JP3271506B2 - Handover control method - Google Patents
Handover control methodInfo
- Publication number
- JP3271506B2 JP3271506B2 JP2889096A JP2889096A JP3271506B2 JP 3271506 B2 JP3271506 B2 JP 3271506B2 JP 2889096 A JP2889096 A JP 2889096A JP 2889096 A JP2889096 A JP 2889096A JP 3271506 B2 JP3271506 B2 JP 3271506B2
- Authority
- JP
- Japan
- Prior art keywords
- base station
- reception level
- radio base
- communication quality
- handover
- 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 - Fee Related
Links
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- Mobile Radio Communication Systems (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、移動通信システム
において、通話中の移動局が他の無線ゾーンに移動した
ときに、移動先の無線ゾーンの通話チャネルを捕捉して
通信を継続するハンドオーバ制御方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handover control in a mobile communication system in which, when a mobile station during a call moves to another wireless zone, the mobile station captures a call channel of a destination wireless zone and continues communication. About the method.
【０００２】[0002]
【従来の技術】図４は、移動通信システムにおけるハン
ドオーバ制御の概要を示す図である。同図において、無
線基地局５１と通信している移動局５４は、無線ゾーン
６１から隣接する無線基地局５２の無線ゾーン６２に移
動するときには、通信を継続するために無線ゾーン６１
のゾーン端でハンドオーバして無線基地局５２の通話チ
ャネルを捕捉する必要がある。2. Description of the Related Art FIG. 4 is a diagram showing an outline of handover control in a mobile communication system. In the figure, when the mobile station 54 communicating with the wireless base station 51 moves from the wireless zone 61 to the wireless zone 62 of the adjacent wireless base station 52, the wireless zone 61 is required to continue the communication.
It is necessary to perform a handover at the end of the zone to capture the communication channel of the radio base station 52.
【０００３】図５は従来のハンドオーバ制御の例を説明
する図であって、数字符号５１〜５３は無線基地局、５
４は移動局、６１〜６３は無線ゾーンを表わしている。
従来のハンドオーバ制御方法の一つは、移動局がゾーン
端に達したとき、すなわち受信レベルまたは通信品質
（ビット誤り率、フレーム誤り率等）の少なくとも一方
が所定値以下になったとき、ハンドオーバ可能な無線基
地局が複数存在する場合には、FIG. 5 is a diagram for explaining an example of conventional handover control. Numerals 51 to 53 denote radio base stations,
4 indicates a mobile station, and 61 to 63 indicate wireless zones.
One of the conventional handover control methods is to perform handover when a mobile station reaches a zone end, that is, when at least one of a reception level or communication quality (a bit error rate, a frame error rate, etc.) falls below a predetermined value. If there are multiple wireless base stations,
【０００４】周囲の他の無線基地局から送出されている
制御信号の受信レベルまたは通信品質を測定し、これら
の受信レベルあるいは通信品質の最大になる無線基地局
を選択し、その無線ゾーンの通話チャネルに切り替えて
通信を継続するように制御する方法である。この方法
は、各無線基地局５１〜５３の位置と移動局５４の進行
方向が図５（ａ）に示すような関係にあるとき有効であ
る。A reception level or communication quality of a control signal transmitted from another surrounding radio base station is measured, a radio base station having the maximum reception level or communication quality is selected, and a call in that radio zone is made. This is a method of controlling to switch to a channel and continue communication. This method is effective when the positions of the wireless base stations 51 to 53 and the traveling direction of the mobile station 54 have a relationship as shown in FIG.
【０００５】従来のハンドオーバ制御方法の他の例とし
て、移動局が、複数の無線基地局からの受信信号の受信
レベルまたは通信品質を検出して、受信レベルのレベル
変動または通信品質の変動を測定し、受信レベルまたは
通信品質が上昇傾向にある無線基地局の無線ゾーンを選
定する方法がある。As another example of the conventional handover control method, a mobile station detects a reception level or a communication quality of a reception signal from a plurality of radio base stations and measures a fluctuation in the reception level or a fluctuation in the communication quality. Then, there is a method of selecting a wireless zone of a wireless base station whose reception level or communication quality tends to increase.
【０００６】このとき、上昇傾向にある無線基地局の無
線ゾーンが複数ある場合は、予め定められた受信レベル
または通信品質を満足し、受信レベルまたは通信品質の
低い無線ゾーンにハンドオーバすることを決定する。At this time, if there are a plurality of radio zones of the radio base station in an upward trend, it is determined that a predetermined reception level or communication quality is satisfied and handover to a radio zone of low reception level or communication quality is performed. I do.
