JP2715526B2 - Base station selection method for mobile communication system and mobile terminal - Google Patents
Base station selection method for mobile communication system and mobile terminalInfo
- Publication number
- JP2715526B2 JP2715526B2 JP1057275A JP5727589A JP2715526B2 JP 2715526 B2 JP2715526 B2 JP 2715526B2 JP 1057275 A JP1057275 A JP 1057275A JP 5727589 A JP5727589 A JP 5727589A JP 2715526 B2 JP2715526 B2 JP 2715526B2
- Authority
- JP
- Japan
- Prior art keywords
- base station
- mobile terminal
- power
- transmission power
- propagation loss
- 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
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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- Mobile Radio Communication Systems (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、移動通信システムの基地局選択方式および
移動端末に関し、特に小ゾーン方式（セルラ方式）の移
動通信システムの基地局選択方式および移動端末に関す
る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station selection system and a mobile terminal of a mobile communication system, and more particularly to a base station selection system and a mobile terminal of a small zone system (cellular system). About the terminal.
従来の一般的な移動通信システムの基地局選択方式
は、移動端末が基地局を選択する場合、単純に基地局が
送信する下り無線回線の信号を最も強い受信電力で受信
した基地局を選択する方式であった〔参考文献ゼット・
シー・フラー（Z.C.Fluhr）著、「アドバンスト・モー
ビル・フォーン・サービス・コントロール・アーキテク
チャ」（Advaced Mobile Phone Service:Control Archi
tecture）、ベル・システム・テクニカル・ジャーナル
（The Bell System Technical Journal）、1979年,1月,
62〜63頁〕。A base station selection method of a conventional general mobile communication system, when a mobile terminal selects a base station, simply selects a base station that receives a signal of a downlink radio channel transmitted by the base station with the strongest reception power. [Ref. Z.
"Advanced Mobile Phone Service Control Architecture" by ZCFluhr (Advaced Mobile Phone Service: Control Archi)
tecture), The Bell System Technical Journal, January 1979,
62-63].
そして最近、自動車電話システムのような小ゾーン方
式の移動無線システムの新たな動向として、加入者が持
ち運び可能な携帯端末に対する需要が高まっている。こ
のような携帯端末は、小型，軽量化が強く要求されるた
め、バッテリもさほど大きくすることができない。つま
り移動通信システムに携帯端末を収容する場合の重要な
課題は、バッテリセービング技術である。特に有効なバ
ッテリセービング技術として、携帯端末の送信電力を、
伝搬損失に応じて制御することにより、通話を行うのに
必要最小限のレベルに保つ送信電力制御が良く知られて
いる。この技術を自動車電話システムに応用し、例え
ば、移動端末が基地局から離れていたり、建物や山の影
になったりして伝搬損失が大きな場合には送信電力のレ
ベルを上げるが、移動端末が基地局に近付いたり、建物
や山の影から出たりして伝搬損失が小さくなる送信電力
のレベルを下げてバッテリのセービングを行うことが考
えられる。Recently, as a new trend of a small-zone mobile radio system such as an automobile telephone system, a demand for a portable terminal that can be carried by a subscriber is increasing. Since such a portable terminal is strongly required to be small and lightweight, the battery cannot be so large. That is, an important issue when a mobile terminal is accommodated in a mobile communication system is a battery saving technique. As a particularly effective battery saving technology, the transmission power of mobile terminals
It is well known that the transmission power is controlled according to the propagation loss so that the transmission power is maintained at a minimum level required for performing a call. Applying this technology to a car phone system, for example, if the mobile terminal is far from the base station or is in the shadow of a building or a mountain and the propagation loss is large, the transmission power level is increased, but the mobile terminal It is conceivable to save the battery by lowering the level of the transmission power at which the propagation loss is reduced by approaching the base station or coming out of the shadow of a building or a mountain.
送信電力制御によりバッテリセービングを行う方法で
は、発呼または着呼により通話を開発する時や通話中の
ゾーン切換え（ハンドオフ）を行う時に、できるだけ伝
搬損失の小さい基地局を選択することにより、最大限の
バッテリセービング効果が得られる。このことは、現行
の自動車電話システムのように、各基地局の送信電力が
ほぼ等しければ、下り無線回線の受信電力が最も強い基
地局を選択すれば、伝搬損失も最も小さくなり最大限の
バッテリセービング効果が得られることになる。In the method of performing battery saving by transmission power control, when developing a call by making or receiving a call, or when performing zone switching (handoff) during a call, the base station having the smallest possible propagation loss is selected. Battery saving effect is obtained. This means that if the transmission power of each base station is almost equal, as in the current mobile phone system, selecting the base station with the strongest reception power of the downlink radio line will minimize the propagation loss and maximize the battery A saving effect is obtained.
