JPS58178650A - Automatic controlling mechanism of data transmitting speed - Google Patents
Automatic controlling mechanism of data transmitting speedInfo
- Publication number
- JPS58178650A JPS58178650A JP57060949A JP6094982A JPS58178650A JP S58178650 A JPS58178650 A JP S58178650A JP 57060949 A JP57060949 A JP 57060949A JP 6094982 A JP6094982 A JP 6094982A JP S58178650 A JPS58178650 A JP S58178650A
- Authority
- JP
- Japan
- Prior art keywords
- speed
- transmission
- transmitting
- automatically
- transmission speed
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Detection And Prevention Of Errors In Transmission (AREA)
- Communication Control (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、公衆通信回線を利用したデータ通信、特に音
響カブラを介したデータ通信ｉ％極力高い伝送速度で実
行できるようにしたデータ伝送速度自動制御機構に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic data transmission rate control mechanism that enables data communication using a public communication line, particularly data communication via an acoustic doubler, at a transmission rate as high as possible.
公衆通信回線、籍に構在着しく昔及した加入電話網な利
用し、更に音響カブラな併用すれば、全国どの２地点間
でも、データ通信な行うことができる。しかしデータ過
信では、電話の場合に比し、伝送周回！ＩＫ対し、はる
かに低い、厳重なビット誤り卓が要求される。このビッ
ト鯖り皐は、接続リンク数、経由する伝送方式、交換方
式により、ばらつきが生じ、しばしば、既ＫｉＩ続され
ている特定２地点の一纏の伝送特性が時間の経過ととも
変動することもある。現在、公衆通信回線綱に音響カブ
ラな用いてデータ通（１１行う場合、一般には最高１，
２００ビット／秒（ｂｐｓ ）、更に％に４件の良い２
地点間に限定すれば、一層高遮の伝送速度が得られる場
合もあると１われているが、通常は、常に１，２００Ｊ
ｌ−な期待することもおぼつかない、もし常に確実な伝
送の行なえる伝送速度とぎえばａｏｏｂｔｓ あるい
は極熾な場合、それ以下罠なってしまい、公衆＠線利用
によって得られる地点選定の自由という利益も、遅い伝
送速度。By using public communication lines, the long-established subscriber telephone network that is located throughout the country, and the use of acoustic duplexers, data communication can be carried out between any two points in the country. However, due to overconfidence in data, compared to the case of telephone calls, the number of transmission laps increases! For IK, a much lower, tighter bit error counter is required. This bit difference varies depending on the number of connected links, the transmission method used, and the exchange method, and the transmission characteristics of two specific points that are already connected often fluctuate over time. There is also. Currently, when transmitting data (11,
200 bits per second (bps), plus a good 2 to 4%
It is said that even higher transmission speeds can be obtained if the transmission speed is limited between points, but normally the transmission speed is always 1,200 J.
I can't even hope for the best. If the transmission speed is such that it can always be transmitted reliably, it will become a trap. Slow transmission speed.
長い伝送所要時間によ−）Ｃ全く相殺されてしまう。The long transmission time will completely cancel out the cost.
本発明の目的は、公衆通侭綱を利用したデータ通信、特
に音響カプラを介して電話網によりデータ通信な行う場
合に、与えられた◆件下で、技術者の熟練や、その操作
に依存することなく、容易に、最高の伝送速度、最短の
伝送所要時間が得られるデータ伝送速度自動制御機構な
提供ｊることにある。The object of the present invention is to provide data communication using public access lines, especially when data communication is performed over a telephone network via an acoustic coupler. The object of the present invention is to provide an automatic data transmission rate control mechanism that can easily obtain the highest transmission rate and the shortest transmission time without having to do so.
データ通信な行う２地点双方に熟練操作者がついていて
、伝送状ｌＩ【監視しながら伝送速度の切換【行ない、
しかも両端の操作者の呼吸がぴったり合って両者が奇跡
的に同様な速度切換を行ない、比較的良好な結果が得ら
れた場合が従来皆無ではなかったにしても、一般には期
待できない。また両端に操作者がついていて、伝送状−
不良の場合、別の、又は音響カブ５を介して利用中の、
電話回線を用いて連絡Ｖ取って伝送速度な切換える場合
は、上記の場合のように操作者の熟練は必要ではないが
、相当な手数と、かなりの時間を要し、しか−２人の操
作者が送受端に貼り付けとなる。A skilled operator is present at both the two points where data communication is to be carried out, and the transmission speed can be switched while monitoring.
