JP2011250066A - Optical communication system and station device aggregation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical communication system and an station device aggregation method which are capable of aggregating station side devices and reducing power consumption even if there is a signal which is not possible to extend transmission distance due to transmission speed or a delay condition.SOLUTION: An optical communication system 301, within a first area 101, comprises a first stage communication device (in a station building) 20including a first stage station side device communicating with at least one subscriber device in subscriber premises 11 within the first area 101 with use of at least one wavelength, and a second stage communication device (in a station building) 20, within a second area 102 including a plurality of first areas 101, including a second stage station side device communicating with the subscriber device, via the first stage communication device (in a station building) 20in the first area 101 including the subscriber device, with use of at least one wavelength different from the wavelength used for communication between the first stage station side device and the subscriber device.

Description

  The present invention relates to an optical communication system and an optical communication method in which communication devices including station side devices are integrated.

  Since the access network has a larger number of devices (station-side devices and subscriber-side devices) than the core network, the power consumption is large. In the future, diversification of user needs and applications is expected, and it is conceivable that various services are transmitted by dividing wavelengths in the form of WDM as shown in FIGS. FIG. 1 shows point-to-point WDM, and FIG. 2 shows WDM-PON. Depending on the service, not only the wavelength but also the station side devices are terminated separately, and the number of devices and the power consumption can be increased accordingly. In the following description, a communication device including a station side device may be referred to as a station. A station building is a building where a communication device is installed.

  As a conventional method for reducing power consumption, there is a method of consolidating the roles of a plurality of stations into one station. A geographical overview in the case of consolidating stations is shown in FIG. In FIG. 3, the positional relationship in the case of consolidating the roles of the stations 1 to 6 in the station 1 is shown. The main effect of the aggregation is that the power consumption other than the communication devices in the office building including the cooling device is reduced by consolidating the communication devices in one place, that is, the power usage efficiency (PUE: Power usage efficiency). It is widely used as a power saving method for data centers (see, for example, Non-Patent Document 1).

“Measures for further CO2 emission reduction by ICT” http: // www. soumu. go. jp / main_soiki / joho_tsusin / policyreports / chousa / ict_globalwarming / pdf / 0804_h1_3. pdf, May 24, 2010 search Fiber Optic Communication Technology Supervision: Yoshihiro Konishi Author: Shinya Yamamoto Nikkan Kogyo Shimbun 1995, P.A. 170 ITU-T G. 8032 Ethernet (registered trademark) ring protection switching

  However, as shown in FIG. 3, in order to consolidate the roles of a plurality of stations in one station for reducing power consumption, the distance between the station and the subscriber's house becomes longer, so that an optical signal can be transmitted. It is necessary to lengthen the distance. As shown in FIG. 4, in general, the lower the transmission speed of an optical signal, the longer the distance can be transmitted because the signal can be reproduced even if the light intensity at the time of reception is weak (see, for example, Non-Patent Document 2). .) Conversely, as the transmission speed increases, the signal cannot be reproduced unless the light intensity at the time of reception is high, so the transmission distance is shortened. In addition to the transmission speed, there are a plurality of factors that determine the transmittable distance, such as the optical output on the transmission side, the presence or absence of FEC (Forward error correction), the type of PD, the allowable delay condition suitable for the protocol, or the service. The services provided to subscribers are expected to diversify in the future, and some of those that can be transmitted over long distances may be mixed with those that cannot. Therefore, it is difficult to gather all the stations uniformly.

  Therefore, the present invention provides an optical communication system and an optical communication method capable of consolidating station-side devices and reducing power consumption even when there is a signal whose transmission distance cannot be extended due to conditions such as transmission speed and delay. The purpose is to provide.

  In order to achieve the above-mentioned object, the present invention divides a signal capable of extending the transmission distance into a signal capable of extending the transmission distance and a signal-side apparatus capable of extending the transmission distance. It was decided to consolidate.

