JP3789432B2

JP3789432B2 - Mobile communication system and composite portable terminal

Info

Publication number: JP3789432B2
Application number: JP2003004313A
Authority: JP
Inventors: 隆章那須田
Original assignee: NEC AccessTechnica Ltd
Current assignee: NEC AccessTechnica Ltd
Priority date: 2003-01-10
Filing date: 2003-01-10
Publication date: 2006-06-21
Anticipated expiration: 2023-01-10
Also published as: JP2004221730A

Description

【０００１】
【発明の属する技術分野】
本発明は移動通信システム及び複合携帯端末に係り、特にＧＰＳ（Global Positioning System）衛星からのＧＰＳ信号を用いて位置情報を得る位置情報検索機能を搭載した複合携帯端末が、通信方式の異なる複数の基地局との間で無線通信する移動通信システム及びそれに用いる複合携帯端末に関する。
【０００２】
【従来の技術】
近年、携帯電話等の携帯端末の市場は成熟し、高機能化や高性能化が図られている。しかし、携帯端末の高機能化や高性能化が進めば進むほど、携帯端末の電池の長寿命化の要求が高くなっている。
【０００３】
一方、移動通信システムの通信方式も各種の方式が提案されており、代表的なものとして多様なコンテンツを扱うことが可能な符号分割多元接続（ＣＤＭＡ：Code Division Multiple Access）方式と、時分割多元接続方式とがある。更に、時分割多元接続方式の代表例としては、ＰＤＣ（Personal Digital Cellular）規格がある。そこで、上記のＣＤＭＡ方式とＰＤＣ規格の両方の通信方式を選択して通信可能な、所謂デュアルモード携帯端末（複合携帯端末）も従来より知られている（例えば、特許文献１参照）。
【０００４】
この特許文献１記載の複合携帯端末は、送信系の直交変調器の入力にモードスイッチを設け、直交変調器及び電力制御増幅器を共用し、電力制御増幅器の出力にモードスイッチを設け、異なるモードの送信系回路に信号を供給し、また、第二局部発振器出力と直交変調器の入力の間に１／２分周回路を設け、更にこの１／２分周回路の動作状態をモード切替により制御できるようにすることで、送信系の一部をＣＤＭＡ用とＰＤＣ用とで共用し、また、無線部を簡略化する構成としたものである。
【０００５】
【特許文献１】
特開２０００−１３２７４号公報（第４頁、図１）
【０００６】
【発明が解決しようとする課題】
しかるに、上記の通信方式が異なる複数の無線通信網に対して通信を行うことが可能な従来の複合携帯端末においては、電源オン時のチャネルサーチや、基地局エリアの端におけるチャネルサーチにおいては、通信方式の異なる無線通信基地局に対して行わなければならず、余分なチャネルサーチを行うことがあり、電力消費が大きいという問題がある。
【０００７】
すなわち、電源オン時には、複合携帯端末は自端末が、異なる複数の通信方式（上記の場合、ＰＤＣ及びＣＤＭＡ）のうちのどの通信方式の基地局のエリアに在圏しているかを確認して待ち受け動作に入るために、基地局から定期的にページングチャネルで送信される信号を、複数の通信方式で順次受信動作を行い、基地局の通信方式を確認してから、通信チャネルを確立するチャネルサーチを行う。
【０００８】
また、複合携帯端末は、待ち受け中及び通話中において現在通信している基地局との第１の通信状態（例えば受信電界レベル）が所定の閾値よりも良好であるときは、そのまま現在通信している基地局との間で、既知の通信方式で通信を継続して行うが、第１の通信状態が所定の閾値以下に劣化したときには、現在通信している基地局のエリアの端に自端末が位置していると判断して、現在通信している基地局に隣接する別の基地局との第２の通信状態を上記の第１の通信状態と比較して、第２の通信状態が第１の通信状態よりも良好になった時に、上記の別の基地局との間で無線通信するように切り替える。
【０００９】
ここで、上記の通信状態の比較の際には、上記の別の基地局の通信方式が複数の通信方式のどれであるか分からないので、上記の別の基地局から定期的にページングチャネルで送信される信号を、複数の通信方式で順次受信動作を行い、当該別の基地局の通信方式を確認してから、通信チャネルを確立するチャネルサーチを行う。
【００１０】
このように、通信方式が異なる複数の無線通信網に対して通信を行うことが可能な従来の複合携帯端末においては、電源オン時のチャネルサーチや、基地局エリアの端におけるチャネルサーチにおいては、通信する基地局の通信方式とは別の通信方式で基地局に対して通信を行うことで、余分なチャネルサーチを行うことがあり、その分、電力消費がかかり、電池寿命を短くするという問題がある。
【００１２】
本発明は以上の点に鑑みなされたもので、通信方式が異なる複数の無線通信網に対して通信を行う複合携帯端末による余分なチャネルサーチを防止することで、複合携帯端末の消費電力を抑制し得る移動通信システム及び複合携帯端末を提供することを目的とする。
【００１５】
【課題を解決するための手段】
上記の目的を達成するため、第１の発明の移動通信システムは、通信方式が互いに異なり、かつ、互いに独立した通信エリアを各々有する複数の基地局と、全地球測位システムで用いられるＧＰＳ衛星と、該複数の基地局のいずれに対しても、その基地局の通信方式で通信可能な複数の通信方式に対応した複数の無線部及び前記ＧＰＳ衛星からのＧＰＳ信号を受信するＧＰＳ受信部を搭載した複合携帯端末とよりなる移動通信システムであって、複合携帯端末を、複数の基地局の通信エリアの位置情報と複数の基地局の通信方式とを対応付けたエリア情報を記憶している記憶部と、通信中の基地局からの信号の受信レベルを所定の閾値と比較する比較手段と、通信中において比較手段により受信レベルが閾値以下の比較結果が得られたときはＧＰＳ受信部の動作をオンとし、受信レベルが閾値より大である比較結果が得られたときは比較手段による比較動作を継続させる制御手段と、制御手段により動作がオンとされたＧＰＳ受信部で受信したＧＰＳ信号に基づき現在の位置情報を算出する位置情報検出部と、位置情報検出部で算出した現在の位置情報と記憶部に記憶されているエリア情報を比較して、現在の位置情報に対応したエリアに隣接するエリアの基地局の通信方式を求める通信方式検索手段と、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と同じ通信方式であるときは、現在動作中の無線部を引き続き動作状態とし、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と異なる通信方式であるときは、複数の無線部のうち通信方式検索手段で求めた通信方式の無線部を動作状態としてチャネルサーチを行い待ち受け状態とする無線部動作制御手段とを有することを特徴とする。
【００１６】
