電話(hua)[英語：Telephone，出自希臘語τ?λε（tēle，意為“遠”）和φων?（phōnē，意為“聲(sheng)音(yin)”），舊譯德律風]是(shi)一種可(ke)以傳(chuan)(chuan)送(song)與接收聲(sheng)音(yin)的(de)遠程通信設備。早(zao)在18世紀歐洲已有(you)“電話(hua)”一詞(ci)，用(yong)來指用(yong)線串成的(de)話(hua)筒（以線串起杯子）。電話(hua)的(de)出現要歸功(gong)于亞歷山大·格拉漢姆·貝爾，早(zao)期電話(hua)機的(de)原理為：說話(hua)聲(sheng)音(yin)為空氣里(li)的(de)復(fu)合振動，可(ke)傳(chuan)(chuan)輸到固(gu)體上，通過(guo)電脈沖于導電金(jin)屬(shu)上傳(chuan)(chuan)遞(di)。貝爾于1876年3月申請了電話(hua)的(de)專(zhuan)利(li)權(quan)。
美國國會(hui)2002年6月(yue)15日(ri)269號決議確認(ren)安東尼奧·穆齊為電話(hua)的發明人。穆齊于1860年首(shou)次向公眾展示(shi)了(le)他(ta)的發明，并在紐約的意大利語報紙上發表了(le)關(guan)于這項發明的介紹。
歷史上(shang)對電話(hua)(hua)的(de)(de)改進(jin)和發明包(bao)括(kuo)：碳粉話(hua)(hua)筒(tong)、人工交換板(ban)、撥號盤、自(zi)動電話(hua)(hua)交換機、程(cheng)控(kong)電話(hua)(hua)交換機、雙音(yin)多頻撥號、語(yu)音(yin)數(shu)字(zi)采樣(yang)等。近年來的(de)(de)新技術包(bao)括(kuo)：ISDN、DSL、網絡電話(hua)(hua)、模擬移(yi)動電話(hua)(hua)和數(shu)字(zi)移(yi)動電話(hua)(hua)等。
這(zhe)一(yi)行業(ye)通(tong)常分為電話(hua)設備制造商和電話(hua)網絡運(yun)營(ying)商。在歷史上(shang)，網絡運(yun)營(ying)商通(tong)常都擁有(you)(you)全國(guo)性的(de)(de)(de)壟斷。近年來(lai)，隨(sui)著全球(qiu)電信市場的(de)(de)(de)開放和集成(cheng)以(yi)及技術(shu)的(de)(de)(de)發展，逐(zhu)漸出(chu)現(xian)多家運(yun)營(ying)商在同一(yi)市場競爭的(de)(de)(de)局面(mian)。例如(ru)，貝爾(er)(er)系統，即AT&T的(de)(de)(de)下屬公司曾擁有(you)(you)美(mei)國(guo)電話(hua)市場的(de)(de)(de)80%。1984年，由于美(mei)國(guo)司法部(bu)反壟斷訴訟(song)，貝爾(er)(er)系統被迫分區(qu)成(cheng)多個(ge)獨立的(de)(de)(de)地方貝爾(er)(er)公司。有(you)(you)一(yi)個(ge)說法可以(yi)說明這(zhe)個(ge)現(xian)象：在AT&T未分區(qu)前(qian)，IBM是美(mei)國(guo)第二大(da)公司。在AT&T分區(qu)成(cheng)七個(ge)公司后(hou)，IBM的(de)(de)(de)排名(ming)變成(cheng)第八名(ming)。
電話機是(shi)通過電信號雙向傳輸話音(yin)的終端設備。
歷史上對電(dian)話(hua)(hua)機的(de)改進和發明包括：碳(tan)粉話(hua)(hua)筒(tong)、電(dian)話(hua)(hua)人工交換板(ban)、撥號盤、自動(dong)電(dian)話(hua)(hua)交換機、程(cheng)控電(dian)話(hua)(hua)交換機、雙(shuang)音多頻撥號、語音數字(zi)采樣等(deng)。新技術包括：ISDN、DSL、模擬移(yi)動(dong)電(dian)話(hua)(hua)和數字(zi)移(yi)動(dong)電(dian)話(hua)(hua)機等(deng)。
電(dian)話電(dian)源(yuan)線(xian)、電(dian)話線(xian)、收線(xian)開(kai)關、受話器(qi)、增音按(an)鈕、送(song)話器(qi)、本機號碼(ma)片、鈴(ling)聲(sheng)及免(mian)提(ti)喇叭、記(ji)(ji)憶代碼(ma)鍵(jian)(jian)(jian)、記(ji)(ji)憶號碼(ma)片、數字按(an)鍵(jian)(jian)(jian)、記(ji)(ji)憶取出鍵(jian)(jian)(jian)、記(ji)(ji)憶儲存鍵(jian)(jian)(jian)、重撥鍵(jian)(jian)(jian)、工(gong)作指(zhi)示(shi)燈、免(mian)提(ti)鍵(jian)(jian)(jian)、R鍵(jian)(jian)(jian)、免(mian)提(ti)送(song)話器(qi)、鈴(ling)聲(sheng)調(diao)(diao)節(jie)開(kai)關、P/T開(kai)關、免(mian)提(ti)接收音量(liang)調(diao)(diao)節(jie)旋鈕。
