Kentucky, West Virginia Mines Try RFID Combined With Telecommunications

To improve safety, the mines are adopting or testing systems that use Axcess International's active RFID tags and readers, integrated with communications technologies from Tunnel Radio or Foundation Telecommunications Inc.
By Claire Swedberg

Sept. 23, 2008—West Virginia and Kentucky mines are using or testing wireless systems that employ telecommunications technology in conjunction with active RFID tags and readers to locate miners in underground tunnels. Although the mines in both states use Axcess International RFID Dot tags, they utilize different wireless platforms to relay RFID and telecommunications data.

An unnamed West Virginia mine, for instance, is using an RFID-based tracking system known as MineAx, provided by Tunnel Radio of America, in conjunction with Tunnel Radios' UltraComm wireless networking technology. Several other West Virginia mining companies will be installing the system later this year as well.

The MineAx system employs Axcess' active RFID tags and wireless readers to ensure real-time data regarding its miners' locations as they move around tunnels underground. The system will help West Virginia mines comply with the Mine Improvement and New Emergency Response Act of 2006, which requires improved communications and emergency plans in the event of an underground mine accident.

With MineAx, when miners enter a shaft, they first pass through an Axcess reader portal. The portal reads the miners' Axcess Micro-Wireless ID active RFID tags, which can be placed in a pocket or attached to a hard hat. The portal emits a 126 kHz signal that awakens a dormant tag, which begins transmitting a signal in the 315 to 433 MHz ultrahigh-frequency (UHF) band. Typically, the portal contains two readers, one located in front of a mine's entrance, the other behind that entrance. The read sequence is then interpreted by Tunnel Radio software and provides data as to whether a particular miner is entering or leaving the mine. Elsewhere throughout the mine, additional RFID readers are deployed.

At the West Virginia site, the readers transmit data to the mine company's back-end system via the UltraComm wireless network, which includes a leaky feeder—a cable deployed throughout the mine that has "gaps" enabling it to function as a radio antenna and thereby emit and receive RF signals along its entire length. The mine utilizes the same UltraComm wireless network to support its two-way telecommunication system, also provided by Tunnel Radio. According to Mark Rose, Tunnel Radio's president and CEO, the two-way wireless communication system enables the mining company to contact underground miners via a Motorola radio each worker carries on a belt.

On the back-end system, Tunnel Radio software interprets that data and displays the employees' locations on a mine map generated from a computer-aided design (CAD) drawing of the mine. On that map, Rose says, a small hat icon represents each individual in the mine, color-coded according to that person's job function or experience. By placing the cursor over a hat, a manager can read the employee's name, as well as any other necessary data about that individual. If a miner has a problem, he can use the Motorola radio to place a call, and the manager or dispatcher can then utilize the RFID system to locate that worker on the display and communicate with him accordingly.

The UltraComm-MineAx system is especially effective, Rose says, in situations in which miners lack specific information, such as which shafts are clear, or which have collapsed or contain fires. In such a case, a dispatcher can determine where the miners are located on the display and, based on information about a fire or collapse, call them and describe what they must do to reach safety.

The system does not always provide real-time data, Rose says, but instead pinpoints the location of the most recent RFID transmission—that is, when the miner last came within range of an RFID reader, and which reader it was. Based on the sequence of transmissions, he explains, as well as information regarding the miner's work assignment for that day, dispatchers can approximate that miner's location.

Tunnel Radio software also allows a user to pull up manifests listing who is in a particular tunnel at any given time, Rose says, and who has recently entered or exited. During an evacuation, for example, a manager can watch names leave the "in" manifest and appear in the "out" manifest.

Rose has been at mines when accidents have occurred, he says, noting, "The first thing managers ask is, 'Who's in?'" At any given time, a mining company may have employees, contractors, electricians, inspectors and various other visitors within its tunnels. "If everyone is electronically tracked, you have a really good idea of who is where," he says.

Tunnel Radio is providing the MineAx Bird Dog system to existing customers using the two-way radio system, and also has some new customers for the combined solution. "We're a one-stop shop, and people really like that," Rose states. Some mines span as much as 80 miles, he says, and the system can transmit data throughout their length. The system has received the requisite Mine Safety and Health Administration (MSHA) and State of West Virginia approvals for operating in that state's mines.

Combining RFID with existing communication systems is a natural fit, says Allan Griebenow, Axcess' president and CEO. Because the wireless backbone is already in place, he adds, it is logical to employ that same backbone for RFID tracking.

According to Griebenow, the active RFID tag is small enough that a person can easily carry it into the mine, but has a transmission range of 150 feet to 1,000 feet in optimal conditions. UHF-based transmissions are the best in this environment, he says, because they are robust and do not interfere with any existing Wi-Fi systems.

Axcess is currently working on further features for the DOT tags and readers, including panic buttons for miners in emergency conditions, as well as sensor capabilities that would transmit a person's temperature or indicate whether that individual is moving.