  Specifically, the optical communication system according to the present invention is in the first range and communicates with at least one subscriber unit in the first range by using at least one wavelength. A first stage communication device including a device and a second range including a plurality of the first ranges, and at least one wavelength different from a wavelength used for communication between the first stage station side device and the subscriber device A second-stage communication device including a second-stage station side device that communicates with the subscriber device via the first-stage communication device in the first range including the subscriber device using a wavelength. .

  The optical communication method according to the present invention is such that the first stage station side device of the first stage communication device within the first range uses at least one wavelength and at least one subscriber device within the first range. The second stage station side device of the second stage communication device in the second range including the plurality of first ranges is used for communication between the first stage station side device and the subscriber unit. At least one wavelength different from the wavelength to be transmitted is communicated with the subscriber device via the first stage communication device in the first range including the subscriber device.

  In this optical communication system and optical communication method, the wavelength of the carrier wave is divided according to various conditions such as the transmission speed of the protocol or the communication service, the allowable delay, and the station to be aggregated is determined for each wavelength. It is possible to avoid problems such as inability to reproduce a signal caused by extending the length of the house.

  Therefore, the present invention provides an optical communication system and an optical communication method capable of consolidating station-side devices and reducing power consumption even when there is a signal whose transmission distance cannot be extended due to conditions such as transmission speed and delay. Can be provided.

  In the optical communication system and the optical communication method according to the present invention, the (N + 1) th stage station side device of the (N + 1) th stage communication device within the (N + 1) th range including a plurality of Nth ranges (N is an integer of 2 or more) Using at least one wavelength different from the wavelength used for communication between the first stage station side apparatus and the subscriber apparatus and the wavelength used for communication between the Nth stage station side apparatus and the subscriber apparatus; Is communicated with the subscriber unit via the first-stage communication device and the N-th communication device in the first range.

  It is possible to optimize power consumption reduction by setting the number of stations to be aggregated for each wavelength to N stages and determining the wavelength accommodation destination station under various conditions.

  The present invention provides an optical communication system and an optical communication method capable of consolidating station-side devices and reducing power consumption even when there is a signal whose transmission distance cannot be prolonged due to conditions such as transmission speed and delay. be able to.

It is a conceptual diagram explaining the conventional optical communication system. It is a conceptual diagram explaining the conventional optical communication system. It is a conceptual diagram explaining the conventional optical communication system. It is a figure explaining the relationship between the transmission speed of an optical signal, and transmission distance. It is a conceptual diagram explaining the optical communication system which concerns on this invention. It is a conceptual diagram explaining the optical communication system which concerns on this invention. It is a conceptual diagram explaining the optical communication system which concerns on this invention. It is a conceptual diagram explaining the optical communication system which concerns on this invention. It is a conceptual diagram explaining the optical communication system which concerns on this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components. Moreover, when it demonstrates without attaching a branch number, it is description common to all the branch numbers of the said code | symbol.

FIG. 5 is a conceptual diagram illustrating the optical communication system 301 according to the first embodiment. The optical communication system 301 is in the first range 101, and uses a first stage station side device that communicates with a subscriber device of at least one subscriber house 11 in the first range 101 using at least one wavelength. A first stage communication device (station building) 20 ₋₁ including a wavelength used in communication between the first stage station side device and the subscriber unit, within a second range 102 including a plurality of first ranges 101; A second stage station side apparatus that communicates with the subscriber apparatus via the first stage communication device (station) 20 _-1 in the first range 101 including the subscriber apparatus using at least one different wavelength. It comprises a second stage communication device (station house) _{20 -2} including, a.

  The optical communication system 301 is configured such that a subscriber device of one subscriber house 11 is connected to station devices of a plurality of station buildings 20, and these station devices are installed in different station buildings 20, and have different accommodation ranges. (101, 102) and their accommodation ranges (101, 102) are in an inclusive relationship.

