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 Bo Yan Department of Computer Science, University of Massachusetts Lowell

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 Bo Yan Department of Computer Science, University of Massachusetts Lowell

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 * log 10 P + 30

expresses an arbitrary power P as x dBm Bo Yan Department of Computer Science, University of Massachusetts Lowell

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 Bo Yan Department of Computer Science, University of Massachusetts Lowell

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  Value in dBm EVDO Ec/Io  Value in dB * 10 EVDO SNR (Signal to Noise Ratio)   Value in range from 0 to 8 SNR[dB] = RSSI[dBm] – NOISE[dBm] Bo Yan Department of Computer Science, University of Massachusetts Lowell

Cellular Network States

 Call states  IDLE, RINGING, OFFHOOK  Incoming phone number  Data activity  IN, OUT, INOUT, DORMANT  Data connection states  DISCONNECTED, CONNECTING, CONNECTED, SUSPEND Bo Yan Department of Computer Science, University of Massachusetts Lowell

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 Bo Yan Department of Computer Science, University of Massachusetts Lowell

Network Performance

 Network Latency  Ping command result  Socket connection latency  Network Goodput  Ping command result  Upload/download test to/from a target server Bo Yan Department of Computer Science, University of Massachusetts Lowell

Location

 Geo-coordinates  Latitude and longitude  Help identify dead zone  Cell tower  Report weak signal coverage Bo Yan Department of Computer Science, University of Massachusetts Lowell

User Behavior

 Accelerometer Sensor  Infer movement from 3D accelerations  Light Sensor  Day time or mid night Bo Yan Department of Computer Science, University of Massachusetts Lowell

Example – Troubleshoot Network Connectivity

PHONE TYPE

CDMA

DATA ENABLED

YES GSM

AIRPLANE MODE

NO

REPLACED BY WI-FI

NO YES

CELLULAR SIGNAL SIM CARD READY

YES

SUPPLICANT STATE

CONNECTED

WI-FI SIGNAL

Bo Yan Department of Computer Science, University of Massachusetts Lowell

Example – Network Latency

LATENCY TO WEBSITE

ABNORMAL NORMAL

LATENCY TO CARRIER

ABNORMAL

LATENCY TO INTERNET PACKET DROP

HEAVY

CELLULAR SIGNAL

Bo Yan Department of Computer Science, University of Massachusetts Lowell