JP3120809B2 - Handoff method for mobile communication system and mobile terminal - Google Patents
Handoff method for mobile communication system and mobile terminalInfo
- Publication number
- JP3120809B2 JP3120809B2 JP11311605A JP31160599A JP3120809B2 JP 3120809 B2 JP3120809 B2 JP 3120809B2 JP 11311605 A JP11311605 A JP 11311605A JP 31160599 A JP31160599 A JP 31160599A JP 3120809 B2 JP3120809 B2 JP 3120809B2
- Authority
- JP
- Japan
- Prior art keywords
- base station
- mobile terminal
- communication
- signal
- base stations
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、自動車電話システ
ムのように複数の基地局間を移動端末が移動しても継続
して通信路を提供する移動通信システムのハンドオフ
(基地局の切り換え)方法及びそれを実現する移動受信機
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handoff of a mobile communication system for providing a communication path continuously even when a mobile terminal moves between a plurality of base stations, such as an automobile telephone system.
The present invention relates to a method of switching base stations and a mobile receiver for realizing the method.
【０００２】[0002]
【従来の技術】自動車電話システムのように複数の基地
局で異なったサービスエリアをカバーしているいわゆる
セル方式の移動通信システムにおいては通話中に移動端
末が移動するために移動端末と通信する基地局を切り換
えて通話を継続させるハンドオフ技術の実現が極めて重
要な課題となっている。従来のハンドオフは、移動端末
からの信号が最も強く受信される基地局と通信が行われ
るように制御しており、通話中の基地局において移動端
末からの受信信号レベルが低下すると、周辺基地局で受
信信号レベルを測定し、最も強く信号が受信される基地
局に移動端末との通信を切り換えるようにしていた。こ
のハンドオフの方法は昭和６０年電子通信学会発行の単
行本「自動車電話」の１９７ページから２００ページに
詳述されている。2. Description of the Related Art In a so-called cellular mobile communication system in which a plurality of base stations cover different service areas, such as an automobile telephone system, a base for communicating with a mobile terminal in order to move during a call. The realization of a hand-off technique for switching stations to continue a call has become a very important issue. In the conventional handoff, communication is performed with a base station that receives a signal from a mobile terminal most strongly. When a received signal level from the mobile terminal is reduced in a base station during a call, a nearby base station is controlled. , The received signal level is measured, and the communication with the mobile terminal is switched to the base station that receives the strongest signal. This handoff method is described in detail in the book "Automobile Telephone" published by IEICE in 1985, pp. 197-200.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら従来のハ
ンドオフ方法では、受信信号レベルが変化してから実際
に基地局を切り換えるまでに時間がかかるから、移動端
末である自動車などがビルの陰にはいるなどして急激に
受信信号レベルが変動した場合には最適な基地局を選択
することができず音質の低下を招いたり、回線が切断さ
れたりすることがあるという欠点がある。However, in the conventional handoff method, it takes time from the change of the received signal level to the actual switching of the base station, so that the mobile terminal, such as a car, is behind the building. For example, when the received signal level fluctuates rapidly, it is not possible to select an optimal base station, resulting in a decrease in sound quality and a disconnection of the line.
【０００４】そこで本発明の目的は、受信信号レベルが
急激に変動しても通話品質に影響を与えないハンドオフ
方法を提供するとともにそのハンドオフを実現する移動
受信機を提供することにある。It is an object of the present invention to provide a handoff method that does not affect the communication quality even if the received signal level fluctuates rapidly, and to provide a mobile receiver that realizes the handoff.
【０００５】[0005]
【課題を解決するための手段】本発明の移動通信システ
ムのハンドオフ方法は、複数の基地局間を移動する移動
端末に対して通信路を逐次変更して継続的に通信路を提
供する移動通信システムのハンドオフ方法であって、移
動端末が複数の基地局と通信可能な位置にあるときに
は、その通信可能なそれぞれの基地局が異なった周波数
で同一の信号を前記移動端末に送信し、かつ前記通信可
能なそれぞれの基地局は前記移動端末からの信号を同時
に受信してダイバーシチを合成することを特徴とする。SUMMARY OF THE INVENTION A handoff method for a mobile communication system according to the present invention provides a mobile communication system for continuously providing a communication path by sequentially changing the communication path for a mobile terminal moving between a plurality of base stations. A system handoff method, wherein when a mobile terminal is at a position where it can communicate with a plurality of base stations, each of the communicable base stations transmits the same signal to the mobile terminal at a different frequency, and Each communicable base station simultaneously receives signals from the mobile terminals and combines diversity.