電(dian)話(hua)通(tong)信(xin)是通(tong)過聲能與電(dian)能相(xiang)互轉(zhuan)換、并(bing)利用(yong)(yong)“電(dian)”這個媒介來(lai)傳輸語言(yan)的(de)一種通(tong)信(xin)技術(shu)。兩個用(yong)(yong)戶要(yao)進行通(tong)信(xin)，最簡單(dan)的(de)形(xing)式就是將(jiang)兩部電(dian)話(hua)機(ji)用(yong)(yong)一對線路連(lian)接起(qi)來(lai)。
當發話(hua)(hua)者拿起電話(hua)(hua)機對著送話(hua)(hua)器講話(hua)(hua)時，聲(sheng)帶(dai)的(de)振(zhen)動激勵空氣振(zhen)動，形(xing)成聲(sheng)波。
聲波作用于送(song)話(hua)器上，使之產生電流，稱(cheng)為話(hua)音電流。
話(hua)(hua)音電流沿著線路傳(chuan)送到對方電話(hua)(hua)機的受話(hua)(hua)器內(nei)。
而受話器作用與送(song)話器剛好相反——把電流轉化為聲波，通(tong)過空氣傳(chuan)至人(ren)的耳朵中。
這樣，就(jiu)完成(cheng)了最(zui)簡單的通(tong)話過程。
電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)是美國人A.G.貝爾于(yu)1876年(nian)發明的(de)。他用(yong)(yong)兩(liang)根(gen)導線連接兩(liang)個結構(gou)(gou)完全相同、在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)鐵上(shang)裝有(you)振(zhen)動(dong)膜(mo)片的(de)送話(hua)(hua)(hua)(hua)(hua)(hua)器和(he)受話(hua)(hua)(hua)(hua)(hua)(hua)器，首先實現(xian)(xian)(xian)兩(liang)端通(tong)話(hua)(hua)(hua)(hua)(hua)(hua)。但(dan)通(tong)話(hua)(hua)(hua)(hua)(hua)(hua)距離短、效(xiao)率低。1878年(nian)出(chu)現(xian)(xian)(xian)了(le)(le)炭精(jing)送話(hua)(hua)(hua)(hua)(hua)(hua)器，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)送話(hua)(hua)(hua)(hua)(hua)(hua)器效(xiao)率大大提高。受話(hua)(hua)(hua)(hua)(hua)(hua)器結構(gou)(gou)也有(you)改(gai)進(jin)。最早(zao)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)是磁(ci)石(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)，靠自備電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，用(yong)(yong)手搖發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)發送呼叫(jiao)信號(hao)。1880年(nian)出(chu)現(xian)(xian)(xian)共電(dian)(dian)(dian)(dian)(dian)(dian)(dian)式電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)，改(gai)由共電(dian)(dian)(dian)(dian)(dian)(dian)(dian)交換(huan)機(ji)集中供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，省(sheng)去手播(bo)發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)和(he)干電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池。