JPH0744496B2 - Battery saving method - Google Patents
Battery saving methodInfo
- Publication number
- JPH0744496B2 JPH0744496B2 JP63134093A JP13409388A JPH0744496B2 JP H0744496 B2 JPH0744496 B2 JP H0744496B2 JP 63134093 A JP63134093 A JP 63134093A JP 13409388 A JP13409388 A JP 13409388A JP H0744496 B2 JPH0744496 B2 JP H0744496B2
- Authority
- JP
- Japan
- Prior art keywords
- power
- station
- slave station
- unique number
- slave
- 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
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
Landscapes
- Mobile Radio Communication Systems (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明はバッテリセイビング方式に関し、特に親局が子
局の受信系を含めた部分の電源の制御を行うバッテリセ
イビング方式に関する。Description: TECHNICAL FIELD The present invention relates to a battery saving system, and more particularly to a battery saving system in which a master station controls a power supply of a part including a reception system of a slave station.
従来、１つの親局と複数の子局とで構成される放送通信
システム等において、１つの親局が複数の子局の電源系
を一括して同じタイミングで制御してバッテリセイビン
グを行うバッテリセイビング方式は、親局がIBS（バッ
テリセイビング）周期内にあるｎ個のBSタイムスロット
に１回だけ子局の電源オフ信号を子局に送信し、子局は
親局からの電源オフ信号を受信した時、受信系も含めて
バッテリセイビング可能な部分の電源をオフし、自局の
カウンタで電源オフの時間をカウントした後、自局の電
源をオンにする方式であった。Conventionally, in a broadcasting communication system or the like including one master station and a plurality of slave stations, one master station collectively controls power supply systems of a plurality of slave stations at the same timing to perform battery saving. In the system, the master station sends the slave station power-off signal to the slave station only once in n BS time slots within the IBS (battery saving) cycle, and the slave station receives the power-off signal from the master station. At that time, the power of the battery-saving part including the receiving system is turned off, the power-off time is counted by the counter of the own station, and then the power of the own station is turned on.
しかしながら、上述した従来のバッテリセイビング方式
は、IBS周期内にあるｎ個のBSタイムスロットに１回し
か子局の電源オフ制御信号が送信されないため、子局の
電源がオンになってから、次の電源オフの時間までの間
に親局と子局間に伝送誤りが生じたような場合には、前
記した電源オフ制御信号を子局において正しく受信する
ことができない場合があり、所要のバッテリセイビング
を行うことが困難になる。そのため、前記した電源オフ
制御信号を子局において正しく受信してこれを認識する
ことができるように保護を与えることが考えられるが、
前記したように電源オフ制御信号はタイムスロットに対
して1/nの割合でしか送信されないため、この間前記し
た電源オフ制御の保護をすることができず、したがって
その間バッテリセイビングを行うことができないという
問題がある。However, in the above-described conventional battery saving method, since the power-off control signal of the slave station is transmitted only once in the n BS time slots within the IBS cycle, the power of the slave station is turned on and then If a transmission error occurs between the master station and the slave station before the power-off time of, the slave station may not be able to correctly receive the power-off control signal described above, and the required battery It becomes difficult to save. Therefore, it is conceivable to give protection so that the slave station can correctly receive the power-off control signal and recognize it.
As described above, since the power-off control signal is transmitted only at a ratio of 1 / n to the time slot, the power-off control described above cannot be protected during this period, and therefore battery saving cannot be performed during that time. There's a problem.
本発明は上述した問題を解消し、親局と子局間の伝送路
の誤りを考慮して親局の電源制御信号に保護を加えるこ
とができるようにしたバッテリセイビング方式を提供す
ることを目的としている。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and provide a battery saving system capable of adding protection to a power control signal of a master station in consideration of an error in a transmission line between the master station and a slave station. I am trying.
