• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 54 subscribers
  • Views 1262 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Multicast messages in Z-Stack

Arash Azarmi
Intellectual 885 points
Other Parts Discussed in Thread: Z-STACK

HI TI Gurus,

In section 9.7 of Z-Stack developers guide on Multicast messages, it states: "if the receiving device is part of the group, it will first _restore_ the group radius and then rebroadcast."

1- What action does restore refer to here? Simply not changing the group radius?

2- When this feature is useful?

Thanks,

  • 0
    TI__Genius 9180 points
    This is defined by the ZigBee Specification, it is useful for multicast communication allowing the message to propagate through the multicast group.

    3.6.6 Multicast Communication
    ...
    A multicast group is a collection of nodes, all registered under the
    same multicast group ID, that are physically separated by a hop distance of no
    more than a given radius, known as the MaxNonMemberRadius.

    3.6.6.3 Upon Receipt of a Member Mode Multicast Frame
    ...
    the value of the NonmemberRadius sub-field shall
    be set to the value of the MaxNonmemberRadius sub-field in the multicast control
    field, and the message shall be transmitted as outlined in the following paragraph.

    Regards,
    TC.
  • 0 in reply to TopCat
    Intellectual 885 points
    Thank you. So _restore_ group radius just means not change it?
  • 0 in reply to Arash Azarmi
    TI__Genius 9180 points
    "physically separated by a hop distance of no more than a given radius, known as the MaxNonMemberRadius", So there can be a max of MaxNonMemberRadius in between members of the multicast group (not total number of hops).

    The NonmemberRadius decrements each hop where there is not a member and then if/when it reaches a member: "the value of the NonmemberRadius sub-field shall be set to the value of the MaxNonmemberRadius sub-field in the multicast control field". So By "_restore_ group radius " it means to restore NonmemberRadius sub-field back to MaxNonmemberRadius.

    Regards,
    TC