Using Mobile Metrics to Drive Network Analysis on Android Devices Bo Yan Department of Computer Science University of Massachusetts Lowell

Network Analysis An important research topic as many communicate via mobile devices Troubleshoot network connectivity Diagnose network performance

What Kind Of Metrics Do We Have Network metrics Signal strength Connection states Latency and bandwidth Context information Location Geo-coordinates Cell tower User Behavior Indoor/outdoor Still/moving

Signal Strength Signal Strength dBm (or dBmW) is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW) X = 10 * log10P + 30 expresses an arbitrary power P as x dBm

Cellular Signal Strength - GSM GSM signal ASU (Active Set Update) An integer value proportional to the received signal strength In range from 0 to 30, and 99, defined in 3GPP TS 27.007 8.5 Signal[dBm] = -113 + 2 * Signal[asu] GSM Bit Error Rate In range from 0 to 7, and 99, defined in 3GPP TS 27.007 8.5 RXQUAL_0, BER < 0.2% RXQUAL_1, 0.2% < BER < 0.4% RXQUAL_2, 0.4% < BER < 0.8% RXQUAL_3, 0.8% < BER < 1.6% RXQUAL_4, 1.6% < BER < 3.2% RXQUAL_5, 3.2% < BER < 6.4% RXQUAL_6, 6.4% < BER < 12.8% RXQUAL_7, 12.8% < BER

Cellular Signal Strength - CDMA CDMA RSSI (Received Signal Strength Indication) Value in dBm CDMA EC/IO Value in dB * 10 The ratio of received pilot energy, Ec, to total received energy, Io. Ec/Io[dB] = RSSI[dBm] – RSCP[dBm] EVDO RSSI EVDO Ec/Io EVDO SNR (Signal to Noise Ratio) Value in range from 0 to 8 SNR[dB] = RSSI[dBm] – NOISE[dBm]

Cellular Network States Call states IDLE, RINGING, OFFHOOK Incoming phone number Data activity IN, OUT, INOUT, DORMANT Data connection states DISCONNECTED, CONNECTING, CONNECTED, SUSPEND

Wi-Fi Network States Wi-Fi supplicant states ASSOCIATED, ASSOCIATING, AUTHENTICATING, COMPLETED, DISCONNECTED, DORMANT, FOUR_WAY_HANDSHAKE, GROUP_HANDSHAKE, INACTIVE, INTERFACE_DISABLED, INVALID, SCANNING, UNINITIALIZED Access Point SSID and BSSID link speed

Network Performance Network Latency Ping command result Socket connection latency Network Goodput Upload/download test to/from a target server

Location Geo-coordinates Latitude and longitude Help identify dead zone Cell tower Report weak signal coverage

User Behavior Accelerometer Sensor Infer movement from 3D accelerations Light Sensor Day time or mid night

Example – Troubleshoot Network Connectivity

Example – Network Latency