上述した従来の移動通信システムの基地局選択方式お
よび移動端末は、各基地局の送信電力がほぼ等しいの
で、下り無線回線の受信電力が最も強い基地局を選択す
れば、伝搬損失も最も小さくできるという原理に基づき
構成されている。しかしながら、現在では、小ゾーン方
式の移動通信システムの需要の急激な増加に応えるため
に、トラヒックの集中する都市部においてゾーンの細分
化が進んでいる。例えば東京における自動車電話のトラ
ヒックの分布は千代田、青山あたりに激しく集中してお
り、NTT（日本電信電話株式会社）ではこれに対処する
ために東京都内のゾーンを細分化して加入者容量の増加
を図っている。同様に各国の主要都市においてゾーンの
細分化が進んでいる。このような事情は1986年８月11日
発行の雑誌「日経エレクトロニクス」の91ページから10
4ページに詳しく紹介されている。In the above-described base station selection method and mobile terminal of the conventional mobile communication system, since the transmission power of each base station is almost equal, if the base station having the highest reception power of the downlink radio channel is selected, the propagation loss can be minimized. It is configured based on the principle. However, at present, zones are being subdivided in urban areas where traffic is concentrated in order to respond to a rapid increase in demand for small-zone mobile communication systems. For example, the distribution of car phone traffic in Tokyo is heavily concentrated around Chiyoda and Aoyama, and NTT (Nippon Telegraph and Telephone Corporation) has subdivided the zones in Tokyo to increase subscriber capacity in order to deal with this. I'm trying. Similarly, zones are being subdivided in major cities in each country. This situation is described from page 91 of Nikkei Electronics, published on August 11, 1986.
See page 4 for details.
将来の移動通信システムにおいては、少なくとも加入
者数が多い都市部では、基地局の数が大幅に増大してシ
ステムコストが高くなるものの、ゾーン半径のきわめて
小さいマイクロゾーンシステムの導入が必須であるとい
える。しかし都市部では多少システムコストが高くても
良いが、加入者数のさほど多くない郊外ではこのような
マイクロゾーンシステムは経済的に引き合わないため、
現行システムのような小ゾーンシステムでサービスを続
けることになる。このように都市部ではマイクロゾーン
を用い郊外では小ゾーンを用いるという両者を併用した
システムにより、加入者の面積密度にバラツキのあるサ
ービスエリアに対して効率的なシステムが構築できるこ
とになる。In future mobile communication systems, at least in urban areas where the number of subscribers is large, the number of base stations will increase significantly and the system cost will increase, but the introduction of a micro-zone system with an extremely small zone radius is essential. I can say. However, in urban areas, system costs may be slightly higher, but in suburbs where there are not many subscribers, such microzone systems are not economically attractive,
The service will continue on a small zone system like the current system. As described above, by using both the micro zone in the urban area and the small zone in the suburbs, an efficient system can be constructed for a service area in which the area density of subscribers varies.
ところで、このような著しく大きさの異なるゾーンが
共存する移動通信システムにおいては、各基地局にゾー
ンの大きさに応じた送信電力が与えられるため、基地局
の送信電力の間に大きな差が生じる。このように基地局
の送信電力の間に大きな差があると、下り無線回線の受
信電力と伝搬損失との間に相関関係が無くなるため、将
来の基地局選択方式をそのまま適用して、移動端末が下
り無線回線の受信電力の最も強い基地局を選択しても、
伝搬損失の最も小さい基地局を選択したことにならず、
送信電力制御技術によりバッテリセービングを行っても
十分な効果は得られないという問題点がある。By the way, in a mobile communication system in which zones of significantly different sizes coexist, transmission power according to the size of the zone is given to each base station, so that a large difference occurs between the transmission powers of the base stations. . If there is such a large difference between the transmission powers of the base stations, there is no correlation between the reception power of the downlink radio channel and the propagation loss. Selects the base station with the strongest received power of the downlink radio line,
Not having selected the base station with the smallest propagation loss,
There is a problem that even if battery saving is performed by the transmission power control technique, a sufficient effect cannot be obtained.
