linux/net/batman-adv/Kconfig
Martin Hundebøll d353d8d4d9 batman-adv: network coding - add the initial infrastructure code
Network coding exploits the 802.11 shared medium to allow multiple
packets to be sent in a single transmission. In brief, a relay can XOR
two packets, and send the coded packet to two destinations. The
receivers can decode one of the original packets by XOR'ing the coded
packet with the other original packet. This will lead to increased
throughput in topologies where two packets cross one relay.

In a simple topology with three nodes, it takes four transmissions
without network coding to get one packet from Node A to Node B and one
from Node B to Node A:

 1.  Node A  ---- p1 --->  Node R                Node B
 2.  Node A                Node R  <--- p2 ----  Node B
 3.  Node A  <--- p2 ----  Node R                Node B
 4.  Node A                Node R  ---- p1 --->  Node B

With network coding, the relay only needs one transmission, which saves
us one slot of valuable airtime:

 1.  Node A  ---- p1 --->  Node R                Node B
 2.  Node A                Node R  <--- p2 ----  Node B
 3.  Node A  <- p1 x p2 -  Node R  - p1 x p2 ->  Node B

The same principle holds for a topology including five nodes. Here the
packets from Node A and Node B are overheard by Node C and Node D,
respectively. This allows Node R to send a network coded packet to save
one transmission:

   Node A                  Node B

    |     \              /    |
    |      p1          p2     |
    |       \          /      |
    p1       > Node R <       p2
    |                         |
    |         /      \        |
    |    p1 x p2    p1 x p2   |
    v       /          \      v
           /            \
   Node C <              > Node D

More information is available on the open-mesh.org wiki[1].

This patch adds the initial code to support network coding in
batman-adv. It sets up a worker thread to do house keeping and adds a
sysfs file to enable/disable network coding. The feature is disabled by
default, as it requires a wifi-driver with working promiscuous mode, and
also because it adds a small delay at each hop.

[1] http://www.open-mesh.org/projects/batman-adv/wiki/Catwoman

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:48 +01:00

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#
# B.A.T.M.A.N meshing protocol
#
config BATMAN_ADV
tristate "B.A.T.M.A.N. Advanced Meshing Protocol"
depends on NET
select CRC16
select LIBCRC32C
default n
help
B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is
a routing protocol for multi-hop ad-hoc mesh networks. The
networks may be wired or wireless. See
http://www.open-mesh.org/ for more information and user space
tools.
config BATMAN_ADV_BLA
bool "Bridge Loop Avoidance"
depends on BATMAN_ADV && INET
default y
help
This option enables BLA (Bridge Loop Avoidance), a mechanism
to avoid Ethernet frames looping when mesh nodes are connected
to both the same LAN and the same mesh. If you will never use
more than one mesh node in the same LAN, you can safely remove
this feature and save some space.
config BATMAN_ADV_DAT
bool "Distributed ARP Table"
depends on BATMAN_ADV && INET
default n
help
This option enables DAT (Distributed ARP Table), a DHT based
mechanism that increases ARP reliability on sparse wireless
mesh networks. If you think that your network does not need
this option you can safely remove it and save some space.
config BATMAN_ADV_NC
bool "Network Coding"
depends on BATMAN_ADV
default n
help
This option enables network coding, a mechanism that aims to
increase the overall network throughput by fusing multiple
packets in one transmission.
Note that interfaces controlled by batman-adv must be manually
configured to have promiscuous mode enabled in order to make
network coding work.
If you think that your network does not need this feature you
can safely disable it and save some space.
config BATMAN_ADV_DEBUG
bool "B.A.T.M.A.N. debugging"
depends on BATMAN_ADV
help
This is an option for use by developers; most people should
say N here. This enables compilation of support for
outputting debugging information to the kernel log. The
output is controlled via the module parameter debug.