Moreover, although there have been cases in the past where the breathing of the operators at both ends matched perfectly and both miraculously performed the same speed change and relatively good results were obtained, it is generally not expected. There is also an operator on both ends, and a transmission form.
If it is defective, another one or the one currently being used via the acoustic cube 5,
Switching the transmission speed by making contact using a telephone line does not require the operator's skill as in the above case, but it does require a considerable amount of effort and time, and requires only two people to operate. The person will paste it on the sending and receiving end.
かかる従来の間、ＩＮな解消するために本発明において
は、受信側から送信側へ送り返して来ることになりてい
る確ｇａ号が送信側へ届かず、これに対応して送僅鉤が
行なった複数回の再送出にも確実な応答が得られない場
合には、送信側が伝送速度を例えば当初の所定値１，２
０Ｑｂｐｓ から６００ｂｐｓ へ低下させ、他方受
信ＩＩ Ｋ ｋ！、１，２００ｂｐｉ に対する同期
検出装置の他に６００ｂｐｓ等の低伝送速度に対する同
期検出装置【備えておいて、６００ ｂｐａ で同期
した場合には受信１１回路ｔ’６００ｂｐｓ 受入れ
に適合させると共に、送信側へ確認信号な送る。この信
号を受電った送信側は６００ｂｐｓ で伝送を続行す
る。送信側で。In order to solve this problem in the past, in the present invention, the confirmation signal that was supposed to be sent back from the receiving side to the sending side did not reach the sending side, and in response to this, a sender's message was not sent. If a reliable response is not obtained even after multiple retransmissions, the transmitting side may change the transmission rate to the initial predetermined value of 1 or 2, for example.
0Qbps to 600bps, while receiving II K k! In addition to the synchronization detection device for 1,200 bpi, there is also a synchronization detection device for low transmission speeds such as 600 bps [If synchronization is performed at 600 bpa, the receiving 11 circuits are adapted to accept t'600 bps, and the transmitting side Send a confirmation signal. The transmitting side receives this signal and continues transmission at 600 bps. on the sending side.
６００ ｂｐｓ に伝送速度【低下させても、なお受
信側から確認信号が送られて来す再送出を繰返えしても
応答が得られない場合は、送信側では伝送速度【、更に
、例えば４００，３００，２００ｂｐｓ と、受信側
から！認信号が得られるようになるまで、低下させて行
く。受信側には上記１，２００゜６００ ｂｐｓ に
対する同期検出装置の他に、４００゜３００．２００ｂ
ｐｌ に対する同期検出装置を備えておいて、同期が
検出された伝送速度の信号受入れに回路状態が適合する
ように設定すると同時に１送信側へ確ＩＩ（！号【送り
返丸す。なお、同期ｔとるために送信側では例えば１ブ
ロツク送出ごとに特殊な同期用ドウ）１會む符号な挿入
するが、伝送速度が高すぎたり回線状態が悪いと、波形
ひずみ、雑音１回路の瞬断等により、受信側で同期がと
れず、誤り率も高くなる。伝送速度を下げれば前記の如
き不工合原因の影響は低下する。上記した送信側、受信
ｌｌＫおける伝送速度切換え、低下 ′に関連する諸操
作は、各伝送速度に対する送信設備、受信設備等のハー
ドウェアを整備し、その制御ｔマイクロプロセサ（ＭＰ
Ｕ）と、所定の操作子＊Ｖ記憶させたＲＯＭとの組合せ
に行なわせれば、全く自動的に、比較的高速で遂行され
る。低下した伝送速度のままデータ伝送な続行すると、
データ伝送量が多い場合には伝送所要時間が着しく延伸
し、一方、回線状態が比較的短時間に良好に回復する場
合もある。もし回線状態が高速な伝送速度に耐えるよう
に回復しているならば、なるべく早く伝送速度【元通り
に引上げるべきであろっ關線律態の回復な検出する適確
、筒塔な手段は存在しないので、本発明者の実験によれ
ば、低下さぜた伝送適度において確実に安定した伝送状
態が所定時間たとえば５分間継続したならば、低下前の
高速伝送速度に戻して送信を試みるのが、性能価格比的
に最も與際的である。もしまだ高速伝送に耐えなければ
、前記の如く全自動で比較的短時間内に伝送速度が低下
されＣｉ足な伝送に移行する。Even if the transmission speed is lowered to 600 bps, the receiving side still sends a confirmation signal.If no response is obtained even after repeated retransmissions, the transmitting side lowers the transmission speed [, and further increases the transmission speed, e.g. 400, 300, 200bps from the receiving side! Continue to lower the level until a positive signal can be obtained. On the receiving side, in addition to the synchronization detection device for 1,200°600 bps, there is also a 400°300.200 bps
