Friday, February 27, 2009

Common Alerting Protocol messages over Radio Data System

In several blogs I've mentioned my work in relation to Common Alerting Protocol (CAP) a standard that is being absorbed by emergency communicators for exchanging situational reports in relation to natural and man-made threats. Past month I was in Sri Lanka, predominantly, attending to field work on the real-time biosurveillance program, my current ongoing project, which is using CAP for issuing health alerts (situational reports) to health workers. During this visit I was invited by CEL Lanka to review their home brewed Radio Data System (RDS) for issuing text alerts over FM radio waves.

The RDS for alerting comprises a special FM radio developed by CEL Lanka that can receive text to display as well as turn on an audible siren according to a priority level, a larger LCD display to be assemble in public spots such as bus stations, road side, trains, etc, and a software module to communicate with the encoder for generating text messages in Sinhala, Tamil, and English languages. This project had been funded by the Information Communication Technology Agency of Sri Lanka (ICTA) under a small grant. CEL Lanka has produced 40 of the LCD units to be deployed in location around the Island.

I recommended that the system incorporate CAP for value addition; more so for being CAP compliant to receive a CAP message and automatically feed the required data to the RDS text element. This way the system can be easily plugged in to any existing Disaster Communication Software system without too many changes such as a P2P CAP Broker. Similar to SMS alerts or Email alerts one can include RDS as another medium for receiving alerts.

CEL Lanka is interested in enabling the system with CAP. We will include the RDS as a plug in to the Sahana Messaging Module. Another similar project is the inclusion of a gateway to send and receive text over HF Radios being developed by Universiti Teknologi Malaysia (UTM). Respere Lanka developed the SMS/Email engine for issuing text alerts. Respere will come in as a partner to develop the web browser based GUI to trigger CAP alerts to be transported through the RDS.

Similar to SMS, RDS also has limitations on the number of characters that each packet can carry. Concatenation of packets pose the same problem as SMS pages; where packets/pages not arrive in the same sequence they are sent. These are some of the few challenges that lie ahead in delivering this component. Over the next few weeks I will be working on the software architecture and the CAP profile for including the RDS in to the Sahana Messaging Module. We intend to apply for a small grant to produce the remaining components.

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