本文件规定: —？本地化消息(LM)格式:不支持通过网络路由分组的联网和传输层协议的NPDU； —？服务通告消息(SAM):例如要在LM中传输的APDU； —？服务响应消息(SRM):例如，确认基于要在LM中传输的ITS应用类[2]提供服务的SAM的APDU； —？程序的相关基本要求。 规范部分是通过对IEEE的规范性引用来完成的？1609.3(TM)-2016。 笔记？这些消息格式规范和基本程序需要根据使用环境（即ISO 21217中规定的ITS站或IEEE 1609.0[13]中规定的WAVE设备或任何其他环境）由完整的程序和SAP规范来补充。

This document specifies: —？the Localized Message (LM) format: an NPDU of a networking & transport layer protocol that does not support routing of a packet through a network; —？the Service Advertisement Message (SAM): an APDU to be transported in an LM, for example; —？the Service Response Message (SRM): an APDU acknowledging a SAM that offered a service based on an ITS application class^[2] to be transported in an LM, for example; —？related basic requirements for procedures. Specifications are partly done by normative references to IEEE？1609.3(TM)-2016. NOTE？These message format specifications and basic procedures need to be complemented by complete procedures and SAP specifications according to the context of usage, i.e. an ITS station specified in ISO 21217, or a WAVE device specified in IEEE 1609.0^[13] or any other context.