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Traditional 802.11 power saving mechanism (PSM) treats multicast and broadcast traffic equally, and suffers significant performance degradation with multicast background traffic. This paper proposes an enhanced PSM that effectively differentiates multicast streams. It re-arranges the virtual bitmap of the traffic indication map (TIM) to carry traffic status for multicast groups and introduces a concept of sequential transmission of multi-addressed data to facilitate differentiation among multicast groups. Our analysis shows that the enhanced PSM can effectively save power in mixed traffic environments. 相似文献
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现代远程教育是一个崭新的领域,它强调以学生为主体的自主学习方式,学习支持服务是其重要组成部分,是保证远程教育成功的关键。学生的学习活动和学习目标的最终实现建立在学习支持服务的基础上,学生的学习效果和学习质量关键要看支持服务的质量如何。从云南地理交通状况的实际出发.分析了远程教育在该地区的特殊需求,从而有针对性地提出了有特色的学习支持服务。 相似文献