【０００７】受信レベルまたは通信品質が上昇傾向にあ
る無線基地局がない場合は、受信レベルまたは通信品質
が最も高い前記無線ゾーンにハンドオーバするように制
御する。このような方法は、各無線基地局５１〜５３の
位置と移動局５４の進行方向が図５（ｂ）に示すような
関係にあるとき有効である。If there is no radio base station whose reception level or communication quality tends to increase, control is performed so as to perform handover to the radio zone having the highest reception level or communication quality. Such a method is effective when the positions of the wireless base stations 51 to 53 and the traveling direction of the mobile station 54 have a relationship as shown in FIG.
【０００８】[0008]
【発明が解決しようとする課題】移動通信システムにお
いて、市街地では無線基地局が高密度に配置され、しば
しば、ゾーン端で複数の無線ゾーンが重なることがあ
る。上述したような従来の各ハンドオーバ制御方法では
通信中の移動局が他の無線ゾーンに移動する際に、制御
信号の受信レベルまたは通信品質が最も高いか、また
は、最も低い無線基地局を選択する。In a mobile communication system, radio base stations are densely arranged in an urban area, and a plurality of radio zones often overlap at a zone end. In each of the conventional handover control methods as described above, when a communicating mobile station moves to another wireless zone, the reception level or communication quality of the control signal is the highest or the lowest wireless base station is selected. .
【０００９】従って図５からも分かるように、次々にハ
ンドオーバ動作が起動されるから、ハンドオーバ時に発
生する瞬断（短時間の無音または雑音状態）により通信
品質が低下するという問題があった。図６に、従来の方
法による無線基地局の密度とハンドオーバ回数との関係
を示す。Therefore, as can be seen from FIG. 5, since the handover operation is started one after another, there is a problem that the communication quality is deteriorated due to an instantaneous interruption (a short-time silence or noise state) occurring at the time of the handover. FIG. 6 shows the relationship between the density of radio base stations and the number of handovers according to the conventional method.
【００１０】この図に示されるように従来の制御方法で
は、基地局の密度が増大するにつれてハンドオーバ回数
が増加していく傾向があることが分かる。本発明は、ハ
ンドオーバ回数をできるだけ少なくして、通信品質の劣
化を抑えると共に、制御信号のトラヒックの増加も抑止
することができるハンドオーバ制御方法を提供すること
を目的とする。[0010] As shown in this figure, it can be seen that the conventional control method tends to increase the number of handovers as the density of base stations increases. SUMMARY OF THE INVENTION It is an object of the present invention to provide a handover control method capable of reducing the number of handovers as much as possible, suppressing deterioration of communication quality, and suppressing an increase in traffic of a control signal.
【００１１】[0011]
【課題を解決するための手段】本発明によれば、上述の
課題は前記特許請求の範囲に記載した手段により解決さ
れる。すなわち、請求項１の発明は、無線基地局と通信
中の移動局がその無線ゾーンのゾーン端に移動し、所要
の回線品質を満たさなくなった場合に、他の無線ゾーン
の通話チャネルに切り替えて通信を継続させるハンドオ
ーバ制御方法において、According to the present invention, the above-mentioned object is solved by the means described in the claims. In other words, according to the first aspect of the present invention, when a mobile station communicating with a wireless base station moves to a zone end of the wireless zone and does not satisfy required line quality, the mobile station switches to a communication channel of another wireless zone. In a handover control method for continuing communication,
【００１２】通信中の無線基地局からの信号の受信レベ
ルまたは通信品質の少なくとも一方が、第一のしきい値
以下になる第一の地点まで移動局が移動した場合に、該
移動局が、周辺の他の全ての無線基地局の送信波の受信
レベルまたは通信品質の測定を開始し、前記第一の地点
から前記通信中の無線基地局からの信号の受信レベルま
たは通信品質の少なくとも一方が、第二のしきい値以下
になる第二の地点に至るまでの前記周辺無線基地局の送
信波の受信レベルと通信品質の変化をそれぞれ調べ、When the mobile station moves to a first point at which at least one of the reception level of the signal from the communicating radio base station and the communication quality is equal to or lower than the first threshold value, the mobile station: Start measuring the reception level or the communication quality of the transmission wave of all the other wireless base stations in the vicinity, and at least one of the reception level or the communication quality of the signal from the communicating wireless base station from the first point is Investigating changes in the reception level and communication quality of the transmission wave of the peripheral radio base station up to the second point that is equal to or less than the second threshold,
【００１３】前記第二の地点における前記周辺無線基地
局の送信波の受信レベルまたは通信品質の少なくとも一
方が、前記第二のしきい値以上であり、かつ、前記受信
レベルの変化の割合または通信品質の変化の割合が最大
であり、かつ、前記第二の地点における前記周辺無線基
地局の送信波の受信レベルまたは通信品質の少なくとも
一方が、周辺基地局中で最低である無線基地局へハンド
オーバするハンドオーバ制御方法である。[0013] At least one of the reception level and the communication quality of the transmission wave of the peripheral radio base station at the second point is greater than or equal to the second threshold, and the rate of change of the reception level or the communication level. Handover to a radio base station in which the rate of change in quality is the maximum and at least one of the reception level or the communication quality of the transmission wave of the peripheral radio base station at the second point is the lowest among the peripheral base stations This is a handover control method.
