In 1984 the European Selective Paging Manufacturer's Association (ESPA for short) defined the serial data interface ESPA 4.4.4 for radio paging systems.
Since then, many producers of call systems, paging systems and alarm servers have implemented this interface and, by doing so, have made it a standard interface that is still widely applied until this day, especially to realize nurse and emergency calls to mobile caregivers.
In the recent past the requirements placed on the mobile alerting processes have, however, changed dramatically. Today, TCP/IP-LAN complements if not replaces the proprietary cabling, WiFi is taking the place of the DECT radio technology, VoIP technology is substituting the ISDN, and simple telephone sets or pagers are being replaced by multifunctional phones. In addition, sites are being increasingly linked and services are centralized.
These changes have been calling for a new kind of data coupling for mobile notification and alerting. In an answer to this call, many of the leading producers of call systems, logistics systems and alarm servers have worked together in an open community of interest to create, under the auspices of Unify GmbH & Co. KG (formerly Siemens Enterprise Communications GmbH & Co. KG) and tetronik GmbH, a common alarm server interface that meets these demands and represents a logical further advancement of the successful ESPA 4.4.4.
Together all participating partners of this process have agreed on an XML-encoded LAN interface with Client-Server-Architecture: the ESPA-X.
ESPA-X is short for:
Enhanced Signaling Protocol for Alarm Processes – XML-based
ESPA-X makes it possible to create a flexible communication platform, bringing together at the one end host systems, alarm management- and logistics systems and, in particular, call systems, with alarm servers (including paging couplers or special gateways) at the other.
Not only does ESPA-X offer standardized implementations for the manufacturers of these systems and guarantee long-term investment security for the customers, it also affords the option of proprietary expansions to utilize the capacity of the different systems in the best possible way.
ESPA-X relieves the host systems from the fast changing demands that are placed on mobile notification and alarm processes and provides a common, easy to realize access to wired and mobile telecommunication.