KR20090099689A - Multi-band awg module for wdm-pon - Google Patents

Abstract

PURPOSE: A multiband AWG module for a WDM-PON is provided to improve the performance of the WDM-PON by making connections of various equipments possible. CONSTITUTION: A WDM-PON device transmits data from an OLT(Optical Line Termination) within a central station to a remote node through one optical cable, and transmits data from the remote node to an optical network unit, that is, a subscriber device through individual wavelengths. A multiband AWG module for the WDM-PON comprises a band splitter(10), AWGs(20,25) and a band combiner(30). The band splitter separates a transmission wavelength transmitted from the OLT. The AWGs have a plurality of periodic transmission wavelengths which are suitable for each wavelength split by the band splitter.

Description

MULTI-BAND AWG MODULE FOR WDM-PON}

The present invention relates to a multi-band AWG module for WDM-PON, more specifically, it is possible to use the C-band and L-band at the same time without replacing expensive equipment, and also to reduce the production cost by manufacturing a single chip The present invention relates to a multi-band AWG module for WDM-PON.

In recent years, communication traffic has been concentrated on subscriber networks due to the rapid increase in the number of Internet users, the increase of speed, and the emergence of new communication businesses such as content delivery network and multimedia web hosting.

In the inter-station network, it is increasing to tera level by using technology such as WDM, which increases the capacity by transmitting optical signals of various wavelengths to one optical fiber at the same time. . On the other hand, xDSL and cable modem based subscriber networks have been limited in providing high quality image quality, various multimedia services provided in real time, and sufficient bandwidth and transmission distance for traffic concentrated in subscriber networks.

As various bandwidth demands occur according to the user layer, the current Mbps-class subscriber network is expanded to 10Mbps ~ 10Gbps per subscriber, and a subscriber network construction that can provide adequate bandwidth according to user's needs in a wide range is required. In order to solve the bottlenecks of subscriber networks and to support various quality of service, the technology of network composition and optical device for wavelength-division multiplexing (WDM) based optical subscriber access network is developed for high speed data transmission. have.

WDM technology is a method of transmitting optical signals with different wavelengths to a single optical fiber at the same time, and it is a transmission technique that can stably increase the transmission capacity while using minimal optical fibers. Accordingly, a WDM Passive Optical Network (WDM-PON) using WDM technology is currently under development in a limited optical fiber infrastructure.

Passive optical subscriber network is a structure in which one optical fiber is connected from a central office (CO) to a remote node (RN) and then connected to individual optical fibers from RN to each subscriber. There is an advantage in that it is possible to significantly reduce the optical cable installation than connecting, the WDM-PON is to assign a different wavelength to the subscriber can transmit a large amount of data and excellent security. In addition, it is easy to improve the performance by narrowing the channel interval or increasing the transmission speed for each channel according to the increase in the demand for more subscribers and services. To implement WDM-PON, a light source with a unique wavelength assigned to each subscriber, a stabilization circuit of oscillation wavelength, and a passive multiplexer / demultiplexer are required.

4 is a schematic configuration diagram of a typical WDM-PON, which transmits a single optical cable from an OLT (Optical Line Termination) (40) in a CO to a remote node (RN) 50, and is a subscriber device in the remote node 50. The optical network unit (ONU) is configured to transmit individual wavelengths. In this case, the downlink signal is transmitted through broadcasting or a specific wavelength, and the uplink uses a TDMA or WDMA scheme to prevent data collision between ONTs.

On the other hand, the ITU-T communication band recommends that wavelengths are specified at 100 GHz intervals, but WDM-PON uses wavelengths transmitted from the C-band in one existing AWG. In this case, C-band and L-band are used.

However, if the 100 GHz interval of the C-band in the AWG is correct, there is a problem that the L-band does not match the interval of 100 GHz. In addition, the bandwidth used by the manufacturer is different, and there is a problem in that it is difficult to integrate it.

