Section: 10.5.4.16 High layer compatibility
Content: The purpose of the high layer compatibility information element is to provide a means which should be used by the remote user for compatibility checking. See annex B. The high layer compatibility information element is coded as shown in figure 10.5.102/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  and table 10.5.125/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] . The high layer compatibility is a type 4 information element with a minimum length of 2 octets and a maximum length of 5 octets. NOTE: The high layer compatibility information element is transported transparently by a PLMN between a call originating entity (e.g. a calling user) and the addressed entity (e.g. a remote user or a high layer function network node addressed by the call originating entity). However, if explicitly requested by the user (at subscription time), a network which provides some capabilities to realize teleservices may interpret this information to provide a particular service. Figure 10.5.102/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ]  High layer compatibility information element If the value part of the IE is empty, the IE indicates "not applicable". NOTE: Octet 4a may be present e.g. when octet 4 indicates Maintenance or Management, or audio visual. Table 10.5.125/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] : High layer compatibility information element