この発明では、複合携帯端末が移動しながらの通信中に、通信中の基地局のエリアの端に来たときにＧＰＳ信号に基づいて検出した現在の位置情報と記憶部のエリア情報とを比較して、複合携帯端末が在圏するエリアに隣接するエリアの基地局の通信方式を求めるようにしたため、次に移動する隣接するエリアの基地局に対してのみチャネルサーチができる。
【００１７】
また、上記の目的を達成するため、第２の発明の移動通信システムは、第１の発明における複合携帯端末を、通信方式検索手段により位置情報検出部で算出した現在の位置情報に対応したエリアに隣接するエリアのエリア情報が記憶部から検索できないときに、通信中の基地局に対して隣接するエリアのエリア情報を要求する情報要求手段と、通信中の基地局から応答送信された隣接するすべてのエリアのエリア情報を受信して移動方向に隣接するエリア情報を取得するエリア情報取得手段とを更に有し、通信方式検索手段は、記憶部に記憶されているエリア情報に替えてエリア情報取得手段で取得したエリア情報を位置情報検出部で算出した現在の位置情報と比較して、隣接するエリアの基地局の通信方式を求め、複数の基地局は、複合携帯端末からエリア情報要求があったときは、隣接するすべての基地局の通信方式と隣接するエリアの位置情報を含むエリア情報を要求元の複合携帯端末へ送信する送信手段を有する構成としたことを特徴とする。
【００１８】
この発明では、複合携帯端末が移動しながらの通信中に、通信中の基地局のエリアの端に来たときにＧＰＳ信号に基づいて検出した現在のエリアに隣接するエリアのエリア情報が記憶部に存在しない時に、通信中の基地局に対して隣接するエリアのエリア情報の送信を要求して、隣接するエリアのエリア情報を取得することができる。
【００１９】
また、上記の目的を達成するため、第３の発明の複合携帯端末は、通信方式が互いに異なり、かつ、互いに独立した通信エリアを各々有する複数の基地局のいずれに対しても、その基地局の通信方式で通信可能な複数の通信方式に対応した複数の無線部、及び全地球測位システムで用いられるＧＰＳ衛星からのＧＰＳ信号を受信するＧＰＳ受信部を搭載した複合携帯端末であって、複数の基地局の通信エリアの位置情報と複数の基地局の通信方式とを対応付けたエリア情報を記憶している記憶部と、通信中の第１の基地局からの信号の受信レベルを所定の閾値と比較する比較手段と、通信中において比較手段により受信レベルが閾値以下の比較結果が得られたときはＧＰＳ受信部の動作をオンとし、受信レベルが閾値より大である比較結果が得られたときは比較手段による比較動作を継続させる制御手段と、制御手段により動作がオンとされたＧＰＳ受信部で受信したＧＰＳ信号に基づき現在の位置情報を算出する位置情報検出部と、位置情報検出部で算出した現在の位置情報と記憶部に記憶されているエリア情報を比較して、現在の位置情報に対応したエリアに隣接するエリアの基地局の通信方式を求める通信方式検索手段と、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と同じ通信方式であるときは、現在動作中の無線部を引き続き動作状態とし、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と異なる通信方式であるときは、複数の無線部のうち通信方式検索手段で求めた通信方式の無線部を動作状態としてチャネルサーチを行い待ち受け状態とする無線部動作制御手段とを有する構成としたものである。
【００２１】
また、上記の目的を達成するため、第４の発明の複合携帯端末は、複数の基地局の通信エリアの位置情報と複数の基地局の通信方式とを対応付けたエリア情報を記憶している記憶部と、通信中の第１の基地局からの信号の受信レベルを所定の閾値と比較する比較手段と、通信中において比較手段により受信レベルが閾値以下の比較結果が得られたときはＧＰＳ受信部の動作をオンとし、受信レベルが閾値より大である比較結果が得られたときは比較手段による比較動作を継続させる制御手段と、制御手段により動作がオンとされたＧＰＳ受信部で受信したＧＰＳ信号に基づき現在の位置情報を算出する位置情報検出部と、位置情報検出部で算出した現在の位置情報と記憶部に記憶されているエリア情報を比較して、現在の位置情報に対応したエリアに隣接するエリアの基地局の通信方式を求める通信方式検索手段と、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と同じ通信方式であるときは、現在動作中の無線部を引き続き動作状態とし、通信方式検索手段で求めた通信方式が、現在通信中の通信方式と異なる通信方式であるときは、複数の無線部のうち通信方式検索手段で求めた通信方式の無線部を動作状態としてチャネルサーチを行い待ち受け状態とする無線部動作制御手段とを有する構成としたものである。
【００２２】
この発明は、第１の発明と同様に、複合携帯端末が移動しながらの通信中に、通信中の基地局のエリアの端に来たときにＧＰＳ信号に基づいて検出した現在の位置情報と記憶部のエリア情報とを比較して、複合携帯端末が在圏するエリアに隣接するエリアの基地局の通信方式を求めるようにしたため、次に移動する隣接するエリアの基地局に対してのみチャネルサーチができる。
【００２４】
【発明の実施の形態】
次に、本発明の実施の形態について図面と共に説明する。図１は本発明になる移動通信システムの一実施の形態の概略システム構成図を示す。同図において、移動通信システムは、本発明になる複合携帯端末の一例であるＧＰＳ搭載複合携帯電話１と、公知の全地球測位システム（ＧＰＳ：Global Positioning System）で用いられるＧＰＳ衛星２と、通信方式がＰＤＣであるＰＤＣ基地局３と、通信方式がＣＤＭＡであるＣＤＭＡ基地局４とから構成される。ＰＤＣ基地局３は、ＰＤＣエリア５の中心に位置し、ＣＤＭＡ基地局４は、ＣＤＭＡエリア６の中心に位置する。両エリア５及び６は、それぞれ互いに独立した通信エリアであり、ここでは一部が重複している。
【００２５】
なお、ここでは、図示及び説明の便宜上、ＰＤＣ基地局３とＣＤＭＡ基地局４とが、互いに隣接するように図示しているが、実際にはＰＤＣ基地局同士、あるいはＣＤＭＡ基地局同士が隣接することもあり、また、設置されている基地局の総数は３以上の多数であることは勿論である。また、ＧＰＳ衛星２は、複数の低軌道衛星であるが、ここではＧＰＳ搭載複合携帯電話１と通信中の１台のＧＰＳ衛星のみを図示している。また、ここでは、異なる複数の通信方式としてＰＤＣとＣＤＭＡを挙げているが、これ以外の通信方式でもよい。
【００２６】
ＧＰＳ搭載複合携帯電話１は、ＧＰＳ衛星２から送信されたＧＰＳ信号を受信して、自端末の位置情報（緯度及び経度）を算出する機能を有する本発明の複合携帯端末であり、例えば図２のブロック図に示す構成とされている。
【００２７】
図２において、ＧＰＳ搭載複合携帯電話１は、ＰＤＣ基地局（図１の３）との間でＰＤＣ信号を無線通信するＰＤＣアンテナ１１と、ＰＤＣアンテナ１１に接続されたＰＤＣ無線部１２と、ＣＤＭＡ基地局（図１の４）との間でＣＤＭＡ信号を無線通信するＣＤＭＡアンテナ１３と、ＣＤＭＡアンテナ１３に接続されたＣＤＭＡ無線部１４と、ＰＤＣベースバンド信号やＣＤＭＡベースバンド信号に含まれる音声情報やデータ情報（画像情報やテキスト情報を含む）を再生する共通ベースバンド部１５と、受話器であるレシーバ１６と、送話器であるマイク１７と、ＧＰＳ信号を受信するＧＰＳアンテナ１８と、受信したＧＰＳ信号を復調してＧＰＳベースバンド信号に再生するＧＰＳ受信部１９と、位置検出部２０と、携帯電話１の各部を統括的に制御する制御部２１と、使用者に対して情報を表示する表示部２２と、使用者が操作する通話ボタンやテンキーなどからなるキー操作部２３と、記憶部２４とから構成されている。