本発明のバッテリセイビング方式は、１つの親局には１
バッテリセイビング周期内にあるｎ個のバッテリセイビ
ングタイムスロットにｎ個の規則性のある固有番号を多
重して全ての子局に送信する手段を備え、１以上の子局
には親局から送られてくる前記タイムスロット内の固有
番号を識別する手段と、実際に得られた固有番号が前記
規則性に依っているか否かを判定し、規則性がない場合
に親局と子局間に伝送路の誤りがあることを認識する手
段と、この誤りを認識したときには規則性がない固有番
号無視し、本来の規則性を満足する固有番号に基づいて
子局が電源をオフにする期間がどうかを判断して子局の
受信系も含めたバッテリセイビング可能な部分の電源を
オフする手段と、子局の電源オフから時間をカウント
し、この時間が所定時間に達したときに子局でオフした
前記部分の電源をオンする手段とを備えている。According to the battery saving method of the present invention, one master station has one
It is provided with means for multiplexing n regular numbers with regularity in n battery saving time slots within the battery saving period and transmitting to all the slave stations. One or more slave stations are sent from the master station. Means to identify the unique number in the incoming time slot and determine whether the unique number actually obtained depends on the regularity, and if there is no regularity, transmit between the master station and the slave station. What is the means of recognizing that there is an error in the road and the period when the slave station turns off the power based on the unique number that does not have regularity when recognizing this error and ignores the original regularity To turn off the power of the battery-saving part including the reception system of the slave station, and to count the time from the power off of the slave station, and turn off at the slave station when this time reaches a predetermined time Power to the above And means for.
上述した構成では、親局が子局の受信系も含めた部分の
電源を制御しながら、子局は電源オンから次の電源オフ
までの時間に、親局と子局間の伝送路の誤りを考慮し、
親局の電源制御情報に保護を加えてバッテリセイビング
を実行する。In the above-mentioned configuration, while the master station controls the power supply of the part including the reception system of the slave station, the slave station has an error in the transmission line between the master station and the slave station during the time from power-on to next power-off. Considering
Protects the power control information of the master station and executes battery saving.
次に、本発明を図面を参照して説明する。 Next, the present invention will be described with reference to the drawings.
第１図は本発明の一実施例のブロック図で、親局Ｂと子
局Ｔがポイントツーポイント方式で親局から子局へ向け
て通信する場合に必要となる部分の構成を示している。FIG. 1 is a block diagram of an embodiment of the present invention, and shows a configuration of a part required when a master station B and a slave station T communicate with each other from the master station to the slave station by a point-to-point method. .
親局Ｂにおいて、11はBSタイムスロットに多重するBS固
有番号を発生するBS固有番号発生回路（BS NO.GEN）、1
2はフレーム同期パターン（F PTN）およびBS固有番号を
無線フレームに多重する多重回路（MUX）、13はベース
バンド信号を変調して子局へ送信する変調回路およびア
ンテナを備える送信部（TX）を示している。In the master station B, 11 is a BS unique number generation circuit (BS NO.GEN) that generates a BS unique number to be multiplexed in a BS time slot, 1
2 is a multiplexing circuit (MUX) that multiplexes a frame synchronization pattern (F PTN) and BS unique number into a radio frame, and 13 is a transmission unit (TX) that includes a modulation circuit that modulates a baseband signal and transmits it to a slave station Is shown.
一方、子局Ｔにおいて、21は親局Ｂから送信された変調
波を受信し、変調波からクロック同期，再生を行い、ベ
ースバンド信号を復調するアンテナ及び復調回路を備え
る受信部（RX）、22はBS固有番号検出回路（BS NO.DE
T）である。このBS固有番号検出回路22は、復調された
ベースバンド信号からフレームパターンを見つけフレー
ム同期を取るフレーム同期回路（FSYNC）23と、フレー
ム同期回路23で作られたフレーム同期信号よりBSタイム
スロットの位置を示すタイミングパルスを作り、ベース
バンド信号よりBSタイムスロット内のBS固有番号を分離
するBS固有番号分離回路（BS NO.DMUX）24とを有してい
る。On the other hand, in the slave station T, 21 receives the modulated wave transmitted from the parent station B, performs clock synchronization and reproduction from the modulated wave, and demodulates the baseband signal. 22 is a BS unique number detection circuit (BS NO.DE
T). The BS unique number detection circuit 22 detects the frame pattern from the demodulated baseband signal, and a frame synchronization circuit (FSYNC) 23 for frame synchronization, and the position of the BS time slot from the frame synchronization signal created by the frame synchronization circuit 23. And a BS unique number separation circuit (BS NO.DMUX) 24 that separates the BS unique number in the BS time slot from the baseband signal.
