KR20130093789A - Wired/wireless converged network applied wavelength division multiplexing and signal tansmitting method - Google Patents

Abstract

PURPOSE: A wired/wireless converged network applied with wavelength division multiplexing (WDM) and a signal transmitting method thereof are provided to apply the WDM for wired optical network to a common public radio interface (CPRI) section, thereby increasing capacity of the CPRI section. CONSTITUTION: A wired network comprises an optical line terminal (OLT) and an optical network unit (ONU). A wireless network comprises a remote equipment controller (REC) and a remote end (RE) that receive an optical signal through CPRI by WDM. The WDM is one of coarse WDM (CWDM) and dense WDM (DWDM). The REC and the RE are connected to at least one CPRI link. The CPRI link is made of one of star, ring, and bus topologies.

Description

WIRED / WIRELESS CONVERGED NETWORK APPLIED WAVELENGTH DIVISION MULTIPLEXING AND SIGNAL TANSMITTING METHOD}

The present invention provides a signal transmission between a radio equipment controller (REC) and a radio equipment (RE) in a radio base station that transmits and receives information through a radio interface using a multi-antenna-carrier, a technique used in a wired optical subscriber network. An apparatus and method applied to an interface for the same.

In a typical cellular radio system, a wireless user's equipment unit communicates with one or more core networks via a Radio Access Network (RAN). Here, the equipment unit of the wireless user may be a mobile terminal such as a portable telephone and a notebook. Alternatively, the wireless user's equipment unit may be a fixed wireless device, for example an Access Point.

A radio access network covers a geographic area divided into cell areas, where each cell area may receive radio service by a radio base station. The coverage of the cell is determined by the wireless equipment at the base station site.

Wireless base stations in conventional cellular communication systems are generally located within a single location and the distance between the baseband circuit and the wireless circuit is relatively short, within a few meters. Unlike conventional wireless base stations, split type wireless base stations include a Radio Equipment Controller (REC) and a Radio End (RE). In a separate wireless base station, the RE may be located near the antenna and the REC may be located at an accessible site. In other words, the separate wireless base station separates REC which performs digital baseband signal processing and wireless base station control and management, and RE which transmits and receives analog and wireless RF signals through an antenna such as filtering, modulation, frequency conversion and amplification. Positioning and placing the REC in the central office can perform efficient cell operation.

At this time, the REC and RE sections are connected by optical fiber, and this section connected by optical fiber is called Common Public Radio Interface (CPRI). In a separate wireless base station, data is transmitted and received between REC and RE through CPRI.

The present invention provides a network and signal transmission method for efficiently improving the capacity of a CPRI interval by applying a wavelength division multiplexing (WDM) used in a wired optical subscriber network to the CPRI interval.

The present invention provides a wired / wireless converged network in which a wired optical subscriber network and a wireless network for operating a separate base station are fused.

 In one embodiment of the present invention, the wired network of the wired / wireless converged network includes an optical line terminal (OLT) and an optical network unit (ONU), and the wireless network of the wired / wireless converged network has a public wireless interface ( And a wireless equipment controller (REC) and a wireless equipment (RE) for transmitting and receiving optical signals via CPRI.

In the wireless network of the wired / wireless converged network according to the first embodiment of the present invention, the REC includes a reflective light source and a seed light source for injecting seed light for an uplink signal or a downlink signal having a fixed wavelength to the reflective light source. The RE may include a reflective light source.

In the wireless network of the wired / wireless converged network according to the second embodiment of the present invention, the RE may include a reflective light source.

In the wireless network of the wired / wireless converged network according to the third embodiment of the present invention, the REC includes a reflective light source and a seed light source for injecting seed light for a downward signal into the reflective light source, and the RE is a reflective light source. It may include.

In the wireless network of the wired / wireless converged network according to the fourth embodiment of the present invention, the REC and RE may include any one of a tunable light source, at least one single mode laser, or a single mode laser array.

In a first embodiment of the present invention, a signal transmission method includes the steps of: transmitting a downward signal having a fixed wavelength injected from a seed light source through a REC to a RE; And transmitting, by the RE, an upward signal having a fixed wavelength injected from the seed light source through the reflective light source to the REC.

In a second embodiment of the present invention, a signal transmission method includes: transmitting, by the REC, a downlink signal to an RE using at least one single mode laser; And transmitting, by the RE, the uplink signal to the REC by recycling the downlink signal through the reflective light source.

In a third embodiment of the present invention, the signal transmission method includes the steps of: transmitting a downward signal having a fixed wavelength injected from a seed light source by the REC to the RE; And transmitting, by the RE, the uplink signal to the REC by recycling the downlink signal through the reflective light source.

In a fourth embodiment of the present invention, the signal transmission method includes the steps of: transmitting, by the REC, a downward signal input through a variable wavelength light source or a single mode laser to an RE; And transmitting, by the RE, the upstream signal inputted through the variable wavelength light source or the single mode laser to the REC.