The present invention is to solve the above problems, an object of the present invention is to provide a multi-band AWG module for WDM-PON that can simultaneously use the C-band and L-band at intervals of 100GHz or 200GHz ITU-T bandwidth To provide.

In addition, to provide a multi-band AWG module for WDM-PON to reduce the production cost by manufacturing a multi-band AWG that can use both C-band and L-band in a single chip.

The multi-band AWG module for WDM-PON according to the present invention transmits a single optical cable from an optical line termination (OLT), which is a device in a central base station (CO), to a remote node, and is an optical device that is a subscriber device at a remote node. In the WDM-PON apparatus transmitting up to the end unit (ONU) in individual wavelengths, a band splitter for separating the transmission wavelength transmitted from the OLT, and a plurality of periodics suitable for each transmission wavelength characteristic separated through the band splitter Waveguide array grating (AWG) having a transmission wavelength characteristic, and a band combiner (Combiner) for combining and outputting the output signal of the plurality of AWG.

On the other hand, in the case of a dual-band AWG module of the C-band and L-band as an embodiment of the present invention, the band splitter, the C & L-band splitter 10 for separating the transmission wavelength of the mixed C-band and L-band The plurality of AWGs are C-band AWGs 20 suitable for C-band characteristics in transmission wavelengths separated by the C & L-band splitter 10 and transmission wavelengths separated in the C & L-band splitter 10. L-band AWG (25) suitable for the L-band characteristics, the band combiner, C & L band comparator for combining and outputting the output signal of the C-band AWG 20 and L-band AWG (25) It is preferable that it is (30).

In another aspect, the present invention, in the band splitter, the transmission wavelength is separated into at least two or more of C-band, L-band, O-band, S-band, E-band, and in the plurality of AWG, It can be configured to include the characteristics of the separated transmission wavelength band and the AWG suitable for each.

At this time, the plurality of AWG is preferably formed on one chip (CHIP).

The present invention can be applied to a WDM-PON system using wavelength bands of different bands using C-bands and L-bands or E-bands or S-band AWGs that meet ITU-T recommendation intervals of 100 GHz or 200 GHz. have. In other words, various devices can be connected to improve the performance of WDM-PON and reduce the cost of the equipment.

In addition, AWG module suitable for the characteristics of C-band and L-band or E-band or S-band can be manufactured on one chip, thereby greatly reducing the production cost.

Hereinafter, with reference to the accompanying drawings will be described in detail the multi-band AWG module for WDM-PON according to the present invention. In adding reference numerals to the components of the drawings, the same components, even if displayed on the other drawings to have the same reference numerals as possible, it is known that it may unnecessarily obscure the subject matter of the present invention Detailed description of functions and configurations will be omitted.

1 is a schematic configuration diagram of a WDM-PON dual band AWG module according to an embodiment of the present invention, Figure 2a is a measurement graph of a WDM-PON dual band AWG according to an embodiment of the present invention, 2b and 2c is a measurement graph of the C-band and L-band in the conventional AWG for WDM-PON, Figure 3a is a simplified diagram of a dual-band AWG module for WDM-PON according to an embodiment of the present invention, 3b and 3c show the shifting of the C-band and L-band in the conventional AWG for WDM-PON.

On the other hand, Figure 4 is a schematic configuration diagram of a general WDM-PON.

Dual band AWG module for WDM-PON according to a preferred embodiment of the present invention, as shown in Figure 1, the C & L-band splitter 10 for separating the transmission wavelength of the C-band and L-band, and the C & L A C-band AWG 20 suitable for the C-band characteristic at the transmission wavelength separated by the band splitter 10, and an L-band suitable for the L-band characteristic at the transmission wavelength separated by the C & L-band splitter 10. And an AWG 25 and a C & L-band combiner 30 for combining and outputting the output wavelengths of the C-band AWG 20 and the L-band AWG 25.

One preferred embodiment of the present invention has been described as an example WDM-PON module using a C-band and L-band, O-band (1260 nm ~ 1360 nm), E-band (1360) that can be used in optical communication AWG suitable for the characteristics of nm ~ 1460 nm), S-band (1460 nm ~ 1530 nm), U-band (1625 nm ~ 1675 nm) and the like can be further configured.

