JP5296009B2 - Base station apparatus and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide means which can reduce cost for accommodating different types of base stations. <P>SOLUTION: A base station apparatus comprises a base band unit, a first radio unit for communicating with the base band unit through an optical line according to a first transmission scheme, and a second radio unit for communicating with the first radio unit according to a second transmission scheme different from the first transmission scheme. The baseband unit includes transmission means for transmitting by multiplexing traffic according to the second transmission scheme to a signal according to the first transmission scheme. The first radio unit includes distribution means for distributing the traffic according to the second transmission scheme multiplexed to the signal according to the first transmission scheme to the second radio unit, and multiplexing means for multiplexing traffic from the second radio unit to a signal according to the first transmission scheme. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  Embodiments described herein relate generally to a base station apparatus and a communication method in which a baseband unit and a radio unit are separated.

  With the development of wireless broadband technologies such as XGP (eXtended Global Platform) and LTE (Long Term Evolution), communication is becoming faster, more sophisticated, and more and more functional. On the other hand, existing communication systems (PHS and third-generation mobile phones) are operated in parallel, and communication carriers need to maintain both new and old infrastructure. One of the operation costs is a line between a base station and a station building. When a next-generation base station (for example, XGP base station) is newly installed at the installation location of an existing base station (for example, IP base station or ISDN base station), it is necessary to add an additional line. There is a problem that additional operation costs (line costs) and equipment costs are required.

JP 2009-171373 A JP-A-5-122135

  As described above, conventionally, in the migration related to the base station installation, the physical medium and transmission method of the line used differ depending on the base station type. In that case, different types of base stations needed to construct networks with different lines and transmission methods. As described above, when a line is used in accordance with each base station type, there is a problem that an operation cost (line cost) and a device cost for accommodating the line are required.

  An object of the present embodiment is to provide a base station apparatus and a communication method that can reduce the cost for accommodating different types of base stations.

  The base station apparatus according to the present embodiment includes a baseband unit, a first wireless unit that communicates with the baseband unit via an optical line using an optical line, and a second transmission method that is different from the first transmission method. A base station apparatus comprising a second radio unit that communicates with the first radio unit, wherein the baseband unit multiplexes and transmits the traffic of the second transmission scheme on the signal of the first transmission scheme A transmission means, wherein the first wireless unit distributes the traffic of the second transmission method multiplexed to the signal of the first transmission method to the second wireless unit; and from the second wireless unit Multiplexing means for multiplexing the traffic of the first traffic to the signal of the first transmission method.

  The communication method according to the present embodiment includes a baseband unit, a first wireless unit that communicates with the baseband unit through an optical line using a first transmission method, and a second transmission method that is different from the first transmission method. A communication method used in a base station apparatus comprising a second radio unit that communicates with a first radio unit, wherein the baseband unit multiplexes traffic of the second transmission scheme onto a signal of the first transmission scheme. The first wireless unit distributes the traffic of the second transmission method multiplexed on the signal of the first transmission method to the second wireless unit, and the traffic from the second wireless unit is It multiplexes with the signal of a 1st transmission system, It is characterized by the above-mentioned.

It is a figure which shows the base station apparatus which concerns on this embodiment. It is a block diagram which shows the structure of a base station apparatus. It is a figure which shows the transmission operation | movement to an IP base station. It is a figure which shows the transmission operation | movement to an ISDN base station. It is a figure which shows the conventional base station apparatus.

  Hereinafter, a base station apparatus and a communication method according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an overall configuration of a base station apparatus according to the present embodiment.

  A baseband unit (BBU) 1 accommodated in an IP relay exchange is installed in the station building, and an XGP base station (RRU; Remote Radio Unit) 21 is installed at an outdoor device installation location such as a rooftop of a building. An IP base station (mobile phone base station) 22 and an ISDN base station (PHS base station) 23 are installed.

  The BBU 11 and the XGP base station (RRU; Remote Radio Unit) 21 are connected by an optical fiber, and CPRI (Common Public Radio Interface) is adopted as a transmission method between them. The RRU 21 is provided with a DIU (Digital Interface Unit) 211 for a CPRI interface, and provides an Ethernet (registered trademark) interface to other IP-based base stations 22 and ISDN base stations 23.

  The IP base station 22 has an Ethernet interface 221 and is connected to the DIU 211. The ISDN base station 23 is equipped with an ISDN-DSU 231 that terminates the ISDN signal, and a CES-RT (Circuit Emulation Service-Remote Terminal) 24 is installed in front of the ISDN-DSU 231. The IP relay exchange of the BBU 11 is provided with a metal line termination unit (INTU) 12 for connecting to the ISDN network.

  FIG. 2 is a block diagram showing the configuration of the RRU 21. As shown in FIG. The RRU 21 includes a DIU 211, a high frequency amplifier 212, a low noise amplifier 213, a transmission filter 214, a reception filter 215, and an antenna 216 for performing wireless communication using XGP. The DIU 211 includes an optical / electrical / electrical / optical converter 201, a CPRI processing unit 202, a D / A converter 203, an A / D converter 204, a PLL timing generator 205, and a switch 206.

  A signal transmitted from the BBU 11 by the CPRI protocol is converted into an electric signal through the optical / electrical converter 201. The signal converted into the electrical signal is distributed to IQ data (XGP traffic) and Ethernet data (IP base station 22 or ISDN base station 23) by a switch 206 of L2 (data link layer) or L3 (network layer). The The clock uses a SYNC frame of the CPRI protocol, and a signal synchronized with the network is distributed to the IP base station 22 or the ISDN base station 23 by the PLL timing generator 205.