また、送信電力の小さな携帯端末が送信電力の大きな
基地局のゾーンに在圏する場合には、基地局の送信電力
と携帯端末の送信電力との間に著しい差が生じる。この
ような場合に、従来の基地局選択方式をそのまま適用し
て、携帯端末が下り無線回線の受信電力が最も強く、そ
の受信電力が通話を行うのに十分な基地局を選択して
も、基地局における上り無線回線の受信電力が不十分な
ために通話を行えない場合が頻繁に起こることが予想さ
れる。このような場合には、携帯端末が発呼信号や着呼
信号を実際に送信した後に、通話が不可能であることが
判明するために、バッテリや周波数の無駄遣いという問
題点が生じる。Also, when a mobile terminal with low transmission power is located in the zone of a base station with high transmission power, a remarkable difference occurs between the transmission power of the base station and the transmission power of the mobile terminal. In such a case, even if the conventional base station selection method is applied as it is, the mobile terminal selects the base station having the strongest received power of the downlink radio channel and the received power is sufficient for making a call. It is expected that frequent calls cannot be made due to insufficient reception power of the uplink radio channel at the base station. In such a case, after the mobile terminal actually transmits the calling signal or the incoming call signal, it is determined that the telephone conversation is impossible, and thus a problem of wasted battery and frequency occurs.
本発明の目的は、大きさの異なるゾーンが共存する移
動通信システムにおいて、送信電力制御技術により最大
限のバッテリセービング効果を得るために伝搬損失の最
も小さい基地局を選択し、更にその基地局と通話可能か
どうかを予め判定することによりバッテリや周波数の無
駄遣いを防ぐ移動通信システムの基地局選択方式と、そ
れを実現する移動端末を提供することにある。An object of the present invention is to provide a mobile communication system in which zones of different sizes coexist, to select a base station having the smallest propagation loss in order to obtain a maximum battery saving effect by a transmission power control technique, and to further select the base station. An object of the present invention is to provide a base station selection method of a mobile communication system for preventing waste of a battery or a frequency by previously determining whether a call is possible and a mobile terminal realizing the method.
本発明は、複数の基地局によりサービスエリアをカバ
ーする移動通信システムの基地局選択方式であって、 各基地局はその送信電力を移動端末に知らしめる信号を
同報し、 移動端末が、周辺基地局の送信電力と実際に受信した下
り無線回路の受信電力とから各周辺基地局と移動端末と
の間の伝搬損失を算出し、前記伝搬損失と移動端末の送
信電力とから各周辺基地局における上り無線回線の受信
電力を推定し、前記上り無線回線の受信電力に基づいて
基地局を選択し交信することを特徴とする。The present invention relates to a base station selection method for a mobile communication system in which a service area is covered by a plurality of base stations, wherein each base station broadcasts a signal notifying its transmission power to the mobile terminal, and the mobile terminal Calculate the propagation loss between each peripheral base station and the mobile terminal from the transmission power of the base station and the received power of the downlink radio circuit actually received, and calculate each peripheral base station from the propagation loss and the transmission power of the mobile terminal. And estimating the reception power of the uplink radio channel in the above, and selecting and communicating with a base station based on the reception power of the uplink radio channel.
また、本発明は、複数の基地局によりサービスエリア
をカバーする移動通信システムの移動端末において、 各周辺基地局の送信電力を求める手段と、 各周辺基地局からの下り無線回線の受信電力を求める
手段と、 前記送信電力と前記下り無線回線の受信電力とから前
記各周辺基地局との間の伝搬損失を求める手段と、 前記伝搬損失と移動端末の送信電力とから各周辺基地
局における上り無線回線の受信電力を推定する手段と、 前記上り無線回線の受信電力と予め定めた閾値とを比
較する手段とを有することを特徴とする。Also, the present invention provides a mobile terminal of a mobile communication system in which a service area is covered by a plurality of base stations. Means for calculating a propagation loss between each of the peripheral base stations from the transmission power and the reception power of the downlink radio channel; and uplink radio in each of the peripheral base stations from the propagation loss and the transmission power of the mobile terminal. It is characterized by comprising: means for estimating the reception power of the line; and means for comparing the reception power of the uplink radio line with a predetermined threshold.
