亞GHz無(wú)線部署的主要優(yōu)先事項(xiàng)

　　建立一個(gè)先進(jìn)的無(wú)線系統(tǒng)，大多數(shù)開(kāi)發(fā)者會(huì)選擇兩工業(yè)，科學(xué)和醫(yī)療（ISM）頻段的options-2.4 GHz或子千兆赫的頻率。將一個(gè)或另一個(gè)與系統(tǒng)的最高優(yōu)先級(jí)配對(duì)，將提供無(wú)線性能和經(jīng)濟(jì)性的最佳結(jié)合。這些優(yōu)先事項(xiàng)可以包括：范圍、功耗、數(shù)據(jù)速率、天線尺寸、互操作性（標(biāo)準(zhǔn)）和全球部署。然而，對(duì)于低數(shù)據(jù)速率應(yīng)用，如家庭安全/自動(dòng)化和智能計(jì)量，亞千兆赫無(wú)線系統(tǒng)提供了幾個(gè)優(yōu)點(diǎn)，包括更長(zhǎng)的范圍、降低的功耗和較低的部署和運(yùn)營(yíng)成本。

　　的sub-GHz無(wú)線電

　　亞千兆赫無(wú)線電可以提供相對(duì)簡(jiǎn)單的無(wú)線解決方案，可以不間斷地使用電池供電，長(zhǎng)達(dá)20年。顯著的優(yōu)勢(shì)超過(guò)2.4 GHz的無(wú)線電包括：

　　Range -- The narrowband operation of a sub-GHz radio enables transmission ranges of a kilometer or more. This allows sub-GHz nodes to communicate directly with a distant hub without hopping from node to node， as is often required using a much shorter-range 2.4 GHz solution. There are three primary reasons for sub-GHz superior range performance over 2.4 GHz applications：

　　As radio waves pass through walls and other obstacles， the signal weakens. Attenuation rates increase at higher frequencies， therefore the 2.4 GHz signal weakens faster than a sub-GHz signal.

　　2.4 GHz radio waves also fade more quickly than sub-GHz waves as they reflect off dense surfaces. In highly congested environments， the 2.4 GHz transmission can weaken rapidly， which adversely affects signal quality.

　　Even though radio waves travel in a straight line， they do bend when they hit a solid edge （like the corner of a building）。 As frequencies decrease， the angle of diffraction increases， allowing sub-GHz signals to bend farther around an obstacle， reducing the blocking effect.