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Wireless technology is becoming increasingly popular throughout government and military entities for infrastructure applications widely used in commercial and industrial companies. With wireless such a hot technology, it is easy to see why users want more — more bandwidth, more distance, more security, more open systems, more mobility and more applications. However, it is challenging to balance all of the user requirements with the complex limitations placed on systems by the laws of physics.

Along with the surge in wireless installations, wireless IO applications are also expected to grow and serve as the information link from many sites to the desktop, offering substantial benefits to those who take advantage of the technology. A wireless IO system can be an end-to-end solution that allows for communication from a central location to instruments in the infrastructure such as pumping stations or substations, thereby eliminating the need for associated buried wire and conduit.

For any agency, it is critical for wireless systems to have reliable data communication in challenging environments such as RF congestion, topology or weather might present.

In the past, the common way to communicate with this equipment was to string wire (either buried or overhead) from the monitoring device to the remote terminal unit (RTU). Before wireless devices were proven to be cost-effective and reliable, flow or telemetry data was collected by sending someone out in a truck to read meters or manually check on the “health” of the pumping station or other applications.

By having the ability to replace wire, trenching and conduit with the IO system (Figure 1), companies and government agencies are able to remotely monitor and relay data such as pressure, temperature, level and flow, and are able to open and close valves and facilitate alarms. The wireless IO system can also be used at remote locations where signals need to be carried across roads, pipelines or through high-traffic or highly populated areas.

Users often want greater security and, at the same time, more open, easier-to-use systems that are better protected from hackers and intruders. The data these systems transport include everything from critical, company-confidential data to life-protecting surveillance information. A systems intruder could cause significant economic and social harm to an organization.

Security is such a critical factor in wireless systems that government regulators have recently become involved. Even though they have not yet imposed minimum-security standards, there are some under discussion. Some examples include those from AES^[1] and AGA^[2] (Table 1). Many companies have provided security for their own systems for years, which may be as simple as proprietary protocols. One complication to this issue is the broad presence and acceptance of Wi-Fi radios such as those found at Internet cafés and many airports. Wi-Fi systems primarily use 820.11 protocols that, by design, present numerous security challenges. These systems are notoriously hacked or otherwise compromised. One such compromise occurs when outlaws “ride along” a system that they have hacked. These outlaws usually don't damage the systems other than interfering with system throughput or causing economic damage. The outlaws take up bandwidth that tends to slow the system. They also do not pay for the access that is subsidized by the paying customers.

Manufacturers of proprietary protocol systems build in security for existing systems by using data encryption, numerous network IDs, multiple hopping sequences and other tactics. When used in combination, these security tools make hacking a tremendous challenge. Many security tools were originally designed into systems to prevent outside interference, especially in frequency hopping spread spectrum (FHSS) radios. Proprietary protocol systems are successful at defeating interference because they anticipate that interference will be present.

Security breaches can be as simple as interfering to stop data flow. This is sometimes referred to as denial of service. If the outlaws are able to lockup the system merely by interfering, they have already caused significant damage. Consider for instance that someone hacks into a water system and halts control of pumps. If that same person then would start fires, the system would be unable to support fire-extinguishing efforts. The results could be catastrophic. Sophisticated security tools can effectively prevent even this low-level interruption.

Higher-level security breaches include actual signal interception and system influence. The most basic systems offer levels of security designed only to prevent such access. The more sophisticated security systems provide nearly insurmountable obstacles to rogue system access. However, this is not a paper on security alone. Many sites, groups, panel and trade groups are actively working together to continually ensure that our systems constantly remain ahead of criminal elements.

Regulatory efforts are addressing security needs by continuing to investigate and encourage the implementation of higher standards. These standards will likely require minimum adherence to encryption schemas as the centerpiece of the security. Another layer will likely include dynamic key changing. This capability allows for a radio system to change keys “on the fly.” With such a system in place, rogue radios are rejected due to built-in screening intelligence.

Web access is another technological advance that has recently received much attention. Users have realized that where there is Internet access, there is the possibility of data access as well. Now, wireless systems are more commonly expected to provide addressability to the RTU site.

Businesses and governments continue to consolidate organization charts, which include information needs for many people. They rely on web access to provide more centralized visibility and data control, thereby enabling business control from anywhere in the world.

As information access and application demands grow, the search for additional wireless uses expands. Crews in remote locations now want web access to monitor entire systems, to check e-mail for critical notices and look to the web for pertinent company or technical information.

More bandwidth allows for larger data file transfers, such as video or photo displays, for security monitoring. Additional capacity can also be used for technical research or support. Plus, with more bandwidth, technicians can send detailed photos to supporting experts far away. They can even just send the photos to experts nearby for technical support and perform the operation immediately.

Wireless provides several benefits not available with traditional wire systems, such as fiber-optic cable. While fiber networks can transport extremely large files over long distances, it can be expensive for many applications. Industry experts anticipate that wireless applications will close the cost gap.

However, when users demand both bandwidth and distance, they must compromise because no single wireless system can offer both. The laws of physics impose restrictions that simply cannot be overcome in all sides of the equation. Powerful, high-bandwidth systems are available, as well as systems that deliver data over long distances. Some are specified to be able to successfully transmit data over 60 miles line of sight. But a ground-based, wireless system will not provide both attributes — at least not in a single hop.

Ground-based systems can deliver long distances with high bandwidth using the aid of repeaters. Such systems often push the cost ceiling because of the additional infrastructure that is required. One solution involves providing a central architecture (usually called a backbone or backhaul) of high-bandwidth radios through a wide area system of higher-distance radios. Companies use high-distance, lower-volume radios to transmit data to the backbone, which then hauls it in larger volumes to a central host (Figure 2).

As providers learn more about the capabilities and applications of wireless systems, we will also learn how to meet the market's needs. Systems have progressed dramatically in a short time. Threats posed by hackers and terrorists require that systems advance quickly to stay ahead of the ever-growing threats. We have already met the economic barriers to data acquisition and control in many environments. As a result, wireless systems have become a major player in meeting the stringent demands of industrial, military, utility and other applications while advancing the integrity of the systems already in place.

1. www.iaik.tu-graz.ac.at/research/krypto/AES/index.php.

2. www.aga.org/.

Jeff Allen is a business development manager at FreeWave Technologies and supports military, agriculture, environmental monitoring and homeland security. Allen's current role requires that he be in the field with many FreeWave customers, in which he has an extensive understanding of applications and technology.