RU2548162C2 - Highly reliable optical ring network - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: large distributed facilities use highly reliable optical networks which are self-healing data transmission ring networks based on single-fibre optical infrastructure, which provides fail-proof user communication in case of non-recurrent breakdowns of optical lines using the wave multiplexing principle, wherein the maximum speed in fibre-optic lines of such networks can reach up to 160 Gbps.

EFFECT: high efficiency and reliability of communication in optical networks for accessing broadband multimedia services of information-telecommunication networks when switching to next generation packet networks, in highly reliable local area data networks with a wide coverage area used in transport infrastructure.

1 dwg

Description

The present invention relates to telecommunication technologies.

The application of this invention in telecommunication networks will allow for the implementation of effective system-network solutions in networks for access to broadband multimedia services, in long-distance local networks, as well as in backbone and other networks, when switching to next-generation broadband packet networks NGN-IMS (Next Generation Network - Internet Multimedia Subsystem - the next generation network - Internet multimedia subsystem).

The application of the present invention will allow to build on its basis highly reliable duplicated self-healing ring packet networks with high efficiency of using optical fiber, using the principle of wave compression, based on typical switches of information packets.

With the help of the present invention, networks of the type "drawn to a point backbone on a switch" with a large (up to 40-60 km) length of lines can be built. Such networks should have a single-fiber ring topology, and one-time fiber breaks should not lead to loss of communication of the subscribers included in them.

This advantage is achieved through the use in the proposed bidirectional ring optical network of duplication of transmission directions along wavelengths, rather than spatial duplication of fibers, as in traditional networks.

This can be achieved by using one group of wavelengths for transmitting information flows in one direction and another group of wavelengths for transmitting in the opposite direction. This advantage opens up the possibility of using only one fiber as the physical propagation medium in the proposed duplicated network, with the provision of automatic recovery when one-time fiber breaks occur.

As a prototype, a packet computer network was selected that uses the structural principle of “a backbone to a switch on a switch” network described in the book: V.G. Olifer, N.A. Olifer. Computer networks. Principles, technologies, protocols: textbook for universities. 2nd ed. - SPb .: Peter, 2005 - 864 p.: Ill., On p. 467, Fig. 10.15.

A prototype is a computer network built on switches of information packets according to the principle “pulled to a point, or collapsed, backbone” - this is a structure in which the union of nodes, segments or networks occurs on the internal backbone of the switch. The advantage of this structure is the high performance of the trunk.

The obvious disadvantage of the prototype is the need to use a large amount of cable systems connecting the central switch (building switch in Figure 10.15 of this book) with peripheral switches (floor switches in Figure 10.15). In addition, with cable breaks shown in Figure 10.15 of the book, the connection of subscribers included in the corresponding floor switches is lost.

The objective of the invention is the creation of such a highly reliable optical network, which provides automatic recovery from broken lines, which has a significantly smaller volume of linear structures than in the prototype, as well as increased (up to 40-60 km) communication range with high efficiency of the use of optical fiber.

The technical result is to improve the operational and technological characteristics of the optical network.

To achieve this objective, it is proposed to supplement the optical network with optical transceivers (four for connecting each subscriber, with transmitters tuned to 2N wavelengths, where N is the number of subscribers included in the network), the first and second optical multiplexers for N wavelengths, and optical multiplexers input-output (two for each subscriber).

It is proposed that a highly reliable ring optical network be implemented as follows: introduce 4N optical transceivers, first and second optical multiplexers at N wavelengths, 2N optical input-output multiplexers, and the group of transceivers located on the central switch side is connected through bidirectional data transmission interfaces to the ports of this switch, and the optical interfaces of these transceivers are connected to the corresponding ports of the first and second optical multiplexers, combined e ports of which are connected via optical ring lines to the corresponding combined ports of optical input-output multiplexers, connected to each other by circular optical lines, and optical transceivers of subscriber switches are connected to the corresponding input-output ports of these multiplexers, which are connected to the corresponding bi-directional data transmission interfaces trunk ports of these switches, and subscriber devices are connected to the remaining ports of the switches.

Based on the proposed highly reliable ring optical network, high-performance long-range broadband access networks with a ring topology with the function of automatic recovery with single line breaks, highly reliable local networks of large enterprises located in vast territories, networks of transport infrastructures, large sea vessels and other objects can be implemented.

Figure 1 shows one example of the construction of a highly reliable ring optical network, where:

1 - packet switch central;

2 ₁₁₁ -2 _N22 - optical transceivers;

3 ₁ , 3 ₂ - the first and second optical multiplexers;

4 - optical input-output multiplexers;

5 - peripheral packet switches;

6 - terminal devices.

The packet central switch 1 is intended for switching packets of information transmitted on the network and between the given network and other networks, for ensuring the operation of interfaces with optical transceivers, for maintaining the functioning of protocols that provide transition to the paths of the redundant port ports in case of failure of the main port port paths.

