JP3853697B2

JP3853697B2 - Radio communication system, radio management apparatus, accommodation apparatus selection method, and program

Info

Publication number: JP3853697B2
Application number: JP2002158030A
Authority: JP
Inventors: 恒太郎伊瀬
Original assignee: Toshiba Solutions Corp
Current assignee: Toshiba Digital Solutions Corp
Priority date: 2002-05-30
Filing date: 2002-05-30
Publication date: 2006-12-06
Anticipated expiration: 2022-05-30
Also published as: JP2004007078A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えばＢｌｕｅｔｏｏｔｈに従う無線通信システム及び通信管理装置並びに収容装置選定方法及びプログラムに関する。
【０００２】
【従来の技術】
無線通信システムの一つであるＢｌｕｅｔｏｏｔｈにおいては、通信可能範囲が建屋内、ビルの一区画内、車両内等のように予め定まった近距離範囲となっている。このため、通信可能範囲においては、一のＢｌｕｅｔｏｏｔｈ端末に対して複数のアクセスポイント（収容装置）が存在することになる。
【０００３】
かかる無線通信システムにおいて、通信路の確立の手順としては、まず問い合わせ（デバイス検出）により接続可能なＢｌｕｅｔｏｏｔｈ端末を検出し、検出された中のアクセスポイントに対して接続要求を行う。アクセスポイントが複数存在する場合には、検出により複数のアクセスポイントが検出されるが、その中の一つを選定し接続要求を出す。
【０００４】
アクセスポイントの選定方式は、自動による選定とユーザの手動による選定が可能だが、この際にアクセスポイントの負荷を考慮しなければ、特定のアクセスポイントにＢｌｕｅｔｏｏｔｈ端末が集中し、負荷が偏りやすい。
【０００５】
【発明が解決しようとする課題】
例えばＢｌｕｅｔｏｏｔｈ技術を用いた無線アクセスにおいては、1台のアクセスポイントの端末接続台数は７台程度であるため、限られた空間で多くのＢｌｕｅｔｏｏｔｈ端末を収容するためには多くのアクセスポイントを密に配置することになる。しかしながら、従来技術では、各無線アクセスポイントは他の無線アクセスポイントの通信リソースを考慮せず自身の通信リソースのみから無線端末の収容可否判断を行なうため、無線アクセスポイント毎の収容無線端末数に偏りが生じることとなる。このため、多くのＢｌｕｅｔｏｏｔｈ端末を収容したアクセスポイントは個々の端末に提供するスループットが低くなり、少ないＢｌｕｅｔｏｏｔｈ端末を収容したアクセスポイントは高いスループットを提供する、不公平が生じるという問題点がある。
【０００６】
本発明の目的は、通信路の確立に際して収容装置に偏りが生じないようにして無線端末を収容することを可能とする無線通信システム及び通信管理装置並びに収容装置選定方法及びプログラムを提供することにある。
【０００７】
【課題を解決するための手段】
上記課題を解決するために本発明による無線通信システムは、所定の通信可能範囲を形成する複数の収容装置と、
所定手順により前記収容装置との間で通信路を確立して通信を行う無線端末と、
前記収容装置が既に確立している前記無線端末との間の通信路の状態に応じて前記収容装置夫々に対し前記無線端末との接続可否を通知する通信管理装置と
を具備し、
前記通信管理装置は、
無線端末から収容装置に対して通信リンクの確立要求を受けたとき当該収容装置からの収容可否の要請を受信する受信手段と
前記収容可否の要請に基づき得られる前記収容装置夫々が既に確立している前記無線端末との間の通信路の状態を記憶する記憶手段と、
この記憶手段に記憶された前記収容装置毎の既に確立している前記無線端末との間の通信路の状態に基づき前記収容装置に対して通知すべき前記無線端末との接続可否を判定する判定手段と
を具備し、
前記記憶手段は、前記収容可否の要請に含まれる収容装置ＩＰアドレスと収容装置起動時刻と収容台数とを記憶し、
前記判定手段は、前記記憶手段の記憶内容から最小の収容台数に対応する収容装置ＩＰアドレスを得ると、当該得られた収容装置ＩＰアドレスと前記収容可否の要請に含まれる収容装置ＩＰアドレスとを比較し、両者が等しければ接続可と判定し、両者が等しくなければ接続不可と判定することを特徴とする。
【０００８】
上記課題を解決するために本発明による通信管理装置は、無線端末から収容装置に対して通信リンクの確立要求を受けたとき当該収容装置からの収容可否の要請を受信する受信手段と
前記収容可否の要請に基づき得られる前記収容装置夫々が既に確立している前記無線端末との間の通信路の状態を記憶する記憶手段と、
この記憶手段に記憶された前記収容装置毎の既に確立している前記無線端末との間の通信路の状態に基づき前記収容装置に対して通知すべき前記無線端末との接続可否を判定する判定手段と
を具備し、
前記記憶手段は、前記収容可否の要請に含まれる収容装置ＩＰアドレスと収容装置起動時刻と収容台数とを記憶し、
前記判定手段は、前記記憶手段の記憶内容から最小の収容台数に対応する収容装置ＩＰアドレスを得ると、当該得られた収容装置ＩＰアドレスと前記収容可否の要請に含まれる収容装置ＩＰアドレスとを比較し、両者が等しければ接続可と判定し、両者が等しくなければ接続不可と判定することを特徴とする。
【０００９】
上記課題を解決するために本発明による収容装置選定方法は、無線端末から収容装置に対して通信リンクの確立要求を受けたとき当該収容装置からの収容可否の要請を受信する受信ステップと