また、25はBS固有番号検出回路22で得られたBS固有番号
に親局と子局間の伝送路の誤りを考慮した保護を加え、
その保護を加えたBS固有番号より子局が電源オフの期間
かどうか判断し、子局の受信系も含めたバッテリセイビ
ング可能な部分の電源をオフする制御信号を発生するバ
ッテリセイビング制御回路（BS CONT）、26は子局の電
源オフから電源オンまでの時間をカウントし、子局でバ
ッテリセイビングした部分の電源をオンにする制御回路
（PWR ON CONT）で、この回路は常時電源がオンになっ
ている。In addition, 25 is added to the BS unique number obtained by the BS unique number detection circuit 22 in consideration of an error in the transmission line between the master station and the slave station,
A battery-saving control circuit (BS that generates a control signal that turns off the power of the battery-saving part including the receiving system of the slave station by judging whether the power supply of the slave station is off from the BS unique number with the protection CONT), 26 is a control circuit (PWR ON CONT) that counts the time from power-off to power-on of the slave station and turns on the power of the battery-saving part of the slave station. This circuit is always powered on. Has become.
第２図は第１図の実施例における各回路部の信号の一例
を示すタイミングチャートである。同図の信号ａ〜ｃは
第１図に示される各回路から出力される信号ａ〜ｅのタ
イミングに対応し、ａは親局Ｂの送信部13で変調する送
信無線フレーム（TX FRAME）、ｂは子局Ｔの受信部21で
復調される受信無線フレーム（RX FRAME）、ｃはBS固有
番号検出回路22で分離されるBS固有番号（RX BS N
O.）、ｄはバッテリセイビング制御回路25で発生する電
源オフ制御パルス（OFF PLS）、ｅは電源オン制御回路2
6から出力される子局の電源制御信号（PWR CONT）を示
している。FIG. 2 is a timing chart showing an example of signals of each circuit section in the embodiment of FIG. Signals a to c in the figure correspond to timings of signals a to e output from each circuit shown in FIG. 1, and a is a transmission radio frame (TX FRAME) modulated by the transmission unit 13 of the master station B, b is a received radio frame (RX FRAME) demodulated by the receiver 21 of the slave station T, and c is a BS unique number (RX BS N separated by the BS unique number detection circuit 22.
O.), d is a power-off control pulse (OFF PLS) generated in the battery saving control circuit 25, and e is a power-on control circuit 2
The power control signal (PWR CONT) of the slave station output from 6 is shown.
これらの図に示すようにIBS周期ＴBSは、ｎ個の無線フ
レームF1〜Fnから成り、各無線フレームにはフレーム同
期パターンと１〜ｎのBS固有番号が多重されている。ま
た1BS周期内で子局の電源がオン，オフする時間は夫々
ＴOFF,TONである。IBS period T BS As shown in these figures consists of n radio frames F1 to Fn, a frame synchronization pattern and 1~n the BS ID number is multiplexed in each radio frame. In addition, the times during which the power supply of the slave station is turned on and off within one BS cycle are T OFF and T ON , respectively.
以上の構成およびタイミングチャートを基に、第１図の
動作を説明する。The operation of FIG. 1 will be described based on the above configuration and timing chart.
まず始めに親局Ｂでは子局Ｔの電源系を制御するため
に、BS固有番号発生回路11でBS固有番号を発生し、第２
図のａに示すように送信無線フレーム（TX FRAME）には
無線フレームF1〜Fnにそれぞれ１〜ｎのBS固有番号とフ
レーム同期パターンが多重回路12で多重され、送信部13
より送出される。First, in order to control the power supply system of the slave station T in the parent station B, the BS unique number generation circuit 11 generates a BS unique number, and the second
As shown in a of the figure, in the transmission radio frame (TX FRAME), the BS unique numbers 1 to n and the frame synchronization pattern are multiplexed by the multiplexing circuit 12 in the radio frames F1 to Fn, respectively, and the transmitter 13
Sent by.
