CN1119009C - 安全接入电话分机系统 - Google Patents
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B3/00—Line transmission systems
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- H—ELECTRICITY
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M9/00—Arrangements for interconnection not involving centralised switching
- H04M9/02—Arrangements for interconnection not involving centralised switching involving a common line for all parties
- H04M9/022—Multiplex systems
- H04M9/027—Frequency division multiplex systems
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5404—Methods of transmitting or receiving signals via power distribution lines
- H04B2203/5408—Methods of transmitting or receiving signals via power distribution lines using protocols
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- H—ELECTRICITY
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- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5429—Applications for powerline communications
- H04B2203/5437—Wired telephone
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B2203/00—Indexing scheme relating to line transmission systems
- H04B2203/54—Aspects of powerline communications not already covered by H04B3/54 and its subgroups
- H04B2203/5429—Applications for powerline communications
- H04B2203/5441—Wireless systems or telephone
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04M2203/60—Aspects of automatic or semi-automatic exchanges related to security aspects in telephonic communication systems
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Abstract
本发明提供一种在建筑物的供电线上进行全双工安全接入供电线载波通信的装置和方法。其中使用系统控制逻辑(A)实现多分机仲裁逻辑;(B)进行加密防止窃听;(C)提供安全性,防止第三方通过主机(2)和分机(4)单元内的数字信号系统截用局线,其方法是各主机和分机在各指令系统改变工作状态的信息中使用唯一的密钥作前置码,随机密码的匹配由用户发起。可防止同一建筑物内其他用户的窃听和盗线。
Description
技术领域
本发明涉及供电线载波电话分机系统领域。尤其是,本发明涉及线路载波电话分机系统的保密系统控制规约,它提供多种分机仲载逻辑、加密、保安和其它电话信令,这种技术被称为安全接入(SA)。
背景技术