前記収容可否の要請に基づき得られる前記収容装置夫々が既に確立している前記無線端末との間の通信路の状態を記憶する記憶ステップと、
この記憶ステップにより記憶された前記収容装置毎の既に確立している前記無線端末との間の通信路の状態に基づき前記収容装置に対して通知すべき前記無線端末との接続可否を判定する判定ステップと
を具備し、
前記記憶ステップは、前記収容可否の要請に含まれる収容装置ＩＰアドレスと収容装置起動時刻と収容台数とを記憶し、
前記判定ステップは、前記記憶手段の記憶内容から最小の収容台数に対応する収容装置ＩＰアドレスを得ると、当該得られた収容装置ＩＰアドレスと前記収容可否の要請に含まれる収容装置ＩＰアドレスとを比較し、両者が等しければ接続可と判定し、両者が等しくなければ接続不可と判定することを特徴とする。
【００１０】
上記課題を解決するために本発明による収容装置選定プログラムは、所定の通信可能範囲に一の無線端末が在るとき当該無線端末に複数の収容装置が存在する無線通信方式に適用されるコンピュータに、
無線端末から収容装置に対して通信リンクの確立要求を受けたとき当該収容装置からの収容可否の要請を受信する受信手順と
前記収容可否の要請に基づき算出される前記収容装置夫々が既に確立している前記無線端末との間の通信路の状態を記憶する記憶手順と、
この記憶手順により記憶された前記収容装置毎の既に確立している前記無線端末との間の通信路の状態に基づき前記収容装置に対して通知すべき前記無線端末との接続可否を判定する判定手順と
を実行させる収容装置選定プログラムであって、
前記記憶手順は、前記収容可否の要請に含まれる収容装置ＩＰアドレスと収容装置起動時刻と収容台数とを記憶し、
前記判定手順は、前記記憶手段の記憶内容から最小の収容台数に対応する収容装置ＩＰアドレスを得ると、当該得られた収容装置ＩＰアドレスと前記収容可否の要請に含まれる収容装置ＩＰアドレスとを比較し、両者が等しければ接続可と判定し、両者が等しくなければ接続不可と判定することを特徴とする。
【００１１】
本発明によれば、無線端末が収容装置と通信しようとする際に、通信管理装置、収容装置選定方法又は収容装置選定プログラムの実行により、低負荷の収容装置と通信路を確立することができ、収容装置の負荷を分散させ、通信品質の偏りを軽減することができる。
【００１２】
【発明の実施の形態】
以下、本発明に係る無線通信システム及び通信管理装置並びに収容装置選定方法及びプログラムの一実施形態を、無線通信方式としてＢｌｕｅｔｏｏｔｈに適用した例について説明する。
【００１３】
図１に示すように、本実施形態のＢｌｕｅｔｏｏｔｈシステムは、複数のアクセスポイント１０、複数のＢｌｕｅｔｏｏｔｈ端末２０を有し、建屋内、ビルの一区画内、車両内等の近距離範囲が通信可能範囲である。
【００１４】
また、本実施形態のＢｌｕｅｔｏｏｔｈシステムは、通信管理装置３０を有する。この通信管理装置３０は通信線４０によりアクセスポイント１０に接続される。そして、一のＢｌｕｅｔｏｏｔｈ端末２０に対し複数のアクセスポイント１０がアクセス可能であるのが、本実施形態の通信管理装置３０は、Ｂｌｕｅｔｏｏｔｈ端末２０が通信を行うとき、負荷が軽いアクセスポイント１０を選定し、該負荷が軽いアクセスポイント１０とＢｌｕｅｔｏｏｔｈ端末２０との間で通信路を確立するようにしている。
【００１５】
また、アクセスポイント１０は通信線５０を介してネットワーク６０及び通信端末７０に接続されている。
【００１６】
ここで、ある時点において、アクセスポイント１０−１は、Ｂｌｕｅｔｏｏｔｈ端末２０−１、２０−２、２０−３を収容し、アクセスポイント１０−２は、Ｂｌｕｅｔｏｏｔｈ端末２０−４を収容している。これらＢｌｕｅｔｏｏｔｈ端末２０−１〜２０−４は、アクセスポイント１０−１又は１０−２を介して互いに通信可能であり、また、ネットワーク４０を介して通信端末５０と通信可能である。
【００１７】
ここで、新たなＢｌｕｅｔｏｏｔｈ端末２０−５が、Ｂｌｕｅｔｏｏｔｈインターフェースを用いてネットワーク６０を介した通信を行なおうとする場合を図２を参照して説明する。図２のステップＳ１として、Ｂｌｕｅｔｏｏｔｈ端末２０−５は、アクセスポイント１０−１との同期確立フェーズの後、通信リンクの確立を要求するＬＭＰ₋ｈｏｓｔ₋ｃｏｎｎｅｃｔｉｏｎ₋ｒｅｑコマンドをアクセスポイント１０−１に送信し、これを受信したアクセスポイント１０−１は通信管理装置３０に収容可否要請を送る（ステップＳ２）。収容可否要請を受信した通信管理装置３０は、自身が管理するアクセスポイント１０−１，１０−２の中で収容Ｂｌｕｅｔｏｏｔｈ端末１０の少ないアクセスポイントを探し、アクセスポイント１０−１がこれに該当しないため、アクセスポイント１０−１は、収容可否判断(不可)を送信する（ステップＳ３）。収容可否判断(不可)を受信したアクセスポイント１０−１は、Ｂｌｕｅｔｏｏｔｈ端末２０−５に通信リンクの確立を拒否するＬＭＰ₋ｎｏｔ₋ａｃｃｅｐｔｅｄコマンドを送信する（ステップＳ４）。
【００１８】
Ｂｌｕｅｔｏｏｔｈ端末２０−５は、さらに通信リンクの確立を要求するＬＭＰ₋ｈｏｓｔ₋ｃｏｎｎｅｃｔｉｏｎ₋ｒｅｑコマンドを、先のアクセスポイント１０−１とは異なるアクセスポイント１０−２に送信し（ステップＳ１）、これを受信したアクセスポイント１０−２は通信管理装置３０に収容可否要請を送る（ステップＳ２）。収容可否要請を受信した通信管理装置３０は、自身が管理するアクセスポイントの中で収容Ｂｌｕｅｔｏｏｔｈ端末１０の少ないアクセスポイントを探し、アクセスポイント１０−２がこれに該当するため、アクセスポイント１０−２には収容可否判断(可)を送信する（ステップＳ３，Ｓ４）。収容可否判断(可)を受信したアクセスポイント１０−２は、Ｂｌｕｅｔｏｏｔｈ端末２０−５に通信リンクの確立を受け付けるＬＭＰ₋ａｃｃｅｐｔｅｄコマンドを送信する（ステップＳ５）。これによりＢｌｕｅｔｏｏｔｈ端末２０−５はアクセスポイント１０−２に収容される（Ｓ６）。
【００１９】
