JP3670155B2

JP3670155B2 - Wireless communication system

Info

Publication number: JP3670155B2
Application number: JP6765199A
Authority: JP
Inventors: 英生池田; 政克丸山; 有一郎後藤; 知多佳真鍋; 善郎西元
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 1999-03-15
Filing date: 1999-03-15
Publication date: 2005-07-13
Anticipated expiration: 2019-03-15
Also published as: JP2000270362A

Description

【０００１】
【発明の属する技術分野】
本発明は，無線通信システムに係り，詳しくは，所定の周波数帯域を共用する複数の通信空間領域（セル）毎に基地局を配置し，各通信空間領域内に属する固定加入者局と当該通信空間領域の基地局との間で無線通信を行う無線通信システムに関するものである。
【０００２】
【従来の技術】
例えば２０ＧＨｚ〜４０ＧＨｚ程度の準ミリ波やミリ波を用いて，半径数km程度の地域にある複数の加入者局と基地局との間でデータの送受信を行う一対多双方向無線通信システムがある。この無線通信システムでは，宅内配線などの加入者に強く依存した工事が減少するため，インターネットへの接続サービスなどの他，映画などの映像データをオンデマンドで提供するなど比較的広い周波数帯域が必要なサービスも安価に提供することができる。
ところで，特に都市部では，複数の住宅棟が林立したマンションなどの増加により特定地域に加入者が集中する傾向がある。あるサービスエリアで利用可能な周波数帯域には限りがあるため，加入者が増加するなどして必要なチャンネル数が増加すると一チャンネルあたりで利用可能な周波数帯域はそれだけ減少することになる。
限りがある周波数帯域の中で一チャンネルあたりで利用可能な周波数帯域を増加させるには，例えば同じ周波数帯域を繰り返し用いればよい。但し，この場合，同じ周波数帯域を用いた複数の通信間で干渉を防止する必要がある。このような干渉を防止しながら同じ周波数帯域の繰り返し使用を行う無線通信システムにセルラシステムがある。
セルラシステムでは，無線通信サービスを提供するサービスエリアをそれよりも狭い複数の通信空間領域（セル）に分割し，隣接するセルには異なる周波数帯域を割り当て，同じ周波数帯域を用いるセルを空間的に分離して配置することにより，上記サービスエリアに割り当てられた周波数帯域を有効利用すると共に，同じ周波数帯域を用いた複数の通信間の干渉を防止している。
【０００３】
【発明が解決しようとする課題】
しかしながら，上記セルラシステムにおいても，隣接するセルには干渉防止のため異なる周波数帯域を割り当てる必要があるから，その分だけ一チャンネルあたりで利用できる周波数帯域が減少してしまうことは避けられない。
本発明は，このような従来の技術における課題を解決するために，無線通信システムを改良し，複数の建築物が近接して建設された建築物群に対して，隣り合う上記建築物間に形成される空間毎に基地局をそれぞれ配置し，上記建築物により所定の周波数帯域を共用する複数の通信空間領域の境界をそれぞれ設定することにより，各通信空間領域毎に同じ周波数帯域を繰り返し使用しながら，同じ周波数帯域を使用した複数の無線通信間の干渉を防止することができる無線通信システムを提供することを目的とするものである。
【０００４】
また，所定の周波数帯域を共用する複数の通信空間領域毎に同じ周波数帯域を繰り返し用いながら複数の通信間の干渉を防止したとしても，例えば複数の加入者局毎にチャンネルが割り当てられる場合，ある通信空間領域に属する加入者局が増加すればするほど加入者一人当たりが利用可能な周波数帯域は減少してしまう。
そこで，本発明の他の目的は，各通信空間領域をさらに複数の小空間領域に分割して上記基地局を各小空間領域毎に配置し，各小空間領域内に属する加入者局と当該小空間領域の基地局との間で行われる指向性を有した無線通信の電波の指向する向きが，隣り合う上記小空間領域間で互いに異なるように，上記基地局と加入者局とを配置することにより，干渉を防止しながら各通信空間領域内で共用する周波数帯域を各小空間領域毎に再使用することができる無線通信システムを提供することである。
さらに，上記加入者局と基地局との間で指向性を有する双方向通信を行う場合に，上記加入者局から基地局への回線と上記基地局から加入者局への回線とで，限られた周波数帯域を分割することになり，各回線で使用できる周波数帯域が実質的に減少してしまう。
そこで，本発明のさらに他の目的は，上記加入者局から基地局への回線と上記基地局から加入者局への回線とで，電波の指向する向きが互いに異なるように上記基地局と加入者局とを配置することにより，干渉を防止しながら上記加入者局から基地局への回線と上記基地局から加入者局への回線とで，同じ周波数帯域を繰り返し使用することができる無線通信システムを提供することである。
また，上記のように複数の建築物が近接して建設された建築物群に対して，隣り合う上記建築物間に形成される空間毎に基地局をそれぞれ配置し，上記建築物により所定の周波数帯域を共用する複数の通信空間領域の境界をそれぞれ設定した場合，ある通信空間領域で行われる無線通信の電波は建築物により遮蔽され，ほとんど他の通信空間領域に達しないが，基地局や加入者局の設置状態や建築物の構造によっては，例えばガラス窓などを電波が透過して，他の通信空間領域に漏れてしまう恐れもある。この問題は，例えば基地局に相当する中継局から加入者局へ無線通信を行う場合にも同様に生じる。
そこで，本発明のさらに他の目的は，上記基地局（中継局を含む）から上記加入者局へ送信される電波の向きを少なくとも電波の到達距離内で各通信空間領域毎に異ならせることにより，ある通信空間領域で行われる無線通信の電波が他の通信空間領域に到達する，いわゆるオーバーリーチがあった場合でも，同じ周波数帯域を用いた複数の通信間で干渉を防止することである。
【０００５】
【課題を解決するための手段】
上記目的を達成するために，請求項１に係る発明は，予め複数のチャンネルが定められた所定の周波数帯域を共用する複数の通信空間領域毎に基地局を配置し，各通信空間領域内に属し且つ上記チャンネルが予め割り当てられた複数の固定加入者局と当該通信空間領域の基地局との間で無線通信を行う無線通信システムにおいて，複数の建築物が近接して建設された建築物群に対して，隣り合う上記建築物間に形成される空間毎に上記基地局と上記複数の固定加入者局とを配置し，上記建築物により各通信空間領域の境界を設定してなり，上記通信空間領域を形成する隣り合う２つの建築物の一方側に上記基地局が配置され，他方側に該基地局と無線通信を行う上記複数の固定加入者局が配置されてなることを特徴とする無線通信システムとして構成されている。
また，請求項２に係る発明は，上記請求項１に記載の無線通信システムにおいて，上記固定加入者局と基地局との間で行われる無線通信の電波が指向性を有しており，各通信空間領域をさらに複数の小空間領域に分割して上記基地局を各小空間領域毎に配置し，各小空間領域内に属する固定加入者局と当該小空間領域の基地局との間で行われる無線通信の電波の指向する向きが，隣り合う上記小空間領域間で互いに異なるように，上記基地局と固定加入者局とを配置してなることをその要旨とする。
また，請求項３に係る発明は，上記請求項１又は２に記載の無線通信システムにおいて，上記所定の周波数帯域の一部又は全ての周波数帯域を各通信空間領域毎或いは各小空間領域毎に繰り返し用いてなることをその要旨とする。
また，請求項４に係る発明は，上記請求項１〜３のいずれか１項に記載の無線通信システムにおいて，上記固定加入者局と基地局との間で指向性を有する双方向通信を行う場合に，上記固定加入者局から基地局への回線と上記基地局から固定加入者局への回線とで，電波の指向する向きが互いに異なるように上記基地局と固定加入者局とを配置してなることをその要旨とする。