前述したように送信電力制御により最大限のバッテリ
セービング効果を得るためには、常に伝搬損失が最小と
なる基地局を選択する必要がある。しかし基地局の送信
電力の間に大きな差がある場合には、各基地局からの下
り無線回線の受信電力を比較しただけでは、伝搬損失の
大小は判定できない。一般に移動通信システムでは、基
地局および移動端末において、送受信に同一のアンテナ
を用いているため、基地局から移動端末への下り無線回
線の伝搬損失と、移動端末から基地局への上り無線回線
の伝搬損失とは同一であると考えられる。そこで移動端
末は、各基地局の送信電力を知ることができれば、その
送信電力と下り無線回線の受信電力との差から伝搬損失
を直接求めて比較することにより、伝搬損失が最小とな
る基地局を選択することができる。更に、移動端末の最
大送信電力と伝搬損失との差から、この基地局における
上り無線回線の受信電力を推定すれば、この基地局と通
話可能かどうかを予め判定できる。即ち、推定した上り
無線回線の受信電力が通話を行うために最低必要な受信
電力よりも大きい場合には、通話可能と判定する。また
推定した上り無線回線の受信電力が、通話を行うために
最低必要な受信電力に満たない場合には、通話不可能と
判定する。As described above, in order to obtain the maximum battery saving effect by transmission power control, it is necessary to always select a base station that minimizes the propagation loss. However, when there is a large difference between the transmission powers of the base stations, the magnitude of the propagation loss cannot be determined only by comparing the reception power of the downlink radio channel from each base station. In general, in a mobile communication system, the same antenna is used for transmission and reception in the base station and the mobile terminal, so that the propagation loss of the downlink radio channel from the base station to the mobile terminal and the uplink radio channel from the mobile terminal to the base station are reduced. It is considered that the propagation loss is the same. Therefore, if the mobile terminal can know the transmission power of each base station, the mobile station directly obtains and compares the propagation loss from the difference between the transmission power and the reception power of the downlink radio channel, so that the base station that minimizes the propagation loss Can be selected. Further, by estimating the reception power of the uplink radio channel at the base station from the difference between the maximum transmission power of the mobile terminal and the propagation loss, it can be determined in advance whether or not communication with the base station is possible. That is, if the estimated reception power of the uplink radio channel is higher than the minimum reception power required for making a call, it is determined that the call is possible. If the estimated reception power of the uplink radio line is less than the minimum reception power required for making a call, it is determined that the call cannot be made.
ここで、各基地局の送信電力を移動端末が知る方法と
しては、基地局が現在の送信電力を示す信号を放送する
方法や、各基地局に送信電力を知ることができるような
基地局IDを予め与えておく方法が考えられる。基地局の
送信電力を状況に応じて変化させるようなシステムでは
前者の方法が、基地局の送信電力を固定とするシステム
では後者の方法が適している。Here, as a method for the mobile terminal to know the transmission power of each base station, there are a method for the base station to broadcast a signal indicating the current transmission power, and a base station ID for allowing each base station to know the transmission power. Is given in advance. The former method is suitable for a system in which the transmission power of the base station is changed according to the situation, and the latter method is suitable for a system in which the transmission power of the base station is fixed.
本発明では、待受け中または通信中の移動端末が各周
辺基地局の下り無線回線を受信し、基地局ごとに送信電
力と実際に受信した下り無線回線の受信電力との差から
伝搬損失を求め、移動端末の最大送信電力と伝搬損失と
の差から各基地局における上り無線回線の受信電力を求
めておく。そして通話開始時には、最も伝搬損失の少な
い基地局を選択して、この基地局における上り無線回線
の受信電力に基づいて通話可能かどうかを判定し、通話
可能と判定した場合には接続要求を行い、通話不可能と
判定した場合には接続要求を禁止する。また通話中に現
在接続中の基地局の伝搬損失よりも小さい伝搬損失を与
える基地局が現れた場合には、その基地局をゾーン切換
えの候補として、現在接続中の基地局の伝搬損失、新し
い基地局の伝搬損失、現在接続中の基地局における上り
無線回線の受信電力および新しい基地局における上り無
線回線の受信電力の値に基づいて、ゾーン切換えを行う
かどうかを判定する。According to the present invention, a mobile terminal in standby or communication receives a downlink radio channel of each peripheral base station, and obtains a propagation loss from a difference between transmission power and reception power of an actually received downlink radio channel for each base station. Then, the reception power of the uplink radio channel at each base station is determined from the difference between the maximum transmission power of the mobile terminal and the propagation loss. At the start of a call, a base station having the least propagation loss is selected, and it is determined whether or not a call is possible based on the received power of the uplink radio line at this base station. If it is determined that the call cannot be made, the connection request is prohibited. When a base station that gives a smaller propagation loss than the currently connected base station during a call appears, the base station is set as a candidate for zone switching, and the propagation loss of the currently connected base station and the new It is determined whether to perform zone switching based on the propagation loss of the base station, the reception power of the uplink radio channel at the currently connected base station, and the reception power of the uplink radio channel at the new base station.
このようにすることで、移動端末は、送信電力制御技
術により最大限のバッテリセービング効果を得られるよ
うに伝搬損失の最も小さい基地局を選択し、更にその基
地局と通話可能かどうかを予め判定することによりバッ
テリや周波数の無駄遣いを防ぐことができる。By doing so, the mobile terminal selects the base station with the smallest propagation loss so that the maximum battery saving effect can be obtained by the transmission power control technology, and further determines in advance whether or not communication with the base station is possible. By doing so, it is possible to prevent wasted battery and frequency.
