電(dian)話(hua)[英語：Telephone，出自希臘(la)語τ?λε（tēle，意(yi)為“遠”）和φων?（phōnē，意(yi)為“聲(sheng)(sheng)音”），舊譯德律風]是一(yi)種可(ke)以傳(chuan)送與接收聲(sheng)(sheng)音的(de)遠程通(tong)(tong)信設備(bei)。早在18世紀(ji)歐(ou)洲(zhou)已有“電(dian)話(hua)”一(yi)詞，用(yong)(yong)來指用(yong)(yong)線串成的(de)話(hua)筒(tong)（以線串起(qi)杯子）。電(dian)話(hua)的(de)出現要歸(gui)功于(yu)亞歷山(shan)大·格拉(la)漢姆·貝爾，早期(qi)電(dian)話(hua)機的(de)原理為：說話(hua)聲(sheng)(sheng)音為空(kong)氣里的(de)復合振動，可(ke)傳(chuan)輸到固體上，通(tong)(tong)過電(dian)脈(mo)沖于(yu)導電(dian)金屬(shu)上傳(chuan)遞(di)。貝爾于(yu)1876年3月申請了(le)電(dian)話(hua)的(de)專利權。
美國國會2002年6月15日(ri)269號決議確認安東尼奧·穆(mu)齊為電話的(de)發(fa)明人(ren)。穆(mu)齊于1860年首次向公眾展示了他的(de)發(fa)明，并(bing)在紐約的(de)意大利語報紙上發(fa)表了關(guan)于這項(xiang)發(fa)明的(de)介(jie)紹(shao)。
歷(li)史上對(dui)電(dian)(dian)(dian)(dian)話(hua)的(de)改進和發(fa)明(ming)包括(kuo)：碳粉話(hua)筒、人工交(jiao)換(huan)板、撥號盤、自動電(dian)(dian)(dian)(dian)話(hua)交(jiao)換(huan)機、程控(kong)電(dian)(dian)(dian)(dian)話(hua)交(jiao)換(huan)機、雙音(yin)多頻(pin)撥號、語音(yin)數(shu)字采樣等。近年來的(de)新技術包括(kuo)：ISDN、DSL、網(wang)絡(luo)電(dian)(dian)(dian)(dian)話(hua)、模擬移(yi)動電(dian)(dian)(dian)(dian)話(hua)和數(shu)字移(yi)動電(dian)(dian)(dian)(dian)話(hua)等。
這一行業通常(chang)分(fen)(fen)為電(dian)話設備制造(zao)商(shang)和電(dian)話網(wang)(wang)絡(luo)(luo)運(yun)(yun)營(ying)商(shang)。在(zai)(zai)歷史上，網(wang)(wang)絡(luo)(luo)運(yun)(yun)營(ying)商(shang)通常(chang)都擁(yong)(yong)有(you)全(quan)國(guo)(guo)性的(de)(de)(de)壟(long)斷。近年來，隨著全(quan)球電(dian)信市場的(de)(de)(de)開放和集成(cheng)(cheng)以及(ji)技術的(de)(de)(de)發展，逐(zhu)漸出現多(duo)(duo)家運(yun)(yun)營(ying)商(shang)在(zai)(zai)同(tong)一市場競爭的(de)(de)(de)局(ju)面。例如(ru)，貝爾系統，即AT&T的(de)(de)(de)下屬公(gong)司曾(ceng)擁(yong)(yong)有(you)美(mei)國(guo)(guo)電(dian)話市場的(de)(de)(de)80%。1984年，由于美(mei)國(guo)(guo)司法部反壟(long)斷訴訟，貝爾系統被迫分(fen)(fen)區成(cheng)(cheng)多(duo)(duo)個獨立的(de)(de)(de)地方貝爾公(gong)司。有(you)一個說(shuo)法可以說(shuo)明這個現象：在(zai)(zai)AT&T未分(fen)(fen)區前，IBM是美(mei)國(guo)(guo)第二大公(gong)司。在(zai)(zai)AT&T分(fen)(fen)區成(cheng)(cheng)七(qi)個公(gong)司后，IBM的(de)(de)(de)排名(ming)變成(cheng)(cheng)第八(ba)名(ming)。
電話(hua)機(ji)是通(tong)過電信(xin)號雙(shuang)向傳輸話(hua)音的終(zhong)端(duan)設備。
歷史上對電(dian)(dian)(dian)話機的改進和(he)發(fa)明包(bao)括(kuo)：碳粉話筒(tong)、電(dian)(dian)(dian)話人工交換板、撥(bo)(bo)號盤、自動電(dian)(dian)(dian)話交換機、程控電(dian)(dian)(dian)話交換機、雙音多(duo)頻撥(bo)(bo)號、語(yu)音數(shu)字(zi)采樣等。新技術包(bao)括(kuo)：ISDN、DSL、模(mo)擬(ni)移動電(dian)(dian)(dian)話和(he)數(shu)字(zi)移動電(dian)(dian)(dian)話機等。