1891年(nian)出(chu)現(xian)(xian)(xian)了(le)(le)旋轉撥號(hao)盤(pan)式自動(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)，它可以發出(chu)直流(liu)撥號(hao)脈沖，控(kong)制自動(dong)交換(huan)機(ji)動(dong)作，選擇被叫(jiao)用(yong)(yong)戶，自動(dong)完成(cheng)交換(huan)功能。從而把電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)通(tong)信推向一個新(xin)(xin)階(jie)段。到(dao)20世(shi)紀(ji)60年(nian)代(dai)末期出(chu)現(xian)(xian)(xian)了(le)(le)按鍵(jian)式全電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)。除脈沖發號(hao)方(fang)式外，又(you)出(chu)現(xian)(xian)(xian)了(le)(le)雙(shuang)音(yin)多頻（DTMF）發號(hao)方(fang)式。隨著(zhu)程(cheng)控(kong)交換(huan)機(ji)的(de)發展，雙(shuang)音(yin)頻按鍵(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)已(yi)逐步普及。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)正在(zai)向集成(cheng)化邁進(jin)，話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)專用(yong)(yong)集成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)已(yi)廣泛(fan)用(yong)(yong)于(yu)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)各組成(cheng)部分。各種多功能電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)和(he)特種用(yong)(yong)途(tu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)也應運而生。到(dao)20世(shi)紀(ji)90年(nian)代(dai)初(chu)，已(yi)有(you)了(le)(le)將(jiang)撥號(hao)、通(tong)話(hua)(hua)(hua)(hua)(hua)(hua)、振(zhen)鈴三種功能集于(yu)一塊集成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)上(shang)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)。隨著(zhu)話(hua)(hua)(hua)(hua)(hua)(hua)音(yin)識別技術(shu)的(de)發展，直接用(yong)(yong)話(hua)(hua)(hua)(hua)(hua)(hua)音(yin)“撥號(hao)”的(de)新(xin)(xin)型電(dian)(dian)(dian)(dian)(dian)(dian)(dian)話(hua)(hua)(hua)(hua)(hua)(hua)機(ji)也正在(zai)出(chu)現(xian)(xian)(xian)。
最(zui)初的電(dian)(dian)(dian)(dian)話機(ji)(ji)（終端）是由(you)微(wei)型(xing)發(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)和(he)電(dian)(dian)(dian)(dian)池構成(cheng)的磁石式電(dian)(dian)(dian)(dian)話機(ji)(ji)，打電(dian)(dian)(dian)(dian)話時，使用者(zhe)用手(shou)搖微(wei)型(xing)發(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)發(fa)出(chu)電(dian)(dian)(dian)(dian)信號呼叫對方，對方啟機(ji)(ji)后(hou)構成(cheng)通話回路(lu)。后(hou)來，1877年愛(ai)迪(di)生（T.E.Edison）發(fa)明(ming)了碳(tan)素送話器(qi)和(he)誘導線路(lu)后(hou)通話距(ju)離延長了。同一年又發(fa)明(ming)了共(gong)電(dian)(dian)(dian)(dian)式電(dian)(dian)(dian)(dian)話機(ji)(ji)。1891年終于(yu)發(fa)展(zhan)到A.B.Strowger發(fa)明(ming)了自(zi)動式電(dian)(dian)(dian)(dian)話機(ji)(ji)。