【００１４】上記受信レベルの変化の割合、または、通
信品質の変化の割合とは、第一の地点から第二の地点に
至る間に、それがどの程度変化したかをいうものであっ
て、それらの変化の度合をいうものである。これは、言
い替えれば、当該区間内における変化の速度に相当す
る。The rate of change in the reception level or the rate of change in the communication quality refers to the degree of change between the first point and the second point. It refers to the degree of these changes. This corresponds, in other words, to the speed of change in the section.
【００１５】[0015]
【発明の実施の形態】図１は、本発明を適用したハンド
オーバ制御方法の一例を説明する図であって、数字符号
１〜４はそれぞれ無線基地局、５は移動局、１１〜１４
はそれぞれ無線ゾーンを表わしている。移動局５は図中
のＡ地点において発呼し、矢印方向へ移動していく。通
信中の無線基地局である無線基地局１からの信号の受信
レベルまたは通信品質の少なくとも一方が所定値以下に
なるＢ地点から、周辺の他の受信可能な全ての無線基地
局の送信波の受信レベルと通信品質の測定を開始する。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining an example of a handover control method to which the present invention is applied. Numerals 1-4 are radio base stations, respectively, 5 are mobile stations, 11-14.
Each represents a wireless zone. The mobile station 5 originates a call at a point A in the figure and moves in the direction of the arrow. From the point B at which at least one of the reception level or the communication quality of the signal from the wireless base station 1 which is the communicating wireless base station becomes equal to or less than a predetermined value, the transmission waves of all other receivable wireless base stations in the vicinity are Start measurement of reception level and communication quality.
【００１６】図中の斜線を施した部分が無線基地局１か
らの信号の受信レベルまたは通信品質の少なくとも一方
が所定値以下である領域を表わしている。さらに、移動
局５が移動して、通信中の無線基地局である無線基地局
１からの信号の受信レベルまたは通信品質の少なくとも
一方がハンドオーバしきい値以下になるＣ地点に到達す
ると、The shaded portion in the figure indicates an area where at least one of the reception level of the signal from the radio base station 1 and the communication quality is equal to or less than a predetermined value. Further, when the mobile station 5 moves and reaches the point C where at least one of the reception level or the communication quality of the signal from the wireless base station 1 which is the communicating wireless base station is equal to or less than the handover threshold,
【００１７】移動局は、Ｃ地点における周辺無線基地局
の送信波の受信レベルまたは通信品質の少なくとも一方
がハンドオーバしきい値以上であり、かつ、Ｂ地点から
Ｃ地点に至までの周辺無線基地局の受信レベルまたは通
信品質の変動検出結果が最大であり、かつ、Ｃ地点にお
ける周辺無線基地局からの送信波の受信レベルまたは通
信品質の少なくとも一方が最低である無線基地局へハン
ドオーバする。[0017] The mobile station may be configured such that at least one of the reception level of the transmission wave of the peripheral radio base station at the point C and the communication quality is equal to or higher than the handover threshold value and the peripheral radio base station from the point B to the point C is located. Then, handover is performed to a radio base station in which the detection result of the fluctuation of the reception level or the communication quality of the communication base station is the maximum and at least one of the reception level and the communication quality of the transmission wave from the peripheral radio base station at the point C is the lowest.