【０００６】また本発明の移動受信機は、移動端末に用
いられる移動受信機であって、複数のアンテナと、該複
数のアンテナのそれぞれの受信信号を同一周波数に周波
数変換する複数の周波数変換器と、該複数の周波数変換
器のそれぞれの出力信号を復調する複数の復調器と、該
複数の復調器のそれぞれの出力信号を合成する合成回路
と、当該移動受信機がハンドオフ状態にあるときには前
記複数の復調器がそれぞれ異なった基地局からの信号を
受信するように前記複数の周波数変換器の受信周波数を
それぞれ異なった値に設定し、当該移動受信機がハンド
オフ状態でないときには前記複数の周波数変換器の受信
周波数を同一の値に設定する制御回路とを有することを
特徴とする。A mobile receiver according to the present invention is a mobile receiver used for a mobile terminal, comprising a plurality of antennas and a plurality of frequency converters for converting received signals of the plurality of antennas into the same frequency. And, a plurality of demodulators for demodulating output signals of the plurality of frequency converters, a combining circuit for combining output signals of the plurality of demodulators, and the mobile receiver is in a handoff state, The receiving frequencies of the plurality of frequency converters are respectively set to different values so that the plurality of demodulators receive signals from different base stations, and the plurality of frequency conversions are performed when the mobile receiver is not in a handoff state. And a control circuit for setting the reception frequency of the device to the same value.
【０００７】[0007]
【作用】ハンドオフの品質を高める方法としてはハンド
オフに要する時間を短縮する方法と、無線回路を同時に
複数張ってダイバーシチ受信する方法とがある。本発明
では後者の方法を採用する。The method of improving the quality of handoff includes a method of shortening the time required for handoff and a method of simultaneously providing a plurality of radio circuits for diversity reception. In the present invention, the latter method is adopted.
【０００８】本発明の移動通信システムのハンドオフ方
法においては、移動端末が基地局の境界すなわちセルの
境界に近づくとハンドオフを開始する。このとき、それ
まで通信していた基地局との回線を維持しつつ、新しい
基地局との回線を設定する。同時に複数の基地局から同
一の移動端末に対して信号を送信する場合、同じ周波数
を用いると干渉を起こすからそれぞれの基地局は互いに
異なった周波数を用いる。移動端末から送信する信号は
単一の周波数であり、その同一周波数の信号を複数の基
地局で同時に受信するようにすれば良い。このようにし
て新しい基地局とも十分に品質良く通信できるようにな
ったところで移動端末は送信周波数を切り換える。その
後しばらくはそれまで通信していた基地局も送信を続け
ると同時に切り換えられた移動端末からの新しい周波数
の信号を受信する。複数の基地局で同一の移動端末から
の信号を受信しているときには交換局においてダイバー
シチ合成を行う。この様にすることによってたとえ片方
の基地局が建物の陰に隠れても、もう一方の基地局と通
信を続けることができ、極めて品質の高いハンドオフを
実現することができる。In the handoff method for a mobile communication system according to the present invention, handoff starts when a mobile terminal approaches a boundary of a base station, that is, a boundary of a cell. At this time, a line with a new base station is set while maintaining a line with the base station with which communication has been performed. When signals are transmitted from a plurality of base stations to the same mobile terminal at the same time, interference occurs if the same frequency is used, so that each base station uses a different frequency. A signal transmitted from a mobile terminal has a single frequency, and a signal having the same frequency may be received by a plurality of base stations simultaneously. The mobile terminal switches the transmission frequency when communication with the new base station becomes possible with sufficient quality. For a while thereafter, the base station with which it has been communicating continues to transmit and at the same time receives a signal of a new frequency from the switched mobile terminal. When a plurality of base stations are receiving signals from the same mobile terminal, diversity combining is performed at the exchange. In this way, even if one base station is hidden behind a building, communication with the other base station can be continued, and extremely high quality handoff can be realized.