  FIG. 6 is a diagram showing the relationship between the station side device 34 and the subscriber side device 30. When viewed from the subscriber's home 11, the subscriber side device 30 is connected to a plurality of station side devices 34, but the distances to them are different. The subscriber side apparatus has a structure capable of transmitting signals using carrier waves having different wavelengths. For example, the subscriber side device 30 includes lasers 31 and wavelength couplers 32 having a plurality of different wavelengths as shown in FIG. Alternatively, the subscriber side device 30 may include a wavelength tunable laser.

  FIGS. 5 and 6 show the case where the transmission distance is divided into two stages, but it is also conceivable that the accommodation range is nested and the transmission distance is further divided into more stages. 7 and 8 are diagrams for explaining the optical communication system 302 when the transmission distance is divided into three stages. FIG. 9 is a diagram illustrating the optical communication system 303 when the transmission distance is divided into n stages.

The optical communication system (302, 303) includes a plurality of Nth ranges (N = 3 in the case of the optical communication system 302 and N is an integer of 2 or more in the case of the optical communication system 303). At least one wavelength within the N + 1th range and different from the wavelength used for communication between the first stage station side apparatus and the subscriber apparatus and the wavelength used for communication between the Nth stage station side apparatus and the subscriber apparatus. The first-stage communication device (station building) 20 _-1 and the N-th communication device (station building) 20 _-N in the first range 101 including the subscriber device using the wavelength, and the subscriber device An N + 1-th stage communication device (station building) 20 _{−N + 1} including an N + 1-th stage station side device that performs communication. The subscriber-side device 30 of the optical communication system (302, 303) is configured to be able to transmit a different number of wavelengths by the number of stages at which the transmission distance is divided.

  6, 8, and 9 are all point-to-point, but there are cases in which optical couplers are respectively passed between the subscriber's house and the station building and between the station building and the station building.

In the optical communication device 301 of FIG. 6, the subscriber unit 30, the signal (e.g., voice or the like low-speed signal and a video, etc. fast to be terminated in the first stage station building 20 _-1 and the second stage station building 20 _-2 , A wireless protocol that allows delay and a wireless protocol that does not allow delay, etc., are transmitted on different carrier waves (λ1, λ2). Note that the number of carrier waves is not limited to two and may be two or more. Signal transmitted from the subscriber unit 30 passes through the wavelength filter 33 in the first stage station building 20 _-1, signal to be terminated in the first stage station building 20 _-1 terminates at line terminal 34 _-1 Is done. The first stage station building _{20 -1} forwards other signals to the second stage station building _{20 -2.} The second stage center office 20 _-2 terminates the signal transferred from the plurality of first stage station building 20 _-1.

The signal that the second stage station building 20 _-2 is transmitted from the subscriber premises 11 such that the nearest station building, for example, first the wavelength filter of the second stage center office 20 ₂ (not shown) signal is terminated in a two-stage center office 20 _-2 and is divided into a signal that is terminated by either of the first stage station building 20 _-1. Then, it terminates the signal line terminal _{34 -2} is terminated at the second stage station building _{20 -2} second stage station building _{20 -2} to transfer other signals to one of the central office _{20 -1} .

In Figure 7 and 8, the subscriber signals transmitted from the subscriber unit 30 to the first stage station building 20 _-1 house 11, only the wavelength that is terminated in the first stage station building 20 _-1 wavelength filter withdrawn by 33, it is terminated at the station side device _{34 -1.} Other signals are transferred to the second stage station building 20 _-2. Similarly, in the second stage station building _{20 -2,} only the signal that is terminated at the second stage station building _{20 -2} extracted by a wavelength filter 33, it is terminated at the optical line terminal _{34 2.} Other signals are transferred to the third stage station building _{20 -3,} is terminated at the station side device _{34 -3.}

  The same applies to FIG. The subscriber side device 30 transmits a signal to the nearest first stage station. The first stage station extracts only the signal to be terminated at its own station by the wavelength filter and transfers other signals to the second stage station. From the second stage station to the (N-1) th stage station is the same as the first stage station, only the signal of the own station is extracted and other signals are transferred to the subsequent station. The Nth stage station terminates all signals transferred from the (N-1) th stage station.

