Method and protocol tester for decoding data encoded in accordance with a protocol description

#The present invention relates to protocol testing, and more particularly to a method and a protocol tester for decoding data encoded in accordance with a protocol description for the performance of a measurement task.

#Particularly in protocol measurement technology, the encoding, decoding and analysis of digital data occupies a central role, with so-called protocol data units being examined by computer software and the information contained therein being extracted. In this context, FIG. 1 shows a procedure known from prior art, in which an interpretative decoder 10 reads a general protocol description 12 and, based on the protocol description, decodes encoded data 14 also read in, and makes the data available as decoded information 16 to a processing device 20. The general protocol description is firm, suited for a plurality of measurement tasks and describes the encoded data, as a maximum, exactly down to each bit. The general protocol description preferably includes information on the meaning of the bits, the names of bit groups, the format of the presentation, for example a string, hexadecimal or binary, and on the formation of summaries in the form of parameters or messages. In contrast to firm decoding routines, which exist unchangeably for certain protocols, interpretative decoding routines, i.e. decoders with an interpreter, have the advantage that the very same hardware can be adapted easily to different protocols by loading the corresponding general protocol description of the associated protocol. Tree-structured protocol descriptions, however, lead to a high storage demand for a reduced calculation expense, while linear protocol descriptions lead to an increased calculation expense for a reduced storage demand.

#There is also the possibility to manually program protocol descriptions for certain repetitive measurement tasks, the disadvantage being that the manually programmed protocol descriptions are designed for a certain measurement task and are therefore already no longer suitable for performing a slightly modified measurement task. In particular, it proves awkward and time-consuming, depending on the measurement task to be resolved, to select and load into the decoder device a suitable protocol description programmed manually in a reduced manner. In order to be able to perform any measurement tasks, it is therefore necessary, in the prior art, to work with the general protocol description which, regardless of whether it shows a linear structure or a tree structure, leads to a high calculation expense for the decoding process.

#FIG. 1 is a schematic representation of elements of a protocol tester known from prior art.

#FIG. 2 is a schematic representation of elements of a second protocol tester known from prior art.

#FIG. 3 is an embodiment of a protocol tester according to the present invention.

#Referring now to FIG. 3 a first embodiment of a protocol tester according to the present invention is shown which executes a compressed protocol description, with protocol elements of the protocol description which are of no relevance with respect to the measurement task being combined with respect to the measurement task to be performed, or, respectively, with dependencies and/or conditions being combined, or respectively, skip commands being incorporated into the protocol description, the skip commands being worded such that at least the subsequent part of the protocol description which is irrelevant with respect to the measurement task is skipped, or, respectively, a stop command being included at a point of the protocol description in case it is certain that all protocol elements of the relevant protocol description have already been decoded. Compared with FIG. 1 one notices that in FIG. 3 in the protocol description the first four protocol elements have been combined, as they are not relevant for the measurement task assumed as an example. This compression of the protocol description is performed by a device 15a for the modification of the protocol description. To this end, an operator is shown a selection menu on a display 17, for example a computer screen, on which the operator can specify a measurement task by a corresponding selection and entry. With regard to the selection and entry by the operator, the device 15a for the modification of the protocol description modifies the general protocol description 12 to the compressed protocol description 12a. The decoder 10, which reads the compressed protocol description 12a, makes available to the processing device 20 decoded information 16a, as is seen more clearly below.

#A compression of the protocol description can particularly occur through one or several of the following steps:

#a) Combining of protocol elements of the protocol description, which are of no relevance with respect to the measurement task; and/or