Tapping into technology
Utility companies will be boosted by updating their control networks.
It is no longer feasible to create a separate network for each and every business application. It is simply not a sustainable way to build a scalable and resilient communications infrastructure. Instead, a single physical infrastructure based on Internet Protocol (IP) with logical segmentation is broadly accepted as the model to adopt in most industries.
The upshot of this evolution is that existing telemetry and process control networks now suffer from a combination of legacy equipment, growth in demand for monitoring and the development of new monitoring techniques. This subject was discussed in detail in 'Testing the waters' in E&T #14 (p44). Many of these existing telemetry and process control networks will be updated over the new five-year Asset Maintenance Period.
As utility companies gradually migrate to this 21st century network, ensuring the support of existing and new applications is mission critical. Legacy traffic is integrated into the IP network using various techniques such as tunneling and protocol translation, thereby allowing integration and migration to a fully converged IP infrastructure.
So how can a water company benefit from the converged network? And what can new applications bring to the mix?
Extending the reach
The use of a single physical network that is logically segmented unlocks the potential for not only improved back-office applications, but also applications that encourage new business processes. It can also offer a significant saving on the physical infrastructure as well as the maintenance and management of this network.
The use of IP ensures that the industry no longer depends on 'security by obscurity', as the new network is built on robust security protocols and policies.
The simple extension of the IP network to the process control and telemetry end points significantly increases the network reach to the whole estate. This therefore offers the potential to significantly increase the reach of the corporate voice and data network. The use of an IP-based infrastructure also gives a greater flexibility in extending the network, allowing additional or hard-to-reach locations to be connected. The underlying physical infrastructure of wireless, satellite, Ethernet or ADSL becomes transparent to the applications allowing a faster deployment. One example of this is the use of satellite technology for fast new site deployment or disaster recovery capabilities.
Auto scanning satellite dishes have now dropped to a price that allows them to be mounted onto vehicles. These vehicles are then equipped with voice and data network capability allowing a site to be up and running within 30 minutes of the vehicle arriving.
With such price decreases we see more companies including utility organisations using satellite as an 'always-on' connection for remote locations where ADSL or leased lines are not possible or cost prohibitive.
It is possible to take this network extension concept further by IP-enabling the fleet of field vehicles and the 'LAN in a van' concept. The applications in the LAN physically connect over Ethernet or wireless and communicate back to the central office over IP. The IP connection is handled via routers using similar techniques to extending the reach of the network to fixed locations. Note that applications do not need to understand the underlying communications infrastructure; this is taken care of by the router using techniques such as 'Mobile IP'.
Mobile IP is an IETF standard (RFC 2002) and allows a host device to be identified by a single IP address even though the device may move from one network to another. Regardless of movement between different networks, connectivity at the different points is achieved seamlessly without user intervention. Roaming from a wired network to a wireless or wide-area network is also done with ease. Mobile IP provides ubiquitous connectivity for users, whether they are within their enterprise networks or away from home and is part of both IPv4 and IPv6 standards.
Mobile IP will select the best communication path depending upon the connections available. This communication path could be GPRS (General Packet Radio Service), wireless, satellite or the latest 3G technologies such as HSDPA (High Speed Download Packet Access). Over the last few years we have seen the number of vehicle monitoring systems increasing, and each of these typically needs an additional GPRS modem to communicate back to the central office and many vehicles now have multiple modems installed.
Using the 'LAN in a van' concept we can reduce this requirement to a single GPRS modem by normalising the in-vehicle communication to Ethernet and IP. This technology enables the use of Wi-Fi as the backhaul communications mechanism. As the vehicle enters either a corporate wireless zone or a Wi-Fi hotspot the router automatically authenticates with the zone and moves the communications path from GPRS to the higher speed Wi-Fi. As we move out of the Wi-Fi zone it will move back to the GPRS or to the next Wi-Fi zone. Mobile IP allows this to be achieved without breaking the TCP/IP session - therefore, we do not have to re-establish the application sessions as the vehicle moves around the country.
The water utility now has the capability to extend the back office functionality out to all the locations within the company. In doing this they benefit from normalising corporate connectivity across all office- and field-based staff. No longer does the field worker have to use dial-up whils at an outstation or come back into the office for software updates. Connectivity available at the remote locations is the same as at the headquarters with laptop updates being pre-positioned so that bandwidth was not unnecessarily consumed. The laptop user has near LAN-like performance for the updates and critical files.
The converged network now allows additional communication mechanisms to be put in place. Integration of wireless technologies can further extend the network reach, laptop users no longer have to physically plug into the network enabling them to work at any location.
Wireless enables the use of new sensor technologies making sensor deployment significantly easier, reducing the wiring required which can be a significant cost in large location. This introduces the concept of 'sensor dust' - the conceptual sprinkling of sensors over a wide area. Wireless sensors with very long battery life are being introduced to the market, with battery lives of ten years and over, this will only increase over time as battery technology advances.
The cost of the wireless communication modules for these sensors can now be as low as £10, depending on the volumes purchased, with the price decreasing all the time. It is much more cost effective to monitor many of the locations that have previously been not economically viable to do so.
We can easily add Wi-Fi coverage to the 'LAN in a van', allowing the laptop, barcode scanners, RFID (radio frequency identification) scanners or hand held video surveillance cameras to be used independently.
