RU79732U1 - UNITED FIBER OPTICAL NETWORK - Google Patents

Abstract

The integrated fiber optic network includes optical taps 2 × 2, 2M trunk fiber lines and M local fiber optic networks (LAN), each containing N terminals. optical couplers (2 × 2) combining the LVOS are connected to the coupler block cascadewise according to the “star” topology with loops and with a central symmetric optical coupler (2 × 2) of the first cascade. The findings of the first stage are connected to the first outputs of the optical couplers (2 × 2) of the second stage, the inputs of the couplers (2 × 2) of the second and subsequent stages are connected to the first outputs of the couplers (2 × 2) of the third and subsequent stages, respectively. The second outputs of the taps (2 × 2) of the second and taps (2 × 2) of the subsequent stages are paired in a loop. The inputs of the couplers (2 × 2) of the last stage through the corresponding 2M trunk fiber lines are connected to the second outputs of the optical couplers (N-1) of the first and second branches of the loop of the corresponding LAN. 1 cp, 2 ill.

Description

The inventive utility model relates to fiber-optic transmission systems, in particular, to fiber-optic networks with time division of signals and can be used to organize serial multiplex communication channels.

Known local fiber-optic network (see V.P. Klimov. - Designing airborne multiplexed channels of information exchange. - M .: publishing house of the Moscow Aviation Institute, 1993, p. 161, 162). Containing N terminals with an optical receiver each with a transmitter and a data bus in the form of a light guide loop, the first and second branches of which are connected by the first input and output ports along (N-1) directional optical couplers, the first terminal is connected to the bus through the beginning and end of the light guide loop, and the second and subsequent terminals are connected to the bus, respectively through the second input ports of the first and subsequent, in the order of their placement along the bus, of the couplers in the first and second branches of the loop, with all terminal transmitters connected to the first branch of the loop, and all receivers to the second branch of the loop. All taps have equal branch coefficients to the bus.

A disadvantage of the known local fiber-optic network is its lack of input and output ports, allowing to build up (cascade) local networks into an integrated network. In addition, in the known network there is a large difference in the powers of the optical signals supplied to the terminal receivers from the transmitters located at the beginning and end of the bus, due to the different level of optical power losses when the signal passes along the bus on taps with equal branch coefficients. Also, due to branch losses, receivers located at the beginning and end of the bus are in significantly different reception conditions at the minimum input power level. It is fundamentally impossible to exclude or reduce these losses, since they ensure the passive bus performance. In addition, this solution is very limited in the possible number of terminals connected to the chain due to the proportional number of terminals to the increase in signal attenuation in the optical couplers.

The united network is known (see patent RU No. 2159509, IPC Н04В 10/12, published November 20, 2000) obtained by cascading local

fiber optic networks with star topology. Connections between local networks are made by trunk fiber optic lines.

A disadvantage of the known network is the lack of a fully connected network when there is no direct connection between any two of its local networks. The consequence of this is the low reliability of the network, since a communication failure of any of the trunk lines leads to disruption of the network as a whole. The power of the optical signal in the case of data exchange between the terminals of different local networks drops N times (where N is the number of terminals in the local network) on each "haul" from one local network to another. The latter limits the number of local area networks to be connected with passive connections between them.

Known fiber optic network (see US patent No. 5404241, IPC Н04В 9/00, published 04/04/1995), including M local fiber optic networks connected to each other by input and output ports, communications are made by the main fiber optic lines. Local networks are made according to the star topology with an N × N optical splitter consisting of (1 × 2) and (2 × 2) optical couplers, connected in such a way that each input is optically connected to each output. The outputs of the N terminals are connected to the corresponding N inputs of the optical splitter, and the inputs of the N terminals are connected to the corresponding N outputs of the optical splitter. Optical amplifiers are included in the trunk lines.

A disadvantage of the known fiber optic network is the complexity of optical splitters due to the large number of couplers (1 × 2) and (2 × 2) required to ensure full connectivity (optical connection of each input to each output), which leads to a high cost and dimensions of the optical splitter and low network reliability. For example, for N = 3 optical splitters, 6 1 × 2 taps are required, for N = 5, 15 (1 × 2) and (2 × 2) taps are required, and for N = 8, 40 (1 × 2) and (2 taps) are required × 2).

