet awaiting transmission into the fiber.
摘要:
A router includes a first processing module (1) adapted to route primary resources as a function of instructions received, inputs (2) adapted to feed the first processing module (1) with primary resources, outputs (3) adapted to collect primary resources switched by said first processing module (1), a second processing module (6) adapted to process secondary resources to be added or dropped, and coupling means (9) including a drop bus (8) and/or an add bus (7) and adapted, on the instructions of the control means (15), to drop either the whole of a primary resource arriving at one of said inputs (2) and/or outputs (3) or a portion thereof to feed said second processing module (6), and/or to add a secondary resource processed by said second processing module to a primary resource received at one of said inputs (2) and/or outputs (3) and in transit to a common destination.
摘要:
A router includes a first processing module (1) adapted to route primary resources as a function of instructions received, inputs (2) adapted to feed the first processing module (1) with primary resources, outputs (3) adapted to collect primary resources switched by said first processing module (1), a second processing module (6) adapted to process secondary resources to be added or dropped, and coupling means (9) including a drop bus (8) and/or an add bus (7) and adapted, on the instructions of the control means (15), to drop either the whole of a primary resource arriving at one of said inputs (2) and/or outputs (3) or a portion thereof to feed said second processing module (6), and/or to add a secondary resource processed by said second processing module to a primary resource received at one of said inputs (2) and/or outputs (3) and in transit to a common destination.
摘要:
A method is dedicated to transmitting data between nodes (Ni) of a group of nodes coupled to an access bus (L2-LSP) of a communications network (R1). The method consists in: i) each time an entry node (N2) of said group receives data addressed to at least one other node of said group, determining the number M of nodes (Ni) of that group through which the data must pass to reach its destination, including said destination node (N4), and that together define a transmission path starting from said entry node (N2), and then assigning to a dedicated field associated with said data a value representative of the number M before transmitting said data, via said access bus, to a first node (N3) of said path, and ii) at each node (Ni) of said path, decrementing by unity the number associated with the data received to obtain a new value of the field and, in the event of a new value equal to a selected comparison value, dropping said data from said path, and, in the event of a new value different from said selected comparison value, replacing the value of the dedicated field associated with the received data by said new value and then transmitting said data and said new value of the associated dedicated field to the next node of said path.
摘要:
Dynamic method of adding data at the nodes of a fiber optic transmission network comprising at least one source node, one destination node and a plurality of intermediate nodes, the nodes being connected by a fiber optic connection. The method comprises the steps of creating at the source node an optical resource comprising portions containing data packets addressed to said destination node and free portions that may be occupied by packets supplied by each of said intermediate nodes, when said resource transits an intermediate node, detecting if said resource comprises free portions if said intermediate node has at least one data packet to transmit, and adding said data packet to a free portion of the frame if said free portion may contain said data packet.
摘要:
The network comprises an optical interconnection tree linking sending points of stations to a receiving point of a concentrator via access links (F1-F3), a coupling system (C) and a common optical link (OL). The stations can send optical signals (λu1, λu2, λu3) each carried by the same “uplink” wavelength (λu). Each station includes a carrier detection system able to detect the presence at its sending point (Ki) of an optical wave at said uplink wavelength (λu) that was not sent by the same station. The detection system cooperates with sending control means to inactivate sending if such presence is detected. The network further includes: an emulator (LDa, Ca, G1-G3) adapted to send auxiliary waves (λa1, λa2, λa3) at said uplink wavelength (λu) and to couple them into the access links (F1-F3) so that they propagate in the downlink propagation direction; and a control system (2a) of the emulator for selectively activating the sending of the auxiliary waves. The invention is particularly applicable to optical access or metropolitan networks.
摘要:
A photonic switching device for switching without contention data in the form of optical packets includes a space switching matrix with a plurality of input ports and a plurality of output ports. A unit external to the space switching matrix includes a buffer memory common to all the output ports of the matrix. Each of the output ports provides access to the buffer memory via a space switching stage consisting of switches having a 1-to-2 switching function.
摘要:
A packet-switched communications network (PSN) includes a multiplicity of nodes (Ni) adapted to switch streams of packets benefiting from circuit emulation services, known as CES packets. The network uses a particular method of resynchronizing the CES streams. According to that method, for a CES stream intended to take an associated path (CE) from an ingress node (N1) passing through a set of nodes including a subset of nodes adapted to resynchronize CES streams selectively, effective resynchronization of said stream by a node selected from said subset is conditioned by a value representative of the cumulative jitter suffered by said stream as far as that node.
摘要:
The invention relates to an optical ring network comprising stations (340) which are connected to at least one optical fiber by means of optical couplers, the two ends of the optical fiber being connected to a point of presence or an optical network access node. The point of presence comprises (k) at least an optical emitter (330-1) which emits a falling optical signal having at lest one first wavelength (420) in the direction of one end of the optical fibers (455) and (ii) at least one optical receiver (330-2) which receives a rising optical signal having at least one second wavelength which is different form the first wavelength. The aforementioned optical network access node comprises means such as a hub (320) which can be used for the communication between the optical receiver (330-2) and the optical emitter (330-1). The wavelengths of the rising signals and the wavelengths of the falling signals are shared by several stations.