The use of Wi-Fi networks at outstations and remote locations makes it simpler to offer contractors and third parties guest access so they can access dedicated in-house contractor applications or their own corporate systems via virtual private network (VPN). Even with the use of the same physical network the guest and corporate traffic is logically isolated and secure, and can be monitored and policed centrally.
Water companies may also look to Wi-Fi to enable even the smallest locations such as the street cabinet. Rather than the field engineer having to balance the laptop on top of the cabinet in the rain by the edge of the road, he or she could connect to the equipment from inside the van. This enables field engineers to access SCADA applications for the equipment they are working on, but also have back-office connectivity allowing them to download the next job, improving their efficiency and workflow.
For larger outstations and water treatment works it may not be practical to have wireless access points cabled back to the main building. In these locations it would be better to use wireless mesh technologies to extend wireless reach without the need for a fixed Ethernet infrastructure. This allows the rapid deployment of wireless networks over a large area and further extension of the 'sensor dust' concept.
Asset management is becoming increasingly important within the water industry. Standards such as PAS 55 defines the need for systematic and coordinated activities and practices through which an organisation optimally manages its assets. Poor asset management will often correlate to poor customer service.
The blanket coverage of wireless mesh in a site means that it is possible to use technologies such as active RFID to track high value items or people in hazardous environments in real time. Companies are producing active RFID tags and 'man down' applications that incorporate vibrating alerts and VoIP communications to check on the status of workers.
Active RFID tags have their own internal power source, and communication with these tags is typically much more reliable than passive tags, owing to the ability of active tags to conduct a 'session' with the reader. The presence of a power source means that active tags may transmit at higher power levels than passive tags, allowing them to be more robust in RF-challenged environments and also transmit over longer distances having operational ranges of hundreds of metres, and a battery life of up to ten years. However, active tags are generally bigger and more expensive to manufacture, but can have additional features such as larger memory of external interfaces.
The use of passive RFID is also of interest to the water utility. Passive RFID tags have no internal power supply, a minute electrical current is induced in the antenna by the incoming radio frequency signal and provides just enough power for the integrated circuit in the tag to power up and transmit a response.
Unlike active tags, passive tags have a limited range of a few metres and so cannot be used for active tracking within a treatment works. The cost of the tag is significantly less - in the order of pence - and they are starting to replace barcodes in many industries. These tags are tracked/scanned using choke points or handheld scanners. Tracking points can now be extended to anywhere the IP network is present, including field vehicles where it would be possible to enable the van back doors as one of the choke points, integrating this with the vans GPS and contributing to a very accurate view of the asset base.
Today, many CCTV and security systems are limited to viewing a building or small geographical area, with limited or no remote access capability. As site security is now extremely important, the security systems need to be extended to encompass the whole estate so that all locations are integrated and there is the capability to remotely view CCTV footage and the status of sites. Rather than using dedicated analogue CCTV cameras that are physically connected back to a video matrix switch, the cameras are connected to the IP infrastructure. This can be achieved using either integrate IP CCTV cameras or existing analogue CCTV cameras with IP gateways.
The IP network now becomes the virtual video matrix switch, allowing connectivity to any camera in the network from anywhere and from a variety of devices such as IP phones, laptops, PDAs and the traditional PTZ (pan, tilt and zoom) security console. It is now a simple task to extend the use of CCTV from purely security to monitoring any physical asset such as water levels in reservoirs or flow and blockages in water courses.
With the converged network in place we can now extend the security infrastructure to include the public address system and the physical security systems so that control for all sites can be achieved from a single location.
It is necessary to consider the bandwidth that IP CCTV will use and ensure that this traffic is prioritised appropriately over our IP network. There are additional techniques to ensure the streaming of video only when there is a potential incident. This can be achieved using intelligent analytics that will detect certain anomalies within the video picture such as a human walking into the picture rather than just seeing movement that a traditional passive infrared detector would identify. This ensures that the video footage is correctly targeted and that bandwidth is not being drained by images that are not required. As a trigger is activated the video stream can be started or it could also be up scaled from a low streaming rate. The video streaming can also be initiated via standard triggers such as doors opening and as well as sending the video stream traditional security alarms can also be triggered.
Unified communication services
Unified communications (UC) has moved on from just replacing traditional voice with IP voice calls into much more. There is now the ability for the IP phone to integrate into many third-party applications including process control application that allow the monitoring of water treatment processes from the IP phone rather than from the a central console.
These IP phones typically use XML (eXtensible Markup Language) to display the information and can have touch screens for easy navigation. Simply logging on to the phone gives an instant view of the status of the treatment works as well as acting as a fully functioning phone.
These statistics can permanently be fed to the IP phone, only being interrupted if a call is in progress. The use of the flexible XML language ensures that there is a large number of applications that can be quickly integrated and deployed without the need to install new clients on laptops and PCs.
Additional applications that could be used in water treatment works and outstations are lighting control, clocking in systems, loan worker solutions, video conferencing. The IP phone can also link into the security and IP CCTV systems.
It is now possible to monitor real-time video using the touch sensitive screen to navigate to the required camera. This, for example, gives the field worker the ability to open a valve and check on the effect by viewing the CCTV camera on a remote site from an IP phone.