Those who know graphs theory are familiar with the “four color theorem“; an example being the world map (relaxed as a planar graph) can be colored with a minimum of four colors such that two countries sharing a border do not share the same color. Researchers at Queen Mary University of London use this theorem to color code cellular network base stations. The base stations are in abstract sense regarded as message Brokers (also termed as “Publisher Subscriber Message Oriented Middleware” – PSMOM) that channel the published message (SMS, Email, Voice packet, data packets, etc) to the Subscriber (or message recipient). Sometimes a subscriber and a publisher can be directly linked through a single broker or they may be linked through several intermediary brokers. The role of the Sahana Alerting Broker, essentially, is similar to that of a cellular base station; where decision-maker or decision-system published risk information is disseminated to the subscribers of the response systems in the form of public warnings or restricted and private alerts (also known as closed user group alerts typically applicable to first responders).