【００１８】図１の場合、ハンドオーバの候補となる無
線基地局は無線基地局２，３，４の３局である。当初
は、無線基地局２と無線基地局３とを比較すると受信レ
ベルまたは通信品質は同程度であるが、移動局５が無線
基地局３の方向に向かって移動しているため、受信レベ
ルや通信品質の変化は、無線基地局３の方が大きい筈で
ある。In the case of FIG. 1, three radio base stations, which are candidates for handover, are radio base stations 2, 3, and 4. Initially, when the radio base station 2 and the radio base station 3 are compared, the reception level or the communication quality is almost the same, but since the mobile station 5 is moving toward the radio base station 3, the reception level or the communication quality is low. The change in the communication quality should be larger in the wireless base station 3.
【００１９】そして、Ｂ地点では無線基地局３の方が無
線基地局２より遠方に位置しているので、無線基地局３
の受信レベルまたは通信品質は、無線基地局２のそれよ
り小さい。一方、Ｃ地点は基地局２および３からほぼ等
距離にあるため受信レベルまたは通信品質は、ほぼ等し
いと考えられる。At the point B, since the radio base station 3 is located farther than the radio base station 2, the radio base station 3
Is lower than that of the radio base station 2. On the other hand, since the point C is almost equidistant from the base stations 2 and 3, the reception level or the communication quality is considered to be almost equal.
【００２０】しかし、Ｂ地点からＣ地点まで移動局が移
動する間の受信レベルまたは通信品質の変化の割合は、
無線基地局３の方が無線基地局２より大きいから、無線
基地局３がハンドオーバ先の候補の一つとなる。However, the rate of change in the reception level or communication quality while the mobile station moves from point B to point C is:
Since the radio base station 3 is larger than the radio base station 2, the radio base station 3 is one of the candidates for the handover destination.
【００２１】先にも述べたように、無線基地局の方向に
向かって移動する方が、他の方向に向かって移動するよ
りも受信レベルや通信品質の変化の割合は大きいと考え
られるが、この点については、無線基地局３と無線基地
局４は、ほぼ、同じ条件といえる。As described above, it is considered that the ratio of the change in the reception level and the communication quality is larger when moving toward the radio base station than when moving toward other directions. In this regard, it can be said that the wireless base station 3 and the wireless base station 4 have substantially the same conditions.
【００２２】そこで、無線基地局３と無線基地局４の受
信レベルまたは通信品質を比較すると、移動局との距離
が遠い分だけ、無線基地局４の方が受信レベルまたは通
信品質が低い。そのため、無線基地局４が選択される。
よって、この場合のハンドオーバ先は無線基地局４とな
る。Therefore, comparing the reception level or the communication quality between the radio base station 3 and the radio base station 4, the reception level or the communication quality of the radio base station 4 is lower because the distance to the mobile station is longer. Therefore, the radio base station 4 is selected.
Therefore, the handover destination in this case is the radio base station 4.
【００２３】移動局の移動方向と現在通信中の無線基地
局からの距離を考慮し、最適な無線基地局へハンドオー
バする判別式を、ｆ(i) ＝a(Ｌ′＿［i］-Ｌｈｏ）＋ｂ
／（Ｌ′＿［i］-Ｌ＿［i］) (ａ，ｂは定数）とする。
この式において、第１項のＬ′＿［i］-Ｌｈｏは移動局
と通信中の無線基地局との距離を評価するものである。Considering the moving direction of the mobile station and the distance from the currently communicating radio base station, the discriminant for handover to the optimal radio base station is given by f (i) = a (L '_ [i] -Lho ) + B
/ (L '_ [i] -L_ [i]) (a and b are constants).
In this equation, L '_ [i] -Lho of the first term evaluates the distance between the mobile station and the communicating radio base station.
【００２４】これは、前記通信中の無線基地局からの位
置が遠い無線基地局を選択するためのものであり、ゾー
ン端に近いほど小さく、ゾーン端では０になる。第２項
の、Ｌ′＿［i］-Ｌ＿［i］ は他の無線基地局と前記移
動局の移動方向との角度を評価するものである。This is for selecting a radio base station that is farther from the communicating radio base station. The radio base station is closer to the zone end, and becomes smaller at the zone end. The second term, L '_ [i] -L_ [i], evaluates the angle between another radio base station and the moving direction of the mobile station.