【０００９】本発明の移動受信機は、アンテナと周波数
変換器と復調器とでなる複数の信号受信部と、合成回路
と、制御回路とを有しており、当該移動受信機のハンド
オフ状態に応じて前記信号受信部が受信する信号の周波
数を前記制御回路で変化させ、前記合成回路でダイバー
シティ合成することにより品質の高いハンドオフを実現
する。A mobile receiver according to the present invention includes a plurality of signal receiving units including an antenna, a frequency converter, and a demodulator, a combining circuit, and a control circuit. Accordingly, the frequency of the signal received by the signal receiving unit is changed by the control circuit, and diversity combining is performed by the combining circuit, thereby realizing high quality handoff.
【００１０】[0010]
【発明の実施の形態】次に、図面を参照して本発明につ
いて詳細に説明する。Next, the present invention will be described in detail with reference to the drawings.
【００１１】第１図には本発明の移動通信システムのハ
ンドオフ方法の一実施例を示す。第１図の状況は、丁度
ハンドオフの最中であり、基地局１１と基地局１２はそ
れぞれ周波数Ｆ1 、Ｆ2で移動端末１５に対して信号を
送信している。移動端末１５はこれらの信号をダイバー
シチ受信することによって安定した信号を受信すること
ができる。移動端末１５からは周波数ｆ1で送信され、
その信号は基地局１１および基地局１２でそれぞれ受信
され、交換局１３でダイバーシチ合成されて端子１０か
ら有線網へと出力される。FIG. 1 shows an embodiment of a handoff method for a mobile communication system according to the present invention. The situation in FIG. 1 is just in the middle of handoff, and the base station 11 and the base station 12 are transmitting signals to the mobile terminal 15 at the frequencies F 1 and F 2 , respectively. The mobile terminal 15 can receive stable signals by diversity receiving these signals. Sent from the mobile terminal 15 at the frequency f 1 ,
The signals are received by the base station 11 and the base station 12, respectively, are diversity-combined by the switching station 13, and output from the terminal 10 to the wired network.
【００１２】第２図に第１図の実施例の詳細な動作を示
す。いま基地局１１が存在する地点Ｘにいる移動端末１
５が基地局１２が存在する地点Ｙまで移動する場合を考
える。地点Ｘから地点Ａまでは基地局１１に十分近く基
地局１２からの信号は受信されないから移動端末１５は
周波数ｆ1を送信し、基地局１１は周波数Ｆ1を送信する
ことで通常の通信が行われている。移動端末１５が地点
Ａを通過すると基地局１２からの通信も受信され始める
から、基地局１２と移動端末１５の間にも回線を設定す
る。このとき基地局１２からは周波数Ｆ2で信号を送信
する。移動端末１５は周波数Ｆ1及びＦ2を受信してダイ
バーシチ合成することにより、安定した受信品質を保つ
ことができる。基地局１２では移動端末１５からの信号
ｆ1を受信する。基地局１１及び基地局１２で受信され
た移動端末１５からの信号は、第１図に示すような交換
局１３へ送られ、そこでダイバーシチ合成される。移動
端末１５が地点Ｂをすぎると、基地局１２からの信号の
方が強く受信されるようになり、移動端末１５は送信信
号の周波数をｆ2に切り換える。このとき基地局１１は
移動端末１５との通信を切断せずに周波数ｆ2を受信す
るとともに周波数Ｆ1を送信し続ける。この様にして依
然ダイバーシチ合成を基地局１１，１２および移動端末
１５の双方で続ける。移動端末１５が地点Ｃをすぎると
基地局１１からの信号は弱くなるので基地局１１と移動
端末１５との回線を切り放し、基地局１１は送受信を止
めて移動端末１５は基地局１２とのみ通信を続ける。こ
の様にすることにより、回線の不安定なセル周辺Ａ−Ｃ
の区間でも移動端末１５は安定して通信を続けることが
出来、品質劣化のないハンドオフを実現することができ
る。なお本実施例で述べたダイバーシチ合成や、地点
Ａ、Ｂ、Ｃ、のハンドオフの処理については本発明では
定義しておらず、どのような方法を用いても良い。FIG. 2 shows the detailed operation of the embodiment shown in FIG. The mobile terminal 1 at the point X where the base station 11 is present
Consider a case where 5 moves to a point Y where the base station 12 exists. From the point X to the point A, the mobile terminal 15 transmits the frequency f 1 and the base station 11 transmits the frequency F 1 because the signal from the base station 12 is not sufficiently received. Is being done. When the mobile terminal 15 passes through the point A, the communication from the base station 12 starts to be received, so that a line is set between the base station 12 and the mobile terminal 15. The time to transmit a signal at the frequency F 2 from the base station 12. The mobile terminal 15 can maintain stable reception quality by receiving the frequencies F 1 and F 2 and performing diversity combining. The base station 12 receives the signal f 1 from the mobile terminal 15. Signals from the mobile terminal 15 received by the base stations 11 and 