WLAN运营解决方案.pptVIP

WLAN无线技术与应用 朱伟雄 weixzhu@ 思科系统（中国）有限公司 议题 WLAN 的增长预期 WLAN 部署场合 WLAN业务应用—数据、语音、视频、定位 WLAN无线标准组织 IEEE 802.11 已完成的标准 IEEE 802.11 - The original 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and IR standard (1999) IEEE 802.11a - 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001) IEEE 802.11b - Enhancements to 802.11 to support 5.5 and 11 Mbit/s (1999) IEEE 802.11c - Bridge operation procedures; standard (2001) IEEE 802.11d - International (country-to-country) roaming extensions (2001) IEEE 802.11e - Enhancements: QoS, (2005) IEEE 802.11F - Inter-Access Point Protocol (2003) Withdrawn February 2006 IEEE 802.11g - 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003) IEEE 802.11h - Spectrum Managed 802.11a (5 GHz) for European compatibility (2004) IEEE 802.11i - Enhanced security (2004) IEEE 802.11j - Extensions for Japan (2004) IEEE 目前发展的标准 IEEE 802.11k - Radio resource measurement enhancements IEEE 802.11m - Maintenance of the standard; odds and ends. IEEE 802.11n - Higher throughput improvements using MIMO IEEE 802.11p - WAVE - Wireless Access for the Vehicular Environment IEEE 802.11r - Fast roaming Working IEEE 802.11s - ESS Mesh Networking IEEE 802.11T - Wireless Performance Prediction (WPP) (test methods and metrics recommendation) IEEE 802.11u - Interworking with non-802 networks (for example, cellular) IEEE 802.11v - Wireless network management IEEE 802.11w - Protected Management Frames IEEE 802.11y - 3650-3700 Operation in the U.S. Note: 802.11 L, O, Q and X are reserved by IEEE and have not been defined. 无线局域网技术演进 无线局域网采用的非专用频段: 工业、科研、医学(ISM)频段 802.11b 工作在 2.4 GHz ISM 频段 速率为 1, 2, 5.5 和 11 Mbps 采用 Direct Sequence Spread Spectrum (DSSS) modulation调制技术 最多可以有 14 个channels 11 U.S channels; 13 ETSI channnels, 14 Japan channels 只有3 不重叠的channels 802.11b典型的速率与距离 802.11g 工作在2.4 GHz ISM 频段 速率为 6, 9, 12, 18, 24, 36, 48 和 54 Mbps 采用 Orthogonal Frequency Division Multiplexing (OFDM) modulation 调制