Known integrated fiber optic network (see patent RU No. 22569635, IPC Н04В 10/12, published 2003), which coincides with the claimed technical solution for the largest number of essential features and adopted as a prototype. The integrated fiber-optic network prototype includes M local fiber-optic networks connected by input and output ports, communications are made by the main fiber-optic lines. Each local area network contains N terminals, each

with an optical receiver and transmitter, and a data bus in the form of a light guide loop, the first and second branches of which are connected by the first input and output ports along (N-1) directional optical couplers, the first terminal is connected to the bus through the beginning and end of the light guide loop, and the second and subsequent terminals, respectively, through the second input ports of the first and subsequent in the order of their placement along the bus couplers in the first and second branches of the loop, with all transmitter terminals connected to the first branch of the loop, and all receivers They are connected with the second branch of the loop, as well as at least one pair of fiber-optic lines, in which the directional optical couplers are connected by the first input and output ports, the lines of the first pair contain (N-2) couplers, and the lines of each subsequent pair contain one less coupler than the lines of the previous pair, the first line of the first pair is connected with the first branch of the light guide loop, and the second line with the second branch of the loop, the first and second lines of each subsequent pair are connected respectively with the first and second line of the previous pair, while the beginnings of the first and second lines of the first pair are connected to the second output ports of the first couplers, respectively, in the first and second branches of the loop, and the first and subsequent couplers are connected in the order of their arrangement in the lines by the second input ports to the second output ports of the second and subsequent couplers in the first and second branches loops, respectively, of the beginning of the first and second lines of each subsequent pair are connected to the second output ports of the first couplers, respectively, in the first and second lines of the previous pair, and the first and subsequent couplers in the lines are connected in the order of their arrangement in the lines by the second input ports to the second output ports of the second and subsequent couplers, respectively, in the first and second lines of the previous pair, the ends of the first lines are the output ports of the network, and the ends of the second lines are its input ports. Local networks are interconnected so that each local network is connected to each other of (M-1) local networks, while it is connected to one local network by at least one input and one output ports, and its R output ports are connected to its R input ports, where R = 0, 1, 2, ... In each line and branches of the LAN loop, the couplers from the first to the last are made with decreasing transmission coefficients from the first input to the second output ports and from the second input to the first output ports .

The well-known integrated fiber-optic network prototype is characterized by low reliability and high cost due to the large number of spatially spaced optical couplers, which requires a correspondingly large number of optical connectors, which further reduces reliability, increases the attenuation of the optical signal, the cost and complexity of installation and operation.

The objective of the proposed technical solution was the creation of such a combined fiber-optic network, which would have increased reliability, low cost and provide full connectivity in a combined network, in which each terminal has optical communication with any terminal of any local network, while significantly reducing the required number of optical couplers and optical connectors.

The problem is solved in that the combined fiber optic network includes 2M trunk fiber optic lines, optical couplers (2 × 2), and M local fiber optic networks (LAN), each containing N terminals, each with an optical receiver and transmitter, and a data bus in the form of a light guide loop, the first and second branches of which are connected by the first input and output ports via (N-1) optical couplers (2 × 2), the first terminal is connected to the bus through the beginning and end of the light guide loop, and the second and subsequent ter the minals, respectively, through the second input ports of the first and subsequent in the order of their placement along the bus couplers (2 × 2) in the first and second branches of the loop, with all terminal transmitters connected to the first branch of the loop, and all receivers connected to the second branch of the loop. Moreover, in contrast to the prototype, in the inventive network optical couplers (2 × 2) are connected to the coupler unit cascadewise according to the “star” topology with loops, the outputs of the central symmetrical optical coupler - the first stage connected to the first outputs of the optical couplers of the second stage, the inputs of the couplers of the second and subsequent stages connected to the first outputs of the third and subsequent cascades, the second outputs of the second and subsequent cascades are paired in a loop, and the inputs of the last cascade through the corresponding 2M trunk fiber optic lines are connected to the second outputs (N-1) of the optical couplers of the first and second branches of the loop of the corresponding local fiber-optic networks.

The taps in the tapping block can be made with decreasing coefficients of the branching of the optical signal into the loop in a harmonic sequence.

Spatially spaced couplers connected in a “star” with loops allow combining them into one unit using welded joints of optical fibers, which further reduces the number of optical connectors, increases network reliability, reduces the cost and attenuation of the optical signal, and simplifies network installation and maintenance . For example, to build an integrated network of eight local networks with 4 terminals in the prototype, 160 taps will be required, and in the proposed solution, only 57 taps. The number of optical connectors is reduced by 3-4 times.

The inventive utility model is illustrated by drawings, where:

figure 1 shows the integrated fiber optic network in which the block of optical couplers is cascaded through the topology of the "star" with loops for combining eight local networks into a combined network;

figure 2 shows the LAN with one input and one output ports.