12 are sent to an exchange 13 as shown in FIG. 1, where diversity combining is performed. When the mobile terminal 15 passes the point B, now towards the signal from the base station 12 is received strongly, the mobile terminal 15 switches the frequency of the transmitted signal to f 2. In this case the base station 11 continues to transmit the frequencies F 1 which receives the frequency f 2 without cutting the communication with the mobile terminal 15. In this way, diversity combining is still continued at both base stations 11, 12 and mobile terminal 15. When the mobile terminal 15 passes the point C, the signal from the base station 11 becomes weak. Therefore, the line between the base station 11 and the mobile terminal 15 is disconnected, the base station 11 stops transmission / reception, and the mobile terminal 15 communicates only with the base station 12. Continue. By doing so, AC around the cell where the line is unstable
In this section, the mobile terminal 15 can continue communication stably, and a handoff without quality deterioration can be realized. Note that the diversity combining described in the present embodiment and the handoff processing at points A, B, and C are not defined in the present invention, and any method may be used.
【００１３】第３図は本発明の移動受信機の一実施例を
示す図である。アンテナ３０，３１で受信された信号
は、それぞれ周波数変換器３２，３３で所望の周波数に
変換されて復調器３４，３５へ送られる。ここで周波数
変換器３２，３３はそれぞれ周波数可変の発振器と乗算
器とから構成されており、制御回路３７からの制御信号
によって独立に受信周波数を制御できるようになってい
る。復調器３４，３５ではそれぞれ受信信号を復調して
合成回路３６へ出力し、合成出力が端子４０から出力さ
れる。端子４１からは移動端末が今ハンドオフのどのよ
うな状態にあるかを示す情報が入力され、制御回路３７
では移動端末がハンドオフ状態にない第２図のＸ−Ａの
ようなときには同一周波数ｆ1を周波数変換器３２，３
３に設定し、通常のダイバーシチ受信を行う。これに対
して移動端末が第２図のＡ−Ｂのようにハンドオフの状
態にあるときには制御回路３７は周波数変換器３２には
ｆ1を、周波数変換器３３にはｆ2をそれぞれ設定して異
なった周波数の信号を受信してダイバーシチ合成を行
う。この様にすることでハンドオフ中は異なった基地局
からの信号を受信してダイバーシチ効果を持たせ、通常
は同一基地局からの信号をダイバーシチ受信することで
通信品質をあげる移動受信機が実現できる。なお、本発
明におけるダイバーシチ合成の方法はどのような方法を
採用しても良い。FIG. 3 is a diagram showing one embodiment of the mobile receiver of the present invention. The signals received by the antennas 30 and 31 are converted to desired frequencies by frequency converters 32 and 33, respectively, and sent to demodulators 34 and 35, respectively. Here, the frequency converters 32 and 33 each include a variable frequency oscillator and a multiplier, and can independently control the reception frequency by a control signal from the control circuit 37. The demodulators 34 and 35 demodulate the received signals and output the demodulated signals to the combining circuit 36, and the combined output is output from the terminal 40. Information indicating the state of the mobile terminal in the handoff state is input from the terminal 41, and the control circuit 37
In the mobile terminal is frequency converter with the same frequency f 1 when like X-A of FIG. 2 is not in the handoff state 32,3
3 to perform normal diversity reception. Mobile terminal control circuit when in the state of handoff as A-B of FIG. 2 37 whereas the f 1 to the frequency converter 32, the frequency converter 33 sets the f 2, respectively Diversity combining is performed by receiving signals of different frequencies. In this way, a mobile receiver that receives signals from different base stations during the handoff to have a diversity effect, and that normally receives signals from the same base station with diversity to improve communication quality can be realized. . In addition, any method may be adopted as the diversity combining method in the present invention.
