TANGO TANGO ALTERNATE NETWORK GRAPH ORGANIZER

Olof Hellqvist <olof.hellqvist@gmail.com>Zak Blacher <zblach@gmail.com>

Agenda• Introduction• Net-X System eXtensions• OLSRd Overview• Channel Changer (CHACHA)• Tango

oOverviewoServeroProtocoloClient

• Demo• Future work• Thanks / Questions

IntroductionProject description:Our assignment was to build a centralized channel assignment framework for wireless mesh networks that interacted with the current distributed channel assignment plugin for olsr CHACHA 

Net-X System eXtensions• Net-X is a Linux-based software framework for

multi-channel/multi-radio wireless mesh networks• Consist of

o A routing layero A channel abstraction layero A modified Network interface card (NIC) driver

• Layer 2.5

OLSRd Overview• Implements Optimized Link State Routing Protocol • Deployed on large scale ad-hoc networks

o i.e. mesh networks o NOT for sensor networks

• Proactive Protocol - distributes routing information in advance.

CHAnnel CHAnger• Distributed algorithm for assigning channel for the

fixed interface.• Replaces the HelloServer in the Optimized Link State

Routing Protocol. • The HelloServer balance the use of the channels for

the fixed interfaces on the nodes in the mesh network.

• Broadcasts channel information to all one- and two- hop neighbours.

TANGO Overview• Tango Alternate Network Graph

Organizer • Centralized Channel Assignment

Framework For Wireless Mesh Networks

TANGO Server• Extendable C++ implementation• Reads and santity checks current

configuration stored in libconfig configuration syntax.

TANGO Server configuration file

config.cfg:

version = "1.0";tango =({    ip = "192.168.30.7";    channel="40";},{    ip = "192.168.30.21";    channel="64";},{    ip = "192.168.30.22";    channel="44";});ip = "192.168.31.200";port = 50000;###eof

• Tango servers utilizes libconfig => configuration file is written in libconfig syntax

TANGO Protocol• TCP based clear text protocol• Clients pull the there current fixed channel• The server will return either the new fixed

channel or -1 depending on if the node exist in the current configuration

TANGO Client• Extension of CHACHA (replaced

least_used_channel)• Periodically updates the channel for the fixed

interface. (polling)

DEMO

Future work• Expand tango server with routing algorithm (they

can either generate configuration files or be embedded in the server).

• Replace the TCP communication with olsr-messages

• Add feedback information from the client in order to make more a intelligent routing intelligent channel choice depending on the nodes environment.

• Expand the configuration options of the server (e.g. channels different standards).

for listening

?