The band is recommended by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector), and the C-bands in the communication band and the 100 GHz interval are shown in Tables 1 and 2 below.

band O E S C L U Starting wavelength [nm] 1260 1360 1460 1525 1565 1625 End wavelength [nm] 1360 1460 1530 1565 1625 1675 Range [nm] 100 100 70 40 60 50

Meanwhile, Table 2 below shows each frequency of the ITU-T.

Center frequency (THz) Average wavelength (nm) Center frequency (THz) Average wavelength (nm) Center frequency (THz) Average wavelength (nm) Center frequency (THz) Average wavelength (nm) 196.6 1524.89 195.3 1535.04 194.0 1545.32 192.7 1555.75 196.5 1525.666 195.2 1535.82 193.9 1546.12 192.6 1556.55 196.4 1526.44 195.1 1536.61 193.8 1546.92 192.5 1557.36 196.3 1527.22 195.0 1537.40 193.7 1547.72 192.4 1558.17 196.2 1527.99 194.9 1538.19 193.6 1548.51 192.3 1558.98 196.1 1528.77 194.8 1538.98 193.5 1549.32 192.2 1559.79 196.0 1529.55 194.7 1539.77 193.4 1550.12 192.1 1560.61 195.9 1530.33 194.6 1540.56 193.3 1550.92 192.0 1561.42 195.8 1531.12 194.5 1541.35 193.2 1551.72 191.9 1562.23 195.7 1531.90 194.4 1542.14 193.1 1552.542 191.8 1563.05 195.6 1532.68 194.3 1542.94 193.0 1553.33 191.7 1563.86 195.5 1533.47 194.2 1543.73 192.9 1554.13 191.6 1564.68 195.4 1534.25 194.1 1544.53 192.8 1554.94 191.5 1565.50

As described above, the present invention is applied to the WDM-PON as shown in FIG. 4 and may be used for the OLT 40 or the remote node 50.

In WDM-PON, since the guaranteed bandwidth provided to each subscriber is very wide, as shown in FIG. 4, services such as TV (IP TV), telephone, video telephone, and the Internet can be integrated.

The remote node (RN) 50 is installed on a manhole or telephone pole in a dense subscriber area, and is mainly composed of a waveguide array grating (AWG), but a wavelength division multiplexer / demultiplexer (WDM) such as a thin film filter. It may be implemented by using, and is connected to the subscriber unit ONT from the remote node 50 using the optical fiber.

In order for the OLT 40 and the ONT to communicate with each other, an optical transmitter and receiver are required for each ONT, and the corresponding optical transmitter and receiver are also required for the OLT 40.

The present invention is a passive device installed in the remote node 50 or the OLT 40 as an AWG having periodic transmission wavelength characteristics to demultiplex the wavelength division multiplexed downlink signal transmitted from the OLT 40 to each ONT. It transmits and transmits to the OLT by wavelength division multiplexing the uplink signal transmitted from each ONT.

Similarly, the AWG in the OLT functions to perform wavelength division multiplexing on the downlink signals transmitted from the OLT to each ONT and to perform wavelength division demultiplexing on the uplink signals transmitted from the ONT to the OLT.

Therefore, the AWG in the OLT 40 and the AWG of the remote node 50 must have the same characteristics. That is, the transmission wavelength of each corresponding terminal must be the same.

In the existing single AWG, the C-band transmitted wavelength is used, and there is a wavelength transmission band in which the AWG is periodically repeated, thereby using the C-band and L-band simultaneously.

However, if the 100 GHz interval of the C-band is correct, the 100 GHz interval of the L-band is not correct. That is, as shown in FIG. 2B, when viewing channel 40 (# 40) in channel 1 (# 1) of the C-band, the wavelength transmission band appears as periodic repetition (A), and is shown in FIG. 2C. As can be seen from the channel 1 (# 1) of the L-band, channel # 40 (# 40) also shows a wavelength transmission band that appears as periodic repetition (B), but as shown in Figs. 3b and 3c, the C-band. If the spacing is correct, the spacing of the L-bands does not match (FIG. 3B), and the spacing of the L-bands does not match the spacing of the C-band (FIG. 3C).