A synchronization detection device for pl is provided, and the circuit state is set so that it is suitable for receiving a signal at the transmission speed at which synchronization is detected. At the same time, the synchronization To achieve this, the transmitting side inserts a special synchronizing code (for example, a special synchronizing code) every time one block is sent out, but if the transmission speed is too high or the line condition is poor, waveform distortion, noise, momentary interruption of one circuit, etc. As a result, synchronization cannot be achieved on the receiving side and the error rate increases. If the transmission speed is lowered, the influence of the above-mentioned causes of failure will be reduced. The operations related to the above-mentioned transmission speed switching and reduction on the transmitting side and receiving side are performed by preparing hardware such as transmitting equipment and receiving equipment for each transmission speed, and by controlling the microprocessor (MP).
U) in combination with a ROM in which predetermined operators *V are stored, the operation can be performed completely automatically and at relatively high speed. If data transmission continues at the reduced transmission speed,
When the amount of data to be transmitted is large, the time required for transmission is considerably extended, while in some cases the line condition can be restored to good condition in a relatively short period of time. If the line condition has recovered to the point where it can withstand high transmission speeds, the transmission speed should be raised to its original level as soon as possible. Therefore, according to the inventor's experiments, if a stable transmission state continues for a predetermined period of time, for example, 5 minutes with moderate transmission, it is possible to return to the high-speed transmission speed before the drop and attempt transmission. is the most flexible in terms of performance and price. If it still cannot withstand high-speed transmission, the transmission speed is fully automatically reduced within a relatively short period of time as described above, and the transition is made to Ci sufficient transmission.
ｊｌ１図は、本発明な音響カプラと組合せた実施例な示
し、１は送１側の伝送速度自動制御機構、１ａはＭＰＵ
、ｌｂはＲＯＭ、ＩＣは送信用ノー−ドウエア、２は受
（Ｉｌｌの伝送速度自動制御機構、２１はＭＰＵ、２ｂ
はＲＯＭ、２Ｃは受信用ハードウェア、３は音響カプラ
、４は電話機、５は公衆通信回線である。送信側伝送速
度自動制御機構ｌは、既述のｍ＜、％ＰＵ１ａと制御中
ｌ［を記憶させたＲＯＭ１ｂとにより、ハードウェアｌ
ｃｔ制御して、入力したデータＤＴなまずｌ、２００ｂ
ｐｓ でカプラ３．電話機４【介して回９５に送出す
る。回線５の状態が良ければ、波形ひずみなどによる同
期乱れが生ぜず、受信側ハードウェア２Ｃの−Ｓをなす
１，２００ ｂｐｓ に対する同期検出装置が動作し
て受信側回路を１，２００ｂｐｌ 伝送（′！！号受
入れに適合させ、同時罠１，２００ｂｐａに対する確ｆ
ｉ（１号を送信側へ送出し、この信号な受取った送信側
制御機構１はそのまま１．２００ｂｐｓ で送信１続
ける。しかし回！ＩＩ５の状態が悪い時は、受信側制御
機構２の中の１，２００ｂｐｓＫ対する同期検出装置が
同期を検出できず、送信側へ確認信号を送らないから、
送信側では７回再送出會繰返えしても同期がとれないこ
とｔ確認したのち伝送速度Ｖ６００ｂｐａ に下げる
。回線の状態が１，２００ｂｐｓ Ｋ対しては同期が
とれなくても、６００ ｂｐｓ では受信側の６００
ｂｐｓ に対する同期検出装置が同期な検出できる
状態の場合は、この検出装置の動作により、受信１１回
路は６００ ｂｐｓ 受入れに適合され、同時に送信
側へ確−信号を送る。この信号を受取った送信側は６０
０ ｂｐ島 で伝送【続ける。６００ ｂｐｓ でも
回線状−が悪くて受信側でまだ同期がとれない時は、上
記と同様な手ＩＮＫより送信側は支圧伝送速度【低下さ
（、受信側から確認信号が送られて来るのｔ待つ。以上
説明した所では、本発明による伝送速度自動制御機構は
、送信側と受信側とでは、その機能が異なる。しかし、
送受両機ｉｌ＠ｖ併有するように構成しても、今日の技
術では余り大形に４ならず高ｉｉにもならないから、送
受いずれにも用〜・られるよ５にするのが好ましく、そ
