Industrial Communication Systems

Routing in Wireless Networks 4-11

this breakage. Finally, the node must send the route error (RERR) message to the corresponding neigh-

bors. e RERR message can be broadcasted if there are many neighbors that need that information

or unicasted

if

there

is

only

one

neighbor.

e

sequence

numbers

for

the

entries

in

the

routing

table

for

the

unreachable

destinations

must

be

set

to

invalid

lifetime.

When

the

link

breakage

happens,

then

the

host can try to locally repair the link if the destination is no further than a specied amount of hops.

If the

RREP

message

is

not

received,

then

it

changes

the

routing

table

status

for

the

entry

to

“invalid.” ...