また，請求項５に係る発明は，上記請求項１〜４のいずれか１項に記載の無線通信システムにおいて，上記基地局から上記固定加入者局へ送信される電波の向きを少なくとも電波の到達距離内で各通信空間領域毎に異ならせてなることをその要旨とする。
また，請求項６に係る発明は，上記請求項５に記載の無線通信システムにおいて，所定の建築物を境界とする隣り合う２つの上記通信空間領域それぞれの基地局を上下方向及び／又は水平方向にずらして配置してなることをその要旨とする。
【０００６】
上記請求項１〜６のいずれか１項に記載の無線通信システムによれば，複数の建築物が近接して建設された建築物群に対して，隣り合う上記建築物間に形成される空間毎に基地局と上記複数の固定加入者局とを配置し，上記建築物により所定の周波数帯域を共用する複数の通信空間領域の境界をそれぞれ設定し，さらに，上記通信空間領域を形成する隣り合う２つの建築物の一方側に上記基地局を配置し，他方側に該基地局と無線通信を行う上記複数の固定加入者局を配置することにより，各通信空間領域毎に同じ周波数帯域を繰り返し使用しながら，同じ周波数帯域を使用した複数の無線通信間の干渉を防止することができる。
しかも，上記請求項２に記載の無線通信システムによれば，各通信空間領域をさらに複数の小空間領域に分割して上記基地局を各小空間領域毎に配置し，各小空間領域内に属する固定加入者局と当該小空間領域の基地局との間で行われる指向性を有した無線通信の電波の指向する向きが，隣り合う上記小空間領域間で互いに異なるように，上記基地局と固定加入者局とを配置することにより，干渉を防止しながら各通信空間領域内で共用する周波数帯域を各小空間領域毎に再使用することができる。その結果，各通信空間領域内で必要なチャンネル数が増加しても，高速な無線通信サービスを提供することが可能となる。
また，上記請求項４に記載の無線通信システムによれば，上記固定加入者局と基地局との間で指向性を有する双方向通信を行う場合に，上記固定加入者局から基地局への回線と上記基地局から固定加入者局への回線とで，電波の指向する向きが互いに異なるように上記基地局と固定加入者局とを配置することにより，干渉を防止しながら上記固定加入者局から基地局への回線と上記基地局から固定加入者局への回線とで，同じ周波数帯域を繰り返し使用することができる。
さらに，上記請求項５又は６のいずれか１項に記載の無線通信システムによれば，上記基地局から上記固定加入者局へ送信される電波の向きを少なくとも電波の到達距離内で各通信空間領域毎に異ならせることにより，ある通信空間領域で行われる無線通信の電波が他の通信空間領域に到達する，いわゆるオーバーリーチがあった場合でも，同じ周波数帯域を用いた複数の通信間で干渉を防止することができる。尚，上記基地局は，ある基地局からの無線電波を受信し，その受信内容を固定加入者局に配信する中継局を含み，オーバーリーチによる干渉を抑制することにより，同一周波数によるＰＭＰ多段中継方式を用いることが可能となり，周波数帯域を有効利用することができる。
【０００７】
【発明の実施の形態】
以下，添付図面を参照して，本発明の実施の形態につき説明し，本発明の理解に供する。尚，以下の実施の形態は，本発明の具体的な一例であって，本発明の技術的範囲を限定する性格のものではない。ここに，図１は本発明の一実施の形態に係る無線通信システムの基本的な構成を示す図である。
本発明の一実施の形態に係る無線通信システムは，例えば複数の住宅棟が林立した集合住宅をサービスエリアとし，サービスエリア内の複数の加入者毎に高速な双方向データ通信サービスを提供するための無線通信システムとして具体化されるものである。
図１に示す如く，本実施の形態に係る無線通信システムは，予め複数のチャンネルが定められた所定の周波数帯域が利用可能なサービスエリアを分割した複数の通信空間領域（セル）１，２毎に基地局１１（１１，…），２１（２１，…）を配置し，各セル１，２内に属する上記チャンネルが予め割り当てられた加入者局（固定加入者局に相当）１０１，１０２（１０１，…），２０１，２０２（２０１，…）と当該セル１，２の基地局１１，２１との間で無線通信を行う点で従来のものと同様である。
一方，本実施の形態に係る無線通信システムが，従来のものと異なるのは，複数の住宅棟（建築物の一例）Ａ，Ｂ，Ｃが近接して建設された建築物群に対して，隣り合う上記住宅棟Ａ，Ｂ，Ｃ間に形成される空間毎に上記基地局１１，２１をそれぞれ配置し，また，同空間毎に加入者局１０１，１０２（１０１，…），２０１，２０２（２０１，…）をそれぞれ配置し，上記住宅棟Ａ，Ｂ，Ｃにより各セル１，２の境界を設定し，上記所定の周波数帯域のほぼ全ての周波数帯域を各セル１，２毎に繰り返し用いる点である。
以下，本実施の形態に係る無線通信システムの基本構成と，その他の実施例について場合分けを行って説明する。
【０００８】
（基本的構成）
図１に示す如く，上記無線通信システムでは，基地局１１，２１が，隣り合う住宅棟Ａ，Ｂ，Ｃ間に形成される空間毎にそれぞれ配置され，上記所定の周波数帯域を共用する複数のセル１，２の境界が住宅棟Ａ，Ｂ，Ｃにより設定される。例えば図１（ｂ）では，住宅棟Ａと住宅棟Ｂとの間の空間にセル１が，住宅棟Ｂと住宅棟Ｃとの間の空間にセル２が設定されている。
各セル１，２において，上記基地局１１，２１は例えば住宅棟Ａ，Ｂの中層部にそれぞれ設けられ，セル１，２内の住宅棟Ｂ，Ｃにある加入者局１０１，１０２，２０１，２０２にそれぞれ双方向無線通信サービスを提供する。
このようにセル１，２の基地局１１，２１を配置することにより，隣り合うセル１とセル２との境界に電波遮蔽効果の高い住宅棟Ｂが配置されることになる。従って，セル１内の基地局１１と加入者局１０１，１０２との間の無線通信と，セル２内の基地局２１と加入者局２０１，２０２との間の無線通信との間の干渉は，その電波が指向性を有しているか否かにかかわらず，ほぼ防止される。
そこで，本実施の形態に係る無線通信システムでは，セル１内の基地局１１と加入者局１０１，１０２との間の無線通信に用いられる周波数帯域と，セル２内の基地局２１と加入者局２０１，２０２との間の無線通信に用いられる周波数帯域とが同じにされる。即ち，セル１とセル２とで同じ周波数帯域が繰り返し用いられる。
これにより，セルラシステムを適用した場合のように，隣り合うセル間で干渉を防止するために周波数帯域を異ならせる必要がなく，複数のセル１，２間で共用する上記所定の周波数帯域のほぼ全てを各セル内の加入者で共有することができ，より高速で高品質の通信サービスを提供することができる。
【０００９】
（実施例１）
但し，例えば加入者別に無線通信サービスを提供する場合に，上記セル１の境界となる住宅棟Ａ，Ｂの加入者が極端に多いとき，即ち上記セル１内で提供するチャンネル数が極端に多いときには，上記所定の周波数帯域のほぼ全ての周波数帯域を上記セル１内の加入者で共有できたとしても，上記セル１内の加入者一人あたりが利用できる周波数帯域は狭くなってしまう。
このようなチャンネル増加に伴う利用周波数帯域の減少を抑制する実施例１を次に説明する。
この実施例１においても，上記基本構成と同様に，隣り合う住宅棟と住宅棟との間に形成された空間にセルが設定される。図２では，住宅棟Ａと住宅棟Ｂとの間に設定されたセル１のみが例示されている。
図２に示す如く，実施例１が，上記基本構成と相違するのは，セル１内に複数の基地局１１，１２，１３が設けられ，基地局１１，１２，１３と加入者局１０１，１０２，１０３との間の無線通信用の電波がそれぞれ指向性を有しており，上記セル１がさらに小さい複数の小空間領域１Ａ，１Ｂ，１Ｃに分割され，隣り合う小空間領域毎に無線通信用の電波の向きが互いに異なるように上記基地局１１，１２，１３と加入者局１０１，１０２，１０３とがそれぞれ配置されている点である。
図２の例では，上記セル１に複数設けられた基地局１１，１２，１３のうち，基地局１１，１３は住宅棟Ｂの上層部と下層部にそれぞれ設けられ，住宅棟Ａの上層部と下層部にある加入者局１０１，１０３との間でそれぞれ無線通信を行うために用いられる。
また，基地局１２は住宅棟Ａの中層部に設けられ，住宅棟Ｂの中層部にある加入者局１０２との間で無線通信を行うために用いられる。