上記の例では、Ｂｌｕｅｔｏｏｔｈ端末２０がアクセスポイント１０に対して通信リンクの確立を要求すると、アクセスポイント１０は通信管理装置３０に収容可否要請を送って通信管理装置３０から収容可否判断を受信するようにしているが、或るＢｌｕｅｔｏｏｔｈ端末２０が或るアクセスポイント１０に通信リンクの確立を要求したとき、当該アクセスポイント１０が既に通信管理装置３０から収容可否判断を受信している場合は、この収容可否判断を当該アクセスポイント１０が保持しておくことで、当該アクセスポイント１０による通信管理装置３０に対する収容可否要請の送出及び通信管理装置３０からの収容可否判断の受信を不要とすることができ、時間短縮を図ることができる。
【００２０】
アクセスポイント１０は、自身の起動時、Ｂｌｕｅｔｏｏｔｈ端末収容時、Ｂｌｕｅｔｏｏｔｈ端末切り放し時のいずれか又はその組合せ時に、その収容Ｂｌｕｅｔｏｏｔｈ端末数を通信管理装置３０に通知する。これにより通信管理装置３０は各アクセスポイントの収容Ｂｌｕｅｔｏｏｔｈ端末数を知り、収容Ｂｌｕｅｔｏｏｔｈ端末数が最小のアクセスポイントをみつけることができる。ここで、Ｂｌｕｅｔｏｏｔｈ端末切り放しとは、Ｂｌｕｅｔｏｏｔｈ端末からＬＭＰ₋ｄｅｔａｃｈコマンドを受信し、Ｂｌｕｅｔｏｏｔｈ端末とのリンクを切断することを意味する。
【００２１】
また、各アクセスポイント１０は、自らが稼働していることを示す稼働通知を定期的に通信管理装置３０に送信してもよい。通信管理装置３０は一定時間以上稼働通知の届かないアクセスポイント１０を管理アクセスポイントから外すようにしてもよい。
【００２２】
また、各アクセスポイント１０は、稼働通知に、現在の収容Ｂｌｕｅｔｏｏｔｈ端末数を示す情報を乗せて通知しても良い。
【００２３】
また、通信管理装置３０は、収容可否要請の受信なしに、定期的に各アクセスポイントに収容可否判断(不可)あるいは収容可否判断(可)を送信してもよい。この場合、最も収容Ｂｌｕｅｔｏｏｔｈ端末数の少ないアクセスポイント１０に収容可否判断(可)を送信し、その他のアクセスポイント１０には収容可否判断(不可)を送信する。
【００２４】
また、各アクセスポイント１０が通信管理装置３０に送信する情報として、収容Ｂｌｕｅｔｏｏｔｈ端末数ではなく、収容Ｂｌｕｅｔｏｏｔｈ端末が過去一定時間内に送受信したパケット数を用いても良い。この場合、通信管理装置３０は、このパケット送受信数の少ないアクセスポイントのみに新たなＢｌｕｅｔｏｏｔｈ端末の収容を許可する。
【００２５】
本実施形態では、通信管理装置３０とアクセスポイント１０が別個に存在する形態にて説明を行なったが、通信管理装置３０の機能がアクセスポイント１０に具備され、物理的には通信管理装置３０とアクセスポイント１０とを分けない構成であっても、本発明は適用可能である。
【００２６】
次に、図３を参照して本実施形態における通信管理装置３０を詳細に説明する。
【００２７】
図３に示すように、本実施形態の通信管理装置３０は、収容状態記憶部３０Ａ、収容可否判定部３０Ｂ及び通信部３０Ｃからなり、図４に示すフローにより、アクセスポイント１０が既に確立しているＢｌｕｅｔｏｏｔｈ端末２０との間の通信路の状態に応じてアクセスポイント１０夫々に対しＢｌｕｅｔｏｏｔｈ端末２０との接続可否を通知するものとなっている。
【００２８】
通信部３０Ｃは、ステップＴ１にて、アクセスポイント１０から収容可否要請を受けとると、これに含まれるアクセスポイントＩＰアドレスとアクセスポイント起動時刻と収容台数とを、収容状態記憶部に送信し、収容状態記憶部３０Ｂはこれを記憶する（ステップＴ２）。
【００２９】
ここで、収容可否要請のフォーマット例を図５に示す。アクセスポイントＩＰアドレスは、アクセスポイントを識別する情報であり、アクセスポイント起動時刻はそのアクセスポイントが再起動したか否かを確認する情報であり、収容台数はそのアクセスポイント１０が現在収容しているＢｌｕｅｔｏｏｔｈ端末数を確認する情報である。
【００３０】
さらに、通信部３０Ｃは、収容可否要請のアクセスポイントＩＰアドレスを収容可否判定部３０Ｂに送信する。収容可否判定部３０Ｂは、収容可否要請のアクセスポイントＩＰアドレスから以下の手順で収容可否判断を行なう。
【００３１】
１．収容状態記憶部３０Ａに記憶されているアクセスポイントの中で収容Ｂｌｕｅｔｏｏｔｈ端末が最小のものを探し、そのアクセスポイントＩＰアドレスを得る（ステップＴ３）。
【００３２】
２．得られたアクセスポイントＩＰアドレスが収容可否要請のアクセスポイントＩＰアドレスとを比較し、等しければ収容可と判断し、そうでなければ収容不可と判断する（ステップＴ４）。
【００３３】
収容可否判定部３０Ｂは、収容可否判断の結果を通信部３０Ｃに送信し、通信部３０Ｃはその可否判断結果に従い収容可否判断(不可)あるいは収容可否判断(可)を収容可否要請の送信アクセスポイント１０へ送信する（ステップＴ５，Ｔ６）。
【００３４】
図６に収容可否判断(可)と収容可否判断(不可)のフォーマットの例を示す。収容可否判断(可)と収容可否判断(不可)の違いは、収容可否判断フィールドの値である。
【００３５】
通信部３０Ｃは、アクセスポイントからの稼働通知を受けとると、これに含まれるアクセスポイントＩＰアドレスとアクセスポイント起動時刻と収容台数と収容済みのＢｌｕｅｔｏｏｔｈ端末２０のＢｌｕｅｔｏｏｔｈアドレスとを、収容状態記憶部３０Ａに送信し、収容状態記憶部３０Ａはこれを記憶する。ここで、稼働通知のメッセージフォーマットの例を図７に示す。アクセスポイントＩＰアドレスはアクセスポイントを識別する情報であり、アクセスポイント起動時刻はそのアクセスポイントが再起動したか否かを確認する情報であり、収容台数と収容済みのＢｌｕｅｔｏｏｔｈ端末２０のＢｌｕｅｔｏｏｔｈアドレスは、そのアクセスポイントが現在収容しているＢｌｕｅｔｏｏｔｈ端末２０を確認する情報である。
【００３６】
