無(wú)線(xiàn)加速數(shù)據(jù)傳輸和通信

　　現(xiàn)在幾乎所有的系統(tǒng)都是無(wú)線(xiàn)的，而不僅僅是連接到互聯(lián)網(wǎng)。為連接筆記本電腦、平板電腦、平板電視、Blu Ray播放器、音頻系統(tǒng)、家庭醫(yī)療系統(tǒng)，甚至是白色家電（冰箱、恒溫器、空調(diào)和供暖系統(tǒng)等），幾乎可以成為連接系統(tǒng)的免費(fèi)連接。連接所有的設(shè)備，大量的無(wú)線(xiàn)接口，包括蜂窩無(wú)線(xiàn)電（GSM、LTE等），藍(lán)牙，Wi-Fi的多種形式（802.11xx，Miracast，WiDi，WiGig）、ZigBee、Z-Wave無(wú)線(xiàn)接口，而其他如WISA（無(wú)線(xiàn)揚(yáng)聲器和音頻協(xié)會(huì)）。

　　以前的文章研究的進(jìn)展發(fā)生與藍(lán)牙接口（見(jiàn)，例如，在高新區(qū)的文章“藍(lán)牙是超低功耗”和“藍(lán)牙低功耗技術(shù)不只是一個(gè)藍(lán)牙版本–這是一個(gè)全新的技術(shù)”），所以這篇文章將集中在Wi-Fi和其他非藍(lán)牙無(wú)線(xiàn)的進(jìn)展。

　　In the Wi-Fi arena， the fifth-generation Wi-Fi is called 802.11ac.The ac standard defines the Wi-Fi interface operating at 5.4 GHz， with backward compatibility with the popular 802.11n standard， which is in wide use today. There are several options when implementing the 802.11ac interface depending on the data transfer speed desired – the maximum data rate when a 3 x 3 or 4 x 4 MIMO transmit/receive interface is implemented can hit about 1.3 Gbits/s， and that speed drops to 866.7 Mbits/s for a 2 x 2 channel system. Additionally， a 1 x 1 transmit/receive system can deliver a data transmission speed of 433.3 Mbits/s， which is almost triple the speed of today’s 802.11n Wi-Fi interfaces. Keep in mind， however， that as with all other flavors of 802.11 the actual throughput users will get with 802.11ac will be much less than the raw throughput. Table 1 offers a brief comparison of 802.11n and 802.11ac characteristics.