このような基地局１１，１２，１３と加入者局１０１，１０２，１０３の配置を行うのは，上記セル１内で利用可能な周波数帯域には限りがあるから，チャンネル数増加による各チャンネルの利用周波数帯域の減少を抑制するためには，上記セル１内で干渉を防止しながら同じ周波数帯域を繰り返し用いる必要があるからである。
例えば図２において，基地局１１を備える小空間領域１Ａでは，基地局１１から加入者局１０１への下り回線は図面右側に向けられており，加入者局１０１から基地局１１への上り回線は図面右側に向けられているが，基地局１２を備える小空間領域Ｂでは，基地局１２から加入者局１０２への下り回線は図面左側に向けられており，加入者局１０２から基地局１２への上り回線は図面右側に向けられている。
即ち，隣り合う上記小空間領域Ａと小空間領域Ｂとでは，加入者局１０１，１０２と基地局１１，１２との間でそれぞれ行われる無線通信に用いられる電波の向きが互いに逆向きとなるように，上記基地局１１，１２と加入者局１０１，１０２とが配置されており，このような基地局と加入者局との配置は，隣り合う小空間領域１Ｂと小空間領域１Ｃとの間でも同様である。
これにより，同じ周波数帯域を用いた複数の通信間の干渉を防止することができる。
従って，加入者が増加するなどして各セル内でチャンネル数が増加した場合でも，各セルを分割する小空間領域の数だけ一チャンネルあたりで利用できる周波数帯域の減少を抑制することができる。
【００１０】
（実施例２）
このようにして，チャンネル数あたりの利用周波数帯域の減少を確保しても，双方向通信を行う場合には，加入者局から基地局への上り回線用と基地局から基地局への下り回線用の周波数帯域が別個に必要となり，ある方向の通信に利用できる周波数帯域は約半分程度に低下してしまう。
そこで，上り回線用と下り回線用とで干渉を防止しながら同じ周波数帯域を繰り返し用いた実施例２について説明する。
この実施例２においても，上記基本構成と同様に，隣り合う住宅棟と住宅棟との間に形成された空間毎に基地局が配置され，セルが設定されているものとする。図３に，上記基本構成のセル１側に面した住宅棟Ａの壁面が示す。
図３に示す如く，この実施例２に係る無線通信システムは，各加入者Ａ１（Ａ１，…）に対して下り回線用の基地局１１及び加入者局１０１，並びに，上り回線用の基地局１２及び加入者局１０２とがそれぞれ別個に設けられ，上り回線用の電波の指向する向きと下り回線用の電波の指向する向きとが互いに異ならされている点で上記基本構成と異なる。
この実施例２では，下り回線用の基地局１１が住宅棟Ａの中層部に指向性アンテナを水平方向に向けて配置されている。また，下り回線用の加入者局１０１は，上記基地局１１に指向性アンテナを向けて配置されている。
一方，上り回線用の基地局１２は住宅棟Ａの最上層に指向性アンテナを下方に向けて配置されている。また，上り回線用の加入者局１０２は，上記基地局１２に指向性アンテナを向けて配置されている。
このような上記基地局１１，１２及び加入者局１０１，１０２の配置により，下り回線用の電波の向きと上り回線用の電波の向きが互いに９０°異ならされているため，上り回線と下り回線とで同じ周波数帯域を繰り返し用いても干渉が生じない。
これにより，上り回線と下り回線とを異なる周波数帯域に配置する必要がなくなり，チャンネルあたりで利用できる周波数帯域をさらに増加させることができる。
【００１１】
（実施例３）
上記実施例２では，上り回線の電波の向きと下り回線の電波の向きが互いに異なるように上記加入者局及び基地局を配置することにより，チャンネルあたりで利用できる周波数帯域をさらに増加させていたが，各セル毎に同じ周波数帯域を利用した複数の通信間の干渉が防止されていることを利用して，ある住宅棟を境界とする２つのセルを上り回線用の無線通信と下り回線用の無線通信にそれぞれ利用するように構成してもよい。このような実施例３の構成を図４に示す。
図４では，住宅棟Ｂを境界とする２つのセル１，２に，住宅棟Ｂにある加入者局に対してそれぞれ下り回線と上り回線が設定されている。
例えば，住宅棟Ｂには加入者局１０３，１０４，２０１，２０２が設けられているが，このうち加入者局１０３と加入者局２０１はそれぞれ，ある加入者Ｂ１の下り回線用と上り回線用の加入者局であり，加入者局１０４と加入者局２０２はそれぞれ，他の加入者Ｂ２の下り回線用と上り回線用の加入者局である。
住宅棟Ｂに属する加入者Ｂ１，Ｂ２に対して下り回線は，セル１にある基地局１１からセル１にある加入者局１０３，１０４への通信により行われる。一方，住宅棟Ｂに属する加入者Ｂ１，Ｂ２に対して上り回線は，セル２にある加入者局２０１，２０２からセル２にある基地局２２への通信により行われる。
そして，図示されていないが，上記セル１にある基地局１１と上記セル２にある基地局２２とは例えば光ファイバーなどを用いた有線回線により接続されており，上記加入者Ｂ１，Ｂ２の無線通信に関する情報交換を上記基地局１１，上記基地局２２間で行い，双方向通信を行うことが可能である。
これにより，住宅棟Ｂに属する加入者Ｂ１，Ｂ２に対して，上り回線と下り回線とで同じ周波数帯域を用いながら，同じ周波数帯域を用いた複数の通信間の干渉を防止することができる。
尚，図４の例では，セル１は住宅棟Ｂに属する加入者の下り回線用としてだけでなく，住宅棟Ａに属する加入者の上り回線通信用として，セル２は住宅棟Ｂに属する加入者の上り回線用としてだけでなく，住宅棟Ｃに属する加入者の下り回線用としても用いられているが，これらの通信は互いに電波の指向する向きが異なるため，同じ周波数帯域を用いていても干渉が防止されている。
ここで，実施例３に係る技術的思想を記載すれば，所定の周波数帯域を共用する複数の通信空間領域毎に基地局を配置し，各通信空間領域内に属する複数の加入者局と当該通信空間領域の基地局との間で無線通信を行う無線通信システムにおいて，ある建築物を境界とする２つの通信空間領域に，上記ある建築物に属する加入者に対応して加入者局と基地局とをそれぞれ設け，かつ上記ある建築物に属する加入者局に対応して２つの通信空間領域にそれぞれ設けられた基地局間を接続し，一方の通信空間領域では，上記ある建築物に属する加入者に関して上記基地局から加入者局へ無線通信を行い，他方の通信空間領域では，上記ある建築物に属する加入者に関して上記加入者局から基地局へ無線通信を行い，両通信空間領域の基地局間で上記ある建築物に属する加入者の無線通信に関する情報を交換する無線通信システムである。
【００１２】
（実施例４）
各実施例は，単独で実施するだけでなく，組み合わせることも可能である。例えば（実施例１）と（実施例２）との構成を組み合わせた実施例４の構成について説明する。ここで，図５に実施例４に係る無線通信システムの構成を示す。
この実施例４においても，上記基本構成や各実施例と同様に，隣り合う住宅棟と住宅棟との間に形成された空間毎に基地局が配置され，セルが設定されているものとする。図５に，上記基本構成のセル１側に面した住宅棟Ａの壁面が示す。
図５に示す如く，この実施例４に係る無線通信システムでは，セル１が複数の小空間領域１Ａ，１Ｂに分割されており，小空間領域１Ａ内に属する各加入者ＡＡ１（ＡＡ１，…）に対して下り回線用の基地局１１及び加入者局１０１，並びに，上り回線用の基地局１２及び加入者局１０２とがそれぞれ別個に設けられ，小空間領域１Ｂ内に属する各加入者ＡＢ１（ＡＢ１，…）に対して下り回線用の基地局１３及び加入者局１０３，並びに，下り回線用の基地局１４及び加入者局１０２４がそれぞれ別個に設けられ，さらに各小空間領域１Ａ，１Ｂにおいて，上り回線用の電波の指向する向きと下り回線用の電波の指向する向きとが互いに異ならされている点で上記基本構成と異なる。
この実施例４では，下り回線用の基地局１１，１３が住宅棟Ａの中層部に指向性アンテナを水平方向に向けて配置されている。また，下り回線用の加入者局１０１，１０３は，上記基地局１１に指向性アンテナを向けて配置されている。
一方，上り回線用の基地局１２は住宅棟Ａの最上層に指向性アンテナを下方に向けて，上り回線用の基地局１４は住宅棟Ａの最下層に指向性アンテナを上方に向けてそれぞれ配置されている。また，上り回線用の加入者局１０２，１０４は，上記基地局１２，１４に指向性アンテナを向けてそれぞれ配置されている。