【００１４】[0014]
【発明の効果】以上に詳細に記したように、本発明によ
れば、通信品質が極めて良好な移動通信システムのハン
ドオフ方法及びそれを実現する移動受信機を提供するこ
とができる。As described above in detail, according to the present invention, it is possible to provide a handoff method for a mobile communication system having extremely good communication quality and a mobile receiver for realizing the method.
【図１】 本発明の移動通信システムのハンドオフ方法
の一実施例を示す図である。FIG. 1 is a diagram illustrating an embodiment of a handoff method for a mobile communication system according to the present invention.
【図２】 第１図の実施例の動作の詳細を説明する図で
ある。FIG. 2 is a diagram for explaining details of the operation of the embodiment of FIG. 1;
【図３】 本発明の移動受信機の一実施例を示す図であ
る。FIG. 3 is a diagram showing one embodiment of the mobile receiver of the present invention.
１１，１２ 基地局 １３ 交換局 １５ 移動端末 ３０，３１ アンテナ ３２，３３ 周波数変換器 ３４，３５ 復調器 ３６ 合成回路 ３７ 制御回路 11, 12 Base station 13 Switching station 15 Mobile terminal 30, 31 Antenna 32, 33 Frequency converter 34, 35 Demodulator 36 Synthesis circuit 37 Control circuit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 濱辺 孝二郎 東京都港区芝五丁目７番１号 日本電気 株式会社内 (56)参考文献 特開 平２−34044（ＪＰ，Ａ) 特開 昭61−171269（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H04B 7/02 - 7/12 H04B 7/26 H04Q 7/00 - 7/38 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Kojiro Hamabe, Inventor 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (56) References JP-A-2-34044 (JP, A) JP-A 61-171269 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H04B 7 /02-7/12 H04B 7/26 H04Q 7/00-7/38
Claims (10)
て通信路を逐次変更して継続的に通信路を提供する移動
通信システムにて、 移動端末が第１の基地局から第２の基地局にハンドオフ
をする際、第１及び第２の基地局と通信ができる場所に
位置し、かつ第２の基地局からの信号の受信レベルが第
１の基地局からの信号の受信レベルよりも高くなる前
に、第１及び第２の基地局は、移動端末から送信された
信号の受信を開始すると共に、上位局は第１及び第２の
基地局が受信した信号のダイバーシチ合成を開始するこ
とを特徴とするハンドオフ方法。1. A mobile communication system for continuously providing a communication path by sequentially changing a communication path for a mobile terminal moving between a plurality of base stations. When performing handoff to the base station, the mobile station is located at a place where communication with the first and second base stations is possible, and the reception level of the signal from the second base station is the reception level of the signal from the first base station. Before the first and second base stations become higher, the first and second base stations start receiving signals transmitted from the mobile terminal, and the upper station performs diversity combining of the signals received by the first and second base stations. A handoff method characterized by initiating.
て通信路を逐次変更して継続的に通信路を提供する移動
通信システムにて、 移動端末が第１の基地局から第２の基地局にハンドオフ
をする際、第１及び第２の基地局と通信ができる場所に
位置し、かつ第２の基地局からの信号の受信レベルが第
１の基地局からの信号の受信レベルよりも高くなる前
に、第２の基地局は、移動端末に対して信号の送信を開
始すると共に、移動端末は第１及び第２の基地局が送信
した信号を同時に受信してダイバーシチ合成を開始する
ことを特徴とするハンドオフ方法。2. A mobile communication system in which a communication path is sequentially changed for a mobile terminal moving between a plurality of base stations to provide a continuous communication path. When performing handoff to the base station, the mobile station is located at a place where communication with the first and second base stations is possible, and the reception level of the signal from the second base station is the reception level of the signal from the first base station. Before the second base station starts transmitting signals to the mobile terminal, the mobile terminal simultaneously receives the signals transmitted by the first and second base stations and performs diversity combining. A handoff method characterized by initiating.