人们已经多次尝试过用建筑物的供电线来进行电话通信,并取得不同程度的成功。线路载波电话分机系统使用1)每条局线的一个主机单元(用作线路载波信号与电话局用户线的接口1和2)一个或多个分机单元,每部分机电话机一个单元(用作所述线路载波信号与所述分机电话机的接口)。全双工通信通常使用两种频率,每个方向用一种频率。通常,包括在各个主机和分站内的发射机和接收机当通信进行时间时工作。考虑到经济的原因,常用音频(语言)信号对载波进行FM调制,其例子为美国专利No.3,949,172和4,701,945。线路载波通信系统的实际使用范围通常被限制在供电线变压器次级线圈性能范围内,并遭受随载波频率和负载条件产生的严重噪声和衰减变化。
虽然通过增加发射机功率电平或提高接收机灵敏度可以多少解决一些噪声和衰减问题,但增加邻近相似系统干扰的可能性,加剧现有线路载波系统所存在的保密和安全性方面的困难。因此,当在同一配电系统内或在有相同线路载波设备的同一寓所内的其他用户可以通过另一用户的线路上进行长途通话并窃听他人通话时,保密性或安全性遭到破坏。但是驾车的人不能扫描和窃听线路载波信号,尽管他可以进行无绳电话RF传输。这些问题的影响已表现在与线路载波业所受限制有些相同的无绳电话业中。无绳电话业中,已用保密编码规约提供了防止第三方从线路捕获信号的保密性能。但是有扫描器或无绳电话接收机的人可以窃听相邻的无绳通话。另外,也没有为使用同一主机的多无绳电话分机提供保密。同样,在线路载波系统中,也不允许一个以上的系统使用同一建筑内的同一供电线。
本发明的主题有些涉及本发明人的前一申请(1991年10月7日申请,顺序号为07/773,009,名称为“多址联接电话分机系统和方法”)。前一申请主要涉及诸如频分多址联接(FDMA)和码分多址联接(CDMA或扩展频谱)之类射频(RF)传输技术的组合。该申请涉及对电话信令、射频和音频传输进行解锁的音频和子音频频率系统控制逻辑钥,从而进行诸如捕获局线、对分机振铃和进行主机单元和分机单元之间的全双二通话等。使用带有密钥的系统控制逻辑信息允许多方非同时使用带有防窃听加密和安全措施的同一配电系统。该系统控制逻辑还防止其他用户打断和终止正在进行的通话。还提供了其它的多分机仲裁逻辑功能,允许一分机保持呼叫并把该呼叫转接到另一分机单元上。使用FDMA,并结合保密/控制钥,可以提供低成本的真正的多址联接和保密性能。
安全接入线路载波电话分机技术的商业应用包括付费节目(PPV)系统的计算机调制解调器接口和全泵(gas pump)/保密局系统,而这些系统难以把电话和双绞线对改成现存的结构。
由于居住在共用供电线的寓所和公寓套间内的人数增加,也因为为克服衰减和噪声问题需要增加发射功率和接收机灵敏度,所以电话分机系统使用独特和巧妙的方法进行加密和安全编码,进行可接受的工作是相当重要的。
发明内容
通过合适地利用本发明使用的安全接入技术,可以克服许多现有技术的限制。安全接入技术(SA)包括使用以音频FSK速率工作的在主机单元控制器和分机单元控制器之间交换信息的数字数据传输信道,该信息由同步字节、唯一的密钥和系统控制钥组成。SA技术需要在音频、RF和系统控制路径上加设硬件“锁”,使它仅在控制到合适的控制钥后才能被连接上(“打开”)。报文可以进行曼彻斯特(Manchester)编码,以去除调制和解调时在信息上的纯直流分量。诸如曼彻斯特编码等数据传输技术在Howanl W.Sams公司1972年第五次编辑的ITT的“无线电工程师参考资料“一文中有描述,把它作为本申请的一部分,供参考。
信息的第一部分的同步字节(8位)顾及接收控制器确定信息是否正在发送,以及跟在密钥后的数字1和0在一起时隙内是否有效。因此,同步字节非常快地对接收控制器内的数字锁相环初始化,使异步通信变得方便。通信相对于振铃命令、脉冲拨号和摘机/闪断信号相当快地初始化是重要的,以使线路截波分机系统对于大多数用户业务来说是透明的。另一方面,把数据速率提高得太高将使数据对由于处理增益损失而产生的噪声和干扰敏感。实际的数据速率为约1-4kBs。
密钥跟在同步字节后,其实际长度是任意的,例如,为16位(2个字节),提供65,536种代码。接收到有效的密码,使跟在后面的控制钥有效。密码可以由控制器随机选择,或者由用户可及的开关手动选择。有一密码匹配程序使主机和分机单元共用相同的密码,因此,能彼此接收控制钥。
控制钥跟在密钥后,它可以根据系统控制逻辑要求的复杂性为1或2个字节。例如,如果第一个字节为“脉冲”命令,则脉冲命令需要2个字节,第二字节规定了脉冲的持续期间,从而区别脉冲拨号的脉冲和呼叫等待等所用的“闪断”脉冲。因此,接照控制钥对透明操作的要求,主机或分机控制器对电话控制信号进行再同步。