次に、本発明の実施例について図面を参照して説明す
る。Next, embodiments of the present invention will be described with reference to the drawings.
第１図は本発明の基地局選択方式の一実施例を説明す
るための移動通信システムを示すブロック図である。FIG. 1 is a block diagram showing a mobile communication system for explaining an embodiment of a base station selection system according to the present invention.
基地局a10と基地局b11と基地局c12とは、現在の送信
電力Pa，Pb，Pcを示す基地局送信電力コードを含む基地
局情報を送信している。The base station a10 and the base station b11 and the base station c12, sending current transmission power P a, P b, the base station information including the base station transmission power code indicating P c.
待受け中の移動端末20は、基地局a10,基地局b11,基地
局c12からの信号を定期的に受信し、信号中の基地局送
信電力コードから送信電力Pa，Pb，Pcを、また実際に受
信した下り無線回線の受信電力をＥａ→ｍ,Eｂ→ｍ,E
ｃ→ｍを求める。そして送信電力Pa，Pb，Pcと下り無線
回線の受信電力Ｅａ→ｍ,Eｂ→ｍ,Eｃ→ｍとの差から各
基地局の伝搬損失La，Lb，Lcを求める。更に移動端末20
の最大送信電力Pmと伝搬損失La，Lb，Lcとの差から各基
地局における上り無線回線の受信電力Ｅｍ→ａ,
Eｍ→ｂ,Eｍ→ｃを求める。Mobile terminal 20 in a waiting state, the base station a10, the base station b11, periodically receives a signal from a base station c12, transmitted from the base station transmission power cord in signal power P a, P b, the P c, Also, the received power of the actually received downlink radio channel is Ea → m , Eb → m , E
Find c → m . The transmit power P a, P b, P c and the reception power E a → m of the downlink radio channel, E b → m, propagation loss L a of each base station from the difference between E c → m, L b, L c Ask for. Mobile terminal 20
From the difference between the maximum transmission power P m and the propagation loss L a , L b , L c , the reception power E m → a ,
Find Em → b and Em → c .
発呼や着呼により通話を開始する場合、移動端末20は
各基地局の伝搬損失La，Lb，Lcを比較し最も伝搬損失の
小さい基地局を選択し、その基地局における上り無線回
線の受信電力と通話を行うために最低必要な受信電力P
thとを比較する。例えば第１図においてLb＜La＜Lcとす
ると、基地局b11を選択して、Ｅｍ→ｂとPthとを比較す
る。そして、Ｅｍ→ｂ≧Pthの場合には、通話可能と判
定し発呼信号や着呼応答信号を送信する。またＥｍ→ｂ
＜Pthの場合には、通話不可能と判定して発呼信号や着
呼応答信号の送信を禁止する。When a call is initiated by an outgoing call or an incoming call, the mobile terminal 20 compares the propagation losses L a , L b , and L c of each base station, selects the base station having the smallest propagation loss, and transmits the uplink radio signal at the base station. The received power of the line and the minimum required received power P for making a call
Compare with th . For example, the L b <L a <L c in Figure 1, select the base station b11, and compares the E m → b and P th. If E m → b ≧ P th , it is determined that communication is possible, and a call signal and a call response signal are transmitted. Also Em → b
In the case of < Pth , it is determined that communication is impossible, and transmission of a call signal and an incoming call response signal is prohibited.
通話中にも、待受け中と同様に、移動端末20は定期的に
伝搬損失La，Lb，Lcを求める。そして現在接続中の基地
局（基地局b11）の伝搬損失（Lb）と他の伝搬損失（La
とLc）とを比較し、現在接続中の基地局（基地局b11）
の伝搬損失（Lb）よりも小さい伝搬損失を与える基地局
が現れた場合には、その基地局をゾーン切換えの候補と
して、現在接続中の基地局の伝搬損失、新しい基地局の
伝搬損失、現在接続中の基地局における上り無線回線の
受信電力および新しい基地局における上り無線回線の受
信電力の値に基づいて、ゾーン切換え可能かどうかを判
定する。During a call, the mobile terminal 20 periodically obtains the propagation losses L a , L b , and L c , as in the standby state. The propagation loss (L b ) of the currently connected base station (base station b11) and the other propagation loss (L a
And L c ), and compares the currently connected base station (base station b11)
If a base station that gives a propagation loss smaller than the propagation loss (L b ) of the base station appears, the base station is set as a candidate for zone switching, and the propagation loss of the currently connected base station, the propagation loss of the new base station, It is determined whether or not zone switching is possible based on the values of the reception power of the uplink radio channel at the currently connected base station and the reception power of the uplink radio channel at the new base station.