【００２８】
上記のＰＤＣ無線部１２は、受信時はＰＤＣアンテナ１１で受信したＰＤＣ信号を復調し、発呼側で作られたＰＤＣベースバンド信号に再生して共通ベースバンド部１５に供給し、送信時は共通ベースバンド部１５から入力された音声信号やデータ情報をＰＤＣ信号に変換してＰＤＣアンテナ１１を介して無線送信する。また、上記のＣＤＭＡ無線部１４は、受信時はＣＤＭＡアンテナ１３で受信したＣＤＭＡ信号を復調し、発呼側で作られたＣＤＭＡベースバンド信号に再生して共通ベースバンド部１５に供給し、送信時は共通ベースバンド部１５から入力された音声信号やデータ情報をＣＤＭＡ信号に変換してＣＤＭＡアンテナ１３を介して無線送信する。
【００２９】
また、上記の位置検出部２０は、ＧＰＳ受信部１９から供給されるＧＰＳベースバンド信号からＧＰＳ搭載複合携帯電話１の現在の位置情報を算出する。この位置情報算出方法自体は、本発明の要旨ではないので、その詳細な説明は省略するが、上記の位置検出部２０は、ＧＰＳ受信部１９から入力された、複数のＧＰＳ衛星からのＧＰＳベースバンド信号の到達時間差やＧＰＳ衛星の軌道から現在位置の位置情報（緯度や経度）を算出する。
【００３０】
また、上記の記憶部２４は、電話帳や地図情報、エリア情報及び各種設定等を予め記憶している。上記のエリア情報としては、ＰＤＣ基地局３によるＰＤＣエリア５及びＣＤＭＡ基地局４によるＣＤＭＡエリア６それぞれの緯度及び経度からなる位置情報と、基地局３及び４の通信方式とが対応付けられた情報である。
【００３１】
次に、本実施の形態の移動通信システム及びＧＰＳ搭載複合携帯電話１の動作について説明する。まず、ＧＰＳ搭載複合携帯電話１の電源オン時の動作について、図３のフローチャートを併せ参照して説明する。使用者が電源がオフとされている状態のＧＰＳ搭載複合携帯電話１の電源を投入（オン）すると（ステップ３０１）、図２に示したＧＰＳ受信部１９及び位置検出部２０が動作を開始して、ＧＰＳ衛星２からのＧＰＳ信号を受信し（ステップ３０２）、ＧＰＳベースバンド信号を得て、位置検出部２０により携帯電話１の現在位置の位置情報（緯度及び経度）が算出される（ステップ３０３）。
【００３２】
次に、制御部２１は、位置検出部２０により算出された携帯電話１の現在位置の位置情報に基づいて、記憶部２４に記憶されているエリア情報を比較参照する（ステップ３０４）。上記の比較参照により、現在位置がまずＣＤＭＡ基地局４によるＣＤＭＡエリア６であるか否か判定され（ステップ３０５）、ＣＤＭＡエリア６であれば、制御部２１はＣＤＭＡ無線部１４を動作させると共に、ＰＤＣ無線部１２を非動作として、ＣＤＭＡ信号の送受信を行えるようにして、ＣＤＭＡ基地局４から定期的に送信された信号を受信して、ＣＤＭＡでのチャネルサーチを行い（ステップ３０６）、通信チャネル確立後、ＣＤＭＡ信号の送受信可能なＣＤＭＡモードにて待ち受け状態に入る（ステップ３０７）。
【００３３】
他方、ステップ３０５でＣＤＭＡエリア６ではないと判定されたときには、制御部２１はＰＤＣエリア５であるか否か判定し（ステップ３０８）、ＰＤＣエリア５であれば、制御部２１はＰＤＣ無線部１２を動作させると共に、ＣＤＭＡ無線部１４を非動作として、ＰＤＣ信号の送受信を行えるようにして、ＰＤＣ基地局３から定期的に送信された信号を受信して、ＰＤＣでのチャネルサーチを行い（ステップ３０９）、通信チャネル確立後、ＰＤＣ信号の送受信可能なＰＤＣモードにて待ち受け状態に入る（ステップ３１０）。
【００３４】
また、ステップ３０８において、ＰＤＣエリア５でもないと判定されたときには、再度ＧＰＳ信号を受信して（ステップ３０２）、再度上記のステップ３０３以降の処理を行う。
【００３５】
このように、本実施の形態では、ＧＰＳ搭載複合携帯電話１の電源オン時に、ＧＰＳ信号から現在位置情報を算出して、この現在位置情報と記憶部２４に記憶しているエリア情報とを比較して、現在位置情報がＰＤＣエリア５であるかＣＤＭＡエリア６であるかを判定して、判定したエリアに対応した通信方式でのみチャネルサーチを行うようにしたため、余分なチャネルサーチをすることが無くなり、余分な電力消費を防止することができる。
【００３６】
次に、ＧＰＳ搭載複合携帯電話１の通話中の動作について、図４のフローチャートを併せ参照して説明する。ＧＰＳ搭載複合携帯電話１はＰＤＣ基地局３又はＣＤＭＡ基地局４と通話中であるときに（ステップ４０１）、受信レベルを確認（計測）する（ステップ４０２）。
【００３７】
ＧＰＳ搭載複合携帯電話１の制御部２１は、この受信レベルを予め設定した所定の閾値と比較し（ステップ４０３）、受信レベルが閾値以上であるときには、ＧＰＳ搭載複合携帯電話１が現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４のエリア５又は６の中央付近に在圏していると判断して、引き続き現在のモードのまま受信レベルの確認を行うが、受信レベルが閾値未満に劣化したときには、ＧＰＳ搭載複合携帯電話１が現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４のエリア５又は６の端に移動したと判断して、現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４のエリア５又は６に隣接する基地局の通信方式を検出するために、無駄な電力消費を抑えるため、それまでオフ状態であったＧＰＳ無線部１９の動作をオンとする（ステップ４０４）。
【００３８】
これにより、ＧＰＳ衛星２から送信されているＧＰＳ信号が、ＧＰＳアンテナ１８を介してＧＰＳ無線部１９により受信・復調されてＧＰＳベースバンド信号とされた後（ステップ４０５）、このＧＰＳベースバンド信号に基づき位置検出部２０により携帯電話１の現在位置の位置情報（緯度及び経度）が算出される（ステップ４０６）。
【００３９】
次に、制御部２１は、位置検出部２０により算出された携帯電話１の現在位置の位置情報に基づいて、記憶部２４に記憶されているエリア情報を比較参照して、現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４に隣接する基地局のエリア情報を取得する（ステップ４０７）。以後は、図３に示したステップ３０５以降の処理が行われ、隣接する基地局の通信方式（ＰＤＣモード又はＣＤＭＡモード）に合致した通信方式のチャネルサーチ後に待ち受け状態となる。
【００４０】
これにより、制御部２１は現在通話中の基地局からの信号の第１の受信レベルと、待ち受け状態で得られる隣接する基地局から定期的に送信される信号の第２の受信レベルとを比較し、第２の受信レベルの方が第１の受信レベルよりも大きくなった時点で、エリア切り替えを行い、通信相手の基地局を隣接する基地局に切り替えると共に、その基地局の通信方式で引き続き通話を継続する。
【００４１】