電話(hua)機設置在電話(hua)通信起點和(he)終點的(de)用(yong)戶側，是電話(hua)網的(de)用(yong)戶終端(duan)設備(bei)。現(xian)(xian)代的(de)電話(hua)機能(neng)夠方便(bian)地實現(xian)(xian)終端(duan)用(yong)戶之間的(de)呼叫和(he)通話(hua)，是經過一百多年來許多人的(de)研(yan)究和(he)無數次的(de)改(gai)進(jin)而形成的(de)。盡(jin)管它們的(de)式樣(yang)千差萬別，但一般(ban)都有如下基本功能(neng)：
1、聲電互換
因(yin)為(wei)要進行快速的(de)、遠(yuan)距離的(de)通信(xin)，不能直接傳送(song)聲音，而(er)必須先把聲音變成電信(xin)號(hao)（即以電作(zuo)為(wei)載體），到(dao)對(dui)方(fang)后再把電信(xin)號(hao)還(huan)原成為(wei)聲音。
2、摘機識別
當主叫方拿起電話機(ji)時，交換(huan)機(ji)應(ying)有能(neng)知道“有人要(yao)打電話”的功(gong)能(neng)，以便交換(huan)機(ji)做好接(jie)續準備。
3、發送信號
自動電(dian)話(hua)機(ji)正是通過(guo)發(fa)送撥號信號來指揮電(dian)話(hua)交換機(ji)的工作(zuo)，并進而建(jian)立兩個電(dian)話(hua)機(ji)之(zhi)間的連(lian)接(jie)的。
4、響鈴
即在(zai)對方來(lai)電(dian)(dian)話時，電(dian)(dian)話機能以鈴聲告訴主人(ren)(ren)：“有人(ren)(ren)來(lai)電(dian)(dian)話了(le)。”
5、電接續
電(dian)話(hua)機中，實現這五(wu)大功能的部件依次是：送受(shou)話(hua)器、叉簧、撥號盤(pan)（或(huo)按鍵(jian)盤(pan)）、電(dian)話(hua)鈴和電(dian)話(hua)回路(lu)。
電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)機(ji)具(ju)有將終(zhong)端的音(yin)(yin)(yin)(yin)(yin)波轉換為(wei)電(dian)(dian)(dian)(dian)子(zi)信(xin)號，通(tong)過電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)線(xian)傳送(song)到遠距離的對方(fang)(fang)(fang)，同時將對方(fang)(fang)(fang)傳送(song)來的電(dian)(dian)(dian)(dian)子(zi)信(xin)號再生為(wei)語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)（音(yin)(yin)(yin)(yin)(yin)波），使其(qi)通(tong)話(hua)(hua)(hua)的功(gong)能(neng)，以(yi)及(ji)發(fa)(fa)(fa)送(song)可(ke)從多個(ge)對方(fang)(fang)(fang)中(zhong)選擇(ze)的信(xin)號（撥號脈沖），告知對方(fang)(fang)(fang)的呼(hu)叫音(yin)(yin)(yin)(yin)(yin)等功(gong)能(neng)。電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)機(ji)由將語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)轉換為(wei)電(dian)(dian)(dian)(dian)流(liu)(liu)發(fa)(fa)(fa)送(song)到電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)線(xian)的送(song)話(hua)(hua)(hua)機(ji)、將對方(fang)(fang)(fang)傳送(song)來的電(dian)(dian)(dian)(dian)流(liu)(liu)還原為(wei)語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)的受話(hua)(hua)(hua)機(ji)、呼(hu)叫對方(fang)(fang)(fang)的撥號或(huo)按(an)鈕、發(fa)(fa)(fa)送(song)呼(hu)叫音(yin)(yin)(yin)(yin)(yin)的鈴聲、將這(zhe)些連接(jie)在電(dian)(dian)(dian)(dian)話(hua)(hua)(hua)線(xian)上(shang)執(zhi)行其(qi)功(gong)能(neng)的線(xian)路網等組(zu)成。