According to one embodiment of the present invention, the capacity of the CPRI interval can be efficiently improved by applying the wavelength multiplexing method used in the wired optical subscriber network to the CPRI interval.

1 shows a network topology between a RE and a REC.
2 is a diagram illustrating a wired and wireless convergence network according to a first embodiment of the present invention.
3 is a diagram illustrating a wired and wireless convergence network according to a second embodiment of the present invention.
4 is a diagram illustrating a wired and wireless convergence network according to a third embodiment of the present invention.
5 is a diagram illustrating a wired and wireless convergence network according to a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a network topology between a RE and a REC.

1A shows one CPRI link between one REC and one RE. 1B shows a plurality of CPRI links between one REC and one RE.

That is, A shows CPRI links between one REC and one RE, and B shows a plurality of CPRI links between one REC and RE. 1C shows a star topology. That is, a plurality of REs may be connected to one REC.

According to one embodiment of the invention, the network topology consisting of REC and RE is not limited. For example, the network topology may be configured as star, ring, and bus, and there may be one or a plurality of CPRI links between the REC and the RE.

In particular, in the present invention, a wavelength division multiplexing scheme (WDM) used in a wired optical subscriber network may be applied to a CPRI link. In this case, the wavelength division multiplexing scheme may be one of a low density wavelength division multiplexing (CWDM) or a high density wavelength division multiplexing (DWDM).

In the present invention, the downlink signal refers to a signal from REC to RE or a signal from OLT to ONU, and the uplink signal refers to a signal from RE to REC or a signal from ONU to OLT.

Hereinafter, an example of a wired / wireless converged network according to an embodiment of the present invention. Here, the wired / wireless converged network means a form in which a wired network and a wireless network are converged. The wired network includes an optical line terminal (OLT) and an optical network unit (ONU), and the wireless network includes a radio equipment controller (REC) and a radio equipment (RE) for transmitting and receiving optical signals through a public radio interface (CPRI). do. In particular, a wireless network includes a radio equipment controller (REC) and a radio equipment (RE) for transmitting and receiving optical signals over a public radio interface (CPRI) in accordance with a wavelength division multiplexing scheme.

2 is a diagram illustrating a wired and wireless convergence network according to a first embodiment of the present invention.

Referring to FIG. 2, REC and RE constituting a wireless network include a reflective light source and a seed light source for injecting seed light for an uplink signal or a downlink signal having a fixed wavelength to the reflective light source. The reflective light source includes a reflective semiconductor optical amplifier (RSAA), a Fabry-Perot Laser Diode (FP-LD), and a reflective external modulator (reflective electro-transistor). An absorption modulator (REAM) or a reflective electro-absorption modulator-semiconductor optical amplifier (REAM-SOA or reflective amplifier modulator: RAM) is integrated.

The seed light source is located at the central station and is injected outside the reflective light source to determine the wavelength of the upstream signal or the downlink signal. The seed light source may be one of a broadband light source or a single mode laser array. Here, the single mode laser array means that a plurality of single mode lasers are configured in an array form. The single mode laser may be a distributed feedback laser (DFB) laser, a distributed Bragg reflector laser (DBR) laser, or may be a vertical-cavity surface-emitting laser (VCSEL).

3 is a diagram illustrating a wired and wireless convergence network according to a second embodiment of the present invention.

FIG. 3 may include a reflective light source only in the RE for cost efficiency as compared to FIG. 2. The REC may send a down signal to the RE using a single mode laser array or individual single mode lasers. The RE may transmit the uplink signal to the REC by recycling the downlink signal to the seed light source.

4 is a diagram illustrating a wired and wireless convergence network according to a third embodiment of the present invention.

4 shows that the downlink light source and the uplink signal light source are configured as reflective light sources. That is, in FIG. 4, the seed light source is utilized for the downlink signal when compared to FIG. 2. The seed light source may be a broadband light source, and multiple single mode lasers or single mode laser arrays may be used. If multiple single mode lasers or single mode lasers are used, processing may be included to improve the reflection sensitivity of the link. The RE may transmit the uplink signal to the REC by recycling the downlink signal.

5 is a diagram illustrating a wired and wireless convergence network according to a fourth embodiment of the present invention.