以上のように本実施例によれば、各基地局はその送信
電力を移動端末に知らしめる信号を同報し、移動端末
が、周辺基地局の送信電力と実際に受信した下り無線回
線の受信電力とから各周辺基地局と移動端末との間の伝
搬損失を算出し、この伝搬損失と移動端末の送信電力と
から各周辺基地局における上り無線回線の受信電力を推
定し、この上り無線回線の受信電力に基づいて基地局を
選択し交信している。As described above, according to the present embodiment, each base station broadcasts a signal notifying its transmission power to the mobile terminal, and the mobile terminal receives the transmission power of the neighboring base station and the reception of the downlink radio line actually received. From the power, the propagation loss between each peripheral base station and the mobile terminal is calculated, and from this propagation loss and the transmission power of the mobile terminal, the reception power of the uplink radio channel at each peripheral base station is estimated. The base station is selected and communicated based on the received power of the base station.
第２図は本発明の移動端末の一実施例のブロック図で
ある。FIG. 2 is a block diagram of one embodiment of the mobile terminal of the present invention.
この移動端末は、アンテナ21と、共用器22と、各周辺
基地局10,11,12の送信電力を求める手段として機能する
受信回路24と、各周辺基地局からの下り無線回線の受信
電力を求める手段として機能する受信電力測定回路23
と、送信電力と下り無線回線の受信電力とから各周辺基
地局との間の伝搬損失を求める手段として機能する演算
器25と、伝搬損失と移動端末の送信電力とから各周辺基
地局における上り無線回線の受信電力を推定する手段と
して機能する演算器29と、演算器25が演算した伝搬損失
および演算器29が推定した上り無線回線の受信電力を記
憶するメモリ26と、上り無線回線の受信電力と予め定め
た閾値とを比較する手段として機能する制御部27と、送
信回路28と、圏外表示ランプ30とを有している。The mobile terminal includes an antenna 21, a duplexer 22, a receiving circuit 24 functioning as a means for determining the transmission power of each of the peripheral base stations 10, 11, and 12, and a reception power of a downlink radio channel from each of the peripheral base stations. Received power measurement circuit 23 that functions as a means for determining
And an arithmetic unit 25 functioning as a means for calculating a propagation loss between each of the peripheral base stations from the transmission power and the reception power of the downlink radio line, and an uplink unit in each of the peripheral base stations from the propagation loss and the transmission power of the mobile terminal. An arithmetic unit 29 functioning as a means for estimating the reception power of the radio channel; a memory 26 for storing the propagation loss calculated by the arithmetic unit 25 and the reception power of the uplink radio channel estimated by the arithmetic unit 29; The control unit 27 functions as a unit for comparing the power with a predetermined threshold, a transmission circuit 28, and an out-of-service indicator lamp 30.
次に、この移動端末の動作を説明するが、各基地局1
0,11,12は、送信電力の値を示す基地局送信電力コード
と基地局IDとを含む基地局情報を送信しているものとす
る。Next, the operation of the mobile terminal will be described.
It is assumed that 0, 11, and 12 are transmitting base station information including a base station transmission power code indicating a value of transmission power and a base station ID.
例えば基地局10の送信する基地局情報は、待受け中や
通話中の移動端末20のアンテナ21、共用器22を経由して
受信電力測定回路23および受信回路24に入力される。受
信電力測定回路23は、下り無線回線の受信電力を測定
し、その結果を演算器25に出力する。受信回路24は、基
地局情報中の基地送信電力コードから求めた送信電力と
基地局IDを、演算器25に対して出力する。演算器25は、
基地局の送信電力の値と下り無線回線の受信電力の値と
の差から伝搬損失を計算し、基地局IDと共にメモリ26に
記憶する。演算器29は、移動端末の最大送信電力と演算
器25から出力される伝搬損失との差から基地局における
上り無線回線受信電力を計算し、基地局IDと共にメモリ
26に記憶する。制御部27は、全ての周辺基地局の基地局
ID、伝搬損失および上り無線回線の受信電力とが求まる
ように受信電力測定回路23および受信回路24を制御す
る。For example, base station information transmitted by the base station 10 is input to the reception power measurement circuit 23 and the reception circuit 24 via the antenna 21 and the duplexer 22 of the mobile terminal 20 during standby or talking. The reception power measurement circuit 23 measures the reception power of the downlink radio channel, and outputs the result to the computing unit 25. The receiving circuit 24 outputs the transmission power and the base station ID obtained from the base transmission power code in the base station information to the computing unit 25. Arithmetic unit 25
The propagation loss is calculated from the difference between the value of the transmission power of the base station and the value of the reception power of the downlink radio channel, and stored in the memory 26 together with the base station ID. Arithmetic unit 29 calculates the uplink radio channel reception power at the base station from the difference between the maximum transmission power of the mobile terminal and the propagation loss output from arithmetic unit 25, and stores
Remember in 26. The control unit 27 is a base station for all peripheral base stations.