従って、例えば、図１において、ＧＰＳ搭載複合携帯電話１がＰＤＣエリア５内にあって、ＰＤＣ基地局３を通して移動通信網の相手端末と通話を行いつつ移動してＣＤＭＡエリア６に近いＰＤＣエリア５の端に来た場合、ＧＰＳ搭載複合携帯電話１はＧＰＳ衛星２からのＧＰＳ信号を受信して算出した現在位置情報を記憶部２４に記憶されているエリア情報と比較することで、隣接する基地局がＣＤＭＡ基地局４であることが分かるため、ＣＤＭＡでのチャネルサーチだけを行って、ＣＤＭＡでの待ち受け状態となり、ＣＤＭＡ基地局４から定期的に送信される信号の受信レベルを確認して、現在通話中のＰＤＣ基地局３からの信号の受信レベルとを比較する。
【００４２】
そして、ＧＰＳ搭載複合携帯電話１が更に移動してＣＤＭＡエリア６に入ると（あるいは入る直前になると）、ＣＤＭＡ基地局４からの信号の受信レベルが、現在通話中のＰＤＣ基地局３からの信号の受信レベルよりも大となるため、ＧＰＳ搭載複合携帯電話１はＰＤＣモードからＣＤＭＡモードに切り替わり、ＣＤＭＡ基地局４を介して相手端末との間の通話を継続する。
【００４３】
このように、本実施の形態では、移動しながらの通話中、基地局エリアの端に来た場合にはＧＰＳ位置情報を受信し、現在位置検出およびエリア検出を行うことにより、次にどちらの通信方式の基地局に対してチャネルサーチを行えばよいかの判断ができるため、余分なチャネルサーチをすることが無くなり消費電力を抑えることが可能である。
【００４４】
次に、本発明の移動通信システム及び複合携帯端末の他の実施の形態について説明する。この実施の形態は、複合携帯端末のブロック構成は図２と同様であるが、通話中の位置情報検出において、検出した現在位置が記憶部２４に記憶されていない場合の動作に特徴を有するもので、図５のフローチャートと共にその動作について説明する。図５中、図３及び図４と同一処理ステップは図示を省略してある。
【００４５】
この実施の形態では、ＧＰＳ搭載複合携帯電話１が現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４のエリア５又は６の端に移動したときに、上記の実施の形態と同様に、ＧＰＳベースバンド信号に基づき位置検出部２０により算出された携帯電話１の現在位置の位置情報に基づいて、記憶部２４に記憶されているエリア情報を比較する（ステップ４０７）。
【００４６】
このとき、記憶部２４に記憶されているエリア情報の中に、現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４に隣接する基地局のエリア情報と一致するものが存在するか否か判定し（ステップ５０１）、一致するものがあれば、図３及び図４と共に説明したと同様にステップ３０５以降の動作を行うが、一致するものが無いときには、現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４に対して、隣接する基地局のエリア情報を要求する（ステップ５０２）。
【００４７】
現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４は、上記のエリア情報要求を受け取ると、隣接するすべての基地局のエリア情報を携帯電話１に対して応答送信するので、この基地局からのエリア情報を携帯電話１が受信する（ステップ５０３）。
【００４８】
続いて、携帯電話１はＧＰＳベースバンド信号に基づき位置検出部２０により算出された携帯電話１の現在位置の位置情報と、現在通話中のＰＤＣ基地局３又はＣＤＭＡ基地局４から受信した隣接するすべての基地局の複数のエリア情報とを比較し、受信した隣接するすべての基地局の複数のエリア情報の中から、携帯電話１の移動方向に対応した、移動先の一の隣接する基地局のエリア情報を取得する（ステップ５０４）。
【００４９】
以後は、図３に示したステップ３０５以降の処理が行われ、隣接する基地局の通信方式（ＰＤＣモード又はＣＤＭＡモード）に合致した通信方式のチャネルサーチ後に待ち受け状態となる。
【００５０】
なお、以上の実施の形態の複合携帯端末では、電源オン時と通話中の基地局の通信エリアの端に移動した時の両方について余分なチャネルサーチを行わない処理をしているが、どちらか一方の処理だけを行うようにしてもよい。
【００５１】
【発明の効果】
以上説明したように、本発明によれば、複合携帯端末の電源オン時に、ＧＰＳ信号に基づいて検出した現在の位置情報と記憶部のエリア情報とを比較して、複合携帯端末が在圏するエリアの基地局の通信方式を求めることにより、現在在圏するエリアの基地局に対してのみチャネルサーチを行うようにしたため、余分なチャネルサーチをすることがなく、消費電力を抑えることができ、電池の長寿命化を実現できる。
【００５２】
また、本発明によれば、複合携帯端末が移動しながらの通信中に、通信中の基地局のエリアの端に来たときにＧＰＳ信号に基づいて検出した現在の位置情報と記憶部のエリア情報とを比較して、複合携帯端末が在圏するエリアに隣接するエリアの基地局の通信方式を求めることにより、次に移動する隣接するエリアの基地局に対してのみチャネルサーチを行うようにしたため、余分なチャネルサーチをすることがなく、消費電力を抑えることができ、電池の長寿命化を実現できる。
【図面の簡単な説明】
【図１】本発明の移動通信システムの一実施の形態の概略システム構成図である。
【図２】本発明の複合携帯端末の一実施の形態のブロック図である。
【図３】図１及び図２に示した携帯電話の電源オン時の動作説明用フローチャートである。
【図４】図１及び図２に示した携帯電話が通話中基地局エリアの端に来た時の動作説明用フローチャートである。
【図５】本発明の複合携帯端末の他の実施の形態の動作説明用の要部のフローチャートである。
【符号の説明】
１ＧＰＳ搭載複合携帯電話
２ＧＰＳ衛星
３ＰＤＣ基地局
４ＣＤＭＡ基地局
５ＰＤＣエリア
６ＣＤＭＡエリア
１１ＰＤＣアンテナ
１２ＰＤＣ無線部
１３ＣＤＭＡアンテナ
１４ＣＤＭＡ無線部
１５共通ベースバンド部
１８ＧＰＳアンテナ
１９ＧＰＳ受信部
２０位置検出部
２１制御部
２４記憶部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile communication system and a composite mobile terminal, and in particular, a composite mobile terminal equipped with a location information search function for obtaining location information using a GPS signal from a GPS (Global Positioning System) satellite includes a plurality of communication systems having different communication methods. The present invention relates to a mobile communication system for wireless communication with a base station and a composite portable terminal used therefor.
