Voic 802.11e over phần 8 pdf

Ngày tải lên: 24/09/2012, 10:40

Ngày tải lên: 24/09/2012, 11:53

... Networks 14 1 QoS in 802 .11 14 3 Legacy 802 .11 MAC 14 3 DCF 14 4 PCF 14 8 Conclusion 15 3 References 15 3 9 Engineering Vo802 .11 Networks for Maximum QoS 15 5 QoS on Vo802 .11 Networks 15 5 Measuring Voice ... Transmissions 17 9 Point-to-Multipoint Links 17 9 Point-to-Point Links 17 9 Limitations in the AP 18 0 Scalability in VoIP Switching 18 1 Conclusion 18 2 References 1...

Ngày tải lên: 14/08/2014, 06:22

... stops and then enters into a random back-off procedure (Figure 2. 3). This prevents 18 Voice over 8 02. 11 16 Voice over 8 02. 11 Table 2. 2 (continued) Mac Service Description Station Type Disassociation ... can associate with multiple stations. AP 3 Voice over Internet Protocol What Is VoIP? Voice over 8 02. 11 is voice over IP used to transport voice over wireless Ethernet....

Ngày tải lên: 14/08/2014, 06:22

... with a voiced/unvoiced flag to represent the exci - tation that is applied to the filter. The filter represents the vocal tract and the voice/unvoiced flag represents whether a voiced or unvoiced ... intergateway communications. Gatekeeper technology evolved out of H .32 3 technology (a VoIP signal - ing protocol described in the next chapter). Because H .32 3 was designed for LANs, an H .32...

Ngày tải lên: 14/08/2014, 06:22

... protocol allows the extension of 802.11b and associated wireless protocols over a wide geographic area. By 94 Voice over 802.11 The 802.11b Network at 20 to 72 Miles Point-to-multipoint links ... Related to Voice over IP Reliability The chief concern service providers have when comparing competitive technol - ogy to the PSTN’s Class 4 and Class 5 switches is reliability. Class 4...

Ngày tải lên: 14/08/2014, 06:22

... needs to be encrypted and authenticated as well as meet strict performance and 120 Voice over 802.11 112 Voice over 802.11 Access point Vo802.11 p hones ❘❙❚ ❘❙❚ ❘❙❚ ❘❙❚ ❘❙❚ ❘❙❚ ❘❙❚ ❘❙❚ Internet Router IP ... Protected Access (WPA) security standard [5, pp. 81–86]. It replaced the comparably weak WEP standard previously offered for Wi-Fi equipment. 114 Voice over 802.11 Table 7.2 A Rang...

Ngày tải lên: 14/08/2014, 06:22

... which the PSTN was built: voice. Voice over a data network requires a great deal of attention to detail in engineering such a network. The primary objection to carrying voice over the Internet Protocol, ... http://www.cisco. com/en/US/products/hw/wireless/ps430/prod_bulletin09186a00800a9e74.html. 1 26 Voice over 802.11 Objections Due to Interference and QoS on Vo802.11 Wireless Networ...

Ngày tải lên: 14/08/2014, 06:22

... upper U-NII band (Figure 10.5). 176 Voice over 802.11 802.11 phone 2 .70 0 GHz 2.400 GHz 2.500 GHz 2.600 GHz Access p oint Figure 10.3 The 2.4-GHz band has three nonoverlapping channels. ( From: [3]. ... their 156 Voice over 802.11 Voice signal processing at the sending and receiving ends, which includes the time required to encode or decode the voice signal from the analog or digital f...

Ngày tải lên: 14/08/2014, 06:22

... 0.25W. 2 08 Voice over 80 2.11 13 Regulatory Considerations for Vo802.11 Networks An objection often raised about Vo802.11 applications is that because the spec- trum used by 80 2.11 (2.4 GHz for 80 2.11b ... the 194 Voice over 80 2.11 A Vo802.11 network can deploy redundant access points to cover for access points that fail. Network planners can also plan for overlapping cells of...

Ngày tải lên: 14/08/2014, 06:22

... 9. 6000 ISM–802.11b 2.4010 2.4730 Part 74 2.4500 2.4835 Part 101 2.4500 2.5000 Part 90 2.4500 2.8350 Part 25 5. 091 0 5.2500 U-NII–low 5.1500 5.2500 U-NII–middle 5.2500 5.3500 Part 97 5.6500 5 .92 50 U-NII–high ... to which the government outsources for their frequency coordination. Amateur Radio—Part 97 Amateur radio frequencies that overlap 802.11b are 2. 390 to 2.450 GHz and 5.650 to...

Ngày tải lên: 14/08/2014, 06:22

... password, 106 classes, 100 , 101 DoS, 109 10 fabrication, 104 –6 insertion, 106 interception, 101 –3 interruption, 109 man-in-the-middle, 105 –6 modification, 106 –8 reaction, 109 replay, 108 –9 repudiation, ... case study, 222–23 WLAN security model, 100 –113 DoS, 109 10 fabrication, 104 –6 interception, 101 –3 interruption, 109 modification, 106 –8 reaction, 109...

Ngày tải lên: 14/08/2014, 06:22

... Systems, make wireless LAN APs that can provide both 80 2.11b and 80 2.11a wireless AP services. If you already have a wireless LAN that uses 80 2.11b and you want to upgrade to 80 2.11a wireless LANs, ... antenna. ã 183 Now that we are familiar with the two advanced security technologies, the 80 2.1X and the VPN technologies, let's use them to build a secure wirele...

Ngày tải lên: 14/08/2014, 14:20