Generalized spare extension field usage in frame protocol data frame

摘要

A protocol (and corresponding equipment) for use in communicating between a sending node (11) and a receiving node (12) a frame (10) including a Spare Extension (SE) section conveying values for one or more information element (IE) fields, and also including a New IE Flags IE or other device for indicating to the receiving node (12) whether the SE section includes valid data for each IE in the SE section. A flag indicating whether valid data is provided in the SE section can be used, and also an IE indicating the length of the SE section. The protocol is such that the receiving node (12) treats an IE field value occurring in the SE section as spare bits if the IE field was introduced for a version of a later release of a specification than that according to which the receiving node (12) was implemented.