[0002]
[Prior art]
In recent years, the market for mobile terminals such as mobile phones has matured, and higher functionality and higher performance have been achieved. However, as the functions and performance of mobile terminals increase, the demand for longer battery life of mobile terminals increases.
[0003]
On the other hand, various communication systems for mobile communication systems have been proposed. As a typical example, a code division multiple access (CDMA) system capable of handling various contents and a time division multiple system are available. There is a connection method. Furthermore, a typical example of the time division multiple access method is the PDC (Personal Digital Cellular) standard. Therefore, a so-called dual mode mobile terminal (composite mobile terminal) that can communicate by selecting both the CDMA system and the PDC standard communication system has been known (see, for example, Patent Document 1).
[0004]
This composite portable terminal described in Patent Document 1 is provided with a mode switch at the input of a quadrature modulator of a transmission system, shares a quadrature modulator and a power control amplifier, is provided with a mode switch at the output of the power control amplifier, and has different modes. A signal is supplied to the transmission system circuit, and a ½ divider circuit is provided between the output of the second local oscillator and the input of the quadrature modulator, and the operation state of the ½ divider circuit is controlled by mode switching. By making it possible, a part of the transmission system is shared for CDMA and PDC, and the radio unit is simplified.
[0005]
[Patent Document 1]
JP 2000-13274 A (page 4, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, in the conventional composite portable terminal capable of communicating with a plurality of wireless communication networks having different communication methods, in channel search at power-on or channel search at the end of the base station area, There is a problem in that power consumption is large because extra channel search may be performed for radio communication base stations with different communication methods.
[0007]
In other words, when the power is turned on, the composite portable terminal waits by checking which communication system is located in the area of the base station of a plurality of different communication systems (in this case, PDC and CDMA). Channel search to establish a communication channel after confirming the communication method of the base station by sequentially receiving the signal transmitted from the base station periodically through the paging channel in order to enter the operation. I do.
[0008]
In addition, when the first communication state (for example, the received electric field level) with the base station that is currently communicating during standby and during a call is better than a predetermined threshold, the composite portable terminal communicates as it is. If the first communication state deteriorates to a predetermined threshold value or less, the terminal is located at the end of the area of the currently communicating base station. The second communication state is compared with the first communication state described above by comparing the second communication state with another base station adjacent to the currently communicating base station. When it becomes better than the first communication state, switching is performed so as to perform wireless communication with the other base station.
[0009]
Here, in the comparison of the above communication states, since it is not known which of the plurality of communication methods is the communication method of the other base station, the paging channel is periodically transmitted from the other base station. A signal to be transmitted is sequentially received by a plurality of communication systems, and after confirming the communication system of the other base station, a channel search for establishing a communication channel is performed.
[0010]
Thus, in a conventional composite portable terminal capable of communicating with a plurality of wireless communication networks having different communication methods, in channel search at power-on or channel search at the end of the base station area, There is a problem that extra channel search may be performed by communicating with the base station using a communication method different from the communication method of the communicating base station, which consumes more power and shortens the battery life. There is.
[0012]
  The present invention has been made in view of the above points.To provide a mobile communication system and a composite mobile terminal capable of suppressing power consumption of the composite mobile terminal by preventing redundant channel search by the composite mobile terminal that communicates with a plurality of wireless communication networks having different communication methods.With the goal.
[0015]
[Means for Solving the Problems]
  To achieve the above objective,The mobile communication system of the invention has a plurality of base stations having different communication methods and independent communication areas, GPS satellites used in the global positioning system, and any of the plurality of base stations. Is a mobile communication system comprising a composite portable terminal equipped with a plurality of radio units corresponding to a plurality of communication methods capable of communicating with the communication method of the base station and a GPS receiving unit for receiving GPS signals from the GPS satellites. The composite portable terminal includes a storage unit storing area information in which position information of communication areas of a plurality of base stations and communication methods of a plurality of base stations are associated with each other, and a signal from the communicating base station Comparing means for comparing the reception level ofDuring communicationThe reception level is below the threshold by the comparison means.When the comparison result is obtained, the operation of the GPS receiving unit is turned on, and when the comparison result whose reception level is larger than the threshold value is obtained, the control means for continuing the comparison operation by the comparison means, and the operation by the control means. Turned onThe position information detector that calculates the current position information based on the GPS signal received by the GPS receiver, the current position information calculated by the position information detector and the area information stored in the storage unit are compared, The communication method of the base station in the area adjacent to the area corresponding to the location information ofCommunicationMethod retrieval means;When the communication method obtained by the communication method search means is the same communication method as the currently communicating communication method, the currently operating radio unit is kept in the operating state, and the communication method obtained by the communication method search means is When the communication method is different from the communication method during communication,Among multiple radio unitscommunicationThe channel search is performed with the radio part of the communication method obtained by the method search means as the operating state, and the standby stateWireless unit operation control meansIt is characterized by having.
[0016]
In the present invention, during the communication while the composite portable terminal is moving, the current position information detected based on the GPS signal when it comes to the end of the area of the communicating base station is compared with the area information in the storage unit. Since the communication system of the base station in the area adjacent to the area where the composite portable terminal is located is obtained, the channel search can be performed only for the base station in the adjacent area that moves next.
[0017]
  In order to achieve the above objective,2The mobile communication system of the invention is the first1Composite portable terminal in the inventionThe communicationWhen the area information of the area adjacent to the area corresponding to the current position information calculated by the position information detection unit by the method search unit cannot be searched from the storage unit, the area information of the area adjacent to the communicating base station is obtained. The information requesting means to request and the area information of all adjacent areas sent back as a response from the communicating base station are received to obtain the area information adjacent to the moving direction.A communication method search means for replacing the area information stored in the storage unit with the area information acquired by the area information acquisition means. Compared to adjacent areasThe base station communication systemSeekingWhen there are area information requests from the composite mobile terminal, the plurality of base stations transmit the area information including the communication method of all adjacent base stations and the location information of the adjacent area to the requesting composite mobile terminal. It has the structure which has a means.
[0018]
In this invention, during the communication while the composite portable terminal is moving, the area information of the area adjacent to the current area detected based on the GPS signal when it comes to the end of the area of the communicating base station is stored in the storage unit. When the mobile station does not exist, it is possible to request the base station in communication to transmit the area information of the adjacent area, and acquire the area information of the adjacent area.