うすれば実用上は極めて便利である。Figure jl1 shows an embodiment in which the acoustic coupler of the present invention is combined, 1 is the automatic transmission speed control mechanism on the sending side, 1a is the MPU
, lb is the ROM, IC is the transmitting nodeware, 2 is the receiver (Ill's transmission speed automatic control mechanism, 21 is the MPU, 2b is the
is a ROM, 2C is receiving hardware, 3 is an acoustic coupler, 4 is a telephone, and 5 is a public communication line. The transmitting side transmission speed automatic control mechanism l is configured by the hardware l by the already mentioned m<, %PU1a and the ROM1b storing the controlling l[
ct control, input data DT catfish l, 200b
Coupler 3 with ps. Telephone number 4 is sent to call 95. If the condition of the line 5 is good, there will be no synchronization disturbance due to waveform distortion, etc., and the synchronization detection device for 1,200 bps, which forms -S of the receiving hardware 2C, will operate and the receiving circuit will transmit 1,200 bpl (' !!Suitable for acceptance of 1,200 bpa simultaneous traps
i(1) to the transmitting side, and the transmitting side control mechanism 1 that received this signal continues transmitting at 1.200 bps.However, when the condition of !II5 is bad, the receiving side control mechanism 2 Because the synchronization detection device for 1,200bpsK cannot detect synchronization and does not send a confirmation signal to the sending side,
On the transmitting side, after confirming that synchronization cannot be achieved even after repeated retransmissions seven times, the transmission speed is lowered to V600 bpa. Even if the line state is not synchronized for 1,200 bps K, at 600 bps, the receiving side's 600
If the synchronization detecting device for bps is in a state where it can detect synchronization, the operation of this detecting device adapts the receiver 11 circuit to accept 600 bps, and at the same time sends a confirmation signal to the transmitting side. The sending side that received this signal is 60
Transmission on 0 bp island [Continue. 600 bps, but if synchronization is still not achieved on the receiving side due to poor line conditions, the transmitting side uses the same method as above to reduce the transmission speed (the confirmation signal is sent from the receiving side). As explained above, the automatic transmission rate control mechanism according to the present invention has different functions on the transmitting side and the receiving side.However,
Even if it is configured to have both transmitting and receiving devices, it is not too large or high II with today's technology, so it is preferable to make it 5 so that it can be used for both transmitting and receiving. This is extremely convenient in practice.
次に第２図は、伝送−に直結した本発明実施例【示し、
６は変復調装置（モデム）、７は綱制御装置（ＮＣＬＩ
）でその他の符号は第１＃Ａの場合と同様である。第
１図に示した実施例ではモデム６０機能は音響カブラに
より、ＮＣＵ７の機能は人間が電話機のダイアルやボタ
ンな操作することによって行なわれている。Next, FIG. 2 shows an embodiment of the present invention directly connected to transmission.
6 is a modem, 7 is a line control device (NCLI)
) and the other symbols are the same as in the case of #1 #A. In the embodiment shown in FIG. 1, the function of the modem 60 is performed by an acoustic coupler, and the function of the NCU 7 is performed by a person operating dials and buttons of a telephone set.
