No Node Left Behind
Individuals, vehicles and other platforms may connect while leaving capacity for user needs.
OrderOne Networks performed a test of its mesh network with 720 nodes at Wireless Information Network Laboratory’s Open Access Research Testbed for Next-Generation Wireless Networks at Rutgers University.
Advances in technology soon may make large-scale mesh networks a reality. The developments will create a system that can handle hundreds of sensors without occupying all the available bandwidth. The advancements improve communication among mobile nodes and support low-bandwidth sensors.
Mesh networks traditionally have trouble scaling up in size because the bandwidth needed to support large numbers of nodes grows at an exponential rate. When the networks reach a certain size, they stop working because all the bandwidth is consumed to keep the network whole. Christopher Davies, chief technology officer, OrderOne Networks, has created a mesh network technology that permits hundreds of nodes to operate while bandwidth use remains between .0062 percent and 6 percent. A mesh network is a group of wired technologies or nodes that are connected through a series of access points; there are at least two pathways to each node.
The OrderOne technology was recently demonstrated with 720 nodes on 400 radios at the Wireless Information Network Laboratory (WINLAB) Open Access Research Testbed for Next-Generation Wireless Networks (ORBIT) at
Ivan Seskar, associate director of information technology for WINLAB, confirms that the test took place and says the technology would provide a “significant improvement of what is publicly available.” However, he did not independently verify and could not confirm the accuracy of the results. Seskar explains that researchers at
Other organizations, military and private, are experimenting with the OrderOne mesh network technology to determine its viability, and one company has licensed it.
Davies credits his prior lack of experience of mesh networks with his network’s success. Instead of researching previous efforts, he examined the mechanisms necessary for the routing protocol he required for use on a separate project.
The first mechanism is the tree structure implicit in every mesh network. Conventional routing protocols force a hierarchy onto the network, breaking the network into groups, then into groups of groups and so on. The OrderOne protocol reveals a tree structure that directly reflects the topology of the network that underlies it. “As the network moves and changes, the OrderOne Networks tree structure moves and shifts with the network because the OrderOne Networks tree structure mirrors the actual network configuration,” Davies explains.
Conventional routing protocols have to break and rebuild their tree structures when the networks move or change. In contrast, the OrderOne protocol can operate without experiencing performance problems even when the tree is in flux.
Another difference between conventional methods and the OrderOne protocol is the use of the tree to route data. OrderOne does not route data through the tree structure; it uses the tree only to find the first route when one does not exist. “This first route is then optimized to be the absolute best route between the two communicating nodes,” Davies states. Conventional hierarchical routing protocols use the head node in each of the groups to route data, resulting in hot spots and the failure to find an alternate path between nodes.
The second routing protocol mechanism is Fisheye State Routing. In this type of routing, the closer nodes in the network are to a specific node, the more often those other nodes will send information about that node. In large networks, nodes that are far away are of less importance than nodes nearby. Davies uses a modified version of this approach in which the setting of node importance is extended along the line of communication rather than occurring just at a single node. When the router sends route updates, neighboring nodes will inform each other about other nodes and how far away they are. Over time, every node in the network will know every other node and a route to reach every other node.
When the network reaches a certain size, too many node updates are included in one control packet, and at that point, the network must decide which route updates are the most important to send.
|The Coalition Warrior Interoperability Demonstration (CWID) 2006 Coalition Forces Air Component commander views part of the maps and overlays representing fictitious positions of friendly and enemy forces in an unclassified scenario at his operational position. OrderOne’s mesh network technology was used in CWID 2007.|
The mechanisms that allow for scalability also allow communication among highly mobile nodes. As long as network users stay within range of one of the routers, they can communicate with the network. Connectivity is a result of speed versus radio range. High-speed communication results when information packets are sent out more quickly.
In a radius of 200 miles, a node traveling at 60 miles per hour can transmit packets every second to keep the network intact. “The important thing for the mobility is that the frequency of packets is correlated to radio range and to speed,” Davies states.
Another feature of OrderOne’s mesh network is its ability to work with low-power devices on the same network as high-power devices. Users can integrate low-capacity sensors into much larger networks, a unique feature among mesh network protocols. Current networks count on all nodes being equal, but according to Davies, his network makes different assumptions. All types of sensors can interoperate on the same converged, heterogeneous network without the need to break the sensors into distinct groups. “We can have all these devices in one seamless network,” he explains.