[0019]
  In order to achieve the above objective,3The composite portable terminal of the present invention has a plurality of communication systems that can communicate with each of a plurality of base stations that have different communication systems and have independent communication areas. It is a composite portable terminal equipped with a plurality of corresponding wireless units and a GPS receiving unit that receives GPS signals from GPS satellites used in the global positioning system, and includes a plurality of base station communication area position information and a plurality of A storage unit that stores area information associated with a communication method of the base station, a comparison unit that compares a reception level of a signal from the first base station in communication with a predetermined threshold,During communicationThe reception level is below the threshold by the comparison means.When the comparison result is obtained, the operation of the GPS receiving unit is turned on, and when the comparison result whose reception level is larger than the threshold value is obtained, the control means for continuing the comparison operation by the comparison means, and the operation by the control means. Turned onThe position information detector that calculates the current position information based on the GPS signal received by the GPS receiver, the current position information calculated by the position information detector and the area information stored in the storage unit are compared, The communication method of the base station in the area adjacent to the area corresponding to the location information ofCommunicationMethod retrieval means;When the communication method obtained by the communication method search means is the same communication method as the currently communicating communication method, the currently operating radio unit is kept in the operating state, and the communication method obtained by the communication method search means is When the communication method is different from the communication method during communication,Among multiple radio unitscommunicationThe channel search is performed with the radio part of the communication method obtained by the method search means as the operating state, and the standby stateWireless unit operation control meansIt is set as the structure which has.
[0021]
  In order to achieve the above objective,4The composite portable terminal of the invention includes a storage unit storing area information in which position information of communication areas of a plurality of base stations is associated with communication methods of a plurality of base stations, and a first base station in communication A comparison means for comparing the reception level of the signal from a predetermined threshold;During communicationThe reception level is below the threshold by the comparison means.When the comparison result is obtained, the operation of the GPS receiving unit is turned on, and when the comparison result whose reception level is larger than the threshold value is obtained, the control means for continuing the comparison operation by the comparison means, and the operation by the control means. Turned onThe position information detector that calculates the current position information based on the GPS signal received by the GPS receiver, the current position information calculated by the position information detector and the area information stored in the storage unit are compared, The communication method of the base station in the area adjacent to the area corresponding to the location information ofCommunicationMethod retrieval means;When the communication method obtained by the communication method search means is the same communication method as the currently communicating communication method, the currently operating radio unit is kept in the operating state, and the communication method obtained by the communication method search means is When the communication method is different from the communication method during communication,Among multiple radio unitscommunicationThe channel search is performed with the radio part of the communication method obtained by the method search means as the operating state, and the standby stateWireless unit operation control meansIt is set as the structure which has.
[0022]
  This invention is the first1As in the invention of the present invention, during the communication while the composite portable terminal is moving, the current position information detected based on the GPS signal when it comes to the end of the area of the base station in communication and the area information of the storage unit Since the communication system of the base station in the area adjacent to the area where the composite portable terminal is located is obtained, the channel search can be performed only for the base station in the adjacent area that moves next.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic system configuration diagram of an embodiment of a mobile communication system according to the present invention. In the figure, a mobile communication system communicates with a GPS-equipped composite mobile phone 1 which is an example of a composite mobile terminal according to the present invention, a GPS satellite 2 used in a known global positioning system (GPS), A PDC base station 3 whose system is PDC and a CDMA base station 4 whose communication system is CDMA are included. The PDC base station 3 is located at the center of the PDC area 5, and the CDMA base station 4 is located at the center of the CDMA area 6. Both areas 5 and 6 are communication areas independent of each other, and a part of them overlaps here.
[0025]
Here, for convenience of illustration and description, the PDC base station 3 and the CDMA base station 4 are illustrated so as to be adjacent to each other, but actually, the PDC base stations or the CDMA base stations are adjacent to each other. Of course, the total number of installed base stations is three or more. The GPS satellite 2 is a plurality of low-orbit satellites, but only one GPS satellite in communication with the GPS-equipped composite mobile phone 1 is shown here. Here, PDC and CDMA are cited as a plurality of different communication methods, but other communication methods may be used.
[0026]
The GPS-equipped composite mobile phone 1 is a composite mobile terminal of the present invention having a function of receiving the GPS signal transmitted from the GPS satellite 2 and calculating the position information (latitude and longitude) of the terminal itself. For example, FIG. The configuration shown in the block diagram of FIG.
[0027]
2, a GPS-equipped composite mobile phone 1 includes a PDC antenna 11 that wirelessly communicates PDC signals with a PDC base station (3 in FIG. 1), a PDC radio unit 12 connected to the PDC antenna 11, and a CDMA. A CDMA antenna 13 for wirelessly communicating a CDMA signal with a base station (4 in FIG. 1), a CDMA radio unit 14 connected to the CDMA antenna 13, and audio information included in a PDC baseband signal or a CDMA baseband signal And a common baseband unit 15 that reproduces data information (including image information and text information), a receiver 16 that is a receiver, a microphone 17 that is a transmitter, and a GPS antenna 18 that receives a GPS signal. A GPS receiver 19 that demodulates a GPS signal and reproduces it into a GPS baseband signal, a position detector 20, and each part of the mobile phone 1 A control unit 21 that performs overall control, a display unit 22 that displays information to the user, a key operation unit 23 including a call button or a numeric keypad operated by the user, and a storage unit 24 are included. Yes.
[0028]
The PDC radio unit 12 demodulates the PDC signal received by the PDC antenna 11 at the time of reception, reproduces the PDC baseband signal generated on the calling side, supplies the PDC baseband signal to the common baseband unit 15, and at the time of transmission. Audio signals and data information input from the common baseband unit 15 are converted into PDC signals and wirelessly transmitted through the PDC antenna 11. The CDMA radio unit 14 demodulates the CDMA signal received by the CDMA antenna 13 at the time of reception, regenerates the CDMA baseband signal generated on the calling side, supplies it to the common baseband unit 15, and transmits it. In some cases, voice signals and data information input from the common baseband unit 15 are converted into CDMA signals and transmitted wirelessly via the CDMA antenna 13.
[0029]
The position detection unit 20 calculates the current position information of the GPS-equipped composite mobile phone 1 from the GPS baseband signal supplied from the GPS reception unit 19. Since the position information calculation method itself is not the gist of the present invention, a detailed description thereof is omitted, but the position detection unit 20 described above is a GPS base from a plurality of GPS satellites input from the GPS reception unit 19. The position information (latitude and longitude) of the current position is calculated from the arrival time difference of the band signals and the orbit of the GPS satellite.
[0030]
In addition, the storage unit 24 stores a telephone directory, map information, area information, various settings, and the like in advance. As said area information, the information which matched the positional information which consists of each latitude and longitude of PDC area 5 by PDC base station 3, and CDMA area 6 by CDMA base station 4, and the communication system of base stations 3 and 4 were matched. It is.
[0031]
Next, operations of the mobile communication system and the GPS-equipped composite mobile phone 1 according to the present embodiment will be described. First, the operation when the GPS-equipped composite mobile phone 1 is turned on will be described with reference to the flowchart of FIG. When the user turns on the power of the GPS-equipped composite mobile phone 1 with the power turned off (step 301), the GPS receiver 19 and the position detector 20 shown in FIG. Then, a GPS signal from the GPS satellite 2 is received (step 302), a GPS baseband signal is obtained, and position information (latitude and longitude) of the current position of the mobile phone 1 is calculated by the position detector 20 (step). 303).
