MANETS Justin Champion Room C203, Beacon Building Tel 3292,

Content Introduction  Why consider this  Types of Network  Issues in transferring data Conclusion

Why is this a consideration So far in lectures we have looked at cellular networks  These are infrastructure based The access points to the network never move The contents within the network will always be in the same point The nodes once issued with a IP address will always be connected at the same point  The university uses a fixed infrastructure network  The Internet is based on a known structure to route information between points

Infrastructure Based Network A B

Other Types of Networks PicoNets  These are a small network of a number of nodes communicate  Good example is Bluetooth with 1 master and 7 slaves communicating Scatternets  A Scatternet is several Piconets sharing one common device These are all examples of adhoc networks  Commonly know as MANETS

Scatternet

Why is this a consideration With mobile networks the infrastructure can change  Consider the previous diagram of a Scatternet  If all devices are accessing the network through an access point This will be fixed as a point into the network  As long as the device is within range  AdHoc networking consists of when there is no set infrastructure These are referred to as MANET’s  Mobile Ad hoc Networks (MANETS)

MANETS – why ? Why ?  By having common communication standards Allows all of the devices to communicate with each other Wireless standards will be covered in another week  No installation required The parties communicating can get together to transfer information No prior knowledge of each other is required No agreement or identification is needed to start the communications

MANETS –Common use Usage  Business meeting All of the parties at the meeting can receive the presentations being used Business details can be exchanged  Game players Come together for the game to play Afterwards then move to another group and join that game  Sensor networks Where a number of wireless nodes are distributed  Emergency Service use Allows a network to set quickly until full infrastructure can be arranged

MANETS – $100 laptop Designed to allow educational computing power in regions of the world that currently can not have it  This should connect them to the Internet and allow people access to resources we take for granted  Using a single connection to get all devices networking  Each device will talk to its neighbours ource/0, , ,00.htm ource/0, , ,00.htm Uruguay has purchased 100,000 of these 29 th Oct 07  m

MANETS – Usage LANDroid  Generating a MANET and adjusting itself to ensure optimal communications

MANET Demo AB C  All Devices are in range All devices receive all communications Sending from A to C is straightforward as no packet routing is required

MANET Demo AB C  A wants to communicate with C Packets can be sent through B

Difficulties Difficulty comes from  Routing information Finding a route through the network  Battery Life Other users could be using your limited battery capability  Security Concerns The routing party could also be taking copies of any data transferred

Routing in a MANET C A B No Route from A to C !

Routing in a MANET The nature of mobile networks indicates that nodes move  This means that a route to a particular point may also change  Special protocols are used to keep the routing table current AdHoc routing protocols which come in two varieties  Re-active  Only finds a route as and when required  Pro-Active  These always search for the best or better routes

Routing in a MANET Examples of adhoc routing protocols  Complete list of all techniques en.wikipedia.org/wiki/Ad_hoc_protocol_list  Example techniques Pro-active  Wireless Routing Protocol (WRP) Re-active  Temporarily Ordered Routing Algorithm (TORA)

Routing using WRP Wireless Routing Protocol (WRP)  Is a table driven method of communicating Each of the nodes will have a table which contains all routes in the network  For WRP these are four tables, Routing, distance, route cost and message retransmission  The method is proactive so The routes are worked out before they are needed They are constantly updated  Giving a overhead to the network and the battery of the device Even routes which may never be needed are calculated and stored

Routing using WRP WRP operates by  Each node must send a “hello” message within a certain time-frame If receiving nodes do not know the “hello” message node the routing table is updated of all receiving nodes  Each node will forward the list of known routes to all other neighbour nodes Neighbour nodes are the ones within range of transmissions The list is sent out periodically Sent out immediately in the event of a change to the network

Routing using TORA Temporally Ordered Routing Algorithm (TORA)  Routes are only created as required  Packets are sent out asking for the destination node This packet is then forwarded to each neighbouring node Until the destination is found or a break is discovered  This method may produce multiple routes to a single destination This is potentially good for load sharing

Sensor Network These are a number of nodes distributed within an area  The nodes can be any size Small would be located in a building to detect fire Large would be placed at location detecting ground movements An example from Intel is used to monitor ship vibration   They need A source of power  Battery or mains Processing and detecting capabilities Wireless Communication to transfer the information  A good research paper on this subject umber= , umber=  This link will only work within the university network

Sensor Network These are a number of nodes distributed within an area  Instead of a few detectors, this uses a large number of small detectors

Security Forwarding packets allows multiple nodes to get access to the data  Security is required if the data is confidential  Easiest method is the use of Internet Protocol Security (IPSEC) Although available for IPv4, it is now mandatory for the use of IPv6 Either the data within the packet can be encrypted or  The entire packet can be placed inside another packet encrypting everything

Security Without security of some kind  How would you know a message is genuine Consider the fire example previously  What would stop someone from sending a spurious signal to active the fire system Ensure your data is confidential  Are you happy for node B to be able to read/store everything you send? A B C Packet 1 Packet 2 Packet 3

Battery Mobile devices by there nature are battery powered  This gives a limited amount of power to the device The biggest use of this power is the wireless networking Using adhoc networking some of the parties will drain the battery without any benefit! (node B in the example below) Also throughput is limited, so if B wishes to communicate part of the available network speed is being used  It is about fair sharing of resources, with each device benefiting A B C Battery Power

Conclusion We have looked at  Networking models PicoNets ScatterNets MANETS  Considerations