て通信路を逐次変更して継続的に通信路を提供する移動
通信システムにて、 第１の基地局と通信中の移動端末は、第１及び第２の基
地局と通信ができる場所に位置し、かつ第２の基地局か
らの信号の受信レベルが第１の基地局からの信号の受信
レベルよりも高くなる前に、第１の基地局との通信を維
持しつつ第２の基地局との通信を開始し、第１及び第２
の基地局は、移動端末から送信された信号を受信して、
上位局は第１及び第２の基地局が受信した信号をダイバ
ーシチ合成することを特徴とするハンドオフ方法。3. A mobile communication system for communicating with a first base station in a mobile communication system for continuously providing a communication path by sequentially changing a communication path for a mobile terminal moving between a plurality of base stations. Is located in a place where it can communicate with the first and second base stations, and before the reception level of the signal from the second base station becomes higher than the reception level of the signal from the first base station, Starting communication with the second base station while maintaining communication with the first base station,
Base station receives the signal transmitted from the mobile terminal,
A handoff method, wherein the upper station performs diversity combining of signals received by the first and second base stations.
て通信路を逐次変更して継続的に通信路を提供する移動
通信システムにて、 第１の基地局と通信中の移動端末は、第１及び第２の基
地局と通信ができる場所に位置し、かつ第２の基地局か
らの信号の受信レベルが第１の基地局からの信号の受信
レベルよりも高くなる前に、第１の基地局との通信を維
持しつつ第２の基地局との通信を開始し、移動端末は第
１及び第２の基地局から送信された信号を受信してダイ
バーシチ合成することを特徴とするハンドオフ方法。4. A mobile communication system for communicating with a first base station in a mobile communication system for continuously providing a communication path by sequentially changing a communication path for a mobile terminal moving between a plurality of base stations. Is located in a place where it can communicate with the first and second base stations, and before the reception level of the signal from the second base station becomes higher than the reception level of the signal from the first base station, The mobile terminal starts communication with the second base station while maintaining communication with the first base station, and the mobile terminal receives signals transmitted from the first and second base stations and performs diversity combining. Handoff method.
が前記第２の信号の受信レベルよりも低くなった後、前
記移動端末は前記第１の基地局との通信を終了すること
を特徴とする請求項１、２、３又は４に記載のハンドオ
フ方法。5. The mobile terminal terminates communication with the first base station after a reception level of a signal from the first base station becomes lower than a reception level of the second signal. The method according to claim 1, 2 , 3, or 4, wherein:
数を送信周波数として用いることを特徴とする請求項
１、２、３、４又は５に記載のハンドオフ方法。 6. The base station and the mobile terminal use different frequencies.
The number is used as a transmission frequency.
The handoff method according to 1, 2, 3, 4 or 5.
て通信路を逐次変更して継続的に通信路を提供し、移動
端末が複数の基地局と通信可能な位置にあるときにそれ
ぞれの基地局は移動端末からの信号を同時に受信し、上
位局はそれぞれの基地局が受信した信号をダイバーシチ
合成する移動通信システムにおける移動端末であって、 第１の基地局との通信中において、第１及び第２の基地
局と通信ができる場所に位置し、かつ第２の基地局から
の信号の受信レベルが第１の基地局からの信号の受信レ
ベルよりも高くなる前に、第１の基地局との通信を維持
しつつ第２の基地局との通信を開始する手段を含んで構
成されることを特徴とする移動通信システムにおける移
動端末。7. A communication path is successively provided to a mobile terminal moving between a plurality of base stations by sequentially changing the communication path, and when the mobile terminal is located at a position where it can communicate with a plurality of base stations. Each base station receives a signal from the mobile terminal at the same time, and the upper station is a mobile terminal in a mobile communication system that diversity-combines the signals received by the respective base stations, and during communication with the first base station, , A location where communication with the first and second base stations is possible and before the reception level of the signal from the second base station becomes higher than the reception level of the signal from the first base station, A mobile terminal in a mobile communication system, comprising: means for starting communication with a second base station while maintaining communication with one base station.
て通信路を逐次変更して継続的に通信路を提供し、移動
端末が複数の基地局と通信可能な位置にあるときにそれ
ぞれの基地局からの信号を同時に受信してダイバーシチ
合成する移動通信システムにおける移動端末であって、 第１の基地局との通信中において、第１及び第２の基地
局と通信ができる場所に位置し、かつ第２の基地局から
の信号の受信レベルが第１の基地局からの信号の受信レ
ベルよりも高くなる前に、第１の基地局との通信を維持
しつつ第２の基地局との通信を開始する手段を含んで構
成されることを特徴とする移動通信システムにおける移
動端末。8. When a mobile terminal moving between a plurality of base stations is provided with a communication path sequentially changed to provide a continuous communication path, and the mobile terminal is located at a position where it can communicate with a plurality of base stations. A mobile terminal in a mobile communication system that receives signals from respective base stations at the same time and performs diversity combining, and in a place where communication with the first and second base stations is possible during communication with the first base station. The second base station is located and maintains communication with the first base station before the reception level of the signal from the second base station becomes higher than the reception level of the signal from the first base station. A mobile terminal in a mobile communication system, comprising means for starting communication with a station.