一燗は音響カプラ利用形として他端な直結形にしてもよ
い。例えばコンビ、−夕の保守技＊ｔが出先からデータ
【送る場合には音響カプラ【用い、保守センタ儒では直
結でもよい。One end of the bottle may be a direct connection type using an acoustic coupler. For example, if a combination is used to send data from a location, an acoustic coupler may be used, and direct connection may be used at the maintenance center.
以上説明したように本発明によれば、公衆通信回線を利
用したデータ通信な、途中で人間が介入する必要なく、
自動的に、回線の状態が許す範囲内の液高伝送速度に近
い速度で行うことかできる。As explained above, according to the present invention, there is no need for human intervention during data communication using public communication lines.
This can be done automatically at a speed close to the liquid high transmission speed within the range permitted by the line conditions.
第１図は音響カブラな併用した本発明の一実施例図、第
２図は公衆通信回線に直Ｗ！優絖した実施例を示す図で
ある。
１・・・送信貴自動制＃機構、Ｉｍ・・・ＭＰＵ、１ｂ
・・・ＲＯＭ、ｌｃ・・・送信側ノ＼−ドウエア、２・
・・受信側自動制御機構、２ａ−ＭＰＵ、２２ｂ−０Ｒ
Ｏ，２Ｃ・・・受信側ハードウェア、３・・・音響カブ
ラ、５・・・公衆通信回線、６・・・モデム、７・・・
ＮＣｔＪ。
代理人 弁理士 縣 ′ＲＪ１！第 １ 図
／
第 ２ 図
グ
ー）ＴFig. 1 shows an embodiment of the present invention which is used in combination with an acoustic cover, and Fig. 2 shows a direct connection to a public communication line. FIG. 3 is a diagram showing an elegant embodiment. 1... Transmission automatic control # mechanism, Im... MPU, 1b
...ROM, lc...Sending side hardware, 2.
・Reception side automatic control mechanism, 2a-MPU, 22b-0R
O, 2C...Receiving side hardware, 3...Acoustic converter, 5...Public communication line, 6...Modem, 7...
NCtJ. Agent Patent Attorney Agata 'RJ1! Figure 1/Figure 2) T
Claims (1)
行う場合に、尚初比較的高速な所定伝送速度で伝送を開
始し、回線障害が検出されない限り該適度で伝送を継続
し、回線障害が検出されたときは所定手順に従い自動的
に順次段階的に切換えて、回線障害が検出されなくなる
まで伝送速度【低下させ、また、この低下した伝送速度
で安定な伝送状態が所定時間継続して認められたときは
、低下させる以前の速度に、伝送速度な自動的に切換え
るようＫしたことをｑ＆像とするデータ伝送速度自動制
御機構。 （２）音響カプラと組合せて伝送速度の自動制御を行う
よ５にした％ｔｆ請求の範！！第１項記載のデータ伝送
速度自＃１１１１１１構。[Claims] 111 When performing data communication between two points using a public communication line, transmission is initially started at a relatively high predetermined transmission speed, and unless a line failure is detected, transmission is continued at the specified speed. If a line failure is detected, the transmission rate is automatically reduced in stages according to a predetermined procedure until the line failure is no longer detected, and a stable transmission condition is maintained at this reduced transmission rate. An automatic data transmission speed control mechanism that automatically switches the transmission speed to the previous speed when it is recognized for a predetermined period of time. (2) %tf claim set to 5 to automatically control transmission speed in combination with an acoustic coupler! ! The data transmission speed described in item 1 is #111111.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57060949A JPS58178650A (en) | 1982-04-14 | 1982-04-14 | Automatic controlling mechanism of data transmitting speed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57060949A JPS58178650A (en) | 1982-04-14 | 1982-04-14 | Automatic controlling mechanism of data transmitting speed |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58178650A true JPS58178650A (en) | 1983-10-19 |
Family
ID=13157148
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57060949A Pending JPS58178650A (en) | 1982-04-14 | 1982-04-14 | Automatic controlling mechanism of data transmitting speed |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58178650A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60186149A (en) * | 1984-03-05 | 1985-09-21 | Fujitsu General Ltd | Data communication system with variable transmission speed |
