Mobile Data Offloading: How Much Can WiFi Deliver?
Mobile Data Offloading: How Much Can WiFi Deliver?
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DOI：
10.1109/tnet.2012.2218122
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发表时间：
2013-04-01
影响因子：
3.7
通讯作者：
Chong, Song
中科院分区：
文献类型：
--
作者：
Lee, Kyunghan;Lee, Joohyun;Chong, Song
本文对通过 WiFi 网络进行 3G 移动数据卸载的性能进行了定量研究。我们在 2010 年 2 月的两周半时间内收集了来自大都市地区的 97 位 iPhone 用户的 WiFi 连接统计数据。我们使用获取的全天轨迹进行轨迹驱动模拟表明，WiFi 已经卸载了约 65% 的总移动数据流量，并节省了 55% 的电池电量，而无需使用任何延迟传输。如果数据传输可以在一定期限内延迟，直到用户进入 WiFi 区域，那么只有当期限远大于数十分钟时才能获得实质性收益。延迟 100 秒时，可实现的增益仅低于 2%-3%，而延迟 1 小时或更长时，流量和节能增益分别增加超过 29% 和 20%。这些结果与现有工作报告的显着增益 (20%-33%) 形成鲜明对比，即使使用从公共汽车或战争驾驶中获取的痕迹进行 100 秒的延迟传输。此外，还提出了基于分布模型的模拟器和理论框架，可以对卸载的平均性能进行分析研究。这些工具对于网络提供商来说非常有用，可以粗略估计给定 WiFi 部署条件下的平均卸载性能。
This paper presents a quantitative study on the performance of 3G mobile data offloading through WiFi networks. We recruited 97 iPhone users from metropolitan areas and collected statistics on their WiFi connectivity during a two-and-a-half-week period in February 2010. Our trace-driven simulation using the acquired whole-day traces indicates that WiFi already offloads about 65% of the total mobile data traffic and saves 55% of battery power without using any delayed transmission. If data transfers can be delayed with some deadline until users enter a WiFi zone, substantial gains can be achieved only when the deadline is fairly larger than tens of minutes. With 100-s delays, the achievable gain is less than only 2%-3%, whereas with 1 h or longer deadlines, traffic and energy saving gains increase beyond 29% and 20%, respectively. These results are in contrast to the substantial gain (20%-33%) reported by the existing work even for 100-s delayed transmission using traces taken from transit buses or war-driving. In addition, a distribution model-based simulator and a theoretical framework that enable analytical studies of the average performance of offloading are proposed. These tools are useful for network providers to obtain a rough estimate on the average performance of offloading for a given WiFi deployment condition.