The state of Kentucky has also been looking into RFID tracking systems that work in tandem with communications backbones. Last week, Foundation Telecommunications Inc. (FTI) completed a pilot for the state using its own satellite communications and tracking system, combined with Axcess RFID tags and communications hardware and integration services from Architron XRF.

The 30-day trial was completed on Sept. 19. In this case, the research team utilized a system of tunnels closely resembling the coal mines of Kentucky. FTI placed 12 wireless nodes every 250 feet throughout the tunnels, which are located in Missouri. Each node, provided by Architron, contained an Axcess interrogator, a telephone handset, a video camera and a computer keyboard that enabled voice, data and video communications.

Testers carried Axcess RFID tags in their pockets, and the tags' 315 to 433 MHz RF signals were picked up by the wireless nodes. In this case, the nodes could forward such data as the individual's ID number, as well as any voice or video data, via an 802.11 wireless mesh system. When the information reached the tunnel's surface, it was received by a satellite dish that then transmitted it to FTI's satellite hub in Salt Lake City.

From there, explains Byron del Castillo, Architron's CEO, the data was made available on a Web server that authorized users in remote locations could then access via the Internet to gain information regarding the miners' location in the tunnels, or real-time audio or video images of what was happening in the mine. Because the nodes were placed 250 feet apart, and since the RFID readers proved able to receive transmissions at about 125 feet, FTI had real-time visibility the entire time a miner was in the tunnels.

The wireless mesh system, del Castillo says, enabled multiple transmissions, including voice, RF data and video, all to be directed to the Internet-based system. "At any time," he explains, "if there was a collapse, we would know what zone they are in."

Kentucky has approved the initial pilot's results, and the system must now receive MSHA approval before FTI can commence marketing it to Kentucky mines. FTI first began discussing such a system with the state approximately two years ago, according to FTI's president and CEO, George Livergood.

"We started looking at RFID companies, and we came across Axcess and liked the technology path they were taking," Livergood says. "That was when we hooked up with them [Axcess and Architron]. With this system, you could be in a conference room in Kentucky and see a miner down in a tunnel in Missouri."

The FTI software system displays a list of employee names, and when a name is selected, it also provides pictures and other details about that particular miner. While awaiting MSHA approval, Livergood says, researchers plan to spend several more weeks working out the mounting of the nodes on tunnel walls. The nodes must be installed within 3 inches of the ceiling, he says, noting. "We've proven without a doubt that wireless mesh works."

Pushing Internet into Small Cable Systems: The Wireless “Last Mile”

Pushing Internet into Small Cable Systems: The Wireless “Last Mile”

The key to a successful implementation of high-speed Internet systems is no different than the proven formula for good cable television operations; large numbers of happy contented subscribers that receive reinforcement of the wisdom of their monthly purchase of services through good experiences with the technology. As in any business, large numbers of satisfied customers remain the one constant of the determination of “success.” Unlike conventional businesses, however, the cable operator must take the technology to the customer. Unlike conventional businesses, the cable operator must provide a wide range of flexible services capable of change with local market conditions. This is particularly true of small cable system operations given the limited numbers of homes passed by the cable plant together with the high fixed costs of new technologies.

Today, multi-megabit wireless technologies exist that allow the small cable operator to cost effectively extend the reach of the most profitable service offering available to the cable operator since the 60’s; that service being high-speed Internet. Typical last mile delivery of Internet services is accomplished via an upgraded two-way cable system. Some cable operator are able to accomplish this task with the addition of two-way electronics only while others must contend with aging cables and connectors configured in a sometimes unworkable two-way cable system architecture.

In the alternative, a number of wireless technologies are available that allow distribution of the two-way high-speed Internet services up to 30 miles in a line-of-sight path with short range coverage using technologies that are relatively immune from path obstructions such as trees or small structures. These technologies present the small cable operator an alternative to time consuming and sometimes costly system upgrades while concurrently extending the coverage area miles beyond the franchise boundaries.

Unlike the capital costs associated with a system wide upgrade in order to offer a service to a select few subscribers, the implementation of a wireless last mile to the Internet subscriber restricts the capital costs of installation solely to those the subscribe to the service. Concurrently, the relatively low capital costs associated with today’s wireless alternatives provide a means to extend the service to other franchise areas, surrounding homes that cannot be reached economically with cable plant extensions or businesses that may not ordinarily consider subscription to the cable services.

A wireless last mile solution provides many small cable operators an immediate solution to the provision of high-speed Internet services whether or not there are future plans to upgrade the system to two-way. At the same time, the “homes passed” by the wireless signal becomes significantly greater though a line-of-sight 30 mile radius coverage area of up to 2,800 square miles in the extreme case using “backhaul installations” and a 10 mile radius of coverage (300 square miles) with typical subscriber installations.

Finally, while it is unlikely that the entire cable channel line-up can be economically microwaved to a nearby community or cluster of homes, the two-way high-speed Internet signal may be easily cost justified for an “Internet Only” service in most areas.

As a result of the consideration of a wireless last mile solution, the small cable operator is now able to significantly increase the number of homes passed by the high-speed Internet service thus meeting the primary objective of successful business operations; large numbers of satisfied customers.