The United Fiber Optic Network (EIA) (see Fig. 1) includes M LVOS (M = 8 is shown in the drawing), 1 ₁ , 1 ₂ , 1 ₃ , ... 1 ₈ , ... 2 M trunk fiber lines (2M = 16 is shown in the drawing) 2 ₁ , 2 ₂ , 2 ₃ , ... 2 ₈ and 3 ₁ , 3 ₂ , 3 ₃ , ... 3 ₈ and the optical coupler unit 4 containing optical couplers (2 × 2) 5 _k , which are connected in k cascades according to the “star” topology with 6 _k-1 loops (3 cascades are shown in the drawing). Wherein . For example, for k = 3, a maximum of 8 LANs can be connected to the EIA, for k = 4, a maximum of 16, etc. The outputs of the central symmetric optical coupler 5 _{1 of the} first stage are connected to the first outputs of the optical couplers 5 _{2 of the} second stage, the inputs of the couplers of the second and subsequent stages are connected to the first outputs of the optical couplers 5 _{3 of the} third stage and couplers (2 × 2) of the subsequent stages, and the second optical coupler outputs 5 ₂ ; of the second cascade, optical taps 5 _{3 of the} third cascades and taps (2 × 2) of the subsequent cascades are pairwise connected by loops 6 ₁ and 6 ₂ , respectively, and the inputs of the taps of the latter (in Fig. 1 of the third cascade 5 ₃ ) through the corresponding 2M trunk fiber lines 2 ₁ -2 _m and 3 ₁ -3 _m (in this example 2 ₁ -2 ₈ and 3 ₁ -3 ₈ ) are connected to the second outputs of the optical couplers 7 _N-1 and 8 _N-1 (where N is the number of terminals) of the branch 9 _i and branches 10 _{i of the} loop of the corresponding LVOS 1 _i (where i = 1, 2, 3, ... M). In this case, the transmitters 11 _j (where j = 1, 2, 3, ... N) of all terminals 12 _{j of} any LAN 1 _i (see Fig. 2) have optical communication with the receivers 13 _{j of} all

12 _j terminals inside LAN 1i through optical couplers 7 _j-1 , 8 _j-1 and a loop 14 _i as well as with receivers of any of the terminals of other LAN through a 5 _k couplers and 6 _k-1 loops _of an optical coupler block 4 and 7 _j- couplers ₁ , 8 _j-1 other local area networks 1 _i . Thus, the full connectivity of all terminals with each other is ensured. This allows you to use the proposed solution to transmit information according to the well-known data exchange protocol, for example, according to GOST 26765.52-87 (not considered in the application). Moreover, the function of the central controller (redundant central controllers) of the integrated network can be performed by any of the terminals of any local network.

To minimize and equalize the attenuation of the optical signal in the couplers in optical links between any terminals, couplers with different branch coefficients are used.

In local networks, the branch coefficients of the junction branches 7 _j-1 and 8 _j-1 to the terminals, as in the prototype, are 1 / (j + 1).

In the block of optical taps, the coefficients of branching into the loop are constant within the cascade and decrease with increasing cascade number k and are equal to 1 / (k + 1).

The integrated fiber optic network (see figure 1) operates as follows. Optical radiation from the transmitter of one of the terminals, for example, 12 _1k LAN, for example, 1 _{1 is} fed to the input of receivers 13 _{j of} all terminals 12 _{j of} this local network through couplers 7 _j-1 , loop 14 and couplers 8 _j-1 , and also through 5 _k taps 6 _k-1 loops, 2 ₁ -2 ₄ , 3 ₁ -3 ₄ trunk lines and 7 _j-1 taps _of local networks 1 ₂ -1 ₈ at the input of receivers 11 _{j of} all terminals 12 _{j of} these LANs. Similarly, the optical emissions of the response signals of the transmitter of any of the terminals of the integrated fiber optic network pass. Similarly, optical emissions are transmitted between any pair of terminals according to transmission protocols with time diversity, for example, according to GOST 26765.52-87.

Claims (2)

1. The integrated fiber optic network, including optical taps 2 × 2, 2M trunk fiber optic lines and M local fiber optic networks (LAN), each contains N terminals, each with an optical receiver and transmitter, and a data bus in the form fiber guide loop, the first and second branches of which are connected by the first input and output ports via (N-1) optical couplers, the first terminal is connected to the bus through the beginning and end of the fiber guide, and the second and subsequent terminals, respectively, through the second input dnye first and subsequent ports in the order of their placement along the bus couplers in the first and second branches of the loop, and all the terminals connected to the first transmitter branch loop, while all receivers are connected to the second branch of the loop, characterized in that

optical couplers (2 × 2) combining the LVOS are connected to the coupler block cascadewise according to the “star” topology with loops and with a central symmetric optical coupler (2 × 2) of the first cascade, the terminals of which are connected to the first outputs of the optical couplers (2 × 2) of the second stage, the inputs of the couplers (2 × 2) of the second and subsequent stages are connected to the first outputs of the couplers (2 × 2) of the third and subsequent stages, respectively, and the second outputs of the couplers (2 × 2) of the second and couplers (2 × 2) of the subsequent stages in pairs combined in helmet uf, and the coupler inputs (2 × 2) of the last stage through the corresponding 2M trunk fiber lines are connected to the second outputs of the optical couplers (N-1) of the first and second branches of the loop of the corresponding LAN. 2. The integrated fiber optic network according to claim 1, characterized in that the taps (2 × 2) in the taps block are made with decreasing coefficients of the branch of the optical signal into the loop in a harmonic sequence.