Davies says his technology has generated interest from the military and large
Davies asserts that as more robots deploy to the field, communications networks need to be 100 percent automated, self-forming and self-healing. In systems limited to a few hundred nodes, network centricity cannot happen the way planners envision it. Instead, a routing protocol that allows all nodes to operate on one network is required. “It sounds like a grand claim, but we have done it,” he shares. “We have not been given a test yet we have not been able to meet.”
OrderOne’s protocol is compatible with Internet protocol version 4 and version 6. The system’s protocol has the unique property of being able to distribute information through a network. For example, if a network included a tank, information could be attached to that node to share how much fuel the tank has. Or soldier nodes could provide information on the soldiers’ health or when they last fired a gun. The information can be stored in a database, allowing network users to search for information they need.
OrderOne’s network could improve military communications by including low-bandwidth sensors and providing the information military members need more quickly. The network does not store information in a central database, and it caches information in an encrypted manner. Users can query about 100,000 sensors at once instead of querying each individually. For example, users could query the location of all AK-47 rifles fired in the past hour and almost instantly have the information because the network has cached that data. The process requires no human administration.
The database also could tie into logistics and the supply chain. Convoys could send an alert that they need a certain supply such as fuel, and the database could inform the convoys of the closest locations for refueling and how long it will take to reach those sites. Personnel can use the network to send messages and obtain information. “It’s in code, ready to be used now,” Davies says.
The U.S. Navy is interested in OrderOne’s mesh network technology, and the Space and Naval Warfare Systems Command (SPAWAR) sponsored the technology in the Coalition Warrior Interoperability Demonstration (CWID) 2007 in May and June. SPAWAR is the Combined Forces Maritime Component commander for the demonstration. Companies interested in participating in CWID answer a federal business opportunity and are required to have sponsorship from a
Technologies that are demonstrated successfully at CWID can advance to an operational experiment then move into a program of record. Technologies follow this vetting process to ensure they meet all the Navy’s requirements as a program of record. Results from CWID were not available at publication but will be posted on the CWID Web site that is listed under Web Resources at the end of the article.
Dr. S. Jeffrey Besser, SPAWAR science and technology lead for experimentation, saw the OrderOne mesh network technology demonstrated at an event on network centricity and recommended it for CWID inclusion. He says that if the technology can be proven, it will be a boon for the Navy because it will allow sailors to scale and communicate. “[OrderOne’s mesh network] can be self-organized, and it can self-heal,” Besser shares. “That’s why it’s really important.”
Whitney states that OrderOne also has asserted its ability to demonstrate its mesh network capabilities while using low bandwidth. “The value of OrderOne is really the value of mesh networks,” he shares.
At the tactical edge, where personnel operate in the battlespace or in emergency response situations, the technology will keep them in touch with one another. Besser believes this is a specific military advantage that will help improve the common operating and common tactical pictures, increase awareness and speed decision making.
OrderOne’s mesh network also could improve tactical edge communications through its ability to handle large sensor fields. Those fields are remote and have a small capacity, yet they must transmit information to the users and, depending on the circumstances, coordinate with and locate each other. The technology would be valuable in disruptive, dangerous situations because it can self-heal and can be used on fast-moving vehicles. Besser says the potential is enormous for decreasing the time between sensing and shooting.
OrderOne’s capabilities would fit into the military’s goal to create network centricity by connecting various nodes in one network. “The power of network centricity is the power of all those nodes communicating at once,” Besser shares. Connecting nodes while using a minimum of bandwidth also is critical for the military. “That has been a stumbling block until now,” Besser states.
Private industry is interested in the OrderOne mesh network as well. Fortress Technologies has licensed the protocol to use in its Fortress Secure Wireless Access Bridge ES520, which is an all-in-one network access device with built-in security. The ES520 combines the functions of an access point, Ethernet switch and security gateway. Fortress plans to integrate the OrderOne technology into the product by the end of the year.
“The reason we chose OrderOne is they are very judicious in the amount of bandwidth they use,” Magued Barsoum, chief technical architect at Fortress Technologies, explains. He continues that this allows users plenty of bandwidth for data. With OrderOne’s mesh network, Fortress can maintain a 5 percent bandwidth overhead, which Barsoum describes as a unique feature.
The combination of speed, mobility, size and the ability to connect seamlessly with hundreds of other nodes also is important to Barsoum and Fortress. They plan to use the OrderOne technology to provide meshing down to the soldier level from other nodes such as ones mounted on land vehicles, unmanned aerial vehicles, the sides of buildings and other locations.