为了满足系统对安全接入的要求,当接收到合适的密钥和控制钥时,所有主要的电话信号和系统控制器操作的控制路径内必须提供硬件锁(数字控制的模拟开关)。
由于现有的线路载波电话分机系统没有结合安全接入技术中主要的原理,所以它们不能以合格的商用方式工作。
因此,本发明的一个目的是提供一种有效的安全接入(SA)通信方法,它提供在单个通信媒介上接入多个信号。
本发明的进一步目的是提供一种线路载波电话通信的方法和系统,它使用SA(安全接入)提供高的保密性,防止未经授权接入用户线,它还对第三方进行通话加密,并在电话分机和局线之间提供几乎透明的互连。
又一个目的是提供一种多分机仲裁逻辑的方法和系统,以为同一条用户线提供多台分机而互不干扰。
另一个目的是提供一种线路载波通信方法和系统,它使用FDMA(频分多址联接),并结合SA(安全接入),以防止较近的相邻传输系统之间或者同一系统中相伴传输之间的干扰影响,并为至少两条电话线提供多址联接双工信号(同时传输)。
再一个目的是提供一种安全接入无绳电话通信方法和系统,它利用与线路载波电话分机系统和方法相同的安全接入技术获得相同的优点。
在阅读了下面结合附图的描述后本发明和方法的这些和其它目的和优点将更清楚。
附图概述
图1是使用单条用户线和多个分机组的线路载波电话分机系统的方框图。
图2是使用在具有同一交流配电系统的寓所内的多条用户线和电话分机的线路载波电话分机系统的方框图。
图3是主机单元系统控制器的状态图。
图4是分机单元系统控制器的状态图。
图5是安全接入线路载波电话分机系统的主机单元的电气方框图,它是用户线与建筑的AC配电系统的接口。
图6是安全接入线路载波电话分机系统的分机单元的电气方框图,它是电话分机与建筑物的供电线分配系统的接口。
本发明的最佳实施例
首先,参见图1所示的线路载波电话分机系统,它使用一条用户线1和多部电话分机6和9。用户线1插入主机单元2,主机单元2为用户线信号(包括振铃、摘机和双工话音)和安全接入供电线载波信号提供接口电路和规约,而该载波信号经交流供电线3通过建筑物载送至分机接口单元4和7。分机单元4和7为单线分机,它提供分别通过软线5和8把安全接入线载波信号接到单线电话机6上的手段。
图1所示的线路载波系统必须以对电话分机用户透明的方式工作。因此,通过主机单元2、交流供电线3和分机单元4,先在主机单元中检测呼入振铃信号,编码成安全接入线路载波信号、通过供电线传输,在分机单元内解码,并转换成分机电话机6的等长振铃信号。当用户取下电话分机的听筒时,进入摘机状态,分机单元4检测到该状态,所述分机单元把它编码成安全接入线路载波信号,并通过供电线3传输给主机单元2,在主机单元2对安全接入线路载波信号解码,由摘机电路捕获用户线。双工话音电路解锁,并连接到该线上,进行双向的声音和/或拨号音和DTMF信号的传输,还有语音调制的线路载波信号,该信号通过供电线3传输,并在主机和分机单元内解码和解调回语音。具体的子系统和对应的功能将参照图5和图6描述。
图1还可以用来图示说明多分机仲裁逻辑。例如,当电话局通过用户线1向主机单元2发送振铃信号时,主机单元2鉴别振铃信号的频率(15至110Hz)和幅度(40Vrms min),并向分机单元4和7发送开始和停止振铃信息,该振铃信息被检出并转换成标准振铃信息,使分机6和7基本上与原电话局振铃信号相同的振铃韵律振铃。假设一用户把电话分机#2(9)摘下,相应的分机单元#A2(7)检测到,该单元向主机单元2发送摘机请求信息。主机单元2进行:1)鉴别密码和摘机信息,2)捕获用户线,3)向两个分机单元发送摘机确认信息。该摘机确认信息仅使分机单元#A2(7)把音频和信令电路连接到其自身7和话机#2(9)之间,允许该用户开始正常的电话通信。如果当话机#2(9)正在使用时,话机#1(6)上的第二用户摘下其听筒,分机单元#A1(4)的系统控制逻辑就向话机#1(6)送忙音,不允许第二用户接入正在进行的通话中,因为在接收到第一摘机确认信息时,系统控制逻辑知道它不能产生摘机请求,并保持拉机。然而,如果当分机#1(6)的第二用户摘机时第一用户在话机#2(9)上挂机,则分机单元#A2(7)向主机单元2发送挂机信息,主机单元2向所有分机单元回送“未确认”(unack)信息(但不是立即挂上)。分机单元#A1(4)一旦接收到该未确认信息,就向主机单元2发送摘机请求,并在从主机接收到确认信息时连接音频信号。主机单元内的逻辑电路在挂机信息后仅在一段足够的时间内不挂断电话局。允许第二分机在接收到主机的未确认信息后请求占线。
