Remote - Fall 2012 - (Page 8)

Feature Article Why Land-Lines May Still be the Best Option for Your Remote Monitoring Network Steve Sanislo, President Global Monitoring Organizations that need to manage the status of equipment operation or the supply of consumables at many remote locations face the problem of collecting and analyzing large amounts of data from sites that are often difficult or inconvenient to visit. The introduction of low-cost remote monitoring systems automated the manual task of checking equipment or site status, enabling organizations to deploy large data collection networks that deliver huge amounts of near real-time operational data from various sources to key personnel and decision makers as well as to various logistics, maintenance and financial applications for statistical analysis and control. Critical to the operation of any remote monitoring network is a reliable communications service that transports data from every monitored point to the people and systems that need it. What was once accomplished almost exclusively by telephone land-line is now more commonly accomplished with a variety of tethered and wireless IP-based solutions. The driving force behind this shift, of course, is connectivity that enables data to be shared in ways never before possible. Land-line technology, however, continues to be a viable alternative that offers its own set of unique advantages. In some circumstances, land-lines may serve as a reliable backup channel; in others, it can serve as the primary connection for remote monitoring systems. As organizations become increasingly reliant on remote monitoring networks to maintain efficient and precise operations, so does their need to understand how remote monitoring networks can fail. Two types of failure must be considered: network-wide failures (that impact all or most of your remotely monitored sites) and last mile failures (that usually affect just a single remote location). Consider the following example (shown in Figure 1) in which pressure gauge data from multiple locations passes through a wireless data service and several Internet-based services on its way to a browser. A failure that occurs between the wireless data provider and the browser disconnects you from all of your remote sites; whereas, a failure that occurs between the wireless data provider and your remote site, the so called last mile failure, affects just a single site. Keep in mind, that the reliability of the Internet is not being questioned. The Internet has proven to be a reliable and robust communications backbone. Security and technical issues that threaten the Internet are resolved by the massive resources of corporations, governments and organizations that have a vested interest in its reliable operation. What needs to be questioned, however, is the reliability of the various services attached to the Internet (cloud-based application platforms, thirdparty data sources, web hosting services and the like) that are critical to the operation of a remote monitoring network. In many cases, such services are operated by companies that may not have the resources or resolve to respond to service interruptions that affect you. But, even the most robust cloud services operated by large corporations with significant resources can fail and take down an entire remote monitoring network for extended periods of time. In April 2011, for example, a cloud-service failure caused by a software upgrade took down a web service operated by the U.S. Department of Energy as well as a number of commercial websites. The problem took five days to fully resolve. More recently, in April 2012, a utility power failure, coupled with an overheated backup generator and a problem with a redundant backup generator, caused an interruption to Amazon’s EC2 Cloud that affected many different commercial websites and web services for several hours. The second type of failure, the last mile failure, occurs along the path from the actual condition being monitored (for example, a pressure gauge as shown in Figure 1) to the communications service provider. This path could be as straightforward as a wireless signal from the monitoring system to a nearby cell tower, or as convoluted as a Wi-Fi link to a corporate LAN to a router through a firewall. In either case, last mile failures are by far the most common type of failure and can be the most difficult and costly to resolve. Problems encountered are often unique or obscure and require technical expertise to resolve or the involvement of disinterested parties (such as property managers and IT departments). In most cases, the responsibility of troubleshooting and repairing last mile failures is with the person in charge of the remote monitoring network. The most serious threat to the ongoing operation of your remote monitoring network, however, are chokepoints intentionally created by others to control the flow of your data in order to safeguard their own business interests. Equipment manufacturers, for example, often require the use of free or fee-based monitoring service to access data from your remote sites. In a worst-case scenario, that monitoring service shuts down for business, legal or technical reasons and you are permanently disconnected from your entire remote monitoring network. Never give anyone exclusive control of any chokepoint in your remote monitoring network! Use a land-line? Are land-lines still used? Are they cost-effective? Can I access data via the web? Are you serious? These are a few of the typical reactions to the suggestion of using a land-line to communicate with a monitoring system at a remote site and the answer to all of these questions is yes. Although the total number of land-lines in use throughout the world dropped drastically from 1990 to 2010, their numbers have stabilized and are actually increasing in certain areas. Flat-rate billing makes the land-line economically viable and land-lines eliminate many of the risks associated with IP-based communications systems. Advances to land-line based remote monitoring systems allow for a full range of Internet connectivity options while preserving the core benefits of the land-line. While much has been gained as a result of the transition from land-line to IP-based communications services, much has been lost in reliability, integrity and security, making a case for designing remote monitoring networks that combine the advantages of both technologies. Land-line technology has evolved during the past 100 plus years to Types of Communications Failures Land-Lines Solve Critical Remote Monitoring Issues Figure 1. The most dreaded failure is the network-wide failure that suddenly disconnects you from all of your remotely monitored sites and adversely affects the operation of your organization. Such failures can occur whenever data flow from all remote sites must funnel through a node of high centrality within your network (often referred to as a chokepoint). The seemingly simple and direct data path illustrated in Figure 1 has many chokepoints, including the communications service provider, multiple ISPs, a web hosting service, cloud services, and various proprietary and third-party software applications. A failure at any of these chokepoints breaks the flow of all data from all remote sites. Complicating the issue is that chokepoints are often controlled by different entities, so there is no single point of responsibility. 8 www.RemoteMagazine.com http://www.RemoteMagazine.com

Table of Contents for the Digital Edition of Remote - Fall 2012

Remote - Fall 2012
Contents
Editor's Choice
New Opportunities in a Wireless World
Why Land-lines May Still be the Best Option for Your Remote Monitoring Network
SCADA Systems – The Best Choice For Water and Wastewater Remote Monitoring
M2M: Why Remote Monitoring Matters
SCADA
Networking
ZigBee Resource Guide
Security
Onsite Power
Enclosures
Environmental Monitoring
Naval Security and Energy Initiatives: Taking Control
Wireless Sensors and Cloud Platform Provides Real-Time Vineyard Environmental Monitoring
Industry News
Simulcast Expands Channel Availability and Cuts Expenses for Public Safety Communications

Remote - Fall 2012