[0032]
Next, the control unit 21 compares and refers to the area information stored in the storage unit 24 based on the position information of the current position of the mobile phone 1 calculated by the position detection unit 20 (step 304). Based on the above comparison reference, it is first determined whether or not the current position is the CDMA area 6 by the CDMA base station 4 (step 305). If it is the CDMA area 6, the control unit 21 operates the CDMA radio unit 14, and The PDC radio unit 12 is deactivated so that a CDMA signal can be transmitted / received, a signal periodically transmitted from the CDMA base station 4 is received, a channel search by CDMA is performed (step 306), and a communication channel After the establishment, a standby state is entered in a CDMA mode in which CDMA signals can be transmitted and received (step 307).
[0033]
On the other hand, when it is determined in step 305 that the area is not the CDMA area 6, the control unit 21 determines whether or not the area is the PDC area 5 (step 308). And the CDMA radio unit 14 is deactivated so that a PDC signal can be transmitted and received, a signal periodically transmitted from the PDC base station 3 is received, and a channel search is performed in the PDC (step). 309), after establishing the communication channel, a standby state is entered in a PDC mode in which a PDC signal can be transmitted and received (step 310).
[0034]
If it is determined in step 308 that it is not the PDC area 5, the GPS signal is received again (step 302), and the processing from step 303 onward is performed again.
[0035]
Thus, in the present embodiment, when the GPS-equipped composite mobile phone 1 is turned on, the current position information is calculated from the GPS signal, and the current position information is compared with the area information stored in the storage unit 24. Thus, since it is determined whether the current position information is the PDC area 5 or the CDMA area 6 and the channel search is performed only by the communication method corresponding to the determined area, an extra channel search may be performed. This eliminates excess power consumption.
[0036]
Next, the operation during a call of the GPS-equipped composite mobile phone 1 will be described with reference to the flowchart of FIG. When the GPS-equipped composite mobile phone 1 is talking with the PDC base station 3 or the CDMA base station 4 (step 401), the reception level is confirmed (measured) (step 402).
[0037]
The control unit 21 of the GPS-equipped composite mobile phone 1 compares this reception level with a predetermined threshold value set in advance (step 403), and when the reception level is equal to or higher than the threshold, the GPS-equipped composite mobile phone 1 is currently talking. It is judged that the PDC base station 3 or the CDMA base station 4 is located in the vicinity of the center of the area 5 or 6, and the reception level is continuously checked in the current mode, but the reception level has deteriorated below the threshold. Sometimes, it is determined that the GPS-equipped composite mobile phone 1 has moved to the end of the area 5 or 6 of the PDC base station 3 or CDMA base station 4 that is currently talking, and the PDC base station 3 or CDMA base station 4 that is currently talking. In order to detect the communication system of the base station adjacent to the area 5 or 6, the operation of the GPS wireless unit 19 that has been in the off state until then is turned on in order to suppress unnecessary power consumption ( Step 404).
[0038]
As a result, the GPS signal transmitted from the GPS satellite 2 is received and demodulated by the GPS radio unit 19 via the GPS antenna 18 and converted into a GPS baseband signal (step 405). Based on this, position information (latitude and longitude) of the current position of the mobile phone 1 is calculated by the position detection unit 20 (step 406).
[0039]
Next, the control unit 21 compares and refers to the area information stored in the storage unit 24 based on the position information of the current position of the mobile phone 1 calculated by the position detection unit 20, and the PDC currently in a call The area information of the base station adjacent to the base station 3 or the CDMA base station 4 is acquired (step 407). Thereafter, the processing after step 305 shown in FIG. 3 is performed, and a standby state is entered after channel search for a communication method that matches the communication method (PDC mode or CDMA mode) of the adjacent base station.
[0040]
As a result, the control unit 21 compares the first reception level of the signal from the currently communicating base station with the second reception level of the signal periodically transmitted from the adjacent base station obtained in the standby state. Then, when the second reception level becomes higher than the first reception level, the area is switched, the base station of the communication partner is switched to the adjacent base station, and the communication system of the base station continues. Continue the call.
[0041]
Therefore, for example, in FIG. 1, the GPS-equipped composite mobile phone 1 is in the PDC area 5, moves while making a call with the other terminal of the mobile communication network through the PDC base station 3, and moves close to the CDMA area 6. The GPS-equipped composite mobile phone 1 receives the GPS signal from the GPS satellite 2 and compares the current position information calculated by receiving the GPS signal from the GPS satellite 2 with the area information stored in the storage unit 24, thereby Since it is understood that the station is the CDMA base station 4, only the channel search by CDMA is performed, the CDMA standby state is entered, and the reception level of the signal periodically transmitted from the CDMA base station 4 is confirmed, The reception level of the signal from the PDC base station 3 that is currently talking is compared.
[0042]
When the GPS-equipped composite mobile phone 1 moves further and enters the CDMA area 6 (or just before entering), the reception level of the signal from the CDMA base station 4 becomes the signal from the PDC base station 3 that is currently talking. Therefore, the GPS-equipped composite mobile phone 1 switches from the PDC mode to the CDMA mode, and continues the call with the partner terminal via the CDMA base station 4.
[0043]
As described above, in this embodiment, during a call while moving, the GPS position information is received when it comes to the end of the base station area, and the current position detection and area detection are performed, so that Since it is possible to determine whether or not to perform a channel search with respect to a communication system base station, it is possible to eliminate power consumption by eliminating unnecessary channel searches.
[0044]
Next, another embodiment of the mobile communication system and the composite portable terminal of the present invention will be described. In this embodiment, the block configuration of the composite portable terminal is the same as that shown in FIG. 2, but it has a feature in the operation when the detected current position is not stored in the storage unit 24 in the position information detection during a call. Now, the operation will be described with reference to the flowchart of FIG. In FIG. 5, the same processing steps as those in FIGS. 3 and 4 are not shown.
[0045]
In this embodiment, when the GPS-equipped composite mobile phone 1 moves to the end of the area 5 or 6 of the PDC base station 3 or CDMA base station 4 that is currently talking, the GPS base Based on the position information of the current position of the mobile phone 1 calculated by the position detection unit 20 based on the band signal, the area information stored in the storage unit 24 is compared (step 407).
[0046]
At this time, it is determined whether or not the area information stored in the storage unit 24 matches the area information of the base station adjacent to the PDC base station 3 or the CDMA base station 4 that is currently talking. (Step 501) If there is a match, the operations in and after step 305 are performed in the same manner as described with reference to FIGS. 3 and 4. If there is no match, the PDC base station 3 or CDMA base station currently in communication The area 4 of the adjacent base station is requested to the station 4 (step 502).
[0047]
When the PDC base station 3 or the CDMA base station 4 that is currently in a call receives the area information request, the area information of all the adjacent base stations is transmitted as a response to the mobile phone 1. The mobile phone 1 receives the area information (step 503).