多分机仲裁逻辑电路允许用户快速按压其分机话机1或2的叉簧两次来保持通话。相应分机单元4或7内产生信号音来确认保持请求状态。分机单元向主机单元2发送保持信息。据此,主机单元进行:1)使用户线无声,同时仍捕获该用户线,2)向所有分机单元每45秒发送3声短振铃声信息或者这样发送10次,此后,如果用户不接电话,则在挂线之前主机振铃两次并等待至少20秒。在此期间,用户可以摘下包括硬布线电话机在内的任一电话分机,通知保持线路的主机单元,结束保持状态;话机1或2向主机单元发送摘机请求,解锁音频通路;如果摘下硬布线电话机,则主机单元测出用户线电压的下降,把捕获的用户线交给该硬布线电话机。在图3和图4中,尤其对系统控制逻辑作了描述。
图2图示出安全接入和多址联接技术的组合应用,在图2中,几所公寓公用一个交流配电系统,并使用多条用户电话线和多套线路载波分机。因为所有“A”单元使用相同的线路载波频率,所以需要安全接入技术在#1公寓线1和#2公寓线15之间提供加密和保安。#1公寓内的用户可以首先按下主机单元#A1(2)上的一个按钮,然后立即在分机单元#A1(4)和#A2(7)上按下相应的按钮,以进行密码匹配。按下按钮使各单元进入学习模式,分机发送在主机单元随机选择密钥的请求,主机送回应答给分机单元。由于#2公寓内的用户不知道#1公寓用户进行的密码匹配,所以其单元A3有不同的编码。这使得A频率单元在非同时的基础上能多方使用交流供电线。主机单元#B(11)和相应的分机单元#B(12)使用不同的多址联接传输频率组,这提供了线路#2(10)对交流供电线媒体的真正同时使用。线路2可以用于调制解调器、传真、付费电视业务或其它电话装置。
除了开机过程之外,图3和图4提供了上面结合图1和图2揭示的系统控制规约的逻辑状态图。如果在“开机”复位期间,单元检测非易失存储器的有效密码,发现没有,那么它提供缺省密码;否则使用存储器内的密码。由于单元上没有通/断开关,所以当交流电源接通时,单元就开机。当发生断电或拨下单元时,则把当前使用的密码存入非易失性存储器,所以电源恢复后仍保持原来的密码。在这种应用中可以使用任何牌号的商用低价微控制器,例如Motorola 6805系列或Ziloy Z8系列。在附录A中提供了本发明的一个实施例所用的这种应用的工作商用编码表,将该表援引在此以作参考。也可以使用其他编码,且这些编码仍归入本发明的范围内。
图5是图1和图2系统的安全接入主机单元2的体系原理图的第1页。在附录B中根据体系规则过程作为完整的电气原理图示出了5-2至5-12各方块。把附录B援引在此以作参考。也可以使用实施本发明人的发明的其它电气原理图,它们也归入本发明的范围内。电话线路1连接到COLIC 5-2上,交流供电线3与电源5-12相接。请特别注意带有附随I/O线20至29的微控制器5-10。“unreg”20输入端提供图3和4的开机/关机复位。注意在电源和时钟29稳定之后才升电,以启动控制器。在降电时,要在时钟和电源变得不稳定之前,使控制器停止工作。通过方块5-12,5-7,5-8和5-11接收和鉴别分机4的数据,并通过线路21输入至微控制器5-10,使数据生效,并排序成系统控制指令。其它的硬件输入端包括电话线路1的振铃检测端24和线路1上硬布线话机的摘机状态检测端23。微控制器5-10的逻辑电路对这些输入进行运算,以提供合适的系统控制响应。24上的振铃信号在数据输出端27上产生振铃信息,并通过5-5,5-6,5-12和3传输给分机单元。当分机单元通过21向电话局请求线路时,主机控制器5-10通过控制端口25使线路1摘机,向分机单元回送确认信息,通过控制端口26和28解除收、发静音,分机既可以与呼叫者通话,也可以在听到电话局拨号音时,发送DTMF信息或脉冲拨号信息,以拨出电话号码。通过控制端口22对脉冲拨号信息进行处理,使之与电话局最佳兼容。图5指出的其它音频和RF信号的流程对于本领域的普通人员来说是明了的。
图6是安全接入分机单元4(或7,12或17)的体系原理图。在附录B中根据体系规划过程作为完整的电气原理图示出了6-2至6-12各方块。话机软线5被连接至SLIC6-2上,交流供电线3与电源6-12相接。请注意带有附随I/O线30至39的微控制器6-10。unreg30输入端提供图3和4的开机/关机复位。注意在电源和时钟39稳定后才升电,以启动控制器。降电时,要在时钟和电源变得不稳定之前,使控制器停止工作。通过方块6-12、6-7、6-8和6-11接收和鉴别主机单元2的数据,并通过线路31输入至微控制器6-10,使数据生效,并排序成系统控制指令。另一硬件输入端为电话分机6的摘机状态检测端33。