本ETS修正案的目的是纠正PE 82和后续V99发布文件中的错误。如果现有范围不应改变，ETS定义了信道聚合单元的操作协议，以64 kbit/s的速度实现多个ISDN信道的同步和聚合，这些信道具有+/-1秒范围内的差分延迟，并具有或不具有八位字节完整性结构。它还解决了与限制在56kbit/s速率的数字网络互通的情况。它适用于使用ISO/IEC 13871的范围广泛的用户数据传输，最多63个信道，但根据ETS 300 144，对视听系统作出了特殊规定，最多24个信道； 聚合可以是基于网络的，也可以与客户场所设备相关联。可用的操作模式（B1、B2、B3、H2）提供了带/不带传输管理开销的选项，用户数据速率等于或小于64 kbit/s或56 kbit/s的精确倍数。聚合信道的数量在会话期间可能会动态变化。给出了处理故障的程序，包括通道丢失和打滑。呼叫控制不在本ETS的范围内。

The purpose of the amendment to this ETS is to correct the errors in the published document following the PE 82 and subsequent V99. Where the existing scope shall not be altered from This ETS defines protocols for the operation of a Channel Aggregation Unit effecting synchronisation and aggregation of multiple ISDN channels at 64 kbit/s, these channels being with a differential delay in the range of +/-1 second and with or without octet integrity structure. It also addresses the case of interworking with a digital network restricted to a rate of 56kbit/s. It is applicable to a wide range of user data transport up to 63 channels using ISO/IEC 13871, but special provision is made for audiovisual systems according to ETS 300 144, up to 24 channels; the aggregation may be network-based or associated with Customer-Premises Equipment. The available operating modes (B1, B2, B3, H2) provide options with/without transmis sion-management overhead and user-dat a rates at or less than the exact multiples of 64 kbit/s or 56 kbit/s.The number of aggregated channels may be varied dynamically during asession. Procedures are given for dealing with faults, including loss of channels and slip. Call control is outside the scope of this ETS.