Network Formation

Network Formation allows a new network to be created by a Coordinator or Router.

  • A Coordinator forms a centralized security network (see Section 2.3.1) and activate its Trust Centre functionality.

  • A Router forms a distributed security network (see Section 2.3.2).

If Network Formation is required on a node, enable it via the attribute u8bdbCommissioningMode. You can start Network Formation from your application by calling the function BDB_eNfStartNwkFormation().

The node performs a scan of the primary set of radio channels specified through the u32bdbPrimaryChannelSet bitmap (attribute) to form a centralized or distributed network with a unique PAN ID on one of the free primary channels. If this network formation fails or the primary channel bitmap is set to zero, the node performs a scan of the secondary set of radio channels. these radio channels are specified through the u32bdbSecondaryChannelSet bitmap (attribute) to form a centralized or distributed network with a unique PAN ID on one of the free secondary channels.

During the formation of a distributed security network by a Router:

  • The above channel scans start with the first channel of the relevant set and cover all the specified channels.

  • If the macro RAND_CHANNEL is TRUE (in the application), a channel is selected at random from the scanned channels.

  • The macro RAND_DISTRIBUTED_NWK_KEY is set to TRUE to choose a network key at random (but may be set to FALSE during application development in order to use a specific network key).

  • The PAN ID and Extended PAN ID are allocated at random (but must not clash with the other networks operating in the neighbourhood).

  • The 16-bit network address of the local is allocated at random.

In all cases, successful Network Formation is indicated by the event BDB_EVENT_NWK_FORMATION_SUCCESS through the callback function APP_vBdbCallback(). The unsuccessful Network Formation is indicated by the event BDB_EVENT_NWK_FORMATION_FAILURE.

If Network Formation is successful, the new network consists of just one node. Further nodes are added to the network using Network Steering (see Network steering) or Touchlink (see Touchlink).

Parent topic:Network commissioning