Communication system, main unit, radio access unit and communication method

Abstract

A plurality of radio access units ( 108 - 1 to 108 - n ) form the single cell (# 120 ) of a first communication system, while forming respective individual multi-cells (# 130 - 1 to # 130 - n ) of a second communication system within the single cell (# 120 ). The plurality of radio access units ( 108 - 1 to 108 - n ) transmit a downstream signal of the first communication system input from a main unit ( 107 ) to a terminal using the first communication system of the single cell (# 120 ), while each transmitting a downstream signal of the second communication system input from the main unit ( 107 ) to a terminal using the second communication system of the corresponding respective one of the multi-cells (# 130 - 1 to # 130 - n ).

1 . A communication system comprising a radio base station apparatus, a main unit connected to the radio base station apparatus and a network, and a plurality of radio access units connected to the main unit, wherein:
 the radio base station apparatus is configured to output a downlink signal of a first communication system to the main unit;   the main unit is configured to output the downlink signal of the first communication system received from the radio base station apparatus and a downlink signal of a second communication system received from the network to each of the plurality of radio access units; and   the plurality of radio access units are configured to define a single cell of the first communication system;   each of the plurality of radio access units is configured to define a multiple cell of the second communication system in the single cell, to transmit the downlink signal of the first communication system received from the main unit to a terminal that uses the first communication system in the single cell, to performs wired protocol signal processing and then wireless protocol signal processing on the downlink signal of the second communication system received from the main unit to generate a resultant signal, and to transmit the resultant signal to a terminal that uses the second communication system in the multiple cell.   
     
     
         2 . The communication system according to  claim 1 , wherein:
 the main unit is connected to each of the plurality of radio access units through an optical transmission channel, and is further configured to output a wavelength-division-multiplexed signal of the downlink signal of the first communication system and the downlink signal of the second communication system to each of the plurality of radio access units through the optical transmission channel; and   each of the plurality of radio access units is further configured to demultiplex the downlink signal of the first communication system and the downlink signal of the second communication system, from the multiplexed signal received from the main unit through the optical transmission channel, to transmit the demultiplexed downlink signal of the first communication system to the terminal that uses the first communication system in the single cell, and to perform the wired protocol signal processing and then the wireless protocol signal processing on the demultiplexed downlink signal of the second communication system.   
     
     
         3 . The communication system according to  claim 1 , wherein:
 the radio base station apparatus is connected to the main unit through a first optical transmission channel;   the radio base station apparatus is further configured to performs wavelength-division-multiplexing on the downlink signal of the first communication system and an uplink signal of the first communication system, and to output the multiplexed signal to the main unit through the first optical transmission channel;   the main unit is connected to each of the plurality of radio access units through a second optical transmission channel, and is further configured to perform wavelength-division-multiplexing on a first multiplexed signal in which the downlink signal of the first communication system received through the first optical transmission channel and the downlink signal of the second communication system are multiplexed per frame, and a second multiplexed signal in which the uplink signal of the first communication system and an uplink signal of the second communication system are multiplexed per frame, and to output the multiplexed signal to each of the plurality of radio access units through the second optical transmission channel; and   each of the plurality of radio access unit is further configured to demultiplex the downlink signal of the first communication system and the downlink signal of the second communication system from the first multiplexed signal received through the second optical transmission channel per frame, to transmit the demultiplexed downlink signal of the first communication system to the terminal that uses the first communication system in the single cell, and to perform the wired protocol signal processing and then the wireless protocol signal processing on the demultiplexed downlink signal of the second communication system.   
     
     
         4 . A communication system comprising a radio base station apparatus, a main unit connected to the radio base station apparatus and a network, and a plurality of radio access units connected to the main unit, wherein:
 the plurality of radio access units are further configured to define a single cell of a first communication system;   each of the plurality of radio access units is further configured to define a multiple cell of a second communication system in the single cell, to output an uplink signal of the first communication system received from a terminal that uses the first communication system in the single cell to the main unit, to perform wireless protocol signal processing and then wired protocol signal processing on an uplink signal of the second communication system received from a terminal that uses the second communication system in the multiple cell to generate a resultant signal, and to output the resultant signal to the main unit;   the main unit is further configured to synthesize the uplink signals of the first communication system received from the plurality of radio access units, to output the synthesized signal to the radio base station apparatus, and to output the uplink signals of the second communication system received from the plurality of radio access units to the network; and   the radio base station apparatus configured to acquire the synthesized uplink signal of the first communication system from the main unit.   
     