The reception power measurement circuit 23 and the reception circuit 24 are controlled so that the ID, the propagation loss, and the reception power of the uplink radio channel are obtained.
発呼または着呼応答の場合、制御部27はメモリ26の内
容より最も伝搬損失の少ない基地局を選び、この基地局
における上り無線回線の受信電力と通話を行うのに最低
必要な受信電力とを比較して、通話可能かどうかを判定
する。通話可能と判定した場合、制御部27は発呼信号ま
たは着呼応答信号を送信するように送信回路28を制御す
る。通話不可能と判定した場合、制御部27は圏外表示ラ
ンプ30を点灯させて、発呼信号または着呼応答信号の送
信を禁止する。In the case of an outgoing call or incoming call response, the control unit 27 selects the base station having the least propagation loss from the contents of the memory 26, and the received power of the uplink radio line at this base station and the minimum required received power for performing a call. Are compared to determine whether a call is possible. If it is determined that the call is possible, the control unit 27 controls the transmission circuit 28 to transmit a call signal or a call response signal. When it is determined that the call cannot be made, the control unit 27 turns on the out-of-service indicator lamp 30 to prohibit the transmission of the call signal or the call response signal.
通話中の制御部27は、メモリ26内の現在接続中の基地
局の伝搬損失と他の伝搬損失とを定期的に比較し、現在
接続中の基地局の伝搬損失よりも小さい伝搬損失を与え
る基地局が現れた場合には、その基地局をゾーン切換え
の候補として、現在接続中の基地局の伝搬損失、新しい
基地局の伝搬損失、現在接続中の基地局における上り無
線回線の受信電力および新しい基地局における上り無線
回線の受信電力の値に基づいて、前記切換えを行うかど
うかを判定する。ゾーン切換えを行うと判定した場合に
は、その基地局に対してゾーン切換え制御を開始するよ
うに送信回路28を制御する。The control unit 27 during a call periodically compares the propagation loss of the currently connected base station in the memory 26 with another propagation loss, and gives a propagation loss smaller than the propagation loss of the currently connected base station. When a base station appears, the base station is set as a candidate for zone switching, and the propagation loss of the currently connected base station, the propagation loss of the new base station, the reception power of the uplink radio line at the currently connected base station, and It is determined whether to perform the switching based on the value of the received power of the uplink radio channel in the new base station. If it is determined that the zone switching is to be performed, the transmitting circuit 28 is controlled so as to start the zone switching control for the base station.
以上詳細に説明したように本発明によれば、大きさの
異なるゾーンが共存する移動通信システムにおいても、
移動端末は、送信電力制御技術により最大限のバッテリ
セービング効果を得られるように伝搬損失の最も小さい
基地局を選択し、更にその基地局と通話可能かどうかを
予め判定することによりバッテリや周波数の無駄遣いを
防ぐことができる。According to the present invention as described in detail above, even in a mobile communication system in which zones having different sizes coexist,
The mobile terminal selects a base station with the smallest propagation loss so that the maximum battery saving effect can be obtained by the transmission power control technique, and further determines in advance whether or not communication with the base station is possible, thereby reducing the battery and frequency. Waste can be prevented.
