<p>Wireless communication has grown very popular, and communication is the key</p><p>to success in many situations. However, most of the common technologies today</p><p>rely on infrastructure and in disaster situations infrastructure might be lost or</p><p>get severely overloaded. This master thesis concerns intermittently connected</p><p>mobile ad hoc networks. A network in which the devices may move freely in any</p><p>direction and still be able to communicate. To be able to demonstrate a network</p><p>protocol called random-walk gossip-based manycast (RWG) my assignment has been</p><p>to implement this protocol using off-the-shelf hardware and software.</p><p>RWG is a multi-hop and partition-tolerant mobile ad hoc manycast network</p><p>protocol. Multi-hop refers to information being able to hop between more than</p><p>two nodes in a network and partition-tolerant means that the protocol works even</p><p>though a network is partitioned. Manycast means that the information should</p><p>be successfully delivered to K of all the potential nodes in the area. The RWG</p><p>protocol makes use of four different packet types, request to forward (REQF), ac-</p><p>knowledgement (ACK), ok to forward (OKTF) and be silent (BS). The actual data</p><p>being sent is carried by REQFs, and is referred to as messages. When a message</p><p>is sent it takes what could be described as a random walk among the nodes in the</p><p>network, hence the name.</p><p>The implementation of the RWG protocol resides in user-space and depends on</p><p>the IEEE 802.11b standard and the raw socket that is specified in the BSD socket</p><p>API. It is written in C and was developed on a machine running Ubuntu. It runs</p><p>on systems that use Linux 2.6 kernels and it supports cross-compiling for ARM</p><p>based devices such as the Nokia N810 internet tablet and the Android dev phone</p><p>1. To be able to demonstrate the protocol I developed my own client application.</p><p>Moreover, an already existing application for Android, Portable Open Search and</p><p>Identification Tool (POSIT), was successfully extended to run on top of the RWG</p><p>implementation. The extension was developed by people in the POSIT project</p><p>and tested in a physical experiment covering five devices.</p><p>The report covers the RWG protocol, the system choice, the implementation</p><p>and the testing of the implementation.</p>

Nowadays, the use of mobile phones and other wireless devices has become an indispensable part of daily life. However, the focus of wireless communication is on infrastructure-based networks, making them prone to service outage if for any reason the infrastructure is overloaded or there is no network coverage. This is the case in a disaster area, where the infrastructure that supports the communication may be destroyed or could become useless. Different approaches to complement the exchange of information in these scenarios are emerging as research results. This thesis concerns Random-Walk Gossip (RWG), which is a protocol to disseminate information in disaster areas. RWG is a many-cast protocol for intermittently connected mobile ad hoc networks. The more people can communicate, the more chances of success there are. Therefore, it is useful to investigate the possibility of implementing such protocols on commodity devices. Since Symbian is currently the most widespread mobile phone operating system, this master's thesis presents the implementation of the protocol in that platform. The protocol is also implemented in Linux and Mac OS X in order to provide heterogeneity. Finally, some aspects of the performance of the protocol in different devices are analyzed, studying the CPU load, memory consumption, radio range, energy consumption and response time of different devices using the protocol. The studies show that the use of the RWG protocol in both laptops and handheld devices is viable.

Wireless communication has grown very popular, and communication is the key to success in many situations. However, most of the common technologies today rely on infrastructure and in disaster situations infrastructure might be lost or get severely overloaded. This master thesis concerns intermittently connected mobile ad hoc networks. A network in which the devices may move freely in any direction and still be able to communicate. To be able to demonstrate a network protocol called random-walk gossip-based manycast (RWG) my assignment has been to implement this protocol using off-the-shelf hardware and software. RWG is a multi-hop and partition-tolerant mobile ad hoc manycast network protocol. Multi-hop refers to information being able to hop between more than two nodes in a network and partition-tolerant means that the protocol works even though a network is partitioned. Manycast means that the information should be successfully delivered to K of all the potential nodes in the area. The RWG protocol makes use of four different packet types, request to forward (REQF), ac- knowledgement (ACK), ok to forward (OKTF) and be silent (BS). The actual data being sent is carried by REQFs, and is referred to as messages. When a message is sent it takes what could be described as a random walk among the nodes in the network, hence the name. The implementation of the RWG protocol resides in user-space and depends on the IEEE 802.11b standard and the raw socket that is specified in the BSD socket API. It is written in C and was developed on a machine running Ubuntu. It runs on systems that use Linux 2.6 kernels and it supports cross-compiling for ARM based devices such as the Nokia N810 internet tablet and the Android dev phone 1. To be able to demonstrate the protocol I developed my own client application. Moreover, an already existing application for Android, Portable Open Search and Identification Tool (POSIT), was successfully extended to run on top of the RWG implementation. The extension was developed by people in the POSIT project and tested in a physical experiment covering five devices. The report covers the RWG protocol, the system choice, the implementation and the testing of the implementation.