送(song)話(hua)(hua)(hua)機(ji)內(nei)有裝滿碳素(su)顆(ke)(ke)粒(li)的小箱(xiang)子(zi)，其(qi)前(qian)方(fang)(fang)(fang)有薄(bo)硬鋁合金振動(dong)板(ban)。振動(dong)板(ban)根據語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)振動(dong)，振動(dong)碳素(su)顆(ke)(ke)粒(li)，碳素(su)顆(ke)(ke)粒(li)傳導電(dian)(dian)(dian)(dian)流(liu)(liu)，隨著顆(ke)(ke)粒(li)的接(jie)觸(chu)程度，電(dian)(dian)(dian)(dian)阻發(fa)(fa)(fa)生變化，生成語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)電(dian)(dian)(dian)(dian)流(liu)(liu)。受話(hua)(hua)(hua)機(ji)接(jie)受對方(fang)(fang)(fang)的語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)電(dian)(dian)(dian)(dian)流(liu)(liu)后，在線(xian)圈(quan)上(shang)生成語(yu)(yu)(yu)音(yin)(yin)(yin)(yin)(yin)電(dian)(dian)(dian)(dian)流(liu)(liu)引(yin)起的磁力，振動(dong)鐵(tie)振動(dong)板(ban)，發(fa)(fa)(fa)出聲音(yin)(yin)(yin)(yin)(yin)。
無(wu)線環路-無(wu)繩電話
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(xian)電(dian)話）
隨著IT技(ji)術的不斷(duan)的飛速發展，嵌入(ru)式終(zhong)端(duan)設備(bei)的處理能力越來越強，21世紀初出(chu)現了一種帶(dai)個(ge)人數據(ju)助理（PDA）的電話機“智能電話”。
智能(neng)(neng)電(dian)話(hua)除了有(you)完整的(de)固定電(dian)話(hua)功(gong)(gong)(gong)(gong)能(neng)(neng)外，通常還具(ju)(ju)有(you)大容量的(de)名片(pian)管(guan)理(li)功(gong)(gong)(gong)(gong)能(neng)(neng)、來(lai)去(qu)電(dian)管(guan)理(li)功(gong)(gong)(gong)(gong)能(neng)(neng)、防止電(dian)話(hua)騷(sao)擾（電(dian)話(hua)防火墻）功(gong)(gong)(gong)(gong)能(neng)(neng)、企業集團(tuan)電(dian)話(hua)名片(pian)（內部名片(pian)）管(guan)理(li)功(gong)(gong)(gong)(gong)能(neng)(neng)，以及輔助辦公(gong)的(de)許(xu)多(duo)功(gong)(gong)(gong)(gong)能(neng)(neng)，比(bi)如：日(ri)程安排、便箋、日(ri)歷、計算器等功(gong)(gong)(gong)(gong)能(neng)(neng)。早期的(de)智能(neng)(neng)電(dian)話(hua)通過撥(bo)號上網(wang)(wang)，具(ju)(ju)有(you)一(yi)定的(de)信息交換(huan)能(neng)(neng)力，實現了發(fa)(fa)送短信、接收(shou)文字(zi)信息的(de)功(gong)(gong)(gong)(gong)能(neng)(neng)。隨著固網(wang)(wang)智能(neng)(neng)電(dian)話(hua)在中國(guo)近十年的(de)發(fa)(fa)展(zhan)，其處理(li)能(neng)(neng)力加(jia)強，逐漸地增加(jia)了智能(neng)(neng)手機（Smartphone）具(ju)(ju)有(you)的(de)功(gong)(gong)(gong)(gong)能(neng)(neng)。
智能電(dian)話已有通(tong)過(guo)因(yin)特網(wang)(wang)上(shang)網(wang)(wang)的(de)能力(li)及(ji)較強的(de)多(duo)媒的(de)體功(gong)能。可以進行(xing)網(wang)(wang)絡(luo)瀏(liu)覽、音視頻的(de)播放、具(ju)有電(dian)子(zi)書、電(dian)子(zi)相框等功(gong)能。同時(shi)智能電(dian)話在(zai)輔助辦公、輔助營銷、娛樂等方面的(de)功(gong)能也有了(le)大(da)大(da)的(de)加(jia)強。在(zai)對傳統固定(ding)電(dian)話顛覆的(de)基礎上(shang)，實現(xian)了(le)更多(duo)的(de)商務功(gong)能和PDA功(gong)能。
