Cabling systems for total building integration
We have become accustomed to engineering successes over the last 70 years or so. Rarely do technology developments not materialize as promised
A common cabling infrastructure could make the 'intelligent' building a reality.
We have become accustomed to engineering successes over the last 70 years or so. Rarely do technology developments not materialize as promised. One such promise was the intelligent building that would transform our civilization. But the much-desired and talked-about intelligent building is hard to find today, even though the concept has been around since the '70s. There are several factors that may have contributed to this state of affairs. Over the past decades, new technologies have generated a trend toward a merging of communications and industrial control signaling methods.
Different technologies offer unique advantages, however, all require a robust and reliable physical (cabling) layer. This must support the higher layers of the open systems interconnect (OSI) architecture. The integration of different technologies depends on standards-based solutions. They play an essential role in the concept of the intelligent building.
For a long time, equipment such as environmental management (HVAC), lighting control, security, fire alarm, smoke detection, voice, video and data services used in commercial buildings and industrial complexes have been designed and installed by different engineering groups, working independently of each other. In all instances, this resulted in duplication of infrastructure, such as cabling and cabling pathways, often leading to conflicts on site. The different engineering disciplines ran parallel to each other, all the way from design to installation, testing, and commissioning. There was little, if any, integration at any stage of a project implementation. Engineering management requires a focused approach to overcome the problem of conflicts between engineering disciplines.
The separation of management responsibilities continued through the lifetime of the building or industrial campus, with the IT manager looking after the computer network and (perhaps) voice networks, and the facilities manager looking after the rest. This is expected to change in the next decade.
One main driver for this change is the realization that building maintenance and alteration costs could amount to more than 60% of the total building life cycle costs. The convergence of various technologies enables the integration of all the communication requirements in commercial buildings and industrial campuses.
Another reason for this development is the proliferation of advanced building technologies resulting in the design and construction of intelligent buildings. An intelligent building is defined as one that provides a productive and cost-effective environment through the optimization of its structure, systems, services and management. These buildings are designed to be more compatible with the environment and have better energy management than previous standard designs. This building "intelligence" translates into a better environment for the users, who will make a more efficient use of the time spent in such a building.
Advances in electronic technology have contributed to common protocols being used at the top layer of the building management system. Ideally, the various devices employed in an intelligent building are linked together via a communications network. At the physical level, the field devices are connected to controllers that are, in turn, linked to a network. These networks are generally connecting specific services, independently of any others. Communication is performed over separate cabling infrastructures, which is inefficient and wasteful.
Putting up an intelligent building requires early planning and design to implement this common cabling structure. There are many benefits to implementing a structured cabling system that is common to the communication needs of intelligent buildings. These include the use of common pathways and spaces, cable, and connecting hardware. Combining the different services enables the design and installation functions of communication to be coordinated and implemented as a common task, rather than split among different disciplines.
Services that can be integrated into a common cabling infrastructure include heating ventilation and air conditioning (HVAC) controls, lighting controls, security (CCTV access) fire/safety system, voice, video, TV and data. All rely on communication protocols that operate at different speeds.
A tremendous effort is being made by different system vendors to move away from proprietary protocols. These vendors are developing standards-based protocols, as already happens in voice, video and data. At present, these protocols (such as EIA 232, EIA 422, EIA 485, Profibus, HART, etc.) use dedicated cabling, each running independently of the others. The distances and number of devices that are used for different services depend on the proprietary protocol used.
Using the concept of structured cabling, perhaps modified to accommodate some services, enables a unified approach to communications cabling. Reducing the myriad of cable types to those specified in structured cabling (Category 3, 5, 5E, UTP, FTP, and optical fiber), improves the efficiency and reliability of the total cabling system.
Another benefit of structured cabling is to enhance the non-standard services by providing cabling specifications that are more advanced than those presently specified. Structured cabling also sets design rules (such as maximum cable lengths), which help to create some order from the present cable chaos in ceilings, access floors, and risers.
It can be easily seen that a common communications cabling infrastructure results in a much improved communications transmission performance. The bandwidth available in structured cabling media is very large compared to EIA 232/485 implementations. How much bandwidth is required to support present and future requirements? A useful guide may be an "empirical law" known as Moore's Law. This states that the central processing unit (CPU) doubles in power every 18 months.
This law can be applied to cabling to determine the potential increase in the requirements of cabling bandwidth. A simple calculation shows that it takes 10 years for a 1 MHz system to expand to 100 MHz. Over 16 years, the 1-MHz system is anticipated to grow beyond 1 Gigahertz! This empirical law can be used as a law to assess needs of cabling infrastructure over its designed lifetime.
Structured cabling media (copper) also offer vastly improved transmission performance, such as better crosstalk, return loss, ACR and ELFEXT. The latter parameters ensure reliable signal transmission.
The use of one set of pathways and common communication spaces, such as closets and equipment rooms, provides real estate efficiencies that produce great economic benefits. Additional economic benefits are derived by reducing the number of contractors installing and commissioning the various systems on a common cabling system.
Kinder, gentler maintenance
According to a recent survey, it is possible to save as much as 30% of the initial costs of cabling in a building project. A more impressive potential saving is that of ongoing costs, which can be around 60%. This shows that an integrated communications cabling system offers the prospect of simplified and cost-effective maintenance.
This concept of system integration through a common cabling infrastructure has already been employed in industrial campuses, hospitals, airports and universities.
In conclusion, integrated communications cabling is the ultimate development of structured cabling that presently is defined only for voice, video and data. In today's enterprises, vital operations are dependent on computer networks for successful business decisions and operations. It is inevitable that other communication services will be integrated on a common cabling infrastructure to enable the implementation of intelligent buildings.
Building automation system management is simplified as a result of cabling integration. This cabling system will lead to the integration of disciplines, such as IT, voice, video and facilities management. A common structured cabling system simplifies building design, construction and operation. It increases building value and marketability-as well as tenant satisfaction.
Patrick Attard is corporate trainer at The Siemon Co.'s Sydney, Australia facility. This article was previously published in our sister publication, Cabling Installation & Maintenance Australia-New Zealand.