| JPS60197039A (en) * | 1984-03-19 | 1985-10-05 | Japanese National Railways<Jnr> | Multiplexing line concentrating system |
| JPS60197037A (en) * | 1984-03-19 | 1985-10-05 | Japanese National Railways<Jnr> | Multiplexing line concentrating system |
| JPS60254942A (en) * | 1984-05-31 | 1985-12-16 | Fujitsu General Ltd | Data communication method with variable transmission speed |
| JPS60254941A (en) * | 1984-05-31 | 1985-12-16 | Fujitsu General Ltd | Data communication method with variable transmission speed |
| JPS611130A (en) * | 1984-03-08 | 1986-01-07 | コ−デツクス・コ−ポレ−シヨン | Adaptive communication rate demod |
| JPS6121147U (en) * | 1984-07-10 | 1986-02-07 | 三洋電機株式会社 | data transmission equipment |
| JPS6387048A (en) * | 1986-09-18 | 1988-04-18 | ラカル データー コミュニケーションズ インコーポレーテッド | High speed modem |
| JPH08223624A (en) * | 1995-02-15 | 1996-08-30 | Nec Corp | Radio selective call receiver and radio data transmitting system |
| JP2008151596A (en) * | 2006-12-15 | 2008-07-03 | Tanita Corp | Load cell and mass meter |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49131610A (en) * | 1973-04-22 | 1974-12-17 | ||
| JPS5154710A (en) * | 1974-11-08 | 1976-05-14 | Ricoh Kk | DEETADENSO HOSHIKI |
| JPS5724142A (en) * | 1980-07-21 | 1982-02-08 | Mitsubishi Electric Corp | Communication speed changeover method in facsimile communication |
-
1982
- 1982-04-14 JP JP57060949A patent/JPS58178650A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49131610A (en) * | 1973-04-22 | 1974-12-17 | ||
| JPS5154710A (en) * | 1974-11-08 | 1976-05-14 | Ricoh Kk | DEETADENSO HOSHIKI |
| JPS5724142A (en) * | 1980-07-21 | 1982-02-08 | Mitsubishi Electric Corp | Communication speed changeover method in facsimile communication |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60186149A (en) * | 1984-03-05 | 1985-09-21 | Fujitsu General Ltd | Data communication system with variable transmission speed |
| JPS611130A (en) * | 1984-03-08 | 1986-01-07 | コ−デツクス・コ−ポレ−シヨン | Adaptive communication rate demod |
| JPH0535613B2 (en) * | 1984-03-19 | 1993-05-27 | Tetsudo Sogo Gijutsu Kenkyusho | |
| JPS60197039A (en) * | 1984-03-19 | 1985-10-05 | Japanese National Railways<Jnr> | Multiplexing line concentrating system |
| JPS60197037A (en) * | 1984-03-19 | 1985-10-05 | Japanese National Railways<Jnr> | Multiplexing line concentrating system |
| JPH0535614B2 (en) * | 1984-03-19 | 1993-05-27 | Tetsudo Sogo Gijutsu Kenkyusho | |
| JPS60254942A (en) * | 1984-05-31 | 1985-12-16 | Fujitsu General Ltd | Data communication method with variable transmission speed |
| JPS60254941A (en) * | 1984-05-31 | 1985-12-16 | Fujitsu General Ltd | Data communication method with variable transmission speed |
| JPS6121147U (en) * | 1984-07-10 | 1986-02-07 | 三洋電機株式会社 | data transmission equipment |
| JPS6387048A (en) * | 1986-09-18 | 1988-04-18 | ラカル データー コミュニケーションズ インコーポレーテッド | High speed modem |
| JPH08223624A (en) * | 1995-02-15 | 1996-08-30 | Nec Corp | Radio selective call receiver and radio data transmitting system |
| US5835508A (en) * | 1995-02-15 | 1998-11-10 | Nec Corporation | Network for transmitting information data without error correction when a transmission channel quality is good, or with redundancy bits of a predetermined length added to each datum when the channel quality is poor |
| JP2008151596A (en) * | 2006-12-15 | 2008-07-03 | Tanita Corp | Load cell and mass meter |
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