FIG. 5 transmits a signal using a wavelength tunable light source capable of variable wavelength, a single mode laser array, or an individual single mode laser without using a reflective light source. That is, a variable wavelength light source, a single mode laser array, or an individual single mode laser may be used as a light source for transmitting a down signal or an up signal.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

201: OLT, REC
202: ONU
203: RE

Claims (20)

In the wired / wireless converged network where a wired network and a wireless network are converged,
The wired network comprises an optical line terminal (OLT) and an optical network unit (ONU),
Wherein said wireless network comprises a radio equipment controller (REC) and a radio equipment (RE) for transmitting and receiving optical signals over a public radio interface (CPRI) in accordance with a wavelength division multiplexing scheme. The method of claim 1,
The wavelength division multiplexing method,
A wired / wireless converged network, which is one of a low density wavelength division multiplexing (CWDM) and a high density wavelength division multiplexing (DWDM). The method of claim 1,
The REC and RE are connected by at least one CPRI link,
The CPRI link is a wired or wireless convergence network, characterized in that consisting of any of the star, ring and bus topology. In the wired / wireless converged network where a wired network and a wireless network are converged,
The wired network comprises an optical line terminal (OLT) and an optical network unit (ONU), the wireless network comprising a radio equipment controller (REC) and a radio equipment (RE) for transmitting and receiving an optical signal,
Wherein the REC and the RE transmit a signal through a public air interface (CPRI) according to a wavelength division multiplexing scheme. 5. The method of claim 4,
The REC,
Transmitting a signal using a reflective light source and a seed light source for injecting seed light for an uplink signal or a downlink signal having a fixed wavelength to the reflective light source,
The RE is a wired or wireless convergence network, characterized in that for transmitting a signal using a reflective light source. The method of claim 5,
The seed light for the uplink signal is processed to reduce the reflection sensitivity of the link. 5. The method of claim 4,
The REC,
Send a down signal to the RE using a seed light source comprising a single mode laser array or an individual single mode laser,
RE is
And transmitting an uplink signal to a REC by recycling the downlink signal to a seed light source. 5. The method of claim 4,
The REC includes a seed light source for injecting a seed light for a downward signal to the reflective light source and the reflective light source,
And the RE comprises a reflective light source. 5. The method of claim 4,
The REC and RE,
A wired / wireless converged network comprising any one of a variable wavelength light source, at least one single mode laser, and a single mode laser array. 9. The method according to any one of claims 4 to 8,
The seed light source,
A wired / wireless converged network, characterized in that it is either a broadband light source, a plurality of single mode lasers, or a single mode laser array. 9. The method according to any one of claims 4 to 8,
The reflective light source,
A wired / wireless converged network characterized in that it is any one of an integrated device incorporating a reflective semiconductor optical amplifier (RSOA), a Fabry-Perot laser diode (FP-LD), a reflective external modulator, and a reflective external modulator and a reflective semiconductor optical amplifier. . In the signal transmission method for transmitting an optical signal through a wired or wireless converged network in which a wired network and a wireless network are converged,
The wireless network includes a radio equipment controller (REC) and a radio equipment (RE) for transmitting and receiving optical signals,
The signal transmission method,
The REC transmitting a downlink signal to an RE; And
The RE transmitting an uplink signal to a REC
Signal transmission method comprising a. The method of claim 12,
The REC transmits the downlink signal to the RE,
The REC transmits a downward signal having a fixed wavelength injected from the seed light source through the reflective light source to the RE,
The RE transmitting the uplink signal to the REC,
And the RE transmits an uplink signal having a fixed wavelength injected from the seed light source through the reflective light source to the REC. The method of claim 13,
The seed light for the upward signal injected from the seed light source is processed to reduce the reflection sensitivity of the link. The method of claim 12,
The REC transmits the downlink signal to the RE,
The REC transmits a downlink signal to the RE using at least one single mode laser or single mode laser array,
The RE transmitting the uplink signal to the REC,
And the RE transmits the uplink signal to the REC by recycling the downlink signal through the reflective light source. The method of claim 12,
The REC transmits the downlink signal to the RE,
The REC transmits a downward signal having a fixed wavelength injected from the seed light source through the reflective light source to the RE,
The RE transmitting the uplink signal to the REC,
And the RE transmits the uplink signal to the REC by recycling the downlink signal through the reflective light source. The method of claim 12,
The REC transmits the downlink signal to the RE,
The REC transmits the downlink signal input through the variable wavelength light source, the single mode laser or the single mode laser array to the RE,
The RE transmitting the uplink signal to the REC,
And the RE transmits an uplink signal input through a tunable light source, a single mode laser, or a single mode laser array to the REC. 18. The method according to any one of claims 13 to 17,
The wavelength division multiplexing method,
A signal transmission method according to any one of low density wavelength division multiplexing (CWDM) and high density wavelength division multiplexing (DWDM). 18. The method according to any one of claims 13 to 17,
The REC and RE are connected by at least one CPRI link,
The CPRI link is a signal transmission method, characterized in that consisting of any of the star, ring or bus topology. 17. The method according to any one of claims 13 to 16,
The reflective light source,
Signal transmission method, characterized in that any one of the integrated semiconductor optical amplifier (RSOA), Fabry Perot laser diode (FP-LD), a reflective external modulator and a reflective external modulator and integrated semiconductor optical amplifier. .

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