Aggregation of stations is effective in reducing power consumption, but it is necessary to lengthen the transmission distance of signals, and it is difficult to aggregate all station devices into one station. However, Figure 5 and by the form of the partial aggregation as the optical communication system 301 of FIG. 6, partially station apparatus is a second stage station building from the first stage station building 20 _-1 20 _-2 will be aggregated to, with respect to aggregated station apparatus to the second stage station building 20 _-2 improves power use efficiency. Similarly, with respect to FIGS. 7 to 9, the power usage efficiency is improved in the portion where the station side devices are integrated.

  Further, by adopting the form of the optical communication system (301, 302, 303), one subscriber side apparatus 30 is connected to the station side apparatuses 34 in a plurality of different office buildings. For this reason, when a part or all of the equipment and facilities required for the operation of the station-side device 34 in any of the stations fails, each wavelength is a passive wavelength filter in a station other than the station to be terminated. Since only passing through 33, a communication state can be secured in any of the stations. At this time, it is difficult to provide the optimal service with the optimal quality because the equipment and facilities in the station are out of order, but it is possible to secure communication between the subscriber's house and the station for some service. It is possible to secure communication as a lifeline.

11: Subscriber's house 20: Communication device or station _20-1 , _20-2 , ..., 20- _N :
First stage communicator, second stage communicator,... N th stage communicator or first stage station, second stage station,..., N stage station 30: Subscriber side device 31 , 31 ₋₁ , 31 ₋₂ : Laser 32: Wavelength coupler 33: Wavelength filter 34, 34 ₋₁ , 34 ₋₂ ,..., 34 _−N : Station side device 51: Transmission path 101, 102,. 10N: first range, second range,..., Nth range 301, 302, 303: optical communication system

Claims (4)

A first stage communicator including a first stage station side device that communicates with at least one subscriber device within the first range using at least one wavelength within the first range;
A plurality of the first ranges are included in a second range, and at least one wavelength different from a wavelength used for communication between the first stage station side device and the subscriber device is used, and the subscriber device is included. A second-stage communication device including a second-stage station-side device that communicates with the subscriber device via the first-stage communication device in the first range.
An optical communication system comprising: A wavelength used in communication between the first stage station side device and the subscriber unit, and an Nth stage station side device, which are in the (N + 1) th range including a plurality of Nth ranges (N is an integer of 2 or more); Using the at least one wavelength different from the wavelength used for communication with the subscriber unit, the subscription via the first stage communication device and the Nth stage communication device in the first range including the subscriber device. The optical communication system according to claim 1, further comprising an (N + 1) th stage communication device including an (N + 1) th stage station side device communicating with an operator apparatus. The first stage station side device of the first stage communication device within the first range communicates with at least one subscriber device within the first range using at least one wavelength;
The second stage station side device of the second stage communication device within the second range including a plurality of the first ranges is different from the wavelength used for communication between the first stage station side device and the subscriber unit. An optical communication method using at least one wavelength and communicating with the subscriber unit via the first stage communication device in the first range including the subscriber unit.   The (N + 1) th stage station side device of the (N + 1) th stage communication device within the (N + 1) th range including a plurality of Nth ranges (N is an integer equal to or greater than 2) is configured such that the first stage station side device and the subscriber unit The first-stage communication in the first range including the subscriber apparatus using at least one wavelength different from the wavelength used in communication and the wavelength used in communication between the N-th stage station side apparatus and the subscriber apparatus Optical communication method for communicating with the subscriber unit via a communication device and an Nth stage communication device.

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