     
         5 . The communication system according to  claim 4 , wherein:
 the plurality of radio access units are each connected to the main unit through an optical transmission channel;   each of the plurality of the radio access units is configured to output a wavelength-division-multiplexed signal of the uplink signal of the first communication system received from the terminal that uses the first communication system and the uplink signal of the second communication system subjected to the wired protocol signal processing, to the main unit through the optical transmission channel; and   the main unit is further configured to demultiplex the uplink signals of the first communication system and the uplink signals of the second communication system from the multiplexed signal received through the optical transmission channel, to synthesize the demultiplexed uplink signals of the first communication system, to output the synthesized signal to the radio base station apparatus, and to output the demultiplexed uplink signals of the second communication system to the network.   
     
     
         6 . The communication system according to  claim 4 , wherein:
 the plurality of radio access units are each connected to the main unit through a first optical transmission channel;   each of the plurality of the radio access units is further configured to perform wavelength-division-multiplexing on a first multiplexed signal in which the uplink signal of the first communication system received from the terminal that uses the first communication system and the uplink signal of the second communication system subjected to the wired protocol signal processing are multiplexed per frame, and a second multiplexed signal in which a downlink signal of the first communication system and a downlink signal of the second communication system are multiplexed per frame, and to output the multiplexed signal to the main unit;   the main unit is connected to the radio base station apparatus through a second optical transmission channel, and is further configured to demultiplex each of the first multiplexed signals received from the plurality of radio access units through the first optical transmission channel into the uplink signal of the first communication system and the uplink signal of the second communication system per frame, to add the demultiplexed uplink signals of the first communication system, to perform wavelength-division-multiplexing on the added uplink signal of the first communication system and the downlink signal of the first communication system, and to output the multiplexed signal to the radio base station apparatus through the second optical transmission channel; and   the radio base station apparatus is further configured to acquire the uplink signal of the first communication system through the second optical transmission channel from the main unit.   
     
     
         7 . A main unit comprising:
 a splitting section configured to split a received downlink signal of a first communication system into a plurality of downlink signals of the first communication system; and   a multiplexing section configured to multiplex each of the downlink signals of the first communication system split in the splitting section with a received downlink signal of a second communication system into a first multiplexed signal, and to output the first multiplexed signal.   
     
     
         8 . The main unit according to  claim 7  further comprising a conversion section that electrooptically converts each of the downlink signals of the first communication system split in the splitting section and the received downlink signal of the second communication system, wherein
 the multiplexing section is further configured to perform wavelength-division-multiplexing on the downlink signal of the first communication system and the downlink signal of the second communication system which are electrooptically converted in the conversion section to generate the first multiplexed signal. 
 
     
     
         9 . The main unit according to  claim 7  further comprising:
 a demultiplexing section configured to demultiplex the downlink signal of the first communication system from a second multiplexed signal in which the downlink signal of the first communication system and an uplink signal of the first communication system are subjected to wavelength-division-multiplexing; 
 a conversion section, configured to optoelectrically convert the downlink signal of the first communication system demultiplexed in the demultiplexing section; and 
 a signal conversion section configured to insert a dummy bit into the received downlink signal of the second communication system, wherein: 
 the splitting section is further configured to split the downlink signal of the first communication system converted into an electrical signal in the conversion section into the plurality of downlink signals of the first communication system; and 
 the multiplexing section is further configured to perform wavelength-division-multiplexing on the first multiplexed signals in which each of the split downlink signals of the first communication system and the downlink signal of the second communication system are multiplexed per frame, and a third multiplexed signal in which the uplink signal of the first communication system and an uplink signal of the second communication system are multiplexed, and to output the wavelength-division-multiplexed signal, the downlink signal of the second communication system including the inserted dummy bit. 
 
