Notification Events 通知事件

  • Notifications describe a general Publish/Subscribe-Concept. Usually the server publishes a service to which a client subscribes. On certain events the server will send the client a event, which could be for example an updated value or an event that occurred.
    Notification描述了一般的发布/订阅概念。通常,服务器端发布服务而客户端前来订阅。在某些事件上,服务器端向客户端发送event,该event可以是例如更新的值 或者发生的事件。
  • SOME/IP is used only for transporting the updated value and not for the publishing and subscription mechanisms. These mechanisms are implemented by SOME/IP-SD.
    SOME / IP仅用于传输更新的值,而不用于发布和订阅机制。这些机制由SOME / IP-SD实现 。
  • When more than one subscribed client on the same ECU exists, the system shall handle the replication of notifications in order to save transmissions on the communication medium. This is especially important, when notifications are transported using multicast messages.

Strategy for sending notifications发送notification的策略

For different use cases different strategies for sending notifications are possible and shall be defined in the service interface. The following examples are common:
对于不同的用例,可以使用不同的发送通知策略,并且应在服务接口中定义。 以下是常见的例子: 

  • Cyclic update循环更新
    send an updated value in a fixed interval (e.g. every 100 ms for safety relevant messages with Alive).
  • Update on change变化更新
    send an update as soon as a “value” changes (e.g. door open).
  • Epsilon change Epsilon更改
    only send an update when the difference to the last value is greater than a certain epsilon. This concept may be adaptive, i.e. the prediction is based on a history; thus, only when the difference between prediction and current value is greater than epsilon an update is transmitted.
    仅当与最后一个值的差异大于某个阈值时才发送更新。 该概念可以是自适应的,比如预测是基于历史值; 因此,只有当预测值和当前值之间的差值大于epsilon时才发送更新。