電(dian)話電(dian)源線、電(dian)話線、收(shou)(shou)線開(kai)關(guan)、受話器(qi)(qi)、增音按(an)鈕、送話器(qi)(qi)、本機號碼(ma)(ma)片(pian)、鈴(ling)聲及(ji)免提喇叭、記(ji)(ji)憶代碼(ma)(ma)鍵(jian)(jian)、記(ji)(ji)憶號碼(ma)(ma)片(pian)、數(shu)字按(an)鍵(jian)(jian)、記(ji)(ji)憶取出(chu)鍵(jian)(jian)、記(ji)(ji)憶儲存鍵(jian)(jian)、重撥(bo)鍵(jian)(jian)、工(gong)作指(zhi)示(shi)燈、免提鍵(jian)(jian)、R鍵(jian)(jian)、免提送話器(qi)(qi)、鈴(ling)聲調節開(kai)關(guan)、P/T開(kai)關(guan)、免提接收(shou)(shou)音量(liang)調節旋(xuan)鈕。
電(dian)話通信(xin)(xin)是(shi)通過聲能與電(dian)能相互(hu)轉換、并利用“電(dian)”這(zhe)個(ge)(ge)媒(mei)介來傳輸(shu)語言的一種通信(xin)(xin)技術(shu)。兩個(ge)(ge)用戶(hu)要(yao)進行通信(xin)(xin)，最簡單的形(xing)式就是(shi)將兩部電(dian)話機用一對(dui)線(xian)路連接(jie)起(qi)來。
當發話者拿起電(dian)話機對著送話器講話時，聲帶的振動激勵空氣振動，形成聲波。
聲波(bo)作用(yong)于送話(hua)器上，使之產(chan)生電流，稱為(wei)話(hua)音電流。
話音電流沿著線路(lu)傳(chuan)送到對方電話機的受話器內(nei)。
而受(shou)話器作用與送話器剛好相反——把(ba)電(dian)流轉化為聲波，通(tong)過空氣傳至人的耳(er)朵中。
這樣，就完(wan)成(cheng)了最簡單的通話過(guo)程(cheng)。
電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)是美國人A.G.貝爾于(yu)1876年(nian)發(fa)明的。他(ta)用兩(liang)根導(dao)線連接(jie)兩(liang)個結構(gou)完全(quan)相(xiang)同、在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)磁鐵上(shang)裝有(you)振(zhen)動膜片的送話(hua)(hua)(hua)(hua)器(qi)和受話(hua)(hua)(hua)(hua)器(qi)，首先實(shi)現(xian)兩(liang)端通(tong)話(hua)(hua)(hua)(hua)。但通(tong)話(hua)(hua)(hua)(hua)距離短、效(xiao)率低(di)。1878年(nian)出(chu)(chu)(chu)(chu)現(xian)了(le)炭精送話(hua)(hua)(hua)(hua)器(qi)，使電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)送話(hua)(hua)(hua)(hua)器(qi)效(xiao)率大(da)大(da)提高。受話(hua)(hua)(hua)(hua)器(qi)結構(gou)也(ye)(ye)有(you)改(gai)進。最早(zao)的電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)是磁石電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)，靠(kao)自(zi)備(bei)電(dian)(dian)(dian)(dian)池供電(dian)(dian)(dian)(dian)，用手(shou)搖發(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)(ji)發(fa)送呼叫(jiao)信號(hao)(hao)。1880年(nian)出(chu)(chu)(chu)(chu)現(xian)共電(dian)(dian)(dian)(dian)式(shi)電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)，改(gai)由(you)共電(dian)(dian)(dian)(dian)交(jiao)換機(ji)(ji)(ji)(ji)(ji)(ji)集中供電(dian)(dian)(dian)(dian)，省去手(shou)播(bo)發(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)(ji)和干電(dian)(dian)(dian)(dian)池。