収容状態記憶部３０Ａは、あるアクセスポイントＩＰアドレスに対して、一定時間以上通信部３０からアクセスポイントＩＰアドレスとアクセスポイント起動時刻と収容台数と収容済みのＢｌｕｅｔｏｏｔｈ端末のＢｌｕｅｔｏｏｔｈアドレスとを受けとらなかった場合、そのアクセスポイントＩＰアドレスに関する情報(アクセスポイント起動時刻と収容台数と収容済みのＢｌｕｅｔｏｏｔｈ端末のＢｌｕｅｔｏｏｔｈアドレス)を記憶から削除する。
【００３７】
収容可否判定部３０Ｂは、上記のステップに代えて、定期的に以下の手順に従い、各アクセスポイントの可否判断結果を通信部３０Ｃに送信しても良い。
【００３８】
１．収容状態記憶部３０Ａを検索し、収容可否判定部３０Ｂの記憶するすべてのアクセスポイントＩＰアドレスを得る。
【００３９】
２．収容状態記憶部３０Ａを検索し、収容Ｂｌｕｅｔｏｏｔｈ端末数の一番少ない収容可否判定部３０Ｂの記憶するすべてのアクセスポイントＩＰアドレスを得る。
【００４０】
３．収容Ｂｌｕｅｔｏｏｔｈ端末数の一番少ないアクセスポイントＩＰアドレスを持つアクセスポイント１０を収容可とし、それ以外のアクセスポイントＩＰアドレスを持つアクセスポイント１０を収容不可と判断。
【００４１】
通信部３０Ｃは、その可否判断結果に従い、各々のアクセスポイント１０に収容可否判断(不可)あるいは収容可否判断(可)を送信する。
【００４２】
また、新たなＢｌｕｅｔｏｏｔｈ端末２０の収容可否判断基準として、収容Ｂｌｕｅｔｏｏｔｈ端末数ではなく、収容Ｂｌｕｅｔｏｏｔｈ端末２０が過去一定時間内に送受信したパケット数を用いても良い。この場合、収容可否要請稼働通知にて収容台数ではなく収容Ｂｌｕｅｔｏｏｔｈ端末２０が過去一定時間内に送受信したパケット数を記し、収容状態記憶部は収容Ｂｌｕｅｔｏｏｔｈ端末数の代わりにこのパケット数を記憶し、収容可否判定部３０Ｂはもっとも収容Ｂｌｕｅｔｏｏｔｈ端末数の少ないアクセスポイント１０の代わりにもっともこのパケット数の少ないアクセスポイント１０にのみ新たなＢｌｕｅｔｏｏｔｈ端末２０の収容を可と判断するようにもできる。
【００４３】
本発明におけるアクセスポイントの選定方法は、選定されるアクセスポイントが固定的でないようにすることで、特定のアクセスポイントへのＢｌｕｅｔｏｏｔｈ端末の集中を防止するものである。
【００４４】
かかる課題を達成するため上記実施形態では、通信管理装置３０において各アクセスポイント１０の収容端末数を把握し、特定のアクセスポイントにＢｌｕｅｔｏｏｔｈ端末が集中しないという条件で、各アクセスポイント１０に対して接続可否の判定結果を通知するようにしている。そして、判定手法としては、収容端末数の一番少ないアクセスポイント１０は収容可とし、それ以外のアクセスポイント１０は収容不可と判断する例を示した。この場合、一般に、収容端末数の大小の比較単位は１であるが、２以上であってもよい。
【００４５】
例えば、大小の比較単位を２とすると、端末数の差が２の場合は同一と見なされるので、一のアクセスポイント１０の収容端末数が他のアクセスポイント１０の収容端末数よりその差分が３を超える数であるとき、当該一のアクセスポイント１０を収容不可とし、他のアクセスポイント１０を収容可とする判断手法を採用することができる。
【００４６】
また、本発明におけるアクセスポイントの選定方法は、選定されるアクセスポイントが固定的でないようにすることでであるから、上記のような各アクセスポイントの負荷均衡を図ることに代えて、ある負荷分担パターンを設定し且つ保持し、該パターンに沿うように、各アクセスポイント１０に対して接続可否の判定結果を通知することもできる。
【００４７】
なお、本実施形態では、アクセスポイント１０と通信管理装置３０との間の情報のやりとりに、ＩＰパケットを用いたＵＤＰ通信を利用する例を示した。しかしながら、ＩＰパケット以外にも他の通信方法にて情報をやりとりした場合にも本発明は適用可能である。その場合は、収容可否要請と稼働通知のメッセージ内のアクセスポイントＩＰアドレスは、例えばＢｌｕｅｔｏｏｔｈアドレスのように、アクセスポイントを一意に識別する情報を用いれば良い。
【００４８】
本発明は、無線通信方式として、Ｂｌｕｅｔｏｏｔｈを例示したが、ＩＥＥＥ８０２．１１ｂを用いた通信方式にも本発明を適用することができる。
【００４９】
なお、通信管理装置３０の一部又は全部は、ハードウェアとして構成する場合の他に、図３、図４に示される各ステップを含むプログラムの実行によっても実現され得る。
【００５０】
【発明の効果】
以上述べたように本発明によれば、通信路の確立に際して収容装置に偏りが生じないようにして無線端末を収容することを可能とする無線通信システム及び通信管理装置並びに収容装置選定方法及びプログラムを提供できるものである。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る無線通信システムを示す構成図。
【図２】同実施形態におけるアクセスポイント選定の手順を示すフローチャート。
【図３】同実施形態における通信管理装置の詳細ブロック図。
【図４】同アクセスポイント選定の手順における通信管理装置の動作を示すフローチャート。
【図５】同実施形態における収容可否要請のフォーマットの例を示す図。
【図６】同実施形態における収容可否判断のフォーマットの例を示す図。
【図７】同実施形態における稼働通知のメッセージフォーマットの例を示す図。
【符号の説明】
１０…アクセスポイント
２０…Ｂｌｕｅｔｏｏｔｈ端末
３０…通信管理装置
３０Ａ…収容状態記憶部
３０Ｂ…収容可否判定部
３０Ｃ…通信部
４０…通信線
５０…通信線
６０…ネットワーク
７０…通信端末[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless communication system, a communication management device, a storage device selection method, and a program according to, for example, Bluetooth.
