【正文】
rate the characteristics of poor ability also insurmountable. Wi Fi technical superiority In recent years, the number of WAP at a rapid pace, wireless network convenience and efficient make its rapid popularization. Whether wireless urban construction, or business unit of LAN opening, or mobile phones Wi Fi function, all with Wi Fi technical advantages of itself is not divided: 1) wider LAN coverage Based on bluetooth radio coverage is very small, radius, and only about 15m Wi Fi radius criterion of up to 100 m, can cover whole building office building, 2) transmission speed Wi Fi technology transmission is very fast, can achieve 11Mbps ( b) or 54Mbps ( a), suitable for high speed data transmission business。無論是無線城市的建設(shè),還是企事業(yè)單位局域網(wǎng)的開通,還是手機(jī)的 WiFi 功能,都與WiFi 技術(shù)自身的優(yōu)勢是分不開的: 1)較廣的局域網(wǎng)覆蓋范圍 基于藍(lán)牙技術(shù)的電波覆蓋范圍非常小,半徑大約只有 15m,而 WiFi 的半徑則可達(dá)100 m,可以覆蓋整棟辦公大樓; 2)傳輸速度快 WiFi 技術(shù)傳輸速度非??欤梢赃_(dá)到 11Mbps()或者 54Mbps (),適合高速數(shù)據(jù)傳輸?shù)臉I(yè)務(wù); 3)無需布線 WiFi 最主要的優(yōu)勢在于不需要布線,可以不受布線條件的限制,因此非常適合移動辦公用戶的需要。 由于 WiFi 使用電波作為傳送媒介, 資料包被截取的可能性高, 這成為用戶所擔(dān)心問題。同時(shí)由于 UWB系統(tǒng)信號的擴(kuò)頻處理增益比較大,即使采用低增益的全向天線發(fā)射,也可使用小于 1mW 的發(fā)射功率實(shí)現(xiàn)幾千米的通信。接收時(shí)將信號能量還原出來,在解擴(kuò)過程中產(chǎn)生擴(kuò)頻增益。 超寬帶(UWB)技術(shù)最初是面向雷達(dá)應(yīng)用來開發(fā)的,一般認(rèn)為它屬于一種無載波通信技術(shù)。其中,超寬帶(Ultra Wide Band,UWB)技術(shù)是在 20世紀(jì)90 年代以后發(fā)展起來的一種具有巨大發(fā)展?jié)摿Φ男滦蜔o線通信技術(shù),被列為未來通信的十大技術(shù)之一 。與常見的通信方式使用連續(xù)的載波不同,UWB 中使用的無線信號中心頻率為 ,帶寬為 ,頻譜范圍很寬,但是發(fā)射功率非常低。寬帶(UWB)自問世后一直被看作是藍(lán)牙技術(shù)的替代品,與其他無線技術(shù)如 WLAN 、藍(lán)牙等相比,超寬帶(UWB)具有低功耗、高帶寬、低復(fù)雜度、低成本的優(yōu)點(diǎn),完全可以滿足短距離家庭娛樂應(yīng)用需求。其數(shù)據(jù)速率可以達(dá)到幾十兆比特每秒到幾百兆比特每秒,有望高于藍(lán)牙100倍,也可以高于IEEE IEEE 。 2 WiFi WiFi技術(shù)簡介 WiFi(Wireless Fidelity,無線高保真)也是一種無線通信協(xié)議。雖然 WiFi 在數(shù)據(jù)安全性方面比藍(lán)牙技術(shù)要差一些,但在電波的覆蓋范圍方面卻略勝一籌,可達(dá) 100 m 左右。與后者相比,WiFi 產(chǎn)品的輻射更小。 4) health and safety The launch of provisions shall not exceed 100 power HaoWa, actual transmission power, about 60 ~ 70 HaoWa, and mobile transmission power about 200 HaoWa ~ 1 tile between handheld interphone, $5 watts. Compared with the latter, Wi Fi products of radiation smaller. 3 conclusions Each kind of wireless munication has its distinctive place, ultrawideband technology transfer rate is high, Wi Fi technology bestrow scope. As wireless munications technology development, people on highspeed shortrange wireless munication request more and more high, ultrawideband technology, Wi Fi technology has broad prospects for development.9 / 9