Cisco 7925G Administration Guide - Page 35

Chapter 2 Overview of the VoIP Wireless Network Understanding WLAN Standards and Technologies Table 2-2 Tx Power, Data Rates, Ranges, and Decibels by Standard Standard Maximum Tx Power1 Data Rate2 Range Receiver Sensitivity 802.11a 40mW 6 Mbps 610 ft (186 m) -89 dBm 9 Mbps 610 ft (186 m) -88 dBm 12 Mbps 558 ft (170 m) -86 dBm 18 Mbps 541 ft (165 m) -85 dBm 24 Mbps 508 ft (155 m) -82 dBm 36 Mbps 426 ft (130 m) -80 dBm 48 Mbps 328 ft (100 m) -76 dBm 802.11g 54 Mbps 295 ft (90 m) -74 dBm 40mW 6 Mbps 722 ft (220 m) -90 dBm 9 Mbps 656 ft (200 m) -89 dBm 12 Mbps 623 ft (190 m) -87 dBm 18 Mbps 623 ft (190 m) -85 dBm 24 Mbps 623 ft (190 m) -82 dBm 36 Mbps 492 ft (150 m) -78 dBm 48 Mbps 410 ft (125 m) -74 dBm 54 Mbps 394 ft (120 m) -73 dBm 802.11b 50mW 1 Mbps 1,027 ft (313 m) -95 dBm 2 Mbps 951 ft (290 m) -89 dBm 5.5 Mbps 853 ft (260 m) -89 dBm 11 Mbps 787 ft (240 m) -85 dBm 1. Adjusts dynamically when associating with an AP if the AP client setting is enabled. 2. Advertised rates by the APs are used. If the Restricted Data Rates functionality is enabled in the Cisco Unified Communications Manager Administration phone configuration, then the Traffic Stream Rate Set IE (CCX V4) is used. Wireless Modulation Technologies Wireless communications uses the following modulation technologies for signaling: • Direct-Sequence Spread Spectrum (DSSS)-Prevents interference by spreading the signal over the frequency range or bandwidth. DSSS technology multiplexes chunks of data over several frequencies so that multiple devices can communicate without interference. Each device has a special code that identifies its data packets and all others are ignored. Cisco wireless 802.11b/g products use DSSS technology to support multiple devices on the WLAN. OL-15984-01 Cisco Unified Wireless IP Phone 7925G Administration Guide for Cisco Unified Communications Manager 7.0(1) 2-5