[0002]
[Prior art]
In Bluetooth, which is one of the wireless communication systems, the communicable range is a predetermined short-range range such as a building, a section of a building, a vehicle, and the like. For this reason, in the communicable range, a plurality of access points (accommodating devices) exist for one Bluetooth terminal.
[0003]
In such a wireless communication system, as a procedure for establishing a communication path, first, a Bluetooth terminal that can be connected is detected by an inquiry (device detection), and a connection request is made to the detected access point. When there are a plurality of access points, a plurality of access points are detected by detection, and one of them is selected and a connection request is issued.
[0004]
As the access point selection method, automatic selection and manual selection by the user are possible. However, if the load of the access point is not taken into consideration at this time, the Bluetooth terminals are concentrated on a specific access point, and the load tends to be biased.
[0005]
[Problems to be solved by the invention]
For example, in wireless access using Bluetooth technology, since the number of terminals connected to one access point is about seven, in order to accommodate a large number of Bluetooth terminals in a limited space, many access points must be arranged densely. Will be placed. However, in the prior art, each wireless access point determines whether or not a wireless terminal can be accommodated only from its own communication resource without considering the communication resources of other wireless access points. Will occur. For this reason, there is a problem that an access point that accommodates many Bluetooth terminals has a low throughput to be provided to each terminal, and an access point that accommodates a small number of Bluetooth terminals provides a high throughput, resulting in unfairness.
[0006]
An object of the present invention is to provide a wireless communication system, a communication management device, a storage device selection method, and a program that enable a wireless terminal to be accommodated without causing bias in the accommodation device when establishing a communication path. is there.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a wireless communication system according to the present invention includes a plurality of accommodating devices that form a predetermined communicable range;
A wireless terminal that establishes a communication path with the accommodating device according to a predetermined procedure and performs communication;
A communication management device for notifying each of the accommodation devices of whether or not they can be connected to the wireless terminal according to a state of a communication path with the wireless terminal that has already been established by the accommodation device ,
The communication management device
Receiving means for receiving a request for availability of accommodation from the accommodation device when receiving a communication link establishment request from the wireless terminal to the accommodation device;
Storage means for storing a state of a communication path with the wireless terminal already established by each of the accommodation devices obtained based on the request for availability;
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored in the storage unit Means and
Comprising
The storage means stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
When the determination unit obtains the accommodation device IP address corresponding to the minimum accommodation number from the storage contents of the storage unit, the determination unit obtains the obtained accommodation device IP address and the accommodation device IP address included in the request for availability. In comparison, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .
[0008]
In order to solve the above problems, a communication management device according to the present invention comprises: a receiving unit that receives a request for accommodation from a receiving device when receiving a communication link establishment request from a wireless terminal to the containing device; Storage means for storing the state of the communication path with the wireless terminal already established by each of the accommodation devices obtained based on the request of
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored in the storage unit and means,
The storage means stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
When the determination unit obtains the accommodation device IP address corresponding to the minimum accommodation number from the storage contents of the storage unit, the determination unit obtains the obtained accommodation device IP address and the accommodation device IP address included in the request for availability. In comparison, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .
[0009]
In order to solve the above-described problem, the accommodation apparatus selection method according to the present invention includes a reception step of receiving a request for accommodation from the accommodation apparatus when receiving a communication link establishment request from the wireless terminal to the accommodation apparatus; A storage step of storing a state of a communication path with the wireless terminal that is already established by each of the accommodation devices obtained based on the request for availability;
Determining whether or not to connect to the wireless terminal to be notified to the accommodating device based on the state of the communication path with the already established wireless terminal for each of the accommodating devices stored in the storing step Comprising steps ,
The storing step stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
In the determination step, when the accommodation device IP address corresponding to the minimum accommodation number is obtained from the storage contents of the storage unit, the obtained accommodation device IP address and the accommodation device IP address included in the request for accommodation are obtained. In comparison, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .
[0010]
In order to solve the above problems, a storage device selection program according to the present invention is applied to a computer applied to a wireless communication system in which a plurality of storage devices exist in a wireless terminal when there is one wireless terminal in a predetermined communicable range. ,
When receiving a communication link establishment request from the wireless terminal to the accommodation device, the reception procedure for receiving the accommodation availability request from the accommodation device and the accommodation devices calculated based on the accommodation availability request have already been established. A storage procedure for storing a state of a communication path with the wireless terminal;
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored by the storage procedure A storage device selection program for executing the procedure and
The storage procedure stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
In the determination procedure, when the accommodation device IP address corresponding to the minimum accommodation number is obtained from the storage content of the storage means, the obtained accommodation device IP address and the accommodation device IP address included in the request for accommodation are obtained. In comparison, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .
[0011]
According to the present invention, when a wireless terminal attempts to communicate with a storage device, a communication path can be established with the low load storage device by executing the communication management device, the storage device selection method, or the storage device selection program. The load on the accommodation device can be distributed to reduce the communication quality bias.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example in which an embodiment of a wireless communication system, a communication management device, a storage device selection method, and a program according to the present invention is applied to Bluetooth as a wireless communication method will be described.
[0013]
As shown in FIG. 1, the Bluetooth system of the present embodiment has a plurality of access points 10 and a plurality of Bluetooth terminals 20, and a short-range range such as in a building, a section of a building, or in a vehicle can be communicated. It is.
[0014]
The Bluetooth system according to the present embodiment includes a communication management device 30. This communication management device 30 is connected to the access point 10 by a communication line 40. A plurality of access points 10 can access one Bluetooth terminal 20, but the communication management device 30 of this embodiment selects an access point 10 having a light load when the Bluetooth terminal 20 performs communication. The communication path is established between the access point 10 and the Bluetooth terminal 20 with a light load.
[0015]
The access point 10 is connected to the network 60 and the communication terminal 70 via the communication line 50.
[0016]
Here, at a certain point in time, the access point 10-1 accommodates the Bluetooth terminals 20-1, 20-2, and 20-3, and the access point 10-2 accommodates the Bluetooth terminal 20-4. These Bluetooth terminals 20-1 to 20-4 can communicate with each other via the access point 10-1 or 10-2, and can communicate with the communication terminal 50 via the network 40.
[0017]
Here, a case where the new Bluetooth terminal 20-5 attempts to communicate via the network 60 using the Bluetooth interface will be described with reference to FIG. As step S1 of FIG. 2, the Bluetooth terminal 20-5 transmits an LMP _- host _- connection _- req command requesting establishment of a communication link to the access point 10-1 after the synchronization establishment phase with the access point 10-1. Then, the access point 10-1 that has received this sends an accommodation permission request to the communication management device 30 (step S2). The communication management device 30 that has received the accommodation permission request searches for access points with fewer accommodation Bluetooth terminals 10 among the access points 10-1 and 10-2 managed by the communication management device 30, and the access point 10-1 does not correspond to this. The access point 10-1 transmits an accommodability determination (impossible) (step S3). The access point 10-1 that has received the accommodability determination (impossible) transmits an LMP _- not _- accepted command that rejects establishment of the communication link to the Bluetooth terminal 20-5 (step S4).
[0018]
The Bluetooth terminal 20-5 further transmits an LMP _- host _- connection _- req command requesting establishment of a communication link to an access point 10-2 different from the previous access point 10-1 (step S1). The received access point 10-2 sends an accommodation permission request to the communication management device 30 (step S2). The communication management device 30 that has received the accommodation permission / inhibition request searches for an access point with fewer accommodation Bluetooth terminals 10 among access points managed by itself, and the access point 10-2 falls under this, so the access point 10-2 Transmits a determination as to whether accommodation is possible (Yes) (steps S3 and S4). The access point 10-2 that has received the accommodability determination (permitted) transmits an LMP _- accepted command for accepting establishment of a communication link to the Bluetooth terminal 20-5 (step S5). Thereby, the Bluetooth terminal 20-5 is accommodated in the access point 10-2 (S6).
[0019]
In the above example, when the Bluetooth terminal 20 requests the access point 10 to establish a communication link, the access point 10 sends an accommodation availability request to the communication management apparatus 30 and receives an accommodation availability determination from the communication management apparatus 30. However, when a certain Bluetooth terminal 20 requests a certain access point 10 to establish a communication link, if the access point 10 has already received a determination on whether or not accommodation is possible from the communication management device 30, this accommodation is performed. Since the access point 10 holds the determination of availability, it is possible to make it unnecessary to send an accommodation availability request to the communication management device 30 by the access point 10 and receive the accommodation availability determination from the communication management device 30. Time can be reduced.
[0020]
The access point 10 notifies the communication management apparatus 30 of the number of accommodated Bluetooth terminals at the time of starting itself, at the time of accommodating Bluetooth terminals, at the time of disconnecting the Bluetooth terminals, or at a combination thereof. Thereby, the communication management apparatus 30 knows the number of accommodated Bluetooth terminals of each access point, and can find the access point with the smallest number of accommodated Bluetooth terminals. Here, disconnecting a Bluetooth terminal means receiving an LMP _- detch command from the Bluetooth terminal and disconnecting the link with the Bluetooth terminal.
[0021]
In addition, each access point 10 may periodically transmit an operation notification indicating that it is operating to the communication management device 30. The communication management device 30 may remove the access point 10 that has not received the operation notification for a certain period of time from the management access point.
[0022]
In addition, each access point 10 may notify the operation notification by adding information indicating the current number of accommodated Bluetooth terminals.
[0023]
In addition, the communication management device 30 may periodically transmit an accommodation availability determination (impossible) or an accommodation availability determination (possible) to each access point without receiving an accommodation availability request. In this case, the accommodability determination (permitted) is transmitted to the access point 10 with the smallest number of accommodating Bluetooth terminals, and the accommodability determination (impossible) is transmitted to the other access points 10.
[0024]
Further, as information transmitted from each access point 10 to the communication management device 30, the number of packets transmitted / received by the accommodated Bluetooth terminal within a certain past time may be used instead of the number of accommodated Bluetooth terminals. In this case, the communication management device 30 permits the accommodation of a new Bluetooth terminal only to the access point with a small number of packet transmission / reception.