このような上記基地局１１，１２，１３，１４及び加入者局１０１，１０２，１０３，１０４の配置により，下り回線用の電波の向きと上り回線用の電波の向きが互いに９０°異ならされ，しかも隣り合う小空間領域毎に電波の向きが異ならされるため，上り回線と下り回線とで，且つ各小空間領域毎に同じ周波数帯域を繰り返し用いても干渉が防止される。
【００１３】
（実施例５）
ところで，上記基本構成及び各実施例では，上記のように複数の住宅棟が近接して建設された建築物群に対して，隣り合う上記住宅棟間に形成される空間毎に基地局をそれぞれ配置し，上記住宅棟により所定の周波数帯域を共用する複数のセルの境界をそれぞれ設定し，あるセルにおいて発せられた無線電波が当該セルの境界にある住宅棟により同じ周波数帯域を用いた複数の通信間の干渉を軽減していた。
ただ，基地局や加入者局の設置状態や建築物の構造によっては，例えばガラス窓などから電波が透過して，他のセルに漏れてしまう恐れもある。
このように，あるセルの無線電波が不要に他のセルにまで達してしまうオーバーリーチによる干渉の発生を防止するために，各セルの基地局から加入者局への電波の向きを少なくともオーバーリーチの範囲で各セル毎に異ならせるように無線通信システムを構成してもよい。ここで，同じ形状の建造物（建築物に相当）が同じ間隔で複数近接して建設された建築物群に対して設定された，各セルの基地局から加入者局への電波の向きを各セル毎に異ならせた実施例５の構成を図６に示す。
図６に示す如く，直進性の高い高周波の電波を用いる基地局６１から発せられた電波は，ほとんどが建造物６Ａにより遮蔽され，他のセルに及ぶことはないが，例えば建造物６Ａのガラス窓を電波が透過した場合，他のセルにある加入者局ａに到達してしまう恐れもある。
これを防止するために，実施例５に係る構成では，図６に示す如く，基地局６１が地面近くに設置されるのに対し，加入者局ａに本来無線通信サービスを提供する基地局６２は建造物６Ａの最上層に設置され，建造物６Ａにある加入者局と建造物６Ｂにある加入者局とでは，基地局６１，６２からそれぞれ受信される電波の向きがそれぞれ異ならされている。
この場合，オーバーリーチにより基地局６１から発せられた電波が他のセルにある加入者局ａに達したとしても，基地局６１，６２が上下方向にずらされて配置されており，加入者局ａは，基地局６２の配置に合わせてアンテナの向きが設定されているため，基地局６１と基地局６２から同じ周波数帯域を用いて送信された無線電波を上記加入者局ａが受信したとしてもその間の干渉を防止することができる。
また，基地局６２から直進した電波が，各建造物６Ｂ，６Ｃの側壁を透過して他のセルに属する加入者局ｂに達するような恐れも考えられる。この場合でも，基地局６２と基地局６４を水平方向にずらして配置し，加入者局ｂのアンテナの向きを上記基地局６４の配置に合わせて設定することにより，上記基地局６２と基地局６４から同じ周波数帯域を用いて送信された電波を上記加入者局Ｂが受信したとしてもその間の干渉を防止することができる。
尚，上記実施例５では，同じ形状の建造物が同じ間隔で規則正しく配列された建築物群を例にしたが，これに限られるものではなく，図７に示す如く，異なる形状（大きさを含む）建造物が異なる間隔で不規則に配列された建築物群に対して適用することも可能である。
さらに，上記の説明では基地局という言葉を用いたが，ある基地局からの無線電波を受信しその受信内容を中継する中継局に各基地局を置き換えることも可能である。複数の中継局により無線電波を中継する従来のＰＭＰ多段中継方式では，オーバーリーチによる干渉を防止するために異なる周波数帯域を各中継局で用いる必要があり，各中継局で利用できる周波数帯域は中継段数が増えるほど圧迫されていたが，本発明により同じ周波数帯域を用いた複数の通信間の干渉を防止することにより，周波数帯域の有効利用が可能となると共に，中継段数を増加させることが容易となり，設備などのコストを低減することができる。
また，上記実施の形態では，建築物が住宅棟である例を説明したが，これに限られるものではなく，例えば工場などが近接した建築物群に対して本発明を適用することも可能である。
【００１４】
【発明の効果】
以上説明した通り，上記請求項１〜６のいずれか１項に記載の無線通信システムによれば，複数の建築物が近接して建設された建築物群に対して，隣り合う上記建築物間に形成される空間毎に基地局と複数の固定加入者局とを配置し，上記建築物により所定の周波数帯域を共用する複数の通信空間領域の境界をそれぞれ設定し，さらに，上記通信空間領域を形成する隣り合う２つの建築物の一方側に上記基地局を配置し，他方側に該基地局と無線通信を行う上記複数の固定加入者局を配置することにより，各通信空間領域毎に同じ周波数帯域を繰り返し使用しながら，同じ周波数帯域を使用した複数の無線通信間の干渉を防止することができる。
しかも，上記請求項２に記載の無線通信システムによれば，各通信空間領域をさらに複数の小空間領域に分割して上記基地局を各小空間領域毎に配置し，各小空間領域内に属する固定加入者局と当該小空間領域の基地局との間で行われる指向性を有した無線通信の電波の指向する向きが，隣り合う上記小空間領域間で互いに異なるように，上記基地局と固定加入者局とを配置することにより，干渉を防止しながら各通信空間領域内で共用する周波数帯域を各小空間領域毎に再使用することができる。その結果，各通信空間領域内で必要なチャンネル数が増加しても，高速な無線通信サービスを提供することが可能となる。
また，上記請求項４に記載の無線通信システムによれば，上記固定加入者局と基地局との間で指向性を有する双方向通信を行う場合に，上記固定加入者局から基地局への回線と上記基地局から固定加入者局への回線とで，電波の指向する向きが異なるように上記基地局と固定加入者局とを配置することにより，干渉を防止しながら上記固定加入者局から基地局への回線と上記基地局から固定加入者局への回線とで，同じ周波数帯域を繰り返し使用することができる。
さらに，上記請求項５又は６のいずれか１項に記載の無線通信システムによれば，上記基地局（中継局を含む）から上記固定加入者局へ送信される電波の向きを少なくとも電波の到達距離内で各通信空間領域毎に異ならせることにより，ある通信空間領域で行われる無線通信の電波が他の通信空間領域に到達する，いわゆるオーバーリーチがあった場合でも，同じ周波数帯域を用いた複数の通信間で干渉を防止することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態に係る無線通信システムの基本的な構成を説明するための図。
【図２】本発明の実施例１に係る無線通信システムの概略構成を示す図。
【図３】本発明の実施例２に係る無線通信システムの概略構成を示す図。
【図４】本発明の実施例３に係る無線通信システムの概略構成を示す図。
【図５】本発明の実施例４に係る無線通信システムの概略構成を示す図。
【図６】本発明の実施例５に係る無線通信システムの概略構成を示す図。
【図７】本発明の実施例５に係る他の無線通信システムの概略構成を示す図。
【符号の説明】
１，２…セル
１Ａ，１Ｂ，１Ｃ…小空間領域
１１，１２…基地局
１０１，１０２，１０３，１０４…加入者局
Ａ，Ｂ，Ｃ…建築物[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a radio communication system, and more specifically, a base station is arranged for each of a plurality of communication space areas (cells) sharing a predetermined frequency band, and the fixed subscriber station belonging to each communication space area and the communication The present invention relates to a wireless communication system that performs wireless communication with a base station in a spatial domain.
