170 likes | 364 Views
Observing Home Wireless Experience through WIFI APs. MOBICOM 2013 Ashish Patro , Srinivas Govindan , Suman Banerjee @University of Wisconsin Madison. Presented By Tianyu Chen @ EmNets Seminar, 2013-9. Motivation. How to identify WIFI experience @ home? Challenges
E N D
Observing Home Wireless Experience through WIFI APs MOBICOM 2013 Ashish Patro, SrinivasGovindan, SumanBanerjee@University of Wisconsin Madison Presented By Tianyu Chen @EmNets Seminar, 2013-9
Motivation • How to identify WIFI experience @ home? • Challenges • WiFi experience != pdr • Solution • Measure WIFI experience by observing TCP throughput • How to measure TCP throughput of a wireless link? • Challenges • TCP throughput != TCP flow • Solution • WiSe AP Deployment (2 NIC, Full Control) • WITT Metric
A closer look @ WiSe AP NIC 2: Sniffer NIC NIC 1: Normal NIC
WITT Metric (WiFiTCP Throughput)Design • a: airtime. Airtime utilization ratio from external sources. • c: local contention. Self generated traffic ratio of the same AP. • r: effective rate. A combined view of PHY rate and loss rate.
Measurement Analysis Methods • Input (>100GB) • WITT[u, a, t] • TCP Throughput of link between user u and AP a at time t • e.g. WITT[laptop1, EAGLE, 19:00-19:05]=20Mbps • Output • Wireless experience across space & time • Causes of poor wireless experience • WiFi/Non-Wifi Interference
Discussion • Key idea • Replace packet delivery rate (0-1 model) with throughput (continuous model) • Key contribution • Define a metric, Witt, to measure wireless TCP throughput • Comment • Cons • Provide a more fine-grained view than previous works • Cost-effective • Pros • Lack of impressive conclusions