     
     
         10 . A main unit comprising:
 a demultiplexing section configured to acquire a plurality of first multiplexed signals in each of which an uplink signal of a first communication system and an uplink signal of a second communication system are multiplexed, to demultiplex each of the acquired first multiplexed signals into the uplink signal of the first communication system and the uplink signal of the second communication system, and to output the demultiplexed uplink signal of the second communication system; and   a synthesis section configured to synthesize the uplink signals of the first communication system demultiplexed in the demultiplexing section, and to output the synthesized signal.   
     
     
         11 . The main unit according to  claim 10  further comprising a conversion section configured to optoelectrically convert the uplink signal of the first communication system and the uplink signal of the second communication system which are demultiplexed in the demultiplexing section, wherein:
 the demultiplexing section is further configured to acquire the plurality of first multiplexed signals subjected to wavelength-division-multiplexing; and 
 the synthesis section is further configured to synthesize the uplink signals of the first communication system converted into electrical signals in the conversion section. 
 
     
     
         12 . The main unit according to  claim 10  further comprising:
 a signal conversion section configured to remove a dummy bit from the uplink signal of the second communication system demultiplexed in the demultiplexing section, and to output the uplink signal of the second communication system; 
 a conversion section configured to electrooptically convert the uplink signal of the first communication system which is obtained by the synthesis in the synthesis section; and 
 a multiplexing section configured to perform wavelength-division-multiplexing on the uplink signal of the first communication system which is electrooptically converted in the conversion section and a downlink signal of the first communication system, and to output the multiplexed signal, wherein 
 the demultiplexing section is further configured to acquire the first multiplexed signal subjected to wavelength-division-multiplexing with a second multiplexed signal in which the downlink signal of the first communication system and the downlink signal of the second communication system are multiplexed per frame, and to demultiplex the acquired first multiplexed signal into the uplink signal of the first communication system and the uplink signal of the second communication system per frame. 
 
     
     
         13 . A radio access unit comprising:
 an acquiring section configured to acquire a downlink signal of a first communication system and a downlink signal of a second communication system;   a protocol processing section configured to perform wired protocol signal processing and then wireless protocol signal processing on the downlink signal of the second communication system acquired in the acquiring section; and   a transmitting section configured to transmit the downlink signal of the first communication system acquired in the acquiring section to a terminal that uses the first communication system in a single cell of the first communication system, the single cell being defined by the radio access unit and the other radio access units, and to transmit the downlink signal of the second communication system which is subjected to the wireless protocol signal processing in the protocol processing section, to a terminal that uses the second communication system in a multiple cell of the second communication system, the multiple cell being defined in the single cell.   
     
     
         14 . The radio access unit according to  claim 13  further comprising a conversion section configured to optoelectrically convert the downlink signal of the first communication system and the downlink signal of the second communication system which are acquired in the acquiring section, wherein:
 the acquiring section is further configured to demultiplex the downlink signal of the first communication system and the downlink signal of the second communication system from a wavelength-division-multiplexed signal of the downlink signal of the first communication system and the downlink signal of the second communication system; 
 the protocol processing section is further configured to perform the wired protocol signal processing and then the wireless protocol signal processing on the downlink signal of the second communication system, the downlink signal being optoelectrically converted in the conversion section; and 
 the transmission section is further configured to transmit the downlink signal of the first communication system, which is optoelectrically converted in the conversion section, to the terminal that uses the first communication system in the single cell, and to transmit the downlink signal of the second communication system which is subjected to the wireless protocol signal processing in the protocol processing section, to the terminal that uses the second communication system in the multiple cell. 
 
     
     
         15 . The radio access unit according to  claim 13  further comprising:
 a conversion section is configured to optoelectrically convert a first multiplexed signal in which the downlink signal of the first communication system and the downlink signal of the second communication system are multiplexed per frame, the downlink signal of the first communication system and the downlink signal of the second communication system being acquired in the acquiring section; 
 a demultiplexing section is configured to demultiplex the first multiplexed signal optoelectrically converted in the conversion section, into the downlink signal of the first communication system and the downlink signal of the second communication system per frame; and 
 a signal conversion section is configured to remove a dummy bit from the downlink signal of the second communication system demultiplexed in the demultiplexing section, wherein: 
 the acquiring section is further configured to acquire the first multiplexed signal subjected to wavelength-division-multiplexing with a second multiplexed signal in which an uplink signal of the first communication system and an uplink signal of the second communication system are multiplexed per frame; and 
 the protocol processing section is further configured to perform the wired protocol signal processing and then the wireless protocol signal processing on the downlink signal of the second communication system in which the dummy bit is removed in the signal conversion section. 
 