[0025]
In this embodiment, the communication management device 30 and the access point 10 are described separately. However, the function of the communication management device 30 is provided in the access point 10, and physically the communication management device 30 and the access point 10. The present invention is applicable even if the access point 10 is not separated.
[0026]
Next, the communication management apparatus 30 in this embodiment will be described in detail with reference to FIG.
[0027]
As shown in FIG. 3, the communication management device 30 of this embodiment includes an accommodation state storage unit 30A, an accommodation availability determination unit 30B, and a communication unit 30C. The access point 10 has already been established by the flow shown in FIG. In accordance with the state of the communication path with the existing Bluetooth terminal 20, the access point 10 is notified of whether or not it can be connected to the Bluetooth terminal 20.
[0028]
When the communication unit 30C receives an accommodation permission request from the access point 10 in step T1, the communication unit 30C transmits the access point IP address, the access point activation time, and the number of accommodations included therein to the accommodation state storage unit. The storage unit 30B stores this (step T2).
[0029]
Here, a format example of the accommodation permission / inhibition request is shown in FIG. The access point IP address is information for identifying the access point, the access point activation time is information for confirming whether or not the access point has been restarted, and the number of accommodation is currently accommodated by the access point 10. This is information for confirming the number of Bluetooth terminals.
[0030]
Further, the communication unit 30C transmits the access point IP address of the accommodation availability request to the accommodation availability determination unit 30B. The accommodation availability determination unit 30B determines accommodation availability from the access point IP address of the accommodation availability request according to the following procedure.
[0031]
1. Among the access points stored in the accommodation state storage unit 30A, the one with the smallest accommodation Bluetooth terminal is searched for and the access point IP address is obtained (step T3).
[0032]
2. The obtained access point IP address is compared with the access point IP address requested for accommodation, and if it is equal, it is judged that accommodation is possible, otherwise it is judged that accommodation is impossible (step T4).
[0033]
The accommodation availability determination unit 30B transmits the result of accommodation availability determination to the communication unit 30C, and the communication unit 30C transmits the accommodation availability determination (impossible) or the accommodation availability determination (possible) according to the availability determination result. 10 (steps T5 and T6).
[0034]
FIG. 6 shows an example of a format for determining whether or not accommodation is possible (possible) and whether or not accommodation is possible (impossible). The difference between the accommodation availability determination (allowed) and the accommodation availability determination (impossible) is the value of the accommodation availability determination field.
[0035]
When the communication unit 30C receives the operation notification from the access point, the communication unit 30C stores the access point IP address, the access point activation time, the number of units accommodated, and the Bluetooth address of the accommodated Bluetooth terminal 20 in the accommodation state storage unit 30A. The accommodation state storage unit 30A stores this information. Here, an example of the message format of the operation notification is shown in FIG. The access point IP address is information for identifying the access point, the access point activation time is information for confirming whether or not the access point has been restarted, and the accommodated number and the Bluetooth address of the accommodated Bluetooth terminal 20 are: This is information for confirming the Bluetooth terminal 20 currently accommodated by the access point.
[0036]
When the accommodation state storage unit 30A does not receive the access point IP address, the access point activation time, the accommodated number, and the Bluetooth address of the accommodated Bluetooth terminal from the communication unit 30 for a certain period of time for a certain access point IP address Then, information related to the access point IP address (access point activation time, accommodated number, and Bluetooth address of the accommodated Bluetooth terminal) is deleted from the storage.
[0037]
The accommodation availability determination unit 30B may periodically transmit the availability determination result of each access point to the communication unit 30C according to the following procedure instead of the above steps.
[0038]
1. The accommodation state storage unit 30A is searched, and all access point IP addresses stored in the accommodation availability determination unit 30B are obtained.
[0039]
2. The accommodation state storage unit 30A is searched, and all access point IP addresses stored in the accommodation availability determination unit 30B having the smallest number of accommodation Bluetooth terminals are obtained.
[0040]
3. It is determined that an access point 10 having an access point IP address with the smallest number of accommodated Bluetooth terminals can be accommodated, and an access point 10 having other access point IP addresses cannot be accommodated.
[0041]
The communication unit 30C transmits an accommodability determination (impossible) or an accommodability determination (possible) to each access point 10 according to the determination result.
[0042]
In addition, as a criterion for determining whether or not a new Bluetooth terminal 20 can be accommodated, the number of packets transmitted and received by the accommodating Bluetooth terminal 20 within a certain past time may be used instead of the number of accommodating Bluetooth terminals. In this case, in the accommodation availability request operation notification, not the accommodated number, but the number of packets transmitted / received by the accommodated Bluetooth terminal 20 in the past fixed time is recorded, and the accommodation state storage unit stores the number of packets instead of the accommodated Bluetooth terminal number, The accommodability determination unit 30B can determine that only the access point 10 with the smallest number of packets can accommodate the new Bluetooth terminal 20 instead of the access point 10 with the smallest number of accommodated Bluetooth terminals.
[0043]
The access point selection method in the present invention prevents the concentration of Bluetooth terminals on a specific access point by making the selected access point not fixed.
[0044]
In order to achieve such a problem, in the above embodiment, the communication management device 30 grasps the number of terminals accommodated by each access point 10 and is connected to each access point 10 on the condition that the Bluetooth terminals are not concentrated on a specific access point. The determination result of availability is notified. As an example of the determination method, an example is shown in which it is determined that the access point 10 having the smallest number of accommodated terminals can be accommodated and the other access points 10 are unacceptable. In this case, in general, the comparison unit of the number of accommodated terminals is 1, but it may be 2 or more.
[0045]
For example, if the large and small comparison units are two, the difference in the number of terminals is considered to be the same if the difference is 2. Therefore, the difference in the number of terminals accommodated by one access point 10 is 3 compared to the number of terminals accommodated by another access point 10. When the number exceeds the threshold, it is possible to adopt a determination method in which the one access point 10 cannot be accommodated and another access point 10 can be accommodated.