1891年(nian)出(chu)(chu)(chu)(chu)現(xian)了(le)旋轉撥(bo)(bo)號(hao)(hao)盤式(shi)自(zi)動電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)，它可以發(fa)出(chu)(chu)(chu)(chu)直流撥(bo)(bo)號(hao)(hao)脈沖(chong)，控制自(zi)動交(jiao)換機(ji)(ji)(ji)(ji)(ji)(ji)動作，選擇被叫(jiao)用戶，自(zi)動完成交(jiao)換功(gong)(gong)能(neng)。從而把電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)通(tong)信推向一個新(xin)階段(duan)。到20世(shi)紀60年(nian)代末(mo)期出(chu)(chu)(chu)(chu)現(xian)了(le)按(an)鍵式(shi)全(quan)電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)。除(chu)脈沖(chong)發(fa)號(hao)(hao)方式(shi)外，又出(chu)(chu)(chu)(chu)現(xian)了(le)雙音(yin)多(duo)(duo)頻（DTMF）發(fa)號(hao)(hao)方式(shi)。隨著(zhu)程控交(jiao)換機(ji)(ji)(ji)(ji)(ji)(ji)的發(fa)展(zhan)(zhan)，雙音(yin)頻按(an)鍵電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)已(yi)逐步普及(ji)。電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)路正在(zai)(zai)(zai)向集成化邁進，話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)專(zhuan)用集成電(dian)(dian)(dian)(dian)路已(yi)廣泛用于(yu)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)路各組(zu)成部分。各種多(duo)(duo)功(gong)(gong)能(neng)電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)和特種用途電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)也(ye)(ye)應運(yun)而生。到20世(shi)紀90年(nian)代初，已(yi)有(you)了(le)將撥(bo)(bo)號(hao)(hao)、通(tong)話(hua)(hua)(hua)(hua)、振(zhen)鈴三種功(gong)(gong)能(neng)集于(yu)一塊集成電(dian)(dian)(dian)(dian)路上(shang)的電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)。隨著(zhu)話(hua)(hua)(hua)(hua)音(yin)識別技術(shu)的發(fa)展(zhan)(zhan)，直接(jie)用話(hua)(hua)(hua)(hua)音(yin)“撥(bo)(bo)號(hao)(hao)”的新(xin)型電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)機(ji)(ji)(ji)(ji)(ji)(ji)也(ye)(ye)正在(zai)(zai)(zai)出(chu)(chu)(chu)(chu)現(xian)。
最初的電(dian)話(hua)(hua)(hua)(hua)(hua)機(ji)(ji)(ji)（終端(duan)）是由微型發(fa)(fa)電(dian)機(ji)(ji)(ji)和電(dian)池構成(cheng)的磁石式電(dian)話(hua)(hua)(hua)(hua)(hua)機(ji)(ji)(ji)，打(da)電(dian)話(hua)(hua)(hua)(hua)(hua)時，使用(yong)者用(yong)手搖(yao)微型發(fa)(fa)電(dian)機(ji)(ji)(ji)發(fa)(fa)出電(dian)信(xin)號呼叫對方(fang)，對方(fang)啟(qi)機(ji)(ji)(ji)后構成(cheng)通話(hua)(hua)(hua)(hua)(hua)回路(lu)。后來，1877年(nian)(nian)愛迪生（T.E.Edison）發(fa)(fa)明(ming)(ming)了碳素(su)送話(hua)(hua)(hua)(hua)(hua)器和誘導線路(lu)后通話(hua)(hua)(hua)(hua)(hua)距離(li)延長了。同一年(nian)(nian)又(you)發(fa)(fa)明(ming)(ming)了共電(dian)式電(dian)話(hua)(hua)(hua)(hua)(hua)機(ji)(ji)(ji)。1891年(nian)(nian)終于(yu)發(fa)(fa)展到A.B.Strowger發(fa)(fa)明(ming)(ming)了自(zi)動式電(dian)話(hua)(hua)(hua)(hua)(hua)機(ji)(ji)(ji)。