環境溫度(du)：-10℃~40℃
相對濕度：45%~95%
大氣壓力：860~1060mbar
環境噪聲：≤60dB(A)
1、工作(zuo)頻率(lv)：300~3400HZ
2、脈沖通斷比：1.6±0.2∶1
3、雙音頻撥(bo)號頻偏：≤±1.5%
4、雙音頻(pin)(pin)信(xin)號電(dian)平：①低頻(pin)(pin)群(qun)：-9±3dB；②高(gao)頻(pin)(pin)群(qun)：-7±3dB；③頻(pin)(pin)率組合中(zhong)高(gao)頻(pin)(pin)分量比低頻(pin)(pin)分量高(gao)2±1dB
5、振鈴(ling)聲級：≥70dB(A)
6、電聲性能：
①在(zai)0公里時，客(ke)觀(guan)發送(song)參(can)考(kao)當(dang)量(liang)≥+3；在(zai)3公里時，客(ke)觀(guan)發送(song)參(can)考(kao)當(dang)量(liang)≤+15；在(zai)5公里時，客(ke)觀(guan)發送(song)參(can)考(kao)當(dang)量(liang)≤+15。
②在(zai)0公里時，客觀(guan)接(jie)收(shou)參(can)考(kao)當量≥－5；在(zai)3公里時，客觀(guan)接(jie)收(shou)參(can)考(kao)當量≤+2；在(zai)5公里時，客觀(guan)接(jie)收(shou)摻考(kao)當量≤+2。
③在(zai)0公里時，客(ke)觀側(ce)(ce)(ce)音參考(kao)當(dang)量(liang)(liang)≥+3；在(zai)3公里時，客(ke)觀側(ce)(ce)(ce)音參考(kao)當(dang)量(liang)(liang)≥+10；在(zai)5公里時，客(ke)觀側(ce)(ce)(ce)音參考(kao)當(dang)量(liang)(liang)≥+10。
高(gao)科技電(dian)(dian)話(hua)(hua)機的(de)發(fa)(fa)(fa)展都(dou)是(shi)隨著無(wu)線通(tong)信的(de)發(fa)(fa)(fa)達而形成(cheng)的(de)。電(dian)(dian)話(hua)(hua)機的(de)發(fa)(fa)(fa)展趨(qu)勢(shi)經過Digital電(dian)(dian)話(hua)(hua)機和(he)PCS后發(fa)(fa)(fa)展到(dao)可(ke)(ke)以用衛星(xing)通(tong)信的(de)IMT-200服務(wu)。IMT-200支持信息的(de)高(gao)速傳送，Packet，畫像(xiang)等多媒體的(de)服務(wu)，將(jiang)來世界各個地方(fang)都(dou)可(ke)(ke)以使用所有(you)聲音電(dian)(dian)話(hua)(hua)，電(dian)(dian)報用戶直通(tong)電(dian)(dian)路(lu)，傳呼和(he)電(dian)(dian)子郵件；隨著電(dian)(dian)子郵件的(de)普及，網(wang)絡也日益(yi)化(hua)，網(wang)絡電(dian)(dian)話(hua)(hua)已是(shi)不可(ke)(ke)阻擋的(de)發(fa)(fa)(fa)展趨(qu)勢(shi)。現有(you)的(de)固定電(dian)(dian)話(hua)(hua)，已經不能提(ti)供人們的(de)需要了。未(wei)來的(de)固定電(dian)(dian)話(hua)(hua)講裝備攝像(xiang)頭(tou)，帶(dai)有(you)色彩的(de)液晶顯示器，我們在接固定電(dian)(dian)話(hua)(hua)的(de)時候，都(dou)能夠看(kan)到(dao)雙(shuang)方(fang)。
精靈世界
】編輯上傳提(ti)供，詞(ci)條屬于(yu)開放(fang)詞(ci)條，當(dang)前頁面(mian)所(suo)展示的詞(ci)條介紹涉及宣傳內容屬于(yu)注冊用(yong)戶個人(ren)編輯行(xing)(xing)為，與【電話機】的所(suo)屬企業/所(suo)有人(ren)/主體無(wu)關(guan)，網站(zhan)不(bu)完全保證內容信息的準(zhun)(zhun)確性、真實性，也不(bu)代表(biao)本(ben)站(zhan)立場，各(ge)項數據信息存在更新不(bu)及時的情況(kuang)(kuang)，僅供參(can)考(kao)，請以官方發(fa)布為準(zhun)(zhun)。如果頁面(mian)內容與實際(ji)情況(kuang)(kuang)不(bu)符，可點擊“反饋”在線向網站(zhan)提(ti)出修改，網站(zhan)將核實后進行(xing)(xing)更正。
反饋