In addition, each manufacturer had a different wavelength, and it was difficult to integrate them in reality, so separate equipment for each band had to be installed.

Therefore, when the band transmitted from the OLT 40 is a C-band, the present invention transmits through the C-band AWG 20 through the C & L-band splitter 10 and is transmitted from the OLT 40. If the band is an L-band, it is transmitted through the L-band AWG 25 through the C & L-band splitter 10. That is, the remote node 50 to which the present invention is applied can be used regardless of which band is used in the OLT 40 or the CO. Of course, in this case, it is preferable to use the AWG of the present invention for the OLT 40 as well.

2a and 3a is a measurement graph through the dual-band AWG of the C-band and L-band according to an embodiment of the present invention, it can be seen that can be used without side or loss.

As described above, the C-band and L-band dual-band AWG was used, but according to the characteristics of the equipment O-band (1260 nm ~ 1360 nm), E-band (1360 nm ~ 1460 nm), The AWG may be additionally configured for the characteristics of the S-band (1460 nm to 1530 nm) and the U-band (1625 nm to 1675 nm).

The embodiments of the present invention described above and illustrated in the drawings should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention if it is obvious to those skilled in the art.

1 is a schematic configuration diagram of a dual band AWG module for WDM-PON according to an embodiment of the present invention;

Figure 2a is a measurement graph of the dual band AWG module for WDM-PON according to an embodiment of the present invention,

2b and 2c is a measurement graph of the C-band and L-band in the conventional AWG for WDM-PON,

Figure 3a is a side view of a dual band AWG module for WDM-PON according to an embodiment of the present invention,

3b and 3c are the ease of the C-band and L-band in the conventional AWG for WDM-PON,

4 is a schematic configuration diagram of a general WDM-PON;

Figure 5 is a schematic diagram of a typical AWG for WDM-PON.

<Description of Symbols for Main Parts of Drawings>

10: C & L-Band Splitter

20: C-Band Arrayed Waveguide Grating (AWG)

25: L-Band Arrayed Waveguide Grating (AWG)

30: C & L-Band Combiner

40: Optical Line Termination (OLT)

50: Remote Node (RN)

Claims (4)

WDM-PON transmits optical fiber from OLT (Optical Line Termination), which is a device within the central base station, to a remote node, and a single wavelength from the remote node to an optical terminal device (ONU), which is a subscriber device. In the device, A band splitter for separating transmission wavelengths transmitted from the OLT, a waveguide array grating having a plurality of periodic transmission wavelength characteristics suitable for each transmission wavelength characteristic separated through the band splitter, and a plurality of AWGs Multi-band AWG module for WDM-PON, characterized in that it comprises a band combiner (Combiner) for outputting the combined output signal. The method of claim 1, The band splitter is a C & L-band splitter 10 for separating transmission wavelengths in which C-bands and L-bands are mixed. The plurality of AWGs are C-band AWG 20 suitable for C-band characteristics at the transmission wavelength separated by the C & L-band splitter 10 and L at the transmission wavelength separated by the C & L-band splitter 10. L-band AWG 25 suitable for band characteristics, The band combiner is a multiband AWG for WDM-PON, characterized in that the C & L band combiner 30 for outputting the combined output signal of the C-band AWG 20 and L-band AWG (25) module. The method of claim 1, The band splitter separates transmission wavelengths into at least two of C-band, L-band, O-band, S-band, and E-band, The plurality of AWG, the multi-band AWG module for WDM-PON, characterized in that it comprises a characteristic of the two or more separate transmission wavelength and suitable AWG. The method according to any one of claims 1 to 3, The plurality of AWG, a multi-band AWG module for WDM-PON, characterized in that formed on one chip (CHIP).

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