子局Ｔでは電源をオンにし、受信部21で親局Ｂで変調さ
れた信号が復調され、第２図のｂに示すタイミングで受
信無線フレーム（RX FRAME）が受信される。In the slave station T, the power is turned on, the reception section 21 demodulates the signal modulated in the master station B, and the received radio frame (RX FRAME) is received at the timing shown in b of FIG.
次に、BS固有番号検出回路22でフレーム同期が取られ、
受信無線フレームから各無線フレームF1〜FnにあるBSタ
イムスロットより、第２図のｃで示すタイミングで受信
BS固有番号が分離され、バッテリセイビング制御回路25
に送られる。Next, the BS unique number detection circuit 22 performs frame synchronization,
Received from the received radio frame from the BS time slot in each radio frame F1 to Fn at the timing shown in c of FIG.
Battery saving control circuit 25
Sent to.
このバッテリセイビング制御回路25は、例えばカウンタ
と、そのカウント値を受信した固有番号と比較する手段
を有し、常時これらの比較を行なう。そして、受信BS固
有番号が第２図のｃで示すようにｎ−3,n−2,n−1,n,1
と受信されるべきものが、例えばｎ−3,n−2,1,n,1と入
力され、３番目の受信BS固有番号が誤って受信されたと
き、バッテリセイビング制御回路25では受信BS固有番号
の保護を行う。即ち、本来は徐々に固有番号が１ずつ増
加されるはずなのに、その規則性を満足していないこと
から、この３番目に入力された固有番号は伝送路の誤り
によって誤って受信されたものと認識し、この３番目に
入力された固有番号の値“1"を無視する。そして、その
規則性を満足する、５番目に入力された受信BS固有番号
の値“1"を1BS周期の始めと判断し、電源オン制御回路2
6へ第２図のｄで示すタイミングで電源オフ制御パルス
を送出する。The battery saving control circuit 25 has, for example, a counter and means for comparing the count value with the received unique number, and always performs these comparisons. The received BS unique number is n-3, n-2, n-1, n, 1 as shown by c in FIG.
Should be received, for example, when n-3, n-2,1, n, 1 is input and the third receiving BS unique number is erroneously received, the battery saving control circuit 25 receives the receiving BS unique number. Protect numbers. That is, although the unique number is supposed to be gradually increased by one, it does not satisfy the regularity. Therefore, the third entered unique number is erroneously received due to an error in the transmission path. Recognize and ignore the value "1" of the unique number input at the third position. Then, it is determined that the value "1" of the 5th input received BS unique number that satisfies the regularity is the beginning of the 1BS cycle, and the power-on control circuit 2
A power-off control pulse is sent to 6 at the timing indicated by d in FIG.
この電源オン制御回路26では、第２図のｅのように電源
オフ制御パルスで電源制御信号を低レベルにし、子局の
受信部も含めてバッテリセイビング可能な部分の電源を
オフにし、同時にタイマをスタートさせる。次にタイマ
でＴOFF時間たったことをカウントした後、電源制御信
号を高レベルに立上げバッテリセイビングしていた部分
の電源をオンにする。In the power-on control circuit 26, the power-supply control signal is set to a low level by the power-off control pulse as shown in e of FIG. 2, the power of the battery-saving part including the receiver of the slave station is turned off, and at the same time the timer is activated. To start. Next, after the timer counts that T OFF time has elapsed, the power supply control signal is raised to a high level to turn on the power of the battery saving portion.
以上の動作を繰り返すことにより、親局が子局の受信系
を含めた部分の電源の制御をしながら、子局は電源オン
から次の電源オフまでの時間に親局と子局間の伝送路の
誤りを考慮し、親局の電源制御信号に保護を加えること
ができる。By repeating the above operation, while the master station controls the power supply of the part including the reception system of the slave station, the slave station transmits between the master station and the slave station during the time from power-on to next power-off. It is possible to add protection to the power control signal of the master station in consideration of the error of the route.