     
     
         16 . A radio access unit comprising:
 a receiving section configured to receive an uplink signal of a first communication system from a terminal that uses the first communication system in a single cell of the first communication system, the single cell being defined by the radio access unit and the other radio access units, and to receive an uplink signal of a second communication system from a terminal that uses the second communication system in a multiple cell of the second communication system, the multiple cell being defined in the single cell;   a protocol processing section configured to perform wireless protocol signal processing and then wired protocol signal processing on the uplink signal of the second communication system received in the receiving section; and   an outputting section configured to output the uplink signal of the first communication system received in the receiving section and the uplink signal of the second communication system which is subjected to the wired protocol signal processing in the protocol processing section.   
     
     
         17 . The radio access unit according to  claim 16  further comprising,
 a conversion section configured to electrooptically convert the uplink signal of the first communication system received in the receiving section and the uplink signal of the second communication system which is subjected to the wired protocol signal processing in the protocol processing section, wherein 
 the outputting section is further configured to perform wavelength-division-multiplexing on the uplink signal of the first communication system and the uplink signal of the second communication system which are electrooptically converted in the conversion section, and to output the multiplexed signal. 
 
     
     
         18 . The radio access unit according to  claim 16  further comprising:
 a signal conversion section configured to insert a dummy bit into the uplink signal of the second communication system subjected to the wired protocol signal processing in the protocol processing section; 
 a multiplexing section configured to multiplex the uplink signal of the first communication system received in the receiving section with the uplink signal of the second communication system into which the dummy bit has been inserted, per frame to generate a first multiplexed signal; and 
 a conversion section configured to electrooptically convert the first multiplexed signal, 
 wherein the outputting section is further configured to perform wavelength-division-multiplexing on the first multiplexed signal electrooptically converted in the conversion section, and a second multiplexed signal in which a downlink signal of the first communication system and a downlink signal of the second communication system are multiplexed per frame, and to output the multiplexed signal. 
 
     
     
         19 . A communication method in a communication system comprising a radio base station apparatus, a main unit connected to the radio base station apparatus and a network, and a plurality of radio access units connected to the main unit, the method comprising the steps of:
 outputting, from the radio base station apparatus, a downlink signal of a first communication system to the main unit;   outputting, from the main unit, the downlink signal of the first communication system received from the radio base station apparatus and a downlink signal of a second communication system received from the network to each of the plurality of radio access units;   defining a single cell of the first communication system by the plurality of radio access units, each of the plurality of radio access units defining a multiple cell of the second communication system in the single cell;   transmitting, from each of the radio access units, the downlink signal of the first communication system received from the main unit to a terminal that uses the first communication system in the single cell;   performing, by each of the radio access units, wired protocol signal processing and then wireless protocol signal processing on the downlink signal of the second communication system received from the main unit, to generate a resultant signal; and   transmitting, from each of the radio access units, the resultant signal, to a terminal that uses the second communication system in the multiple cell.   
     
     
         20 . A communication method in a communication system comprising a radio base station apparatus, a main unit connected to the radio base station apparatus and a network, and a plurality of radio access units connected to the main unit, the method comprising the steps of:
 defining a single cell of a first communication system by the plurality of radio access units, each of the plurality of radio access units defining a multiple cell of a second communication system in the single cell;   outputting, from each of the radio access units, an uplink signal of the first communication system received from a terminal that uses the first communication system in the single cell to the main unit;   performing, by each of the radio access units, wired protocol signal processing and then wireless protocol signal processing on an uplink signal of the second communication system received from a terminal that uses the second communication system in the multiple cell, to generate a resultant signal;   outputting, from each of the radio access units, the resultant signal to the main unit;   synsethizing, by the main unit, the uplink signals of the first communication system received from the plurality of radio access units,   outputting, from the main unit, the synthesized signal to the radio base station apparatus,   outputting, from the main unit, the uplink signals of the second communication system received from the plurality of radio access units to the network; and   acquiring the synthesized uplink signal of the first communication system from the main unit by the radio base station apparatus.