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Wireless technology adds a new dimension to accessing plant data

21st February 2013


<p align="left"><font size="1">Wireless technology makes it possible to incorporate new strategic measurements and other data to solutions that simply were either not practical or even possible to implement in a wired communications environment.</font></p><p align="left"><font size="1">When wireless technology is usedsolutions for process optimisationdevice managementreal-time equipment condition monitoringenergy managementpersonnel trackingasset trackingsecurityand enterprise asset management can all work in unison to address both industrial asset utilisation and availability.</font></p><p align="left"><font size="1">There are some limitations to a wired infrastructureespecially in the plant environment. New applications often require upgraded cabling and expansion to existing applications may require additional cabling.</font></p><p align="left"><font size="1">Along with the cabling itselfthere are many associated costs with this kind of infrastructure. In order to expand cabling within a plantcostly engineering studies need to be performed so that the most appropriate wiring locations and paths can be determined.</font></p><p align="left"><font size="1">Alsodepending on the age and condition of the existing environmentsome issues may need to be remediated when cabling is added. For exampleasbestos may exist behind walls that are used to house the cabling. Trenching may be required to run new cabling. The environment inherently raises issues that need to be taken into considerationsuch as excessive heatmagnetic fieldsand other characteristics of a plant environment. Wireless networking can be used to eliminate these problems.</font></p><p align="left"><font size="1">Wireless networks provide the connectivity required by the existing and new applicationsbut also allow for some additional benefits. Deploying a wireless network for a particular application allows access even in places where it is impossible to run cables (Fig.1). A wireless network can be designed to be self-healing and redundant so that single points of failure in the network are virtually eliminated. Roaming can be configured so that a mobile worker can traverse the entire plant and never lose connectivity to a centrally managed application.</font></p><p align="left"><font size="1"> </font><strong></strong></p><p align="left"><strong><font face="ITC Caslon 224 Bold" color="#ff0000">Strategic site review</font></strong></p><p align="left"><strong><font size="1"> </font></strong></p><p align="left"><strong><font size="1">As in the case of wired networking deploymentsan engineeringor sitesurvey will need to be performed in order to determine the most efficient placement of wireless networking devices. Typically these studies are considerably less expensive than studies executed for wired networks.</font></strong></p><p align="left"><strong><font size="1">A properly designed and deployed wireless network is fully expandable and has a very short-term return on investment (ROI).</font></strong></p><p align="left"><strong><font size="1">For this reasonIPS uses a team approach to developing wireless solutions. This begins with a strategic review that includes representatives from various functional units to ascertain currentnear-term and future needs. It also involves working closely with the facility/corporate IT department to address connectivity and security needs and requirements. Crucialtoois the RF site survey that not only ascertains current wireless activity at a particular facilitybut also RF signal measurements and coverage.</font></strong></p><p align="left"><strong><font size="1">When this has been carried outIPS engineers are able to generate a low-impacthighly-coordinated<br />non-disruptivecomprehensive report that includes both strategic alternatives and a recommended action plan.</font></strong></p><p align="left"><strong><font size="1">For examplethe report is vendor agnosticbeing driven by best practices rather than particular suppliers. It takes a holistic systems approach to securityuses a common wireless infrastructureand integrates third-party solutions into the total offering. The result is a proposal for fully engineered solutions aimed at: process optimisation; safety and security; asset performance maintenance; asset management material tracking; condition monitoring; and IT communications.</font></strong></p><p align="left"><strong><font size="1">In additionIPS experts continually audit technology evolutionvendor strategiesstandards bodiesand government regulation and compliance issues. Working with wireless partners such as ApprionAlvarion and 3eTI ensures that potential customers have the very latest on IONWiMax and WiFi technologies respectively.</font></strong></p><p align="left"><strong><font size="1"> </font><strong></strong></strong></p><p align="left"><strong><strong><font face="ITC Caslon 224 Bold" color="#ff0000">Myths and facts</font></strong></strong></p><p align="left"><strong><strong><font size="1"> </font></strong></strong></p><p align="left"><strong><strong><font size="1">The catch-all term &lsquo;wi-fi&rsquo; refers to the protocols contained in the 802.11aband g standardswhich represent wireless technologies typically deployed in the homeofficeand plant environment. Beware of sales hype: it is a myth that the a and g standards operate at 54Mbps but on different frequencies. 802.11b and 802.11g utilise the same wireless frequency range (2.4GHz)but offer different speeds. 802.11g is significantly fasterproviding a data rate of 54Mbpswhile 802.11b provides 11Mbps.</font></strong></strong></p><p align="left"><strong><strong><font size="1">From a distance perspectivewi-fi can be classified into indoor and fixed outdoor wireless. Distances of up to 25km can be achieved with fixed outdoor wireless using either 2.4- or 5-GHz frequency by choosing a high-gain antenna (provided there is line of sight). In indoor applicationsfixed outdoor wireless offers a distance up to 100 metres; howeverinterior building materials reduce the signal work efficiency from 30-50metres between devices.</font></strong></strong></p><p align="left"><strong><strong><font size="1">Another drawback for these technologies is that a number of other devicessuch as cordless telephones and microwave ovensalso utilise the 2.4-GHz band. A properly conducted site survey will determine these points of contention and will assure that they are alleviated in the final design and deployment.