[0046]
Further, since the access point selection method in the present invention is to prevent the selected access points from being fixed, instead of balancing the load of each access point as described above, a certain load sharing is performed. It is also possible to set and hold a pattern, and to notify each access point 10 of the determination result of whether or not connection is possible, along the pattern.
[0047]
In the present embodiment, an example in which UDP communication using an IP packet is used for exchanging information between the access point 10 and the communication management apparatus 30 has been described. However, the present invention can also be applied when information is exchanged by other communication methods besides IP packets. In such a case, information for uniquely identifying the access point may be used as the access point IP address in the message indicating whether the accommodation is permitted or not, and for example, a Bluetooth address.
[0048]
Although the present invention exemplifies Bluetooth as a wireless communication system, the present invention can also be applied to a communication system using IEEE802.11b.
[0049]
Note that part or all of the communication management apparatus 30 can be realized by executing a program including the steps shown in FIGS. 3 and 4 in addition to the case where the communication management apparatus 30 is configured as hardware.
[0050]
【The invention's effect】
As described above, according to the present invention, a wireless communication system, a communication management device, a storage device selection method, and a program capable of storing wireless terminals without causing bias in the storage device when establishing a communication path. Can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a wireless communication system according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a procedure for selecting an access point in the embodiment.
FIG. 3 is a detailed block diagram of a communication management apparatus according to the embodiment.
FIG. 4 is a flowchart showing the operation of the communication management apparatus in the access point selection procedure.
FIG. 5 is a view showing an example of a format for requesting accommodation permission in the embodiment.
FIG. 6 is a view showing an example of a format for determining whether or not accommodation is possible according to the embodiment;
FIG. 7 is a view showing an example of an operation notification message format in the embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Access point 20 ... Bluetooth terminal 30 ... Communication management apparatus 30A ... Accommodation state memory | storage part 30B ... Accommodability determination part 30C ... Communication part 40 ... Communication line 50 ... Communication line 60 ... Network 70 ... Communication terminal

Claims

A plurality of accommodating devices forming a predetermined communicable range;
A wireless terminal that establishes a communication path with the accommodating device according to a predetermined procedure and performs communication;
A communication management device for notifying each of the accommodation devices of whether or not they can be connected to the wireless terminal according to a state of a communication path with the wireless terminal that has already been established by the accommodation device ,
The communication management device
Receiving means for receiving a request for availability of accommodation from the accommodation device when receiving a communication link establishment request from the wireless terminal to the accommodation device;
Storage means for storing a state of a communication path with the wireless terminal already established by each of the accommodation devices obtained based on the request for availability;
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored in the storage unit Means and
Comprising
The storage means stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
When the determination unit obtains the accommodation device IP address corresponding to the minimum accommodation number from the storage contents of the storage unit, the determination unit obtains the obtained accommodation device IP address and the accommodation device IP address included in the request for availability. A wireless communication system characterized in that if the two are equal, it is determined that the connection is possible, and if the two are not equal, it is determined that the connection is impossible .

When receiving a communication link establishment request from the wireless terminal to the accommodation device, the receiving means for receiving the accommodation availability request from the accommodation device and the accommodation device obtained based on the accommodation availability request are already established. Storage means for storing a state of a communication path with the wireless terminal;
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored in the storage unit and means,
The storage means stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
When the determination unit obtains the accommodation device IP address corresponding to the minimum accommodation number from the storage contents of the storage unit, the determination unit obtains the obtained accommodation device IP address and the accommodation device IP address included in the request for availability. A communication management device characterized in that, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .

The said accommodation apparatus is equipped with a means to notify the said communication management apparatus of the number of accommodation terminals regularly, at the time of starting, at the time of the terminal accommodation, the time of terminal disconnection, or the combination of these. Communication management device.

4. The communication management apparatus according to claim 2, further comprising means for periodically transmitting the determination result of the connection possibility by the determination means to the accommodation apparatus without receiving the accommodation availability request.

When the wireless terminal and the accommodation device comply with Bluetooth, the accommodation device requests the communication management device whether or not to accommodate the wireless management device in response to the wireless terminal transmitting an LMP _- host _- connection _- req command to the accommodation device. The communication management device according to any one of claims 2 to 4, wherein

When receiving a communication link establishment request from the wireless terminal to the accommodation device, a reception step of receiving a request for accommodation from the accommodation device, and each of the accommodation devices obtained based on the request for availability is already established. A storage step of storing a state of a communication path with the wireless terminal;
Determining whether or not to connect to the wireless terminal to be notified to the accommodating device based on the state of the communication path with the already established wireless terminal for each of the accommodating devices stored in the storing step Comprising steps ,
The storing step stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
In the determination step, when the accommodation device IP address corresponding to the minimum accommodation number is obtained from the storage contents of the storage unit, the obtained accommodation device IP address and the accommodation device IP address included in the request for accommodation are obtained. A storage device selection method comprising: comparing and determining that connection is possible if both are equal, and determining that connection is not possible if both are not equal .

When one wireless terminal is present in a predetermined communicable range, a computer applied to a wireless communication system in which a plurality of accommodating devices exist in the wireless terminal,
When receiving a communication link establishment request from the wireless terminal to the accommodation device, the reception procedure for receiving the accommodation availability request from the accommodation device and the accommodation devices calculated based on the accommodation availability request have already been established. A storage procedure for storing a state of a communication path with the wireless terminal;
Determining whether or not connection with the wireless terminal to be notified to the accommodation device is possible based on the state of the communication path with the already established wireless terminal for each of the accommodation devices stored by the storage procedure a containment device selection program for executing the procedure,
The storage procedure stores a storage device IP address, a storage device activation time, and a storage number included in the request for availability.
In the determination procedure, when the accommodation device IP address corresponding to the minimum accommodation number is obtained from the storage content of the storage means, the obtained accommodation device IP address and the accommodation device IP address included in the request for accommodation are obtained. A storage device selection program characterized in that, if both are equal, it is determined that connection is possible, and if both are not equal, it is determined that connection is impossible .