Control and data flow aspects in the design of a wireless data radio modem: a case study

We present the design of a radio modem for the MOBITEX wireless data system. The MOBITEX interface specification defines the protocols that are used for communication between the MOBITEX network and mobile terminal devices. The specification refers to the ISO/OSI standards and defines the link layer and the physical layer of the air-link radio protocol for mobile terminals, as well as the network layer protocol that describes how packets are transmitted between the sender and the addressee. Because the design of a MOBITEX radio modem should serve as an application case study for identifying the needs in a joint air-link and network protocol design, we use different existing design methods and software tools for the specification of the lower three layers. For analyses and design we use Rumbaugh's object modeling technique (OMT). For implementation and validation we apply the standardized specification and description language SDL and data-flow oriented system specifications.