微控制器6-10的逻辑对这些输入进行运算,提供合适的系统控制响应。主机的振铃信息生效并通过端口34发送给SLIC6-2,SLIC,SLIC 6-2使分机话机6振铃。当用户摘下分机时,端口33指示控制器在34关闭高压振铃信号,检查使用中的其它分机的系统状态,如果所有分机都空闲,则通过38打开发射机,通知主机2接入局线1,接收通过31返回的“共同确认”信息,使该信息生效,并通过36使话音通道解除静音。分机单元既可以与呼叫者通话,也可以在听到拨号音后发送DTMF信号式脉冲拨号信息,以拨出电话号码,分机单元还可以通过端口35和slic 6-2内在软线5上产生低线路电压的硬件,对代替话机6连接的话机配套设备表示线路1正为硬布线话机使用。
从上面的讨论不难表明图1-6所示系统有多种变化。一种明显的变化是把此处描述的安全接入技术应用于无绳分机电话系统,其中用RF载波代替供电线路载波,用天线代替供电线接口。
另一种变化是用CVSD(连续可变斜率增量调制)和FSK调制来代替模拟压缩扩展器和FM调制技术。CVSD也可以当作带有压缩扩展的单比特A/D转换器。CVSD要求发射机和接收机有16KB至32KB的FSK速率,这符合一些商用接收机芯片的实际情况。编码技术能为数字数据数据传输提供安全性。
许多接收机芯片还提供FM信号分路性能,为音频和控制信令增加一些手段。例如,安全接入控制信令可以在上边带传输,同时在下边带传输音频信号。这可以提供操作的透明度而在一些信令工作期间不使音频静音。另外用子音频调制技术可以实现分立的数据信道。
在安全接入信息和其同步技术的结构、系统控制指令以及密码结构/长度上可以作一些变化。因为在发射机和接收机之间有锁频,可实现同步数据传输技术,这简化了数据鉴别。
虽然结合一些具体的实施例对本发明作了描述和图示说明,但本技术领域的熟练人员将清楚,不脱离此处图示说明、描述和要求权利的本发明的原理可以作出种种变化和改进。
本发明可以用其它具体的形式实施而不脱离本发明的精神或主要特征。从各方面来说,所述的实施例仅应看作为说明,而不是限制。因此,本发明的范围由所附的权利要求书来指出而不是上述的描述。所有落入权利要求等效含义和范围内的变化均包括在该范围之内。
Claims (3)
1、一种安全接入电话通信系统,在主机单元和分机单元之间发送和接收电话通信,该系统包含:主机单元和分机单元;
(a)所述主机包含:
与通信线相连接的单元;
与所述与通信线相连接的单元连接的混合单元;
从所述混合单元接收信号的压缩器;
从所述压缩器接收单元的发送振荡器;
从所述发射振荡器接收信号,并向所述分机单元发送信号的发送器;
从所述分机单元接收信号的接收器;
从所述接收机接收信号的音频滤波器;
从所述音频滤波器接收信号并向所述与通信线相连接的单元传送信号的扩展器;以及
微处理器,控制所述与通信线相连接的单元、所述混合单元、所述发送振荡器、所述扩展器和所述接收器,并与之通信;
(b)所述分机单元包含:
与通信线相连接的单元;
与所述与通信线相连接的单元连接的混合单元;
从所述混合单元接收信号的压缩器;
从所述压缩器接收单元的发送振荡器;
从所述发射振荡器接收信号,并向所述主机单元发送信号的发送器;
从所述主机单元接收信号的接收器;
从所述接收机接收信号的音频滤波器;
从所述音频滤波器接收信号并向所述与通信线相连接的单元传送信号的扩展器;以及
微处理器,控制所述与通信线相连接的单元、所述混合单元、所述发送振荡器、所述扩展器和所述接收器,并与之通信。
2、如权利要求1所述的安全接入电话通信系统,其特征在于,所述主机单元还包含:
传感器,用于感应所述接收到在所述通信线上的信号;
传输载波发生器,用于产生传输载波;
调制器,用于用所述音频和数据信号对所述传输载波进行调制;
耦合器,将电话线耦合到所述主机单元。
3、如权利要求1所述的安全接入电话通信系统,其特征在于,所述分机单元还包含:
传感器,用于感应所述接收到在所述通信线上的信号;
传输载波发生器,用于产生传输载波;
调制器,用于用所述音频和数据信号对所述传输载波进行调制;
耦合器,将电话线耦合到所述主机单元。
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US08/034,086 | 1993-03-22 |
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CN1124078A CN1124078A (zh) | 1996-06-05 |
CN1119009C true CN1119009C (zh) | 2003-08-20 |
