SMART ACK Usage Scenario

Owned by Matthias Kassner
11-Jul-2024
2 min read

The goal of SMART ACK is to provide a mechanism whereby an energy-constrained device can retrieve information (transmit a request, receive a response) from a line-powered device with minimal required energy.

The illustration below shows the steps that are potentially involved in retrieving such information. Note that not all steps might be present.

image-20240708-085541.png
SMART ACK Usage Scenario

The illustration above shows possible steps and actors involved for an energy-harvesting device in retrieving information from a user application. Note that not all steps and actors need to be present:

  • EH Device (For instance a Heating Valve)
    The energy-constrained EH DEVICE transmits a request towards the USER APPLICATION to obtain the latest desired set point value

  • Repeater #1
    As there is no direct connection between EH Device and the EnOcean IP Gateway, the first-level repeater Repeater #1 repeats the request from EH Device

  • Repeater #2
    As there is no direct connection between Repeater #1 and EnOcean IP Gateway, the second-level repeater Repeater #2 repeats the request from Repeater #1

  • EnOcean IP Gateway (For instance a USB 300 EnOcean Gateway connected to an IP Access Point)
    EnOcean IP Gateway receives the request from EH Device as EnOcean radio telegram (with two-level repeating by Repeater #1 and Repeater #2 in between) and converts this into IP format

  • IP Infrastructure
    IP Infrastructure(for instance a company network connected to the cloud) receives the IP request from EnOcean IP Gateway and forwards it to the User Application running in the cloud.

  • User Application
    User Application receives the request for the latest set point value and provides this value in the response which then is propagated the same way back.

This illustration shows the complexity (and time delay) involved in such as request / response sequence. The steps involved into the request / response can be categorized into two groups:

  • Radio propagation delay
    This is the time required for the propagation of the radio telegram from the sender (EH Sensor) to the receiver (EnOcean Gateway) and vice versa.

  • Infrastructure processing delay
    This is the time required for the processing of the received radio telegram request until the corresponding response is ready for transmission.