  On the other hand, Ethernet data from the IP base station 22 or the ISDN base station 23 is input to the RRU 21 via the switch 206. The CPRI processing unit 202 multiplexes the input Ethernet data in the Ethernet communication area of the CPRI protocol. The CPRI signal obtained by multiplexing the Ethernet data and the XGP traffic is transmitted to the BBU 11 after being converted into an optical signal through the electric / optical converter 201.

  Regarding the base station apparatus configured as described above, the connection relation and operation of each part will be described according to each embodiment.

Example 1
In FIG. 3, BBU11 and RRU21 are connected by CPRI using a physical medium as an optical fiber. Between the BBU 11 and the RRU 21, XGP traffic is transmitted using the IQ data area on the CPRI, and traffic of the IP base station 22 is multiplexed using the Ethernet communication area. The multiplexed signals are distributed at the L2 or L3 level by the router or switch by the BBU 11 and the RRU 21 with the traffic of the XGP and the IP base station 22. The RRU 21 also provides the network reference clock received from the BBU 11 via the CPRI as the reference clock for the IP base station 22.

  In this way, by sharing the traffic of the XGP base station 21 and the IP base station 22 using the CPRI, it becomes possible to consolidate between the station building and the base station into one optical fiber line. . Further, the optical line terminator (OLT or ONU) conventionally used for connection between the BBU 11 and the IP base station 22 becomes unnecessary.

(Example 2)
In FIG. 4, BBU 11 and RRU 21 are connected by CPRI using a physical medium as an optical fiber. Between the BBU 11 and the RRU 21, XGP traffic is multiplexed using the IQ data area on the CPRI, and traffic of the ISDN base station 23 is multiplexed to the RRU 21 using the Ethernet communication area. In the multiplexed signal, the traffic of XGP and ISDN base station 23 is distributed at R2 or L3 level by RRU21. The CES-RT 24 converts the Ethernet signal from the RRU 21 into an ISDN signal and transmits it to the ISDN base station 23. By adopting the CES technology, the clock can also be transmitted using the IP network.

  In this way, by sharing the traffic of XGP and ISDN base station 23 using CPRI, it becomes possible to consolidate between the station building and the base station into one optical fiber line.

  FIG. 5 shows an example of a conventional base station apparatus. Thus, for each base station (ISDN base station (PHS base station), IP base station (mobile phone base station), XGP base station (RRU), metal (ISDN), optical fiber (PON), Since the optical fiber (CPRI) is drawn, an operation cost is generated for each line, and the interface devices for connecting the lines are also different, which increases the equipment cost.

  On the other hand, as shown in FIG. 1, in the present embodiment, traffic between the XGP, the IP base station 22 and the ISDN base station 23 is shared using the CPRI, so Can be consolidated into one optical fiber (CPRI) line. In addition, since the optical line terminator (OLT or ONU) that has been conventionally used is unnecessary, the equipment cost can be reduced.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. For example, although the XGP base station has been described in the above embodiment, the present invention can also be applied to an LTE base station, a WiMAX base station, or the like. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 11 ... Baseband unit (BBU), 12 ... INTU, 21 ... XGP base station (RRU), 211 ... DIU, 22 ... IP base station, 221 ... Ethernet interface, 23 ... ISDN base station, 231 ... ISDN-DSU, 24 ... CES-RT, 201 ... Optical / electrical, electrical / optical converter, 202 ... CPRI processing unit, 203 ... D / A converter, 204 ... A / D converter, 205 ... PLL timing generator, 206 ... switch 212, high frequency amplifier, 213, low noise amplifier, 214, transmission filter, 215, reception filter, 216, antenna.

Claims (2)

A baseband unit, a first wireless unit that communicates with the baseband unit via a CPRI (Common Public Radio Interface) system via an optical line, an ISDN second wireless unit that communicates with the first wireless unit , A base station apparatus comprising a conversion unit that mutually converts IP (Internet Protocol) and ISDN (Integrated Services Digital Network) between a first wireless unit and the second wireless unit ,
The baseband unit is
Transmission means for multiplexing and transmitting the IP traffic and the reference clock signal to the CPRI signal;
The first wireless unit is
Distributing means for distributing the IP traffic multiplexed on the CPRI signal and a reference clock signal to the conversion unit ;
Multiplexing means for multiplexing IP traffic from the conversion unit onto the CPRI signal ,
The conversion unit is
The IP traffic and the reference clock signal distributed by the distributing means are converted into ISDN traffic and a reference clock signal by CES (circuit emulation service), and ISDN traffic from the second radio unit is converted into IP traffic by CES. A base station apparatus characterized by the above. A baseband unit, a first radio unit in communication with CPRI (Common Public Radio Interface) scheme via the baseband unit and the optical line, a second wireless unit in ISDN systems that communicate with the first wireless unit, the A communication method used in a base station apparatus including a conversion unit that mutually converts IP (Internet Protocol) and ISDN (Integrated Services Digital Network) between a first wireless unit and the second wireless unit. ,
In the baseband unit,
The IP traffic and the reference clock signal are multiplexed with the CPRI signal and transmitted.
In the first wireless unit,
Distributing the IP traffic multiplexed with the CPRI signal and a reference clock signal to the conversion unit ;
Possess to multiplex the IP traffic from the conversion unit to the CPRI signal,
In the conversion unit,
The distributed IP traffic and reference clock signal are converted into ISDN traffic and reference clock signal by CES (circuit emulation service), and ISDN traffic from the second wireless unit is converted into IP traffic by CES. Communication method.

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