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CN (1) | CN1119009C (zh) |
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1993
- 1993-03-22 US US08/034,086 patent/US5530737A/en not_active Expired - Lifetime
-
1994
- 1994-03-21 AU AU67661/94A patent/AU6766194A/en not_active Abandoned
- 1994-03-21 CA CA002155220A patent/CA2155220C/en not_active Expired - Lifetime
- 1994-03-21 EP EP94915766A patent/EP0691059B1/en not_active Expired - Lifetime
- 1994-03-21 JP JP6521338A patent/JPH08511381A/ja active Pending
- 1994-03-21 DE DE69433861T patent/DE69433861T2/de not_active Expired - Lifetime
- 1994-03-21 BR BR9406019A patent/BR9406019A/pt not_active IP Right Cessation
- 1994-03-21 WO PCT/US1994/003110 patent/WO1994022257A1/en active IP Right Grant
- 1994-03-21 ES ES94915766T patent/ES2227526T3/es not_active Expired - Lifetime
- 1994-03-21 CN CN94192156A patent/CN1119009C/zh not_active Expired - Fee Related
- 1994-03-21 KR KR1019950704062A patent/KR100196492B1/ko not_active IP Right Cessation
- 1994-03-21 AT AT94915766T patent/ATE270017T1/de not_active IP Right Cessation
-
1995
- 1995-11-22 TW TW084112430A patent/TW321811B/zh active
-
1996
- 1996-04-29 US US08/639,508 patent/US5852785A/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
EP0691059A1 (en) | 1996-01-10 |
DE69433861T2 (de) | 2005-07-28 |
EP0691059B1 (en) | 2004-06-23 |
CA2155220A1 (en) | 1994-09-29 |
US5530737A (en) | 1996-06-25 |
AU6766194A (en) | 1994-10-11 |
CN1124078A (zh) | 1996-06-05 |
ATE270017T1 (de) | 2004-07-15 |
ES2227526T3 (es) | 2005-04-01 |
BR9406019A (pt) | 1995-12-19 |
US5852785A (en) | 1998-12-22 |
JPH08511381A (ja) | 1996-11-26 |
KR100196492B1 (ko) | 1999-06-15 |
TW321811B (zh) | 1997-12-01 |
KR960701552A (ko) | 1996-02-24 |
DE69433861D1 (de) | 2004-07-29 |
WO1994022257A1 (en) | 1994-09-29 |
EP0691059A4 (en) | 1999-11-24 |
CA2155220C (en) | 1999-08-17 |
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