Decimal error correction of SMS messages for automated data collection

Error Correction is a broad topic which is used across various fields from Deep Space Communications to Computer Science applications like Data Storage. The basic idea here is to recover lost data in the channel due to noise and interference. In Telecommunications, this is done by common methods like Automatic Repeat Request, Forward Error Correcting Codes or Hybrid methods which combine both. In this research, an SMS messaging system is developed for Health Care purposes which include broadcasting and polling of SMS messages targeted for Health Intervention among adolescent Latino girls.

The concept of Error Correction is further extended to correct mistyped Decimal poll numbers which are received from participants. The SMS Messaging System itself consists of a Windows Desktop Application which is connected to a GSM modem for sending and receiving SMS messages. An SQL Server database is used for storing the message and client information. The communication between the GSM modem and the database is done using a third party Windows service which is running in the background.

The purpose of the research here is to investigate the use of one of the Hybrid Schemes of Error Correction for an automated data collection system that uses SMS messages for conducting polls among multiple participants. The participants are assumed to reply with decimal digits as answers to poll questions. The decimal digits consist of redundancy in the original data in the form of check digits. This data is broadcast to participants using a GSM modem and the responses are collected and stored in a database.

Decimal Error Correction is used to correct the incoming SMS messages with Single Error Correcting codes similar to the binary version of Hamming Codes. A VBScript is used to process every incoming message with algorithm used for Decimal Error Correction. The system is designed to send automatic reply messages for successful as well as incorrect responses which are analogous to an Automatic Repeat Request System. Finally, simulation results are shown for comparing the performance of the error correction methodology used.