Reliable Wireless Communication—Everything is Mobile

A 1.946Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

Over the last 15 years there have been tremendous advances in wireless networking. The vast majority of commercial wireless networks, WLANS, were developed to allow enterprise users to work away from a hard wired network connection. This freedom from wired connections spread from businesses to home and beyond. As a result, we enjoy Wi-Fi access at work, school, restaurants and even airports. It isn't a coincidence that the Internet and wireless networks have shared parallel development paths. As the availability of information has proliferated online, users have demanded more convenient access to that information.

Mining and heavy construction also have undergone a technology revolution over the past 10 years. GPS Machine Control applications have brought more efficiency to earthmoving than any other advancement since the invention of the hydraulic cylinder. Initially many of these systems utilized 900MHz serial radios to transmit GPS corrections from a base station to the machine. Since then multiple factors have stretched the capability and capacity of those early wireless networks. First, users require access to data across ever larger job sites. Second, users want to share more types of data, and in larger files which requires more capacity from their networks. Back in the day it was cool to transmit GPS corrections wirelessly, but today users also want to remotely upload models, and download production data. They want to stay caught up on email, report work hours, purchase supplies online, and check the scores from last night's game. This demand for Wi-Fi access and greater bandwidth has led many to install Wi-Fi access points on their job sites. These are great as long as you're standing next to the site office. But this approach creates a new set of problems as machines and people move beyond the range of the access point or repeater.

From practical experience we know that today's large-scale construction site is full of motion--from the machines to the people. This near constant motion is a challenge to traditional fixed wireless networks. At the same time, the need for reliable wireless communications has grown from a like-to-have to a must-have for successful and profitable operations. These challenges have left many in our industry to wonder how to solve this vexing problem.

The good news is, by understanding a few fundamentals, this problem can be solved. A new segment of wireless communications, kinetic mesh networking, is poised to bring greater mobility, flexibility and reliability to GPS machine control.

Kinetic Mesh is Better by Design
Already proven in the military and mining industries, Kinetic Mesh networks are designed from the ground up to be reliable, resilient, and flexible in providing broadband connectivity in some of the harshest environments. Existing deployments cover areas as large as 125 square miles. Each node includes multiple radios using different frequencies so they are no longer limited to that one 900MHz frequency. Additionally, each radio within a node has the ability to maintain multiple persistent connections. Nodes scan for new connections and calculate the fastest routes, 200 times per second. Any node can be activated as a Wi-Fi access point. As a self-healing, peerto-peer network, there is no single point of failure in kinetic mesh. Each node is independent, with full routing capability and persistent connections, so it can route traffic by switching radio channel or frequency the moment it senses interference or obstruction like another machine, building, wall or pile of materials. The kinetic mesh network also has Ethernet connections so it can connect to wired networks and the Internet, ensuring everyone on a project can communicate around the work site, to the office and beyond.

Kinetic mesh networks thrive in mobile environments.

Leveraging Kinetic Mesh for GPS Machine Control
Kinetic Mesh is easy to deploy and administer. Flexibility, scalability, and availability of wireless communications are equally important in a mine or a large-scale construction site. The network must be easily deployed, be exceptionally rugged to endure harsh conditions, and be able to reliably provide coverage to an ever-changing landscape.

Kinetic Mesh can help contractors on large-scale construction projects by providing three important aspects of communication: Coverage, Connectivity and Capacity. Coverage is often taken for granted. Of the three, coverage is probably the easiest to achieve, and the item most commonly discussed by all network providers. Connectivity is much more elusive. Traditional hierarchal network designs which rely on a parent child relationship between the access point and the client are common in industrial applications, but are not suited to dynamic moving environments. If an access point fails, every machine connected to that access point suddenly and fatally becomes disconnected from the network. Additionally, as a machine moves around a job site it will naturally move away from an access point. The 802.11 protocol requires clients to maintain access point connections as long as possible. This works great in a static environment where you don't want your Wi-Fi device continuously hopping from access point to access point. But in a mobile environment, it can have detrimental effects. Initially as the signal becomes weaker, throughput is dramatically restricted. When the signal gets too weak to maintain a connection, the machine drops the connection and begins looking for another. Whether the reconnection is fast or slow, it is a significant disruption to many applications.

Rajant is one of the only true peer to peer mesh networks where any device can talk with any other device. This is critical in maintaining continuous connectivity. Even if you move out of range from an access point, you can still have connections to other equipment. Rajant Kinetic Mesh networks utilize multiple radios operating on different frequencies. Different frequencies have different capabilities. By utilizing multiple frequencies in each device, you can take advantage of the strengths of them all.

Capacity is another often over looked factor. Many system providers claim to provide high capacity, but few can deliver. It is not uncommon for multiple machines to work in one area. If they are relying on a parent/child network with access points and single client radios on the machines, then the access point serving the congested area, has to split its bandwidth among all machines connected to it. In other words, hierarchal networks don't like density. Rajant on the other hand thrives in dense environments. Density creates an environment where BreadCrumbs have more connections. Higher frequencies with the greatest bandwidth are utilized more in a dense environment. Rajant BreadCrumbs also have the ability to send and receive data simultaneously. The has the effect of moving data across the wireless network to a wired network or internet connection, much faster than hierarchal networks which use store and forward. Not only does store and forward slow down data flow across the network, it also limits throughput.

No Single Point of Failure
Finally, Kinetic Mesh is more reliable because it has no single point of failure. Both the network architecture and the design insure you do not have a single point of failure. The reliability of your wireless network is extremely important since a failure in communication can mean you're job is stopped. You have invested a great deal of money in Machine Control. Purchasing the most reliable wireless network insures you receive the total ROI you are expecting. Reliable, wireless communications via Kinetic Mesh is the next iteration in GPS Machine Control.

Todd Rigby is Vice President, Business Development, for Rajant Corporation.

A 1.946Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE

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