が前記第２の信号の受信レベルよりも低くなった後、前
記第１の基地局との通信を終了する手段を含んで構成さ
れることを特徴とする請求項７又は８に記載の移動通信
システムにおける移動端末。9. A communication system comprising means for terminating communication with the first base station after a reception level of a signal from the first base station becomes lower than a reception level of the second signal. The mobile terminal in the mobile communication system according to claim 7, wherein the mobile terminal is operated.
なる周波数を用いることを特徴とする請求項７、８又は
９に記載の移動端末。 10. A transmission frequency and a reception frequency which are different from each other.
9. The method according to claim 7, wherein
10. The mobile terminal according to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11311605A JP3120809B2 (en) | 1999-11-01 | 1999-11-01 | Handoff method for mobile communication system and mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11311605A JP3120809B2 (en) | 1999-11-01 | 1999-11-01 | Handoff method for mobile communication system and mobile terminal |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29418290A Division JP3179091B2 (en) | 1990-10-30 | 1990-10-30 | Handoff method for mobile communication system and mobile terminal |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000256009A Division JP3214500B2 (en) | 2000-08-25 | 2000-08-25 | Base station and switching station in mobile communication system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000115830A JP2000115830A (en) | 2000-04-21 |
| JP3120809B2 true JP3120809B2 (en) | 2000-12-25 |
Family
ID=18019274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11311605A Expired - Lifetime JP3120809B2 (en) | 1999-11-01 | 1999-11-01 | Handoff method for mobile communication system and mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3120809B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3492646B2 (en) | 2001-04-20 | 2004-02-03 | 松下電器産業株式会社 | Base station search method and mobile wireless terminal device |
-
1999
- 1999-11-01 JP JP11311605A patent/JP3120809B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000115830A (en) | 2000-04-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2841900B2 (en) | Handoff method | |
| JP3031306B2 (en) | Mobile radio equipment | |
| CN1655555B (en) | Method, apparatus and system for multiple protocol wireless communications in a WLAN | |
| JP3110333B2 (en) | Transmit diversity circuit for TDMA wireless device | |
| JP3111906B2 (en) | Wireless base station device | |
| US5459873A (en) | Method and communication system for improved channel scanning and link establishment determinations | |
| EP2175572A2 (en) | Transmitting and receiving apparatus and method | |
| WO2003032524A1 (en) | Method for in-building distribution using wireless access technologiy | |
| JPH07184251A (en) | Method and device for preventing hit of mobile radio terminal equipment | |
| KR100703417B1 (en) | Method and apparatus for receiving signal using diversity in wireless network | |
| US6477385B1 (en) | Mobile communication system and method for establishing synchronization in mobile communications | |
| JP3214500B2 (en) | Base station and switching station in mobile communication system | |
| JP3120809B2 (en) | Handoff method for mobile communication system and mobile terminal | |
| JP3179091B2 (en) | Handoff method for mobile communication system and mobile terminal | |
| JP3390784B2 (en) | Dynamic channel selection method in radio communication system and base station radio transmission / reception apparatus using the selection method | |
| JP3639168B2 (en) | Communication control method, mobile communication system, base station, and mobile station | |
| JP2699684B2 (en) | Mobile receiver | |
| JPH07264651A (en) | Mobile communication system | |
| JPH10107727A (en) | Radio relay system | |
| JPH10107726A (en) | Transmission output changeover radio repeater communication system | |
| JPH07245577A (en) | Diversity communication equipment | |
| JP3339112B2 (en) | Digital cordless telephone equipment | |
| JP3208343B2 (en) | Diversity device | |
| JP3908574B2 (en) | Mobile communication system and mobile terminal | |
| JP3538178B2 (en) | Mobile station registration method, mobile communication system, mobile station and communication network |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20000919 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071020 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081020 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091020 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091020 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101020 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111020 Year of fee payment: 11 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111020 Year of fee payment: 11 |