[0002]
[Prior art]
  For example, there is a one-to-many bidirectional wireless communication system that transmits and receives data between a plurality of subscriber stations and a base station in an area having a radius of several kilometers using a quasi-millimeter wave or millimeter wave of about 20 GHz to 40 GHz. In this wireless communication system, construction that strongly depends on subscribers such as in-home wiring is reduced, so a relatively wide frequency band is required such as providing video data for movies etc. on demand in addition to Internet connection services. Services can be provided at low cost.
  By the way, especially in urban areas, subscribers tend to concentrate in specific areas due to an increase in condominiums in which a plurality of residential buildings are forested. Since the frequency band that can be used in a certain service area is limited, the frequency band that can be used per channel decreases as the number of necessary channels increases as the number of subscribers increases.
  In order to increase the usable frequency band per channel in the limited frequency band, for example, the same frequency band may be used repeatedly. However, in this case, it is necessary to prevent interference between a plurality of communications using the same frequency band. There is a cellular system as a wireless communication system that repeatedly uses the same frequency band while preventing such interference.
  In a cellular system, a service area that provides a wireless communication service is divided into a plurality of communication space regions (cells) that are narrower than that, and different frequency bands are assigned to adjacent cells, and cells using the same frequency band are spatially separated. By arranging them separately, the frequency band assigned to the service area is effectively used, and interference between a plurality of communications using the same frequency band is prevented.
[0003]
[Problems to be solved by the invention]
  However, even in the above cellular system, it is necessary to assign different frequency bands to adjacent cells in order to prevent interference. Therefore, it is inevitable that the frequency band that can be used per channel is reduced accordingly.
  In order to solve such problems in the prior art, the present invention improves the wireless communication system, and a group of buildings in which a plurality of buildings are constructed in close proximity to each other between the adjacent buildings. Base stations are arranged in each space to be formed, and the same frequency band is repeatedly used for each communication space area by setting boundaries of multiple communication space areas that share a predetermined frequency band by the above building. However, an object of the present invention is to provide a wireless communication system capable of preventing interference between a plurality of wireless communications using the same frequency band.
[0004]
  In addition, even if the same frequency band is repeatedly used for each of a plurality of communication space areas sharing a predetermined frequency band and interference between a plurality of communications is prevented, a channel may be allocated to each of a plurality of subscriber stations, for example. As the number of subscriber stations belonging to the communication space region increases, the frequency band available for each subscriber decreases.
  Therefore, another object of the present invention is to further divide each communication space area into a plurality of small space areas and arrange the base station for each small space area so that the subscriber stations belonging to each small space area The base station and the subscriber station are arranged so that the directivity directions of radio communication with directivity performed between the base stations in the small space area are different from each other between the adjacent small space areas. Accordingly, it is an object of the present invention to provide a wireless communication system capable of reusing a frequency band shared in each communication space region for each small space region while preventing interference.
  Further, when bidirectional communication having directivity is performed between the subscriber station and the base station, the line from the subscriber station to the base station and the line from the base station to the subscriber station are limited. Therefore, the frequency band that can be used in each line is substantially reduced.
  Therefore, still another object of the present invention is to join the base station and the base station so that the directions of radio waves are different between the line from the subscriber station to the base station and the line from the base station to the subscriber station. Wireless communication that can repeatedly use the same frequency band on the line from the subscriber station to the base station and the line from the base station to the subscriber station while preventing interference. Is to provide a system.
  In addition, a base station is arranged for each space formed between adjacent buildings with respect to a group of buildings in which a plurality of buildings are constructed close to each other as described above. When the boundaries of multiple communication space areas that share a frequency band are set, radio waves transmitted in a certain communication space area are shielded by the building and hardly reach other communication space areas. Depending on the installed state of the subscriber station and the structure of the building, for example, radio waves may pass through a glass window and leak into other communication space areas. This problem also occurs when, for example, wireless communication is performed from a relay station corresponding to a base station to a subscriber station.
  Therefore, still another object of the present invention is to make the direction of the radio wave transmitted from the base station (including the relay station) to the subscriber station different for each communication space area at least within the reach of the radio wave. This is to prevent interference between a plurality of communications using the same frequency band even when there is a so-called overreach in which radio communication radio waves performed in a certain communication space area reach other communication space areas.
[0005]
[Means for Solving the Problems]
  In order to achieve the above object, the invention according to claim 1 is arranged such that a base station is arranged in each of a plurality of communication space areas sharing a predetermined frequency band in which a plurality of channels are determined in advance, In a wireless communication system that performs wireless communication between a plurality of fixed subscriber stations to which the channel belongs and a base station in the communication space area, a group of buildings in which a plurality of buildings are constructed in the vicinity On the other hand, the base station and the plurality of fixed subscriber stations are arranged for each space formed between the adjacent buildings, and the boundaries of the communication space areas are set by the buildings.Therefore, the base station is arranged on one side of two adjacent buildings forming the communication space area, and the plurality of fixed subscriber stations that perform radio communication with the base station are arranged on the other side.It is comprised as a radio | wireless communications system characterized by this.
  According to a second aspect of the present invention, in the wireless communication system according to the first aspect, radio waves of wireless communication performed between the fixed subscriber station and the base station have directivity, The communication space area is further divided into a plurality of small space areas, and the base station is arranged for each small space area. Between the fixed subscriber station belonging to each small space area and the base station in the small space area, The gist of the invention is that the base station and the fixed subscriber station are arranged so that directions of radio waves to be performed are different from each other between the adjacent small space areas.
  The invention according to claim 3 is the wireless communication system according to claim 1 or 2, wherein a part or all of the predetermined frequency band is assigned to each communication space region or each small space region. The gist is to use it repeatedly.
  According to a fourth aspect of the present invention, in the wireless communication system according to any one of the first to third aspects, bidirectional communication having directivity is performed between the fixed subscriber station and a base station. In this case, the base station and the fixed subscriber station are arranged so that the directions of the radio waves are different between the line from the fixed subscriber station to the base station and the line from the base station to the fixed subscriber station. The gist of this is
  Claims5The invention according to claim 1 to claim 14In the wireless communication system according to any one of the above, the direction of the radio wave transmitted from the base station to the fixed subscriber station is different for each communication space region at least within the reach of the radio wave. The gist.
  Claims6The invention according to claim 15The gist of the wireless communication system described in 1 is that base stations of two adjacent communication space areas with a predetermined building as a boundary are arranged to be shifted in the vertical direction and / or the horizontal direction.