電(dian)(dian)(dian)(dian)話(hua)(hua)機(ji)設(she)置在(zai)電(dian)(dian)(dian)(dian)話(hua)(hua)通(tong)信起點和(he)終(zhong)(zhong)點的(de)用戶側，是(shi)電(dian)(dian)(dian)(dian)話(hua)(hua)網(wang)的(de)用戶終(zhong)(zhong)端設(she)備。現(xian)代的(de)電(dian)(dian)(dian)(dian)話(hua)(hua)機(ji)能夠(gou)方便地(di)實現(xian)終(zhong)(zhong)端用戶之間的(de)呼叫和(he)通(tong)話(hua)(hua)，是(shi)經過一百多年來許多人的(de)研(yan)究和(he)無(wu)數次(ci)的(de)改進而形(xing)成的(de)。盡管它們的(de)式(shi)樣千差萬別，但一般都(dou)有如(ru)下基本(ben)功能：
1、聲電互換
因為要(yao)進行快速的(de)(de)、遠(yuan)距離的(de)(de)通信(xin)，不(bu)能(neng)直接傳送聲音(yin)，而必須先把(ba)聲音(yin)變成電(dian)(dian)信(xin)號(hao)（即(ji)以電(dian)(dian)作為載體），到(dao)對(dui)方后再把(ba)電(dian)(dian)信(xin)號(hao)還(huan)原成為聲音(yin)。
2、摘機識別
當主叫(jiao)方(fang)拿起(qi)電話機(ji)時，交換機(ji)應有(you)能(neng)知道(dao)“有(you)人要(yao)打電話”的(de)功能(neng)，以便交換機(ji)做(zuo)好(hao)接續準備。
3、發送信號
自動電話機正(zheng)是通過發送撥(bo)號信號來指(zhi)揮電話交換(huan)機的工作，并進而建立兩個電話機之(zhi)間(jian)的連接的。
4、響鈴
即在對方來電話時，電話機能(neng)以鈴聲告訴主(zhu)人：“有人來電話了。”
5、電接續
電(dian)話(hua)(hua)機中(zhong)，實現這五大(da)功(gong)能的部件(jian)依次是：送(song)受話(hua)(hua)器、叉簧、撥(bo)號盤(pan)（或按鍵盤(pan)）、電(dian)話(hua)(hua)鈴(ling)和電(dian)話(hua)(hua)回路。
電(dian)(dian)(dian)話機(ji)具(ju)有將(jiang)(jiang)終(zhong)端的(de)(de)(de)(de)音(yin)(yin)波轉換(huan)為電(dian)(dian)(dian)子信(xin)號，通(tong)過電(dian)(dian)(dian)話線傳送(song)(song)(song)(song)到遠距離(li)的(de)(de)(de)(de)對(dui)(dui)方(fang)(fang)(fang)，同時將(jiang)(jiang)對(dui)(dui)方(fang)(fang)(fang)傳送(song)(song)(song)(song)來的(de)(de)(de)(de)電(dian)(dian)(dian)子信(xin)號再生(sheng)(sheng)為語音(yin)(yin)（音(yin)(yin)波），使其(qi)通(tong)話的(de)(de)(de)(de)功能，以及(ji)發(fa)送(song)(song)(song)(song)可從多個對(dui)(dui)方(fang)(fang)(fang)中選擇的(de)(de)(de)(de)信(xin)號（撥號脈沖），告知對(dui)(dui)方(fang)(fang)(fang)的(de)(de)(de)(de)呼(hu)叫音(yin)(yin)等功能。電(dian)(dian)(dian)話機(ji)由將(jiang)(jiang)語音(yin)(yin)轉換(huan)為電(dian)(dian)(dian)流(liu)發(fa)送(song)(song)(song)(song)到電(dian)(dian)(dian)話線的(de)(de)(de)(de)送(song)(song)(song)(song)話機(ji)、將(jiang)(jiang)對(dui)(dui)方(fang)(fang)(fang)傳送(song)(song)(song)(song)來的(de)(de)(de)(de)電(dian)(dian)(dian)流(liu)還原為語音(yin)(yin)的(de)(de)(de)(de)受(shou)話機(ji)、呼(hu)叫對(dui)(dui)方(fang)(fang)(fang)的(de)(de)(de)(de)撥號或按鈕、發(fa)送(song)(song)(song)(song)呼(hu)叫音(yin)(yin)的(de)(de)(de)(de)鈴(ling)聲(sheng)、將(jiang)(jiang)這些連接在電(dian)(dian)(dian)話線上(shang)執(zhi)行其(qi)功能的(de)(de)(de)(de)線路(lu)網(wang)等組成(cheng)。