</font></strong></strong></p><p align="left"><strong><strong><font size="1">802.11aon the other handutilises the 5-GHz bandproviding speeds up to 54Mbps. The advantage of using this protocol is thatsince few devices utilise the 5-GHz bandinterference or signal contention is virtually non-existent. Alsowhile 802.11b and 802.11g are compatible with each other802.11a is not compatible with eitherso once againthere are few devices competing for this frequency. Note that 802.11nthe multi-in multi-out standardhas yet to be ratified. Finally there is the 802.11y standardbut this is only in use in the US at the moment.</font></strong></strong></p><p align="left"><strong><strong><font size="1"> </font><strong></strong></strong></strong></p><p align="left"><strong><strong><strong><font face="ITC Caslon 224 Bold" color="#ff0000">Security issue</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1"> </font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1">Wireless security is another hotbed for myths. For exampleit is a myth that wireless networks are easily hacked. If implemented properly they are also very secure against jammingtoo. It is a fact that wireless networks could be insecurebut an attack would require in-depth knowledge and some very expensive equipment. It is also a fact that security measures do slow down wireless speeds.</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1">Now let us look at the security standards. Wireless equivalent privacy (WEP) is intended to provide confidentiality. Howeverit has several serious weaknessesnot least that it can be cracked within minutes using readily-available software. WEP2 is a stop-gap enhancement designed to overcome thisand has the added advantage of being implementable on equipment that is not able to handle wi-fi protected access (WPA) or WPA2.</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1">For its partWPA was established as an intermediate measure during the preparation of 802.11i. Its password or pass phrase must be great than 6-8 characters to ensure full security. WPA2 goes to the next levelimplementing the now mandatory requirements of 802.11i. ImportantlyWPA2 also introduces AES-based &lsquo;counter mode with cipher block chaining message authentication code&rsquo; (CCMP) algorithm. CCMP is now mandatory for all new devices.</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1">Then there is WPA2 PSKor pre-shared key mode. This ideal for homes and small offices and requires each user to enter a pass phrase before access is possible. Such phrases can use 8-63 printable ASCII characters or 64 Hex. Bear in mindhoweverthat a weak pass phrase equals weak security.</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1">Finally there is the extensible authentication protocol (EAP) under WPA and WPA2. This is a universal authentication framework that employs a number of authentication protocols and also implements a four-way handshake. Herethe AP sends a nonce-value to the client who now has all the attributes to construct the pairwise master key (PMK). The client sends its own nonce-value to the APtogether with a message identity code (MIC). The AP sends the group temporal key (GTK) and a sequence number with a MIC. The client then sends confirmation and as soon as the PTK is obtainedit is divided into five separate keys.</font></strong></strong></strong></p><p align="left"><strong><strong><strong><font size="1"> </font><strong></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font face="ITC Caslon 224 Bold" color="#ff0000">In real life</font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1"> </font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1">One IPS client needed to constantly monitor the temperature profile on a steam pipe in order to reduce condensation and prevent damage that could have run into millions of Dollars. A wired solution proved to be logistically unfeasibleso a wireless solution was successfully implemented.</font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1">Another client was keen to boost perimeter security with the addition of motion detectionvideo and other sensors. Because of the terrain around the site and the prohibitive cost of a wired solutiona wireless network was implemented.</font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1">In another projectIPS helped a client meet Occupational Safety and Health Administration (OSHA) recommendations that there should be activation notification whenever a safety shower is in use. The task of installing activation sensors on over 1000 showers and integrating them with emergency services proved an ideal use of wireless technology.</font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1">Although many myths still surround the use of wireless technologyit is becoming increasingly accepted by many industries around the world. As a resultIPS has already successfully implemented wireless projects for a diverse range of companiesincluding: Ontario PowerPetro CanadaHusky EnergyPPGTate &amp; LyleBowaterTexas UtilitiesFlorida Power3MHuntsman and Orlando Utilities &ndash; to name but a few.</font></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><font size="1">Today potential applications of wireless technology include such broad-ranging applications as personnel tracking/locatingfield operator efficiencyfield maintenance efficiency and plant security. Add to this a host of others &ndash; including process managementsafety event monitoringleak detectionkey performance measurements and disaster recovery &ndash; and it is not hard to see why wireless is becoming the technology of choice for an increasing number of companies.</font><strong><font face="Zapf Dingbats Bold" size="1" color="#ff0000">v</font></strong></strong></strong></strong></strong></p><p align="left"><strong><strong><strong><strong><strong><font size="1"> </font><em></em></strong></strong></strong></strong></strong></p><p><strong><strong><strong><strong><strong><em><font face="ITC Caslon 224 Book Italic" size="1">Gary Williams is Principal Consultant Wireless EMEA Enterprise Networks &amp; Security Services with Invensys Process Systems (IPS).</font></em></strong></strong></strong></strong></strong></p>&quot;








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