【００２５】すなわち、前記無線基地局が移動局の移動
方向にあるか否かを判別するためのものであり、同一距
離にある基地局の場合、移動方向の正面にある基地局が
最も大きな値を採る。定数ａ，ｂは上記の第１項と第２
項の重みを任意に変化させるためのものであり、Ｌ＿
［i］ , Ｌ′＿［i］ ，Ｌｈｏ［i］ の設定等により
異なる。以下にハンドオーバ制御手順と使用されている
記号の意味を示す。That is, it is for determining whether or not the radio base station is in the moving direction of the mobile station. In the case of base stations at the same distance, the base station in front of the moving direction has the largest value. Take. The constants a and b are defined by the first term and the second
This is for arbitrarily changing the weight of the term.
It depends on the settings of [i], L '_ [i], Lho [i], and the like. The following describes the handover control procedure and the meaning of the symbols used.
【００２６】 移動局は、移動中は現在捕捉している
無線基地局からのレベルを監視し、このレベルがある一
定値ＬS まで下がると周囲の他の受信し得る全ての無線
基地局の受信レベル（Ｌ＿［i］，i：基地局番号）を測
定する。ただしハンドオーバ後の無線ゾーンにおいて１
度も受信レベルがＬS に満たない場合は、捕捉している
無線基地局の受信レベルが最大値であることをもってＬ
S とする。The mobile station monitors the level from the currently acquired radio base station while moving, and when this level falls to a certain value L S , reception of all surrounding radio base stations that can be received is performed. The level (L_ [i], i: base station number) is measured. However, 1 in the wireless zone after handover
If the reception level is less than L S , the reception level of the radio base station being captured is the maximum value.
S.
【００２７】 さらに直進し、現在捕捉している無線
基地局からの信号の受信レベルがハンドオーバするしき
い値Ｌｈｏまで下降したとき、で受信された無線基地
局の受信レベルを再測定する（Ｌ′＿［i］）。When the vehicle goes straight further and the reception level of the signal from the currently acquired radio base station falls to the threshold value Lho for handover, the reception level of the radio base station received at the time is measured again (L ′). _ [I]).
【００２８】 上記、により受信されたＬ＿
［i］,Ｌ′＿［i］ から、上記の判定式ｆ(ｉ)を計算
し、この値が最小になった無線基地局へハンドオーバす
る。以上の制御を流れ図として示したのが図２である。
同図中に“Ｓ−１”〜“Ｓ−５”として付された符号は
下記の説明と対応する。The above received L_
From [i], L '_ [i], the above-described determination formula f (i) is calculated, and handover is performed to the wireless base station having the minimum value. FIG. 2 is a flowchart showing the above control.
The reference numerals given as “S-1” to “S-5” in the figure correspond to the following description.
【００２９】すなわち、移動局は移動中に現在通信中の
無線基地局からの信号の受信レベルと通信品質を測定し
ている。（Ｓ−１） そして、受信レベルまたは通信品質の内の少なくとも一
方が予め定めた所定の値以上であるか否かを調べ、それ
が所定の値以上である間は、現在通信中の無線基地局と
の間で通信を続ける。（Ｓ−２）That is, the mobile station measures the reception level and the communication quality of the signal from the wireless base station with which it is currently communicating while moving. (S-1) Then, it is checked whether at least one of the reception level and the communication quality is equal to or higher than a predetermined value, and while the reception level or the communication quality is equal to or higher than the predetermined value, the wireless base station currently in communication is checked. Continue communication with the station. (S-2)
【００３０】もし、受信レベルまたは通信品質の内の少
なくとも一方が所定値より低下したときには、他の受信
可能な全ての無線基地局から送出されている制御信号の
受信レベルと通信品質の変化の割合を調べる。（Ｓ−
３） そして、通信中の無線基地局の受信レベルと通信品質の
内、少なくとも一方が、予め定めたハンドオーバしきい
値より低下したら、（Ｓ−４）If at least one of the reception level and the communication quality falls below a predetermined value, the ratio between the change in the communication level and the reception level of the control signal transmitted from all other receivable radio base stations. Find out. (S-
3) If at least one of the reception level and the communication quality of the communicating radio base station falls below a predetermined handover threshold, (S-4)