第１図は本発明の基地局選択方式の一実施例を説明する
ための移動通信システムのブロック図、 第２図は本発明の移動端末の一実施例のブロック図であ
る。 10…基地局ａ 11…基地局ｂ 12…基地局ｃ 20…移動端末 21…アンテナ 22…共用器 23…受信電力測定回路 24…受信回路 25…演算器 26…メモリ 27…制御部 28…送信回路 29…演算器 30…圏外表示ランプ Ｅａ→ｍ,Eｂ→ｍ,Eｃ→ｍ…移動端末における下り無線
回線の受信電力 La，Lb，Lc…伝搬損失 Pa，Pb，Pc…送信電力 Ｅｍ→ａ,Eｍ→ｂ,Eｍ→ｃ…基地局における上り無線回
線の受信電力FIG. 1 is a block diagram of a mobile communication system for explaining an embodiment of a base station selection system of the present invention, and FIG. 2 is a block diagram of an embodiment of a mobile terminal of the present invention. 10 ... base station a 11 ... base station b 12 ... base station c 20 ... mobile terminal 21 ... antenna 22 ... duplexer 23 ... reception power measurement circuit 24 ... reception circuit 25 ... arithmetic unit 26 ... memory 27 ... control unit 28 ... transmission circuit 29 ... calculator 30 ... service indication lamp E a → m, E b → m, E c → m ... received power L a downlink radio channel in a mobile terminal, L b, L c ... propagation loss P a, P b , P c ... transmission power Em → a , Em → b , Em → c ... reception power of the uplink radio channel at the base station
Claims (2)
ーする移動通信システムの基地局選択方式であって、 各基地局はその送信電力を移動端末に知らしめる信号を
同報し、 移動端末が、周辺基地局の送信電力と実際に受信した下
り無線回路の受信電力とから各周辺基地局と移動端末と
の間の伝搬損失を算出し、前記伝搬損失と移動端末の送
信電力とから各周辺基地局における上り無線回線の受信
電力を推定し、前記上り無線回線の受信電力に基づいて
基地局を選択し交信することを特徴とする移動通信シス
テムの基地局選択方式。1. A base station selection method for a mobile communication system in which a service area is covered by a plurality of base stations, wherein each base station broadcasts a signal notifying its transmission power to the mobile terminal. Calculate the propagation loss between each peripheral base station and the mobile terminal from the transmission power of the peripheral base station and the received power of the downlink radio circuit actually received, and calculate each of the peripheral base stations from the propagation loss and the transmission power of the mobile terminal. A base station selection method for a mobile communication system, comprising: estimating reception power of an uplink radio channel in a station, selecting a base station based on the reception power of the uplink radio channel, and performing communication.
ーする移動通信システムの移動端末において、 各周辺基地局の送信電力を求める手段と、 各周辺基地局からの下り無線回線の受信電力を求める手
段と、 前記送信電力と前記下り無線回線の受信電力とから前記
各周辺基地局との間の伝搬損失を求める手段と、 前記伝搬損失と移動端末の送信電力とから各周辺基地局
における上り無線回線の受信電力を推定する手段と、 前記上り無線回線の受信電力と予め定めた閾値とを比較
する手段とを有することを特徴とする移動通信システム
の移動端末。2. A mobile terminal of a mobile communication system in which a service area is covered by a plurality of base stations, means for determining transmission power of each peripheral base station, and means for determining reception power of a downlink radio channel from each peripheral base station. Means for calculating a propagation loss between the peripheral base stations from the transmission power and the reception power of the downlink radio channel; and an uplink radio channel in each peripheral base station from the transmission loss and the transmission power of the mobile terminal. A mobile terminal of a mobile communication system, comprising: means for estimating the received power of the mobile communication system; and means for comparing the received power of the uplink radio channel with a predetermined threshold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1057275A JP2715526B2 (en) | 1989-03-09 | 1989-03-09 | Base station selection method for mobile communication system and mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1057275A JP2715526B2 (en) | 1989-03-09 | 1989-03-09 | Base station selection method for mobile communication system and mobile terminal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02237231A JPH02237231A (en) | 1990-09-19 |
| JP2715526B2 true JP2715526B2 (en) | 1998-02-18 |
Family
ID=13050985
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1057275A Expired - Lifetime JP2715526B2 (en) | 1989-03-09 | 1989-03-09 | Base station selection method for mobile communication system and mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2715526B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2702614B1 (en) * | 1993-03-09 | 1995-04-14 | Alcatel Radiotelephone | Method for controlling the power of the access packet emitted by a mobile in a radiocommunication system, and system implementing this method. |
| ES2173717T3 (en) * | 1999-04-30 | 2002-10-16 | Cit Alcatel | SOFT DELIVERY METHOD IN CDMA USING ASCENDING LINK MEASUREMENTS. |
| JPWO2002037715A1 (en) * | 2000-10-31 | 2004-03-11 | 松下電器産業株式会社 | Mobile station apparatus and handover method |
| JP2009225132A (en) * | 2008-03-17 | 2009-10-01 | Nec Corp | Image display system, image display method and program |
| WO2013183731A1 (en) | 2012-06-06 | 2013-12-12 | 京セラ株式会社 | Communication control method, base station, user terminal, processor and recording medium |
-
1989
- 1989-03-09 JP JP1057275A patent/JP2715526B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02237231A (en) | 1990-09-19 |
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