Exploiting the benefits of wireless mesh networks
Is wireless technology ready for commercial buildings? Billal Vindhani of 4-noks UK explains why the benefits of wireless mesh networks are too good for facility managers to pass up.
Developments in wireless standards now mean that wireless mesh networks are ready to take their rightful place in the system integrator’s tool box.
Conditions for implementation of this technology are favourable.
On one hand the economic situation has changed over the last decade, resulting in budget constraints and unaffordable maintenance expenses.
On the other hand legislative changes demand that building owners and facilities managers achieve greater efficiencies.
These are the core issues facing the building automation market. However, every problem has a solution, and we believe one such solution is the wider use of wireless sensor technology.
A key development in recent years has been in mesh networks. This has been made possible by advances in micro-electronics and miniaturisation, allowing more computing power to be embedded in inexpensive devices. A mesh network is a local area network (LAN), which is usually wireless and decentralised in nature.
Each node (such as data communication equipment) or data terminal equipment (such as a digital telephones, printer, router or computer workstation) is connected to many others and configured to enable connections to be rerouted around broken or blocked paths.
A mesh network is capable of self-discovery on the network. As nodes leave the network, the mesh topology allows the nodes to reconfigure routing paths based on a new network structure. The characteristics of mesh topology and ad-hoc routing provide greater stability in changing conditions or failure at single nodes. Through this relaying process, a packet of wireless data finds its way to its ultimate destination, passing through whatever intermediate nodes are available. The result is, a mesh of intersecting communication lines.
Mesh networks offer a range of benefits, as outlined below.
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| Untangling cable issues — mesh networks are self configuring. |
Self-configuring: Mesh networks are self-configuring because each device in the network contains a micro-controlled router. This means that changing the network or adding a new wireless controller is a simple process. The network discovers newly ‘installed’ devices and incorporates them into the network, without the need for a system administrator.
Self-healing: Just as importantly, mesh networks are self-healing. If a device loses contact with one neighbour, it simply finds another one to ‘talk’ to. This makes mesh networks extremely reliable. The more nodes that are in range of one another, the denser the network is, and the more reliable it becomes.
Simplified maintenance: Wireless networks, whether mesh or another topology, are easier to maintain. Maintenance personnel can use a laptop or handheld diagnostic device to communicate and perform diagnostics, without running wires. This is a significant advantage in cases where controllers are located inside storage tanks, on top of towers, or in other locations that are hard to reach.
Reduced life-cycle costs: Installation cost savings are usually enough to justify wireless controllers. Additionally, wireless networks continue to generate savings throughout their lifecycle because they are so easy to maintain, move, or replace.
Flexibility: Free from wiring and all the associated problems and costs, wireless controllers can be placed virtually anywhere. Instead of hiring wiring architects and teams of technicians, then phasing installation over a period of weeks or months, one person can walk around the building, placing controllers wherever needed. This is a fundamental change in how facility environments can be managed. Instead of placing controllers where they are easy to wire, controllers can be placed where they are actually needed in order to optimise building performance and environment, and to keep up with floor plan changes.
There are a number of applications where wireless networks offer immediate advantages and opportunities for building owners.
Retrofits and upgrades: Since over 90% of existing buildings are wired, the immediate potential for using wireless controller networks in these buildings is in phased upgrades, expansions, or layering new capabilities onto the existing wired network. For example, building owners can use wireless to enhance environmental controls and achieve dramatic gains in energy efficiency.
Commercial offices: Office environments and layouts often change in response to the varying business needs of tenants or companies. In a life-cycle perspective, wireless solutions offer significant savings and less disruption for tenants or occupants.
Retail: Large retail spaces that were previously hard to wire can take advantage of wireless controller networks. A constantly changing building layout makes wireless an attractive solution. The potential energy savings are especially attractive to retailers because they typically operate on extremely thin profit margins.
New construction: Increasingly, new buildings are expected to take advantage of wireless technology to reduce initial costs and offer tenants greater flexibility and on-going savings.
Hotels/hospitality industry: Wireless solutions allow changes or retrofits with minimal disruption to customers, helping to avoid customer dissatisfaction or loss of income.
Museums and historic buildings: Glass, marble, high ceilings or sealed wall construction are often found in museums and older buildings. Wireless technology offers a unique solution to implement controls without damaging the historical integrity.
Fast-track projects: Deadlines that would be impossible to meet with wired systems are made possible, and simplified using wireless networks.
High-cost installation areas: In some applications, the savings from wireless can be large, such as when union electricians perform installations, when electrical codes of practice require conduits, or when trenches between buildings are required.
Small remote structures: Areas that previously were not worth the cost and trouble can now be monitored and controlled, such as parking gates, pumping stations, warehouses and storage facilities.
Dangerous installations: Many walls in older buildings cannot be penetrated without exposing workers to asbestos or creating other health and safety issues. Wireless networks help avoid these problems.
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One of the greatest benefits of wireless networks in building automation may well be energy-efficiency, made possible by the easy, low-cost deployment of sensors and controls wherever needed. A typical commercial building uses thermostats to control air temperature in zones with little special resolution for heating, cooling, or ventilation requirements. Often sensors and controllers are sparsely used to limit the capital cost of the control system. As a result, climate conditions are often too hot or too cold, insufficiently ventilated, and energy inefficient.
Since energy-efficient control systems typically produce double-digit savings, the ability to go wireless for low installation costs is a powerful incentive for many organisations. By installing a wireless mesh control network over a wide area, many organisations can reduce wasted lighting and heating expenditure. Just as wireless technology has transformed other communications, from cell phones to home PC networks, wireless is ready to take its place as a cost effective, flexible solution for building automation and control.
Not only does wireless networking dramatically reduce installation costs, it continues to produce savings through simplified maintenance, flexibility, and the opportunity to improve building performance for significantly reduced energy costs. For both new structures and old, wireless networking is expected to grow significantly, improving existing applications retrospectively and opening up new ones as the technology advances and matures.
Billal Vindhani is managing director of 4-noks UK Ltd.
