Section: 9.3.2.2 Bearer capability 1 and bearer capability 2
Content: The bearer capability 1 information element shall be included if and only if at least one of the following six cases holds: - the mobile station wishes another bearer capability than that given by the bearer capability 1 information element of the incoming SETUP message; - the bearer capability 1 information element is missing or not fully specified in the SETUP message; - the bearer capability 1 information element received in the SETUP message is accepted and the "radio channel requirement" of the mobile station is other than "full rate support only mobile station"; - the bearer capability 1 information element received in the SETUP message indicates speech and is accepted and the mobile station supports CTM text telephony; - the bearer capability 1 information element received in the SETUP message indicates speech and is accepted and the mobile station supports other codecs for GERAN than GSM speech version 1; - the bearer capability 1 information element received in the SETUP message included the "fixed network user rate" parameter. When the bearer capability 1 information element is followed by the bearer capability 2 IE in the SETUP, the above rules apply to both bearer capability 1 IE and bearer capability 2 IE. Except those cases identified in 3GPP TS 27.001[ General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) ]  [36], if either bearer capability needs to be included, both shall be included. Furthermore, both bearer capability information elements may be present if the mobile station wishes to reverse the order of occurrence of the bearer capability information elements (which is referred to in the repeat indicator information element, see subclause 10.5.4.22) in cases identified in 3GPP TS 27.001[ General on Terminal Adaptation Functions (TAF) for Mobile Stations (MS) ]  [36]. If the mobile station wishes to indicate capability for an alternative call mode, which can be entered during the call through in-call modification, this is indicated by adding a bearer capability information element (bearer capability 2 information element, see subclause 5.3.6).