Communication synchronous

A. Synchronous communications uses a clock signal that is separate from the data signal communication can only happen during a tick of the timing signal. 

The third core connector is the synchronous communication, it connects activities whose execution requires communication between the actors involved (e.g., during project meetings). 

To integrate synchronous and asynchronous communication tools into distributed work sessions, a framework was created which rnodularly incorporates different tools into one interface. In this context, synchronous communication comprises all those services which support multimedia conferencing. This includes not only the real-time transmission of audio/video data, but also the usage of locally installed design tools by the whole team. 

For the integration with AHEAD, the communication process is independent from the process models described in Chapter 2. The communication process adds communication and cooperation possibilities to the C3 model (see Sect. 2.4). Detailed information about synchronous communication for certain tasks is provided. On the one hand, this is done by specifying requirements in terms of Quality of Service for the transmission. Figure 3.48 shows the parameters necessary for different communication types. 

A conference management system is an important mechanism for formalizing interactions between communicating parties. Only such a system enables a controlled flow of a synchronous communication. 

There is a further influence of the synchronous communications on the project duration. Synchronous communications between the activities occupy the required persons of the participating organizational units. Employees are picked from the activity network and scheduled for the discussion by the simulation model. These employees cannot execute other activities during this time. Such communication relationships are a characteristic for design processes, and therefore their effect should be examined more carefully in future. 

For an integration with AHEAD, the communication process during a cooperation is to be seen independent of the process models of the other IMPROVE subprojects in the first step. The communication process extends the C3 model of communication and cooperation possibilities. To do so, detailed information about synchronous communication for certain tasks is provided. This is achieved by using a layered model (see Sect. 3.3) of communication relationships. This model is connected to the model of AHEAD to offer the possibility to model multimedia conferences as separate management tasks, for enabling KomPaKt to get configuration information from AHEAD etc. 

Synchronous communication comprises services such as audio-visual realtime data exchange, which can be used for conferences between locally distributed design team members. Asynchronous tools such as email or audio message allow communication if the team members are not available simultaneously. 

Work processes performed during a concrete design project are represented using the semi-formal C3 notation (see Subsect. 2.4.4). In particular, C3 provides modeling concepts for the activities in design processes, the information items (products) created and employed during the activities, and the complex interdependencies between different activities (such as synchronous communication between several actors) and between activities and information items (information flow). 

For each process P,, define a process P/ which consists of P,- in synchronous communication with the kernel fragment Ki dealing with its signals. Both intercommunicate only on the signals Si scheduled by Pi and on the clock ... 

Synchronized communication and control algorithm are coordinated in a way that input data are taken, then communicated, control output computed, then communicated, and lastly actuated. 

CORBA objects are accessed by applications, for example by Java applets or CGI (common gateway interface) scripts for Web services though the HOP (Internet Inter-ORB Protocol). HOP is a general protocol for communication between objects and applications. Once an application talks HOP, for example, by loading an ORB Java class, all CORBA services can be accessed. One of the weaknesses of CORBA, especially in the computational chemistry context, is that it is rather geared towards synchronous communication. An immediate response is not always a reasonable prerequisite for this type of application. 

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