The operation of the GSM chipset, the modem, and the entire eCall system must be exhaustively tested in the development phase, and its performance verified in production, to provide confidence that it will communicate reliably in all specified conditions. Just like a mobile phone handset, the in-band modem must be able to operate in the presence of multiple sources of interference, or with a weak signal, and must correctly implement a complex protocol for establishing and maintaining a voice/data connection.
Ultimately, automotive system suppliers will have to verify the performance of eCall systems (and other in-car mobile phone technologies) on the road, in a live network. But the use of a network simulator before live testing takes place allows the manufacturer to test in the laboratory every aspect of an eCall system’s interaction with any mobile network globally. Isolated from a live network, the simulator enables the tester to perform repeatable tests in which failures can be accurately attributed to a known cause, without interference from the random and uncontrolled events that occur in a live network.
An instrument such as the MD8475A from Anritsu is suitable for this: it operates as a base station simulator, supporting the 3GPP protocols in operation today, and beginning from legacy GSM up to the latest LTE-Advanced standards. Through a user-friendly graphical interface (in the case of the MD8475A, this is called ‘Smart Studio’), the device designer can quickly implement hundreds of pre-defined test routines. It also provides an environment for the creation of abnormal network behaviour. Furthermore, specific software packages allow its enhancement