なお、前記実施例においては、ポイントツーポイント通
信の場合について説明してきたが、ポイントツーマルチ
ポイント通信の場合でも本発明が適用できることは上述
の説明から明らかである。It should be noted that although the case of point-to-point communication has been described in the above embodiment, it is apparent from the above description that the present invention can be applied to the case of point-to-multipoint communication.
以上説明したように本発明は、親局ではｎ個の規則性の
ある固有番号を多重して全ての子局に送信し、子局では
親局から送られてくる固有番号を識別し、実際に得られ
た固有番号が前記規則性に依っているか否かを判定し、
規則性がない場合に親局と子局間に伝送路の誤りがある
ことを認識し、この誤りを認識したときには規則性がな
い固有番号を無視し、本来の規則性を満足する固有番号
に基づいて子局が電源をオフにする期間がどうかを判断
して子局の受信系も含めたバッテリセイビング可能な部
分の電源をオフし、かつ子局の電源オフから時間をカウ
ントし、この時間が所定時間に達したときに子局でオフ
した前記部分の電源をオンしているので、親局が子局の
受信系も含めた部分の電源を制御しながら、子局は電源
オンから次の電源オフまでの時間に、親局と子局間の伝
送路の誤りを考慮し、親局の電源制御信号に保護を加え
ることができる効果がある。As described above, according to the present invention, the master station multiplexes n unique numbers with regularity and transmits them to all the slave stations, and the slave stations identify the unique numbers sent from the master station and actually It is determined whether or not the unique number obtained in step 1 above depends on the regularity,
When there is no regularity, it recognizes that there is an error in the transmission line between the master station and the slave station, and when this error is recognized, the unique number with no regularity is ignored and the unique number that satisfies the original regularity is recognized. Based on this, the power of the slave station is determined to be off, the power of the battery-saving part including the reception system of the slave station is turned off, and the time is counted from the power off of the slave station. When the predetermined time is reached, the power of the part turned off in the slave station is turned on, so while the master station controls the power of the part including the reception system of the slave station, In the time until the power is turned off, there is an effect that the power control signal of the master station can be protected in consideration of an error in the transmission line between the master station and the slave station.
第１図は本発明のバッテリセイビング方式の一実施例の
ブロック図、第２図は第１図中の信号ａ〜ｅのタイミン
グチャートを示す。 11……BS固有番号発生回路、12……多重回路、13……送
信部、21……受信部、22……BS固有番号検出回路、23…
…フレーム同期回路、24……BS固有番号分離回路、25…
…バッテリセイビング制御回路、26……電源オン制御回
路。FIG. 1 is a block diagram of an embodiment of the battery saving system of the present invention, and FIG. 2 is a timing chart of the signals a to e in FIG. 11 ... BS unique number generation circuit, 12 ... Multiplexing circuit, 13 ... Transmission unit, 21 ... Reception unit, 22 ... BS unique number detection circuit, 23 ...
… Frame synchronization circuit, 24 …… BS unique number separation circuit, 25…
… Battery saving control circuit, 26 …… Power-on control circuit.