送(song)(song)(song)(song)話機(ji)內有裝(zhuang)滿(man)碳(tan)素(su)顆(ke)粒的(de)(de)(de)(de)小(xiao)箱子，其(qi)前方(fang)(fang)(fang)有薄(bo)硬鋁合金振(zhen)(zhen)動(dong)(dong)板。振(zhen)(zhen)動(dong)(dong)板根據語音(yin)(yin)振(zhen)(zhen)動(dong)(dong)，振(zhen)(zhen)動(dong)(dong)碳(tan)素(su)顆(ke)粒，碳(tan)素(su)顆(ke)粒傳導(dao)電(dian)(dian)(dian)流(liu)，隨著顆(ke)粒的(de)(de)(de)(de)接觸程(cheng)度，電(dian)(dian)(dian)阻發(fa)生(sheng)(sheng)變(bian)化，生(sheng)(sheng)成(cheng)語音(yin)(yin)電(dian)(dian)(dian)流(liu)。受(shou)話機(ji)接受(shou)對(dui)(dui)方(fang)(fang)(fang)的(de)(de)(de)(de)語音(yin)(yin)電(dian)(dian)(dian)流(liu)后，在線圈上(shang)生(sheng)(sheng)成(cheng)語音(yin)(yin)電(dian)(dian)(dian)流(liu)引起(qi)的(de)(de)(de)(de)磁力(li)，振(zhen)(zhen)動(dong)(dong)鐵振(zhen)(zhen)動(dong)(dong)板，發(fa)出(chu)聲(sheng)音(yin)(yin)。
無(wu)線環路-無(wu)繩(sheng)電話
電話子母機
數字無繩電話
模擬無繩電話
移動電話手機
小靈通（無線電(dian)話）
隨著IT技術(shu)的(de)不斷(duan)的(de)飛速發展(zhan)，嵌入式終端(duan)設(she)備的(de)處理能力越來越強，21世(shi)紀初出現了一種(zhong)帶個(ge)人數據助理（PDA）的(de)電話(hua)機(ji)“智(zhi)能電話(hua)”。
智能(neng)(neng)電(dian)(dian)話除了有(you)完整的(de)(de)(de)(de)固定(ding)電(dian)(dian)話功(gong)能(neng)(neng)外，通(tong)(tong)常還具有(you)大容(rong)量(liang)的(de)(de)(de)(de)名(ming)片管理(li)(li)(li)功(gong)能(neng)(neng)、來去電(dian)(dian)管理(li)(li)(li)功(gong)能(neng)(neng)、防止(zhi)電(dian)(dian)話騷擾(rao)（電(dian)(dian)話防火墻）功(gong)能(neng)(neng)、企(qi)業(ye)集團電(dian)(dian)話名(ming)片（內部名(ming)片）管理(li)(li)(li)功(gong)能(neng)(neng)，以及輔助辦(ban)公的(de)(de)(de)(de)許多功(gong)能(neng)(neng)，比如：日(ri)程安排、便箋、日(ri)歷、計算器等功(gong)能(neng)(neng)。早期的(de)(de)(de)(de)智能(neng)(neng)電(dian)(dian)話通(tong)(tong)過撥(bo)號上網，具有(you)一定(ding)的(de)(de)(de)(de)信息交換能(neng)(neng)力，實現了發送(song)短(duan)信、接收文字信息的(de)(de)(de)(de)功(gong)能(neng)(neng)。隨著固網智能(neng)(neng)電(dian)(dian)話在中國近十年的(de)(de)(de)(de)發展，其(qi)處理(li)(li)(li)能(neng)(neng)力加(jia)(jia)強，逐漸地(di)增加(jia)(jia)了智能(neng)(neng)手機（Smartphone）具有(you)的(de)(de)(de)(de)功(gong)能(neng)(neng)。
智(zhi)能(neng)電(dian)話(hua)已有通過因特網(wang)上網(wang)的能(neng)力(li)及較強的多媒的體功(gong)能(neng)。可以進(jin)行網(wang)絡瀏覽、音視頻的播放、具有電(dian)子(zi)書、電(dian)子(zi)相(xiang)框等(deng)功(gong)能(neng)。同時(shi)智(zhi)能(neng)電(dian)話(hua)在(zai)輔助辦公、輔助營銷、娛樂等(deng)方面的功(gong)能(neng)也有了大大的加強。在(zai)對(dui)傳(chuan)統(tong)固定電(dian)話(hua)顛覆的基礎上，實現了更(geng)多的商(shang)務功(gong)能(neng)和(he)PDA功(gong)能(neng)。
