Wifi Bluetooth War

The paper describes tests run to determine the effect of using bluetooth and wifi in near proximity like on various network cards nowadays. They found that when bluetooh is being used wifi effectiveness drops drastically though the converse is not nearly as notable for bluetooth. To solve this issue AHF was used to disable bluetooth on the bands that were being used for wifi on the same card but this doesn't solve all the issues. Use of AHF causes bluetooth and wifi to have 0 interference if the adapters are at a distance of 2m from each other. Various methods are being used to allow for full bandwidth use: the most common inter card communication to balance packets. Noncollaborative methods also exist which rely on sending smaller packets so less data need be resent if failure occurs. Another system which uses bit error rate spams data on channels and determines the one with the least interference to send data on. Other collaborative techniques simply kill one transmitter when another is in use much like a mutex on data sending between the cards.
If found the knowledge that bluetooth and wifi are running on nearly the same bandwith extremely interesting. I did not know that the technologies were so similar and the main difference between them is simply power consumption. Knowing more about the basis of what our project runs on has provided greater insight into what is possible and the limitations of our idea. It also explains some issues I noted when testing with different devices as the hop nodes: when a phone with wifi was used signal to the mobile node occurred much more quickly. I find the issue extremely interesting and note that the current setup is worlds better than it was 7 years ago.

Multicast Over Mobile Ad-Hoc Networks

The Paper describes MANETs which are simply mobile ad hoc networks. Current multicast protocols assume a static network and do not handle the movement of nodes or network reconfiguration well. The networks are also limited because the amount of control information sent along the network should be minimized due to battery issues. The simplest form of providing MANETs is through flooding which each packet is broadcast through the network to every node once but this causes formation of loops and packet collision. Nodes join by a single node broadcasting its id in a message to the others as well as net forming metric. The system then generates new numbers for these nodes which spread the network following the metric. If a node cannot find a parent it calls for a Branch reconstruction which can cause packet loss. The restructuring involves broadcasting a message to all nodes that are nearby to attempt to join the network. the message is forwarded from nearby nodes until the source receives the message that it is on the network. Other algorithms including mesh broadcasting are mentioned followed by deferential destination multicast which is rather similar to our network structure.
Our network being based on bluetooth sockets does not need the same types of structures to generate the network. All nodes will attempt to connect to all paired nodes but will be able to alter connections when reaching the cap of 7 connections. Due to the nature of bluetooth, we always know when a node has dropped off or fallen out of range and the network will automatically reconnect them to the network if a message is received from them or they are again in range when the message is sent. The routing table will then update to take into account the node's movement.

Mesh Networks: Commodity Multihop Ad Hoc Nets

Although much research has been done in the field of ad hoc networks, they have not seen common usage in the general populace, the DoD and disaster recovery have used ad hoc networks but in general they are unused. The system described uses wireless routers or bridges to extend the range of the current network and act as a router without the need for a networking cable. The paper discusses existing networks that do this and say that the current systems if integrating MANET algorithms would be able to easily extend their network quickly. The system uses sets of multiphop information to layer the levels of sending data along to other nodes in the network. The network relies on a wireless backbone to provide service for the mobile nodes and maintaining a complete graph creating a wireless backhaul communication system. The network would be simple to deploy and self managing allowing users to join or drop off the network quickly and easily. The systems are not well used because the availability of such a network is not easily acquirable but could be given little work. There are several IEEE specs that define addressing for small quickly changing networks that allow for maximal flexibility on these networks. One of the solutions is the WiMAX towers that are nowadays being used for 4G access on cell phones as well as internet like Verizon fios's wireless service. The combination of WiMAX and wifi can enable longer range high speed internet to smaller local wireless networks and form a large mesh network. The paper also describes various methods for reducing interference when various nodes can collide waves in the same space. Finally for routing data the network would determine at the time of sending what would be the 'best' route for the data to follow. The system is again designed for fair sharing which most current protocols are not.
I find the paper to have been rather uninformative save for combining the findings of various existing plans and ideas. Many of the technologies described are being used now but do not support the ad-hoc capabilites as of yet. Some of the design constraints described in the paper are good ideas for our network like ensuring routes if there exist any in case of drop out nodes or unexpected interference. The idea of a framework of wireless nodes with various ad hoc users sounds a rather lot like tamulink-wpa but with potential to be more versatile.