简介:随着科技的发展,广播设备不断更新,MD录音机以其体积小、重量轻、携带方便、存储量大、存储介质寿命长、编辑功能强大、音质好等优点,已逐渐成为广播领域外出录音和节目编辑的主用设备之一。
简介:Inthispaper,thecapabilityofIEEE802.11bDistributedCoordinationFunction(DCF)modesupportingofConstantBitRate(CBR)andVariableBitRate(VBR)VoiceoverIP(VoIP)trafficisinvestigated.Then,thecapacityof802.11bWirelessLocalAreaNetwork(WLAN)systemcarryingvoicecallsinawiderangeofscenarios,includingvaryingdelayandpacketlossrateconstraintsisanalyzedandevaluated.BothG.711andG.729voiceencodingschemesandarangeofvoiceinter-arrivaltimeareconsidered.Theanalysesandsimulationresultsshowthatcapacityishighlysensitivetothedelaybudgetallocatedtothesumofpacketizationandwirelessnetworkdelays.Foragivenpacketlossrateconstrained,G.729isshowntohaveacapacitygreaterthanthatwhenG.711isused.ThesimulationresultsshowthatbysupportingVBRunderDCFmodethenetworkhastheapproximatelytwicemuchcapacityassupportingCBRhas,regardlessoftheencodingschemesandtheinter-arrivaltime.