[0006]
  Claims 1 to above6According to the wireless communication system according to any one of the above, with respect to a group of buildings in which a plurality of buildings are constructed close to each other, the base station and the above-described units are formed for each space formed between the adjacent buildings. Place multiple fixed subscriber stations and set boundaries for multiple communication space areas that share the specified frequency band with the buildingFurther, the base station is arranged on one side of two adjacent buildings forming the communication space area, and the plurality of fixed subscriber stations that perform radio communication with the base station are arranged on the other side.By doing so, it is possible to prevent interference between a plurality of wireless communications using the same frequency band while repeatedly using the same frequency band for each communication space region.
  Moreover, according to the wireless communication system of the second aspect, each communication space area is further divided into a plurality of small space areas, and the base station is arranged for each small space area. The base station so that the directivity directions of radio communication radio waves having directivity performed between the fixed subscriber station to which it belongs and the base station in the small space area are different between the adjacent small space areas. And the fixed subscriber station can reuse the frequency band shared in each communication space region for each small space region while preventing interference. As a result, it is possible to provide a high-speed wireless communication service even if the number of necessary channels in each communication space area increases.
  Further, according to the wireless communication system of the fourth aspect, when performing bidirectional communication having directivity between the fixed subscriber station and the base station, the fixed subscriber station to the base station By arranging the base station and the fixed subscriber station so that the direction of the radio wave is different between the line and the line from the base station to the fixed subscriber station, the fixed subscriber can be prevented while preventing interference. The same frequency band can be repeatedly used for the line from the station to the base station and the line from the base station to the fixed subscriber station.
  Furthermore, the above claim 5Or 6According to the wireless communication system according to any one of the above, by changing the direction of the radio wave transmitted from the base station to the fixed subscriber station for each communication space region at least within the reach of the radio wave, Even when there is a so-called overreach in which radio waves of wireless communication performed in a certain communication space area reach other communication space areas, interference can be prevented between a plurality of communications using the same frequency band. The base station includes a relay station that receives a radio wave from a certain base station and distributes the received content to a fixed subscriber station, and suppresses interference due to overreach so that PMP multi-stage relay using the same frequency is performed. It becomes possible to use the method, and the frequency band can be used effectively.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following embodiment is a specific example of the present invention, and is not of a nature that limits the technical scope of the present invention. FIG. 1 is a diagram showing a basic configuration of a radio communication system according to an embodiment of the present invention.
  The wireless communication system according to an embodiment of the present invention is to provide a high-speed two-way data communication service for each of a plurality of subscribers in a service area using, for example, a housing complex including a plurality of residential buildings as a service area. It is embodied as a wireless communication system.
  As shown in FIG. 1, the radio communication system according to the present embodiment has a plurality of communication space areas (cells) 1 and 2 divided into service areas in which a predetermined frequency band in which a plurality of channels are defined in advance can be used. , And base stations 11 (11,...), 21 (21,. 101,..., 201, 202 (201,...) And the base stations 11 and 21 of the cells 1 and 2 are similar to the conventional one in that wireless communication is performed.
  On the other hand, the wireless communication system according to the present embodiment is different from the conventional one in that a plurality of residential buildings (an example of a building) A, B, and C are constructed close to each other. The base stations 11 and 21 are arranged for each space formed between the adjacent residential buildings A, B, and C, and the subscriber stations 101, 102 (101,...), 201, 202 are provided for each space. (201,...) Are arranged, the boundaries of the cells 1 and 2 are set by the residential buildings A, B, and C, and almost all the frequency bands of the predetermined frequency band are repeated for each of the cells 1 and 2. It is a point to use.
  Hereinafter, the basic configuration of the radio communication system according to the present embodiment and other examples will be described by dividing into cases.
[0008]
(Basic configuration)
  As shown in FIG. 1, in the wireless communication system, base stations 11 and 21 are arranged for each space formed between adjacent residential buildings A, B, and C, and share a plurality of the predetermined frequency bands. The boundary between the cells 1 and 2 is set by the residential buildings A, B, and C. For example, in FIG. 1B, the cell 1 is set in the space between the residential building A and the residential building B, and the cell 2 is set in the space between the residential building B and the residential building C.
  In each of the cells 1 and 2, the base stations 11 and 21 are provided, for example, in the middle layers of the residential buildings A and B, respectively, and the subscriber stations 101, 102, 201, and the like in the residential buildings B and C in the cells 1 and 2, respectively. The two-way wireless communication service is provided to each 202.
  By arranging the base stations 11 and 21 of the cells 1 and 2 in this way, the residential building B having a high radio wave shielding effect is arranged at the boundary between the adjacent cells 1 and 2. Therefore, the interference between the radio communication between the base station 11 and the subscriber stations 101 and 102 in the cell 1 and the radio communication between the base station 21 and the subscriber stations 201 and 202 in the cell 2 is Regardless of whether the radio wave has directivity or not, it is almost prevented.
  Therefore, in the radio communication system according to the present embodiment, the frequency band used for radio communication between the base station 11 in the cell 1 and the subscriber stations 101 and 102, the base station 21 in the cell 2 and the subscriber The frequency band used for wireless communication with the stations 201 and 202 is made the same. That is, the same frequency band is repeatedly used in cell 1 and cell 2.
  Thus, unlike the case where a cellular system is applied, it is not necessary to change the frequency band in order to prevent interference between adjacent cells, and the predetermined frequency band shared by the plurality of cells 1 and 2 is almost the same. Everything can be shared by subscribers in each cell, and a higher speed and higher quality communication service can be provided.
[0009]
Example 1
  However, for example, when providing a wireless communication service for each subscriber, the number of channels provided in the cell 1 is extremely large when the subscribers of the residential buildings A and B serving as the boundary of the cell 1 are extremely large. Sometimes, even if almost all of the predetermined frequency band can be shared by subscribers in the cell 1, the frequency band that can be used by each subscriber in the cell 1 becomes narrow.
  A first embodiment that suppresses the decrease in the use frequency band accompanying such channel increase will be described below.
  Also in the first embodiment, cells are set in a space formed between adjacent residential buildings as in the basic configuration. In FIG. 2, only the cell 1 set between the residential building A and the residential building B is illustrated.
  As shown in FIG. 2, the first embodiment is different from the basic configuration described above in that a plurality of base stations 11, 12, 13 are provided in the cell 1, and the base stations 11, 12, 13 and the subscriber station 101, The radio waves for wireless communication with 102 and 103 have directivity, and the cell 1 is further divided into a plurality of smaller small space areas 1A, 1B, and 1C, and wireless for each adjacent small space area. The base stations 11, 12, 13 and the subscriber stations 101, 102, 103 are arranged so that the directions of radio waves for communication are different from each other.
  In the example of FIG. 2, among the plurality of base stations 11, 12, and 13 provided in the cell 1, the base stations 11 and 13 are respectively provided in the upper layer portion and the lower layer portion of the residential building B. And subscriber stations 101 and 103 in the lower layer are used for wireless communication.
  The base station 12 is provided in the middle layer of the residential building A and is used for wireless communication with the subscriber station 102 in the middle layer of the residential building B.
  The arrangement of the base stations 11, 12, 13 and the subscriber stations 101, 102, 103 is limited because the frequency band that can be used in the cell 1 is limited. This is because it is necessary to repeatedly use the same frequency band while preventing interference in the cell 1 in order to suppress a decrease in the use frequency band.
  For example, in FIG. 2, in the small space area 1A including the base station 11, the downlink from the base station 11 to the subscriber station 101 is directed to the right side of the drawing, and the uplink from the subscriber station 101 to the base station 11 is Although it is directed to the right side of the drawing, in the small space area B including the base station 12, the downlink from the base station 12 to the subscriber station 102 is directed to the left side of the drawing, and from the subscriber station 102 to the base station 12. The up line is directed to the right side of the drawing.
