There are plenty of anecdotal stories of seemingly random delays lasting multiple hours or even days in many countries where we work. While network congestion and growing infrastructure are often to blame for SMS unreliability, there are also legitimate concern that delays may be an indication of deliberate message filtering and monitoring.
What has emerged is an environment in which activists and human rights defenders are unable to clearly understand what networks - and what behavior - is safe or hazardous for themselves or their contacts. The end goal of this research, put simply, is to change this paradigm. Rumors of keyword filtering are not helpful; what is helpful is any evidence of surveillance.
SMSTester is a simple Android app that allows a user create a set of keywords to be sent as SMS messages. This allows the user to explore differences in latency for any type of message - from basic, everyday text like ‘milk’ or ‘newspaper’ to politically inflammatory text such as ‘revolution.’
We then set up a logging mechanism to timestamp and record each SMS as it is sent (from the sender side) or received (on the receipt side). By comparing the sent and received timestamps, we’re very easily able to calculate message latency from one SIM to another.
The application is designed to be installed on both sides of a single SMS conversation: a sender uses the app to automatically transmit a series of messages to the receiver, where incoming messages are logged upon receipt. Diagnostic data from the send side can be optionally included in the message payload itself such that the receive side can parse, analyze and display test results without needing access to data from the send side. This feature drastically improves flexibility and enables effective testing without requiring physical co-location.
Each message sent is coded with a unique GUID by the application so that data sets from both sides can be later combined if necessary. The output of the data is stored on the device SDCard in comma separated value (CSV) format, which makes it easy to import and parse in any office spreadsheet application.
MobileActive.org
SMSTester for Android Locations
There are plenty of anecdotal stories of seemingly random delays lasting multiple hours or even days in many countries where we work. While network congestion and growing infrastructure are often to blame for SMS unreliability, there are also legitimate concern that delays may be an indication of deliberate message filtering and monitoring.
What has emerged is an environment in which activists and human rights defenders are unable to clearly understand what networks - and what behavior - is safe or hazardous for themselves or their contacts. The end goal of this research, put simply, is to change this paradigm. Rumors of keyword filtering are not helpful; what is helpful is any evidence of surveillance.
SMSTester is a simple Android app that allows a user create a set of keywords to be sent as SMS messages. This allows the user to explore differences in latency for any type of message - from basic, everyday text like ‘milk’ or ‘newspaper’ to politically inflammatory text such as ‘revolution.’
We then set up a logging mechanism to timestamp and record each SMS as it is sent (from the sender side) or received (on the receipt side). By comparing the sent and received timestamps, we’re very easily able to calculate message latency from one SIM to another.
The application is designed to be installed on both sides of a single SMS conversation: a sender uses the app to automatically transmit a series of messages to the receiver, where incoming messages are logged upon receipt. Diagnostic data from the send side can be optionally included in the message payload itself such that the receive side can parse, analyze and display test results without needing access to data from the send side. This feature drastically improves flexibility and enables effective testing without requiring physical co-location.
Each message sent is coded with a unique GUID by the application so that data sets from both sides can be later combined if necessary. The output of the data is stored on the device SDCard in comma separated value (CSV) format, which makes it easy to import and parse in any office spreadsheet application.
MobileActive.org
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