環(huan)境溫度：-10℃~40℃
相(xiang)對濕度(du)：45%~95%
大氣壓力：860~1060mbar
環境噪聲：≤60dB(A)
1、工作頻率：300~3400HZ
2、脈(mo)沖通(tong)斷比：1.6±0.2∶1
3、雙音頻(pin)撥號頻(pin)偏(pian)：≤±1.5%
4、雙音頻(pin)(pin)信號電平：①低頻(pin)(pin)群(qun)：-9±3dB；②高頻(pin)(pin)群(qun)：-7±3dB；③頻(pin)(pin)率(lv)組合中高頻(pin)(pin)分量(liang)比低頻(pin)(pin)分量(liang)高2±1dB
5、振(zhen)鈴聲級：≥70dB(A)
6、電聲性能：
①在(zai)0公(gong)(gong)里時(shi)，客觀發(fa)送參(can)(can)考(kao)(kao)當量≥+3；在(zai)3公(gong)(gong)里時(shi)，客觀發(fa)送參(can)(can)考(kao)(kao)當量≤+15；在(zai)5公(gong)(gong)里時(shi)，客觀發(fa)送參(can)(can)考(kao)(kao)當量≤+15。
②在0公里時，客觀(guan)(guan)接(jie)收(shou)參(can)考(kao)當量≥－5；在3公里時，客觀(guan)(guan)接(jie)收(shou)參(can)考(kao)當量≤+2；在5公里時，客觀(guan)(guan)接(jie)收(shou)摻(chan)考(kao)當量≤+2。
③在0公(gong)里時(shi)，客(ke)觀(guan)側(ce)音(yin)參考(kao)當(dang)量(liang)≥+3；在3公(gong)里時(shi)，客(ke)觀(guan)側(ce)音(yin)參考(kao)當(dang)量(liang)≥+10；在5公(gong)里時(shi)，客(ke)觀(guan)側(ce)音(yin)參考(kao)當(dang)量(liang)≥+10。
高(gao)科技(ji)電(dian)(dian)話機的(de)(de)(de)(de)發(fa)展都(dou)(dou)是隨著無線通(tong)信(xin)的(de)(de)(de)(de)發(fa)達而形成的(de)(de)(de)(de)。電(dian)(dian)話機的(de)(de)(de)(de)發(fa)展趨勢(shi)經過Digital電(dian)(dian)話機和PCS后(hou)發(fa)展到可(ke)以(yi)用衛星通(tong)信(xin)的(de)(de)(de)(de)IMT-200服(fu)務(wu)(wu)。IMT-200支持信(xin)息的(de)(de)(de)(de)高(gao)速傳送，Packet，畫像(xiang)等多媒體的(de)(de)(de)(de)服(fu)務(wu)(wu)，將來世界各個地(di)方(fang)都(dou)(dou)可(ke)以(yi)使(shi)用所有(you)聲音電(dian)(dian)話，電(dian)(dian)報用戶直通(tong)電(dian)(dian)路，傳呼和電(dian)(dian)子郵件(jian)；隨著電(dian)(dian)子郵件(jian)的(de)(de)(de)(de)普(pu)及，網絡也日益化，網絡電(dian)(dian)話已是不(bu)可(ke)阻擋的(de)(de)(de)(de)發(fa)展趨勢(shi)。現有(you)的(de)(de)(de)(de)固(gu)定電(dian)(dian)話，已經不(bu)能提供人們的(de)(de)(de)(de)需要(yao)了。未來的(de)(de)(de)(de)固(gu)定電(dian)(dian)話講裝備攝像(xiang)頭，帶有(you)色彩的(de)(de)(de)(de)液(ye)晶顯示器，我們在接固(gu)定電(dian)(dian)話的(de)(de)(de)(de)時候，都(dou)(dou)能夠(gou)看到雙(shuang)方(fang)。
精(jing)靈(ling)世(shi)界(jie)
】編輯上傳提(ti)供，詞(ci)條屬(shu)于開放詞(ci)條，當前(qian)頁(ye)(ye)面(mian)所展示的(de)(de)詞(ci)條介紹涉及(ji)宣傳內容屬(shu)于注冊用戶(hu)個人(ren)編輯行為，與【電(dian)話機(ji)】的(de)(de)所屬(shu)企業/所有人(ren)/主體無關，網站(zhan)不完全(quan)保證內容信(xin)息的(de)(de)準確性、真實(shi)性，也(ye)不代表本站(zhan)立場，各項數據信(xin)息存在更新不及(ji)時的(de)(de)情況，僅供參考，請以官(guan)方(fang)發布為準。如果頁(ye)(ye)面(mian)內容與實(shi)際情況不符，可點擊(ji)“反饋”在線向網站(zhan)提(ti)出修改，網站(zhan)將核實(shi)后進行更正(zheng)。
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