Optical transceivers 2 are intended for converting an electric linear signal into an optical signal, inputting optical power into optical fiber optical fibers of optical lines, converting an optical signal coming from the lines into an electric linear signal, diagnosing emergency conditions of a laser transmitter and optical receiving power levels.

The first and second optical multiplexers 3 ₁ , 3 ₂ are intended for combining component wave signals coming from optical transmitters through ports of the corresponding wavelengths into an aggregate multi-wave signal, and also for separating aggregate signals coming from ring lines into component signals of the corresponding wavelengths, fed to the inputs of the respective optical receivers.

Optical input-output multiplexers 4 ₁₁ -4 _N2 are intended for extracting signals from the ring optical line of the corresponding wavelengths of the main and reserve directions (paths) of transmission and transmission of signals of other wavelengths in transit, as well as for inputting the corresponding wavelength signals into the line.

Peripheral packet 5 switches are designed to carry out information packet switching at the subscriber group level, to communicate with the central switch, to ensure the operation of interfaces with optical transceivers, to maintain the functioning of protocols that provide transition to the backup port paths in case of main port port path failures.

Terminal devices 6 are intended for input-output of information of users (subscribers), as well as for maintaining the functioning of the stack of network protocols and network user interfaces.

The main advantages of the proposed highly reliable ring optical network are as follows.

1. An important advantage of the proposed network is the possibility of using an economical ring single-fiber topology, which requires small amounts of linear structures.

2. The proposed network allows to provide a large length (up to 40-60 km) of ring optical lines, which opens up the possibility of its use for covering large areas.

3. The proposed network, when using a single-fiber ring topological structure, provides automatic recovery of performance with single line breaks, ie single breaks do not lead to the loss of communication of network subscribers.

4. The proposed network ensures the efficient use of optical fiber through the application of the principle of wave compaction. The total transmission speed in the ring line can reach values of about 100 Gbit / s.

5. A significant advantage of the proposed network is the possibility of exclusive use by subscribers of the entire bandwidth of the wave channels allocated to them (up to 10 Gb / s) and the symmetry of the bandwidth of transmission directions, which is an advantageous difference between the proposed network and many other networks that implement the temporary separation of the channel resource between subscribers (for example, wand ring, Cambridge ring, GPON passive network and others).

The proposed highly reliable ring optical network was implemented in FSUE TsNIIS (in the branch of LO TsNIIS) based on the following components.

As switches of packages 1 of the central and 5 peripheral, we used switches of packets of the L3 and L2 level, respectively, developed and released at the Central Research Institute for Scientific and Technical Information (experimental samples), and also in the process of experiments, packet switches manufactured by D-Link DES 3800 series were used for this purpose.

As transceivers 2 ₁₁₁ -2 _N22 optical, transceiver modules TRSF15d-80, installed directly in the switches, and also as a part of media converters of the MCFP2 type - 10/100/1000, were used.

As the first and second optical multiplexers, serial CWDM-multiplexers were used, developed and manufactured by Component, type CWDM-MUX 1 × 4 1550-1610 3.0 LC / UPC 1.5 m.

As optical optical input-output multiplexers, serial optical input-output multiplexers developed and manufactured by LLC Protelecom of the type CWDM OADM-2F-15-MOD 111-1313 (1314) (2 fiber 1 channel) were used.

As terminal devices, personal computers were used as standard, paired with a video camera via TV tuners Behold TV Voyage, USB, Retail (to demonstrate the network’s operability in video broadcast mode). The implemented network segment was used as a part of the experimental design of the CWDM-PON broadband access network segment, which was then built into the research stand of the Central Scientific Research Institute for Central Research, for the Central Research Institute of Communications, FSUE TsNIIS, at the St. Petersburg branch (LO TsNIIS). research and demonstration of elements of the hardware-software complex of emergency warning and public information (PAK KSEOIN), where it is currently functioning properly as part of an experimental segment and CWDM-PON with a total length of ring lines of 40 km (4 fiber drums of 10 km each).

Claims (1)

A highly reliable ring optical network, including a central packet switch, peripheral packet switches and terminal devices, characterized in that it contains optical transceivers, four for each terminal device, while the transmitting parts of the transceivers are tuned to 2N wavelengths, where N is the number of terminal devices included in the network, and also contains the first and second optical multiplexers for N wavelengths and optical input / output multiplexers, two for each terminal device moreover, the ports of maximum speed of the central packet switch are connected with the higher hierarchy of the network, and the ports of lower speed of this switch are connected to the electrical bidirectional interfaces of the optical transceivers located on the side of the central switch, and the optical interfaces of these transceivers are connected to the corresponding ports of the first and second optical multiplexers the combined ports of which are connected by means of circular optical lines with the corresponding combined pores optical input / output multiplexers connected to each other by circular optical lines, input / output multiplexer output ports are connected to receiving ports, and input multiplexer input ports are to transmitting optical transceiver ports located on the terminal side, bidirectional data transmission interfaces of these transceivers are connected to the ports of the maximum speed of the peripheral switches, and the ports of lower speed of these switches are connected to the network interfaces of the terminal devices ystv.