  That is, in the adjacent small space area A and small space area B, the directions of radio waves used for wireless communication performed between the subscriber stations 101 and 102 and the base stations 11 and 12 are opposite to each other. Thus, the base stations 11 and 12 and the subscriber stations 101 and 102 are arranged, and the arrangement of the base station and the subscriber station is such that the small space area 1B and the small space area 1C are adjacent to each other. The same applies to between.
  As a result, interference between a plurality of communications using the same frequency band can be prevented.
  Therefore, even when the number of channels increases in each cell due to an increase in subscribers, it is possible to suppress a decrease in the frequency band that can be used per channel by the number of small space areas that divide each cell.
[0010]
(Example 2)
  In this way, when two-way communication is performed even if the reduction of the frequency band used per channel is ensured, the downlink from the subscriber station to the base station and the downlink from the base station to the base station A separate frequency band is required, and the frequency band that can be used for communication in a certain direction is reduced to about half.
  Therefore, a second embodiment in which the same frequency band is repeatedly used while preventing interference between the uplink and the downlink will be described.
  Also in the second embodiment, similarly to the above basic configuration, it is assumed that a base station is arranged for each space formed between adjacent residential buildings and a cell is set. FIG. 3 shows the wall surface of the residential building A facing the cell 1 side of the basic configuration.
  As shown in FIG. 3, the radio communication system according to the second embodiment includes a downlink base station 11 and a subscriber station 101 for each subscriber A1 (A1,...), And an uplink base station. 12 and the subscriber station 102 are provided separately, and are different from the above basic configuration in that the direction in which the uplink radio wave is directed and the direction in which the downlink radio wave is directed are different from each other.
  In the second embodiment, the downlink base station 11 is arranged in the middle layer of the residential building A with the directional antenna facing in the horizontal direction. The downlink subscriber station 101 is arranged with a directional antenna facing the base station 11.
  On the other hand, the uplink base station 12 is arranged on the uppermost layer of the residential building A with the directional antenna facing downward. The uplink subscriber station 102 is arranged with the directional antenna facing the base station 12.
  Due to the arrangement of the base stations 11 and 12 and the subscriber stations 101 and 102, the direction of the downlink radio wave and the direction of the uplink radio wave are different from each other by 90 °. No interference occurs even when the same frequency band is repeatedly used.
  Thereby, it is not necessary to arrange the uplink and downlink in different frequency bands, and the frequency band that can be used per channel can be further increased.
[0011]
(Example 3)
  In the second embodiment, the frequency band that can be used per channel is further increased by arranging the subscriber station and the base station so that the direction of the uplink radio wave and the direction of the downlink radio wave are different from each other. However, taking advantage of the fact that interference between multiple communications using the same frequency band for each cell is prevented, two cells bounded by a certain residential building are connected to wireless communication for uplink and downlink. You may comprise so that it may each utilize for radio | wireless communication. Such a configuration of the third embodiment is shown in FIG.
  In FIG. 4, a downlink and an uplink are set for the subscriber stations in the residential building B in the two cells 1 and 2 with the residential building B as a boundary.
  For example, in the residential building B, subscriber stations 103, 104, 201, and 202 are provided. Of these, the subscriber station 103 and the subscriber station 201 are for the downlink and the uplink of a certain subscriber B1, respectively. The subscriber station 104 and the subscriber station 202 are the subscriber stations for the downlink and the uplink of the other subscriber B2, respectively.
  For the subscribers B1 and B2 belonging to the residential building B, the downlink is performed by communication from the base station 11 in the cell 1 to the subscriber stations 103 and 104 in the cell 1. On the other hand, for the subscribers B1 and B2 belonging to the residential building B, the uplink is performed by communication from the subscriber stations 201 and 202 in the cell 2 to the base station 22 in the cell 2.
  Although not shown, the base station 11 in the cell 1 and the base station 22 in the cell 2 are connected by a wired line using, for example, an optical fiber, and wireless communication of the subscribers B1 and B2 is performed. It is possible to exchange information on the base station 11 and the base station 22 to perform bidirectional communication.
  Thereby, it is possible to prevent interference between a plurality of communications using the same frequency band for the subscribers B1 and B2 belonging to the residential building B while using the same frequency band for the uplink and the downlink.
  In the example of FIG. 4, cell 1 is used not only for the downlink of the subscriber belonging to the residential building B but also for the uplink communication of the subscriber belonging to the residential building A, and the cell 2 is a subscription belonging to the residential building B. It is used not only for the user's uplink, but also for the subscriber's downlink for the residential building C, but these communications use the same frequency band because the directions of radio waves are different from each other. Interference is also prevented.
  Here, if the technical idea according to the third embodiment is described, a base station is arranged for each of a plurality of communication space areas sharing a predetermined frequency band, and a plurality of subscriber stations belonging to each communication space area and In a wireless communication system that performs wireless communication with a base station in a communication space area, a subscriber station and a base correspond to subscribers belonging to the certain building in two communication space areas with a certain building as a boundary. Each base station provided in each of the two communication space areas corresponding to a subscriber station belonging to a certain building, and one communication space area belongs to the above certain building Wireless communication is performed from the base station to the subscriber station for the subscriber, and in the other communication space area, wireless communication is performed from the subscriber station to the base station for the subscriber belonging to the certain building. Above between base stations A wireless communication system for exchanging information relating to the wireless communication subscriber belonging to a certain building.
[0012]
Example 4
  Each embodiment can be combined as well as implemented alone. For example, the configuration of the fourth embodiment that combines the configurations of (first embodiment) and (second embodiment) will be described. FIG. 5 shows the configuration of the wireless communication system according to the fourth embodiment.
  Also in the fourth embodiment, as in the basic configuration and each of the embodiments, a base station is arranged for each space formed between adjacent residential buildings and a cell is set. . FIG. 5 shows the wall surface of the residential building A facing the cell 1 side of the basic configuration.
  As shown in FIG. 5, in the wireless communication system according to the fourth embodiment, the cell 1 is divided into a plurality of small space areas 1A and 1B, and each subscriber AA1 (AA1,...) Belonging to the small space area 1A. , The downlink base station 11 and the subscriber station 101, and the uplink base station 12 and the subscriber station 102 are provided separately, and each subscriber AB1 ( A base station 13 and a subscriber station 103 for downlink, and a base station 14 and a subscriber station 1024 for downlink are provided separately for AB1,. , Which differs from the above basic configuration in that the direction in which the uplink radio wave is directed and the direction in which the downlink radio wave is directed are different from each other.
  In the fourth embodiment, the downlink base stations 11 and 13 are arranged in the middle layer of the residential building A with the directional antenna facing in the horizontal direction. Further, the downlink subscriber stations 101 and 103 are arranged with a directional antenna facing the base station 11.
  On the other hand, the uplink base station 12 has a directional antenna facing downward on the uppermost layer of the residential building A, and the upstream base station 14 has a directional antenna facing upward on the lowermost layer of the residential building A. Has been placed. Further, the subscriber stations 102 and 104 for the uplink are respectively arranged with the directional antennas facing the base stations 12 and 14.
  Due to the arrangement of the base stations 11, 12, 13, 14 and the subscriber stations 101, 102, 103, 104, the direction of the downlink radio wave and the direction of the uplink radio wave are different from each other by 90 °. In addition, since the direction of the radio wave is different for each adjacent small space area, interference is prevented even when the same frequency band is repeatedly used for the uplink and the downlink and for each small space area.
[0013]
(Example 5)
  By the way, in the said basic composition and each Example, with respect to the building group in which several residential buildings were constructed in the vicinity as mentioned above, a base station is respectively provided for every space formed between the said adjacent residential buildings. And the boundary of a plurality of cells sharing a predetermined frequency band is set by the residential building, and a plurality of radio waves emitted from a certain cell are used by the residential building at the boundary of the cell. Interference between communications was reduced.
  However, depending on the installation state of the base station and the subscriber station and the structure of the building, for example, radio waves may be transmitted from a glass window or the like and leak to other cells.