【００３１】通信中以外の無線基地局で、受信レベルま
たは通信品質の少なくとも一方がハンドオーバしきい値
以上であり、かつ、先の（Ｓ−３）で調べた受信レベル
あるいは通信品質の変化の割合が最も大であり、かつ、
受信レベルと通信品質の内の少なくとも一方が各無線基
地局中最低である無線基地局へハンドオーバする。（Ｓ
−５）At the radio base station other than the one that is not communicating, at least one of the reception level and the communication quality is equal to or higher than the handover threshold, and the ratio of the change in the reception level or the communication quality checked in the above (S-3). Is the largest, and
Handover is performed to the radio base station having at least one of the reception level and the communication quality which is the lowest among the radio base stations. (S
-5)
【００３２】図３は、本発明のハンドオーバ制御方法を
採った場合と従来の方法を採った場合の無線基地局密度
とハンドオーバ回数の関係を示す図である。同図では、
判定式ｆ（ｉ）中のａ，ｂの値は、それぞれ、ａ＝１／
２０，ｂ＝１とした。この図から全ての前記無線基地局
密度においてハンドオーバ回数が低減されることが分か
る。また、前記無線基地局密度が増加すると、より効果
が増大することが分かる。FIG. 3 is a diagram showing the relationship between the radio base station density and the number of handovers when the handover control method of the present invention is adopted and when the conventional method is adopted. In the figure,
The values of a and b in the determination formula f (i) are respectively a = 1 /
20, b = 1. From this figure, it can be seen that the number of handovers is reduced at all the radio base station densities. Also, it can be seen that the effect increases as the radio base station density increases.
【００３３】[0033]
【発明の効果】以上説明したように、本発明のハンドオ
ーバ制御方法では、ハンドオーバ対象となる無線ゾーン
が複数存在する場合に、各無線基地局の送信波の受信レ
ベル、または、通信品質が、しきい値の条件を満たすと
共に、一定区間における、その変化の割合が最大である
無線基地局の内の、移動局での受信レベルまたは通信品
質が最低である無線ゾーンへハンドオーバ先を決定す
る。As described above, according to the handover control method of the present invention, when there are a plurality of radio zones to be handed over, the reception level of the transmission wave or the communication quality of each radio base station is reduced. A handover destination is determined to a wireless zone in which the reception level or the communication quality at the mobile station is the lowest among the wireless base stations having the maximum rate of change in a certain section while satisfying the threshold condition.
【００３４】これにより、同一無線ゾーン内で移動でき
る距離が増加し、ハンドオーバ回数が低減するので、通
信品質を向上させることができると共にハンドオーバに
伴う制御信号のトラヒックの増加を防ぐことができる利
点がある。As a result, the distance that can be moved within the same radio zone is increased, and the number of handovers is reduced. Therefore, there is an advantage that communication quality can be improved and an increase in traffic of control signals due to the handover can be prevented. is there.
【図１】本発明を適用したハンドオーバ制御方法の一例
を説明する図である。FIG. 1 is a diagram illustrating an example of a handover control method to which the present invention has been applied.
【図２】本発明のハンドオーバ制御方法の動作示す流れ
図である。FIG. 2 is a flowchart showing the operation of the handover control method of the present invention.
【図３】本発明の方式と従来の方式の無線基地局密度と
ハンドオーバ回数との関係を示す図である。FIG. 3 is a diagram showing the relationship between the radio base station density and the number of handovers in the system of the present invention and the conventional system.
【図４】移動通信システムにおけるハンドオーバ制御の
概要を示す図である。FIG. 4 is a diagram showing an outline of handover control in a mobile communication system.
【図５】従来のハンドオーバ制御の例を説明する図であ
る。FIG. 5 is a diagram illustrating an example of conventional handover control.
【図６】従来の方式を採った場合の基地局密度に対する
ハンドオーバ回数を示す図である。FIG. 6 is a diagram illustrating the number of handovers with respect to the base station density when a conventional method is adopted.