Claims (1)
親局が１以上の子局の電源系を一括して同じタイミング
で管理制御するようにしたバッテリセイビング方式にお
いて、親局には１バッテリセイビング周期内にあるｎ個
のバッテリセイビングタイムスロットにｎ個の規則性の
ある固有番号を多重して全ての子局に送信する手段を備
え、子局には親局から送られてくる前記タイムスロット
内の固有番号を識別する手段と、実際に得られた固有番
号が前記規則性に依っているか否かを判定し、規則性が
ない場合に親局と子局間に伝送路の誤りがあることを認
識する手段と、この誤りを認識したときには規則性がな
い固有番号を無視し、本来の規則性を満足する固有番号
に基づいて子局が電源をオフにする期間がどうかを判断
して子局の受信系も含めたバッテリセイビング可能な部
分の電源をオフする手段と、子局の電源オフから時間を
カウントし、この時間が所定時間に達したときに子局で
オフした前記部分の電源をオンする手段とを備えたこと
を特徴とするバッテリセイビング方式。1. A system comprising one master station and one or more slave stations,
In the battery saving system in which the master station collectively controls the power supply systems of one or more slave stations at the same timing, the master station has n battery saving time slots in n battery saving time slots within one battery saving cycle. Is provided with means for transmitting the unique number with regularity to all the slave stations, and the slave station has means for identifying the unique number in the time slot sent from the master station, Means for deciding whether or not the unique number depends on the regularity, and recognizing that there is an error in the transmission line between the master station and the slave station when there is no regularity, and a rule when recognizing this error. Ignoring unique numbers that do not have the same characteristics, and based on the unique numbers that satisfy the original regularity, determine whether the period during which the slave station will turn off the power and determine the battery-saving part of the battery including the reception system of the slave station. Power off Means counts the time from the power-off of the slave station, the battery Say Bing scheme, characterized in that the time and means for turning on the power of the portion off the child station when it reaches a predetermined time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63134093A JPH0744496B2 (en) | 1988-05-31 | 1988-05-31 | Battery saving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63134093A JPH0744496B2 (en) | 1988-05-31 | 1988-05-31 | Battery saving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01303815A JPH01303815A (en) | 1989-12-07 |
| JPH0744496B2 true JPH0744496B2 (en) | 1995-05-15 |
Family
ID=15120271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63134093A Expired - Lifetime JPH0744496B2 (en) | 1988-05-31 | 1988-05-31 | Battery saving method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0744496B2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5272501A (en) * | 1975-12-15 | 1977-06-17 | Nippon Telegr & Teleph Corp <Ntt> | Selective call communication system |
-
1988
- 1988-05-31 JP JP63134093A patent/JPH0744496B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5272501A (en) * | 1975-12-15 | 1977-06-17 | Nippon Telegr & Teleph Corp <Ntt> | Selective call communication system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01303815A (en) | 1989-12-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1169923A (en) | Digital radio paging communication system | |
| CA1220290A (en) | Power saving system for time-division multiple access radiocommunication network | |
| CA1257653A (en) | Radio communication system with power saving disablement prior to call handling processes | |
| US6639905B1 (en) | Communication network | |
| JPH0119660B2 (en) | ||
| JPS5986928A (en) | Base station identifying method | |
| US7587195B2 (en) | Wireless communications apparatus made operative in dependent upon a received signal strength | |
| JPS632504B2 (en) | ||
| EP0735787A2 (en) | Selective call receiver for FM multiplexer broadcast | |
| EP1180696A3 (en) | System and method for locating mobile devices | |
| EP0143458A3 (en) | Radio communication system operable in cooperation with a vox system | |
| EP4333530A1 (en) | Wake-up method and apparatus, and electronic device | |
| WO2009044368A2 (en) | Power saving method and system for wireless communications device | |
| CN101163329A (en) | Method of implementing SCDMA system terminal-to-terminal direct communication and uses thereof | |
| JPH01500954A (en) | Modem and data communication systems | |
| EP2105037B1 (en) | System, method and apparatus employing tone and/or tone patterns to indicate the message type in wireless sensor networks | |
| JPH0744496B2 (en) | Battery saving method | |
| US20070053316A1 (en) | Method and system of accessing a de-keyed base station | |
| EP1271894A4 (en) | Packet transmitter unit, packet receiver unit and packet transmission system | |
| JPH08194022A (en) | Wireless automatic meter inspection system | |
| WO2023286153A1 (en) | Interference avoidance system, interference avoidance method, and interference avoidance device for radio communication | |
| JP2538961B2 (en) | Selective call communication method | |
| JPH0660284A (en) | Transmitting/receiving method for radio type alarm system | |
| JP2550759B2 (en) | Line delay change detection system | |
| CN205195712U (en) | DTMF signal reception circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090515 Year of fee payment: 14 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090515 Year of fee payment: 14 |