Alvarion BreezeACCESS Wi2 System Manual page 195

10.2.2.1 Operational Modes
Three different roles can be assigned to a local mesh node: Master, Alternate Master, or Slave.
Each role governs how AP upstream and downstream links are established by the node.
Master: Root node that provides the upstream link to the ground network that the other nodes
want to reach. The master never tries to connect to any other node. It waits for links from
downstream alternate master or slave nodes.
NOTE
It is possible to have several masters for the same mesh ID connected to the ground network. This
can be used to provide redundant paths to the ground network for downstream nodes.
Alternate Master: First establishes an upstream link with a master or alternate master node.
Next, operates as a master node waits for links from downstream alternate master or slave
nodes.
Slave: Can only establish an upstream link with master or alternate master node. Slave nodes
cannot establish downstream links with other nodes.
10.2.2.2 Node Discovery
Discovery of another node to link with is limited to nodes with the same mesh ID. The link is
established with the node that has the best score based on the following calculation:
Score = SNR - (Number of hops x SNR cost of each hop)
If a node looses its upstream link, it automatically discovers and connects to another available node.
10.2.2.3 Operating Channel
If a mesh operates on a dynamic frequency selection (DFS) channel, the master node selects the
operating channel. If another node detects radar and switches channels, that node reports the channel
switch to the master node, which initiates a channel switch for the nodes connected to it. This allows
the local mesh to converge on a specific channel.
A node that uses a DFS channel and that loses connection with its master, scans channels to find a
master on another channel, which can be a new master or the same master.
If the local mesh does not operate on a DFS channel, configure the radios in one of the following
ways:
Configure the radios on all nodes to use the same fixed channel.
BreezeMAX Wi² and BreezeACCESS Wi² System Manual
Local Mesh Terminology
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