Signal: An open-source cross-platform universal messaging system with feedback support

This research addressed challenges of the cross-platform push messaging service where every modern device could send messages and receive feedback among a multitude of different receiving devices. The design and implementation of Signal-a universal cross-platform messaging system-was proposed as a solution. Signal provided both the messaging service middleware and application. It comprised a set of messaging languages for describing, querying and mapping message payloads as well as defining and customizing feedback. These languages were describable, human readable, and extensible, each of which came equipped with its own parser. The Signal architecture was designed for scalability by building extensible modules and applying scalable convenient tools, namely, RabbitMQ, Google-GSON and Quartz Scheduler. Its real-time schedulers were well-suited for a wide range of message payloads. It could deliver messages, practically, to all major messaging platforms with accessible APIs, HTML5-enabled WebSockets, and TCP-based applications. The research was validated via two case studies. The results showed ease of deployment through the unified Signal APIs while being able to attain a 100% reach to receivers with the best achievable performance of more than 1,300,000 basic notification payloads in a second.