  In this way, in order to prevent the occurrence of interference due to overreach in which the radio wave of a certain cell reaches other cells unnecessarily, the direction of the radio wave from the base station of each cell to the subscriber station is at least overreachable. The wireless communication system may be configured so as to be different for each cell in the range. Here, the direction of radio waves from the base station of each cell to the subscriber station set for a group of buildings with the same shape (corresponding to a building) built in close proximity at the same interval. FIG. 6 shows the configuration of the fifth embodiment that is different for each cell.
  As shown in FIG. 6, most of radio waves emitted from the base station 61 using high-frequency radio waves with high straightness are shielded by the building 6A and do not reach other cells. For example, the glass of the building 6A When radio waves pass through the window, there is a possibility that the subscriber station a in another cell may be reached.
  In order to prevent this, in the configuration according to the fifth embodiment, as shown in FIG. 6, the base station 61 is installed near the ground, whereas the base station 62 that originally provides the wireless communication service to the subscriber station a. Is installed in the uppermost layer of the building 6A, and the directions of radio waves received from the base stations 61 and 62 are different between the subscriber station in the building 6A and the subscriber station in the building 6B. .
  In this case, even if a radio wave emitted from the base station 61 due to overreach reaches the subscriber station a in another cell, the base stations 61 and 62 are shifted in the vertical direction, and the subscriber station a indicates that the subscriber station a has received radio waves transmitted from the base station 61 and the base station 62 using the same frequency band because the antenna orientation is set in accordance with the arrangement of the base stations 62. Can also prevent interference between them.
  In addition, there is a possibility that radio waves traveling straight from the base station 62 may pass through the side walls of the buildings 6B and 6C and reach the subscriber station b belonging to another cell. Even in this case, the base station 62 and the base station 64 are shifted in the horizontal direction, and the antenna direction of the subscriber station b is set in accordance with the arrangement of the base station 64, whereby the base station 62 and the base station are arranged. 64, even if the subscriber station B receives radio waves transmitted using the same frequency band, interference between them can be prevented.
  In the fifth embodiment, an example of a group of buildings in which buildings with the same shape are regularly arranged at the same interval is used as an example. However, the present invention is not limited to this, and as shown in FIG. It is also possible to apply to a group of buildings in which buildings are randomly arranged at different intervals.
  Furthermore, although the term “base station” is used in the above description, each base station can be replaced with a relay station that receives radio waves from a certain base station and relays the received contents. In the conventional PMP multi-stage relay system in which radio waves are relayed by a plurality of relay stations, it is necessary to use different frequency bands in each relay station in order to prevent interference due to overreach. Although the pressure was increased as the number of stages increased, the present invention prevents the interference between a plurality of communications using the same frequency band, thereby enabling effective use of the frequency band and easily increasing the number of relay stages. As a result, the cost of equipment can be reduced.
  In the above embodiment, an example in which the building is a residential building has been described. However, the present invention is not limited to this example, and the present invention can be applied to a group of buildings close to factories, for example. is there.
[0014]
【The invention's effect】
  As described above, the above claims 1 to6According to the wireless communication system according to any one of the above, for a group of buildings in which a plurality of buildings are constructed close to each other, a plurality of base stations and a plurality of base stations are formed for each space formed between the adjacent buildings. Multiple fixed-communication subscriber stations and set the boundaries of multiple communication space areas that share the specified frequency band with the buildingFurthermore, the base station is arranged on one side of two adjacent buildings forming the communication space area, and the base station is not connected to the other side. Place multiple fixed subscriber stations for line communicationBy doing so, it is possible to prevent interference between a plurality of wireless communications using the same frequency band while repeatedly using the same frequency band for each communication space region.
  Moreover, according to the wireless communication system of the second aspect, each communication space area is further divided into a plurality of small space areas, and the base station is arranged for each small space area. The base station so that the directivity directions of radio communication radio waves having directivity performed between the fixed subscriber station to which it belongs and the base station in the small space area are different between the adjacent small space areas. And the fixed subscriber station can reuse the frequency band shared in each communication space region for each small space region while preventing interference. As a result, it is possible to provide a high-speed wireless communication service even if the number of necessary channels in each communication space area increases.
  Further, according to the wireless communication system of the fourth aspect, when performing bidirectional communication having directivity between the fixed subscriber station and the base station, the fixed subscriber station to the base station By arranging the base station and the fixed subscriber station so that the direction of the radio wave is different between the line and the line from the base station to the fixed subscriber station, the fixed subscriber station can be prevented while preventing interference. The same frequency band can be repeatedly used for the line from the base station to the base station and the line from the base station to the fixed subscriber station.
  Furthermore, the above claim 5Or 6According to the wireless communication system described in any one of the above, the direction of the radio wave transmitted from the base station (including the relay station) to the fixed subscriber station is determined for each communication space region at least within the radio wave reach. To prevent interference between multiple communications using the same frequency band, even when there is a so-called overreach where radio waves in a certain communication space area reach other communication space areas. can do.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a basic configuration of a wireless communication system according to an embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of a wireless communication system according to Embodiment 1 of the present invention.
FIG. 3 is a diagram illustrating a schematic configuration of a wireless communication system according to a second embodiment of the present invention.
FIG. 4 is a diagram illustrating a schematic configuration of a wireless communication system according to a third embodiment of the present invention.
FIG. 5 is a diagram illustrating a schematic configuration of a wireless communication system according to a fourth embodiment of the present invention.
FIG. 6 is a diagram illustrating a schematic configuration of a wireless communication system according to a fifth embodiment of the present invention.
FIG. 7 is a diagram showing a schematic configuration of another wireless communication system according to Embodiment 5 of the present invention.
[Explanation of symbols]
  1, 2, ... cell
  1A, 1B, 1C ... small space area
  11, 12 ... Base station
  101, 102, 103, 104 ... subscriber stations
  A, B, C ... Buildings

Claims

A base station is arranged for each of a plurality of communication space areas sharing a predetermined frequency band in which a plurality of channels are defined in advance, and a plurality of fixed subscriber stations that belong to each communication space area and to which the channels are assigned in advance In a wireless communication system that performs wireless communication with a base station in the communication space area,
For a group of buildings constructed in the vicinity of a plurality of buildings, the base station and the plurality of fixed subscriber stations are arranged for each space formed between the adjacent buildings, and the building Ri Na by setting the boundary of the communication space domain by,
On one side of the two buildings adjacent forming the communication space region the base station is located, the Rukoto such by the plurality of fixed subscriber stations are arranged to perform the base station and the wireless communication on the other side A wireless communication system.

Radio waves of wireless communication performed between the fixed subscriber station and the base station have directivity, and each communication space area is further divided into a plurality of small space areas, and the base station is divided into each small space area. Arranged for each
The base stations are arranged such that the directivity directions of radio waves for radio communication performed between a fixed subscriber station belonging to each small space area and a base station in the small space area are different between adjacent small space areas. The wireless communication system according to claim 1, wherein a station and a fixed subscriber station are arranged.

3. The wireless communication system according to claim 1, wherein a part or all of the predetermined frequency band is repeatedly used for each communication space region or each small space region. 4.

When performing bidirectional communication with directivity between the fixed subscriber station and the base station, a line from the fixed subscriber station to the base station and a line from the base station to the fixed subscriber station, The radio communication system according to any one of claims 1 to 3, wherein the base station and the fixed subscriber station are arranged so that directions of radio waves are different from each other.

The radio communication system according to any one of claims 1 to 4 , wherein a direction of a radio wave transmitted from the base station to the fixed subscriber station is made different for each communication space area at least within a radio wave reachable range. .

6. The radio communication system according to claim 5 , wherein base stations of two adjacent communication space areas having a predetermined building as a boundary are arranged so as to be shifted in the vertical direction and / or the horizontal direction.