[0048]
Subsequently, the mobile phone 1 receives the location information of the current location of the mobile phone 1 calculated by the location detection unit 20 based on the GPS baseband signal and the adjacent information received from the PDC base station 3 or CDMA base station 4 that is currently talking. One adjacent base station of the destination corresponding to the moving direction of the mobile phone 1 from the plurality of area information of all the adjacent base stations received by comparing with the plurality of area information of all the base stations Area information is acquired (step 504).
[0049]
Thereafter, the processing after step 305 shown in FIG. 3 is performed, and a standby state is entered after channel search for a communication method that matches the communication method (PDC mode or CDMA mode) of the adjacent base station.
[0050]
Note that in the composite portable terminal of the above embodiment, processing is performed not to perform an extra channel search both when the power is turned on and when moving to the end of the communication area of the base station that is talking. Only one process may be performed.
[0051]
【The invention's effect】
As described above, according to the present invention, when the composite portable terminal is turned on, the composite portable terminal is located by comparing the current position information detected based on the GPS signal with the area information in the storage unit. By finding the communication method of the base station in the area, the channel search is performed only for the base station in the area that is currently in the area, so there is no extra channel search and power consumption can be reduced, Longer battery life can be achieved.
[0052]
In addition, according to the present invention, the current position information detected based on the GPS signal and the area of the storage unit when the composite portable terminal is in communication while moving and comes to the end of the area of the communicating base station By comparing the information and obtaining the communication method of the base station in the area adjacent to the area where the composite mobile terminal is located, the channel search is performed only for the base station in the adjacent area that moves next Therefore, unnecessary channel search is not performed, power consumption can be suppressed, and battery life can be extended.
[Brief description of the drawings]
FIG. 1 is a schematic system configuration diagram of an embodiment of a mobile communication system of the present invention.
FIG. 2 is a block diagram of an embodiment of a composite portable terminal of the present invention.
FIG. 3 is a flowchart for explaining an operation when the mobile phone shown in FIGS. 1 and 2 is turned on.
4 is a flowchart for explaining operations when the mobile phone shown in FIGS. 1 and 2 comes to the end of the base station area during a call. FIG.
FIG. 5 is a flowchart of the main part for explaining the operation of another embodiment of the composite portable terminal of the present invention.
[Explanation of symbols]
1 GPS-equipped composite mobile phone
2 GPS satellites
3 PDC base station
4 CDMA base stations
5 PDC area
6 CDMA area
11 PDC antenna
12 PDC radio unit
13 CDMA antenna
14 CDMA radio unit
15 Common baseband part
18 GPS antenna
19 GPS receiver
20 Position detector
21 Control unit
24 storage unit

Claims

A plurality of base stations having different communication methods and independent communication areas, GPS satellites used in the global positioning system, and communication of the base station to any of the plurality of base stations A mobile communication system comprising a composite portable terminal equipped with a plurality of wireless units corresponding to a plurality of communication methods capable of communicating by a method and a GPS receiving unit that receives GPS signals from the GPS satellites,
The composite portable terminal is:
A storage unit storing area information in which position information of communication areas of the plurality of base stations is associated with communication methods of the plurality of base stations;
A comparison means for comparing a reception level of a signal from a communicating base station with a predetermined threshold;
When the comparison means obtains a comparison result with the reception level equal to or lower than the threshold value during communication, the GPS receiver is turned on, and a comparison result with the reception level greater than the threshold value is obtained. Is a control means for continuing the comparison operation by the comparison means;
A position information detecting unit that calculates current position information based on the GPS signal received by the GPS receiving unit whose operation is turned on by the control unit ;
By comparing the current position information calculated by the position information detection unit and the area information stored in the storage unit, a communication method of a base station in an area adjacent to the area corresponding to the current position information is obtained. Communication method search means,
When the communication method obtained by the communication method search means is the same communication method as the communication method currently being communicated, the wireless unit that is currently operating is continuously operated, and the communication method obtained by the communication method search means is when a communication method different from the communication system currently in communication, the radio unit to the standby state performs channel search radio section as the operation state of the communication system which has been determined by the communication method searching unit among the plurality of radio units A mobile communication system , comprising: an operation control unit .

The composite portable terminal is in communication when the area information of an area adjacent to the area corresponding to the current position information calculated by the position information detection unit by the communication method search unit cannot be searched from the storage unit. Information requesting means for requesting area information of the adjacent area to the base station, and area information adjacent to each other in the moving direction by receiving area information of all adjacent areas transmitted as a response from the communicating base station Area information acquisition means for acquiring the area information acquired by the area information acquisition means in place of the area information stored in the storage section by the position information detection section. Compared with the calculated current location information to determine the communication method of the base station in the adjacent area ,
When there is a request for the area information from the composite mobile terminal, the plurality of base stations request the area information including the communication method of all adjacent base stations and the location information of the adjacent area as the request source. the mobile communication system according to claim 1, further comprising a transmitting means for transmitting to.

A plurality of radio units corresponding to a plurality of communication schemes capable of communicating with each of a plurality of base stations having communication areas different from each other and having communication areas independent of each other, and A composite portable terminal equipped with a GPS receiver that receives GPS signals from GPS satellites used in the global positioning system,
A storage unit storing area information in which position information of communication areas of the plurality of base stations is associated with communication methods of the plurality of base stations;
A comparison means for comparing the reception level of the signal from the first base station in communication with a predetermined threshold;
When the comparison means obtains a comparison result with the reception level equal to or lower than the threshold value during communication, the GPS receiver is turned on, and a comparison result with the reception level greater than the threshold value is obtained. Is a control means for continuing the comparison operation by the comparison means;
A position information detecting unit that calculates current position information based on the GPS signal received by the GPS receiving unit whose operation is turned on by the control unit ;
By comparing the current position information calculated by the position information detection unit and the area information stored in the storage unit, a communication method of a base station in an area adjacent to the area corresponding to the current position information is obtained. Communication method search means,
When the communication method obtained by the communication method search means is the same communication method as the communication method currently being communicated, the wireless unit that is currently operating is continuously operated, and the communication method obtained by the communication method search means is when a communication method different from the communication system currently in communication, the radio unit to the standby state performs channel search radio section as the operation state of the communication system which has been determined by the communication method searching unit among the plurality of radio units A composite portable terminal comprising: an operation control unit .

Comparing the first reception level of the signal from the first base station in communication with the second reception level of the signal from the second base station in the adjacent area in the standby state; Characterized in that it further comprises switching means for switching a base station to communicate from the first base station to the second base station when the reception level of 2 becomes higher than the first reception level. The composite portable terminal according to claim 3 .

When area information of an area adjacent to the area corresponding to the current position information calculated by the position information detection unit by the communication method search unit cannot be searched from the storage unit, the base station in communication Information requesting means for requesting area information of adjacent areas, and area information acquisition for receiving area information of all adjacent areas transmitted in response from the communicating base station and acquiring area information adjacent in the moving direction And the communication method search means includes the current position calculated by the position information detection unit in the area information acquired by the area information acquisition means instead of the area information stored in the storage unit. 4. The composite portable terminal according to claim 3, wherein a communication method of a base station in the adjacent area is obtained in comparison with information.