１〜４ 無線基地局 ５ 移動局 １１〜１４ 無線ゾーン 1-4 wireless base station 5 mobile station 11-14 wireless zone
フロントページの続き (56)参考文献 特開 平８−154264（ＪＰ，Ａ) 特開 平９−37327（ＪＰ，Ａ) 特開 平８−88877（ＪＰ，Ａ) 特開 平８−331637（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H04Q 7/00 - 7/38 H04B 7/24 - 7/26 Continuation of the front page (56) References JP-A-8-154264 (JP, A) JP-A-9-37327 (JP, A) JP-A-8-88877 (JP, A) JP-A-8-331637 (JP) , A) (58) Field surveyed (Int. Cl. 7 , DB name) H04Q 7/ 00-7/38 H04B 7 /24-7/26
Claims (1)
ゾーンのゾーン端に移動し、所要の回線品質を満たさな
くなった場合に、他の無線ゾーンの通話チャネルに切り
替えて通信を継続させるハンドオーバ制御方法におい
て、 通信中の無線基地局からの信号の受信レベルまたは通信
品質の少なくとも一方が第一のしきい値以下になる第一
の地点まで移動局が移動した場合に、 該移動局が、 周辺の他の全ての無線基地局の送信波の、受信レベルと
通信品質の測定を開始し、 前記第一の地点から前記通信中の無線基地局からの信号
の受信レベルまたは通信品質の少なくとも一方が、第二
のしきい値以下になる第二の地点に至るまでの前記周辺
無線基地局の送信波の受信レベルと通信品質の変化をそ
れぞれ調べ、 前記第二の地点における前記周辺無線基地局の送信波の
受信レベルまたは通信品質の少なくとも一方が、前記第
二のしきい値以上であり、 かつ、前記受信レベルの変化の割合または通信品質の変
化の割合が、最大であり、 かつ、前記第二の地点における前記周辺無線基地局の送
信波の受信レベルまたは通信品質の少なくとも一方が周
辺基地局中で最低である無線基地局へハンドオーバする
ことを特徴とするハンドオーバ制御方法。When a mobile station communicating with a radio base station moves to a zone end of the radio zone and does not satisfy required line quality, the mobile station switches to a communication channel of another radio zone and continues communication. In the handover control method, when the mobile station moves to a first point at which at least one of the reception level of the signal from the communicating radio base station or the communication quality is equal to or lower than the first threshold value, Starting measurement of the reception level and communication quality of the transmission waves of all the other wireless base stations in the vicinity, at least the reception level or the communication quality of the signal from the wireless base station in communication from the first point. One examines the change of the reception level and the communication quality of the transmission wave of the peripheral radio base station until reaching the second point that is equal to or less than the second threshold value, At least one of the reception level or the communication quality of the transmission wave of the line base station is equal to or greater than the second threshold, and the rate of change in the reception level or the rate of change in the communication quality is the maximum, A handover control method is characterized in that a handover is performed to a radio base station having at least one of a reception level of a transmission wave of the peripheral radio base station and communication quality at the second point among the peripheral base stations.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2889096A JP3271506B2 (en) | 1996-02-16 | 1996-02-16 | Handover control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2889096A JP3271506B2 (en) | 1996-02-16 | 1996-02-16 | Handover control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09224275A JPH09224275A (en) | 1997-08-26 |
| JP3271506B2 true JP3271506B2 (en) | 2002-04-02 |
Family
ID=12261000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2889096A Expired - Fee Related JP3271506B2 (en) | 1996-02-16 | 1996-02-16 | Handover control method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3271506B2 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100311506B1 (en) * | 1998-11-04 | 2001-11-15 | 서평원 | HandOff Control Method in Mobile Communication System |
| JP3877135B2 (en) | 2000-07-05 | 2007-02-07 | 株式会社エヌ・ティ・ティ・ドコモ | Peripheral zone table creation method and apparatus, program and storage medium in mobile communication system |
| JP2002232929A (en) | 2001-02-01 | 2002-08-16 | Ntt Docomo Inc | Hand-over control method, mobile station and communication controller |
| WO2005004510A1 (en) | 2003-06-30 | 2005-01-13 | Fujitsu Limited | Mobile terminal device, base station device, server device, and radio connection method |
| KR100659935B1 (en) * | 2005-11-07 | 2006-12-21 | 삼성전자주식회사 | Method for determining handover target cell in mobile communication system |
| JP4836672B2 (en) | 2006-06-06 | 2011-12-14 | 株式会社東芝 | Base station, terminal, radio communication apparatus, and radio communication method |
| JP2008236079A (en) | 2007-03-16 | 2008-10-02 | Kyocera Corp | Wireless communication equipment and wireless communication method |
| JP5215821B2 (en) * | 2008-11-17 | 2013-06-19 | 京セラ株式会社 | Mobile station apparatus and handover method |
| JP2011004127A (en) * | 2009-06-18 | 2011-01-06 | Nec Corp | Base station device, mobile communication system, and handover control method |
-
1996
- 1996-02-16 JP JP2889096A patent/JP3271506B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09224275A (en) | 1997-08-26 |
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