A CORBA-based client-server system.

MY company is looking to develop a prototype distributed Client-Server implementation, based around the CORBA architecture. It is envisaged that a monitoring station will eventually contain sensors to measure various pollutants and indicators of air quality, but initially the company will focus on nitrogen oxides as a basic proof of concept. The company has decided on an architecture for the system that comprises: the Monitoring Station, which can be installed wherever required and communicate with the rest of the system over wireless 4G networks; a Regional Centre, to which all monitoring stations in a particular geographical area will be connected; and a central Environmental Centre, to which the regional monitoring stations will report. The idea behind this architecture is both to distribute the processing and communications within the system, and to provide resilience should, for example, the central environmental centre become unavailable for some period of time. The company have asked you to prototype the system, and to make recommendations as to the suitability of the architecture and the platform selected. The requirements of the system can be broken down into a number of separate systems which will need to communicate in a client-server manner to solve the overall requirements. 1. The Monitoring Station The Monitoring Station is a stand-alone monitoring system, to be prototyped as a CORBA server, that supports certain functionality 2. The Regional Centre The Regional Centre is to be prototyped as a CORBA server that supports the following functionality at least: Receives requests to register Monitoring Stations and maintains a list of connected devices Receives alerts from connected Monitoring Stations, and maintains a log of these alerts Triggers an alarm at the Environmental Centre when two alarms happen within a specified time frame Returns the log upon request Polls all connected Monitoring Stations when requested to do so, and returns a set of readings A preliminary IDL starting specification might be: Typedef sequence<Reading> Log_of_alarm_readings; Typedef sequence<Reading> Set_of_readings; interface RegionalCentre { readonly attribute string name; readonly attribute Log_of_alarm_readings log; void raise_alarm (in Reading alarmReading ); Set_of_readings take_readings(); void add_monitoring_station(in string station_name, in string station_location, in string station_ior); } ; 3. The Environmental Centre The Environmental Centre is to be prototyped as a CORBA server that supports the following functionality at least: Receives confirmed alarms from Regional Centres Alerts the operator when a confirmed alarm is received Allows agencies (e.g. the Environment Agency, local councils, local pressure groups, etc.) to register for notifications in case of alarms Maintains a list of connected Regional Centres Polls all Regional Centres upon request and displays the results of readings returned, highlighting readings of concern A preliminary IDL starting specification might be: interface EnvironmentalCentre { void raise_alarm(in Reading alarm_reading); void register_agency(in string who, in string contact_details, in string region_of_interest); void register_regional_centre(in string centre_name) } ;