Wireless System Implementation for Facilities Managers
WIRELESS SYSTEM IMPLEMENTATION
The facility manager will be called upon to assist with various types of installations
WLAN: A wireless LAN is the most common installation for a facility manager in a general office environment.
PDA: Some organizations with a mobile work force may implement a wireless system for handheld devices.
Satellite Antenna: Organizations of all types are considering satellite systems, in many instances as backup to wired connections for disaster recovery purposes.
Cellular Repeater: Facilities of all types and sizes might benefit from a cellular telephone repeater system. System Planning The implementation of a wireless system requires up-front planning to be successful. Advance planning about the wireless application, the type of device, bandwidth, where devices will be located in the facility, costs, security and connection with the network is essential. Vendors/Installer Often a system will be installed by a vendor who sells the equipment. The facility manager’s role may be to find and select that vendor and oversee the installation. This is much like finding a vendor for any purpose in the facility. In seeking a wireless vendor, it is difficult to determine the skill of a potential vendor. Because the technology is so new, there are new vendors in the field. It is important to judge the skill and experience of a potential vendor to handle the proposed system. Ideally, the vendor will have already done a number of installations that will provide a reference. Some vendors may provide equipment from only one company and will push the brand that they provide. It is best to determine what equipment is desired before contacting vendors. The vendor should provide and configure the equipment and conduct any coverage studies that are needed. Be sure to include security configuration in the contract. It is usually appropriate when contracting for the installation of these types of systems to define performance specifications in the contract. These specifications tie satisfactory system performance to the conclusion and payment of the contract. Performance will be expressed in the terms like, “the ability of the system to connect to a wireless device in certain areas of the facility with a certain signal strength or decibel level.” The contract should require testing that proves that the performance is met.
The wireless LAN is installed within the facility. The first consideration in planning such a system is what the application will be such as e-mail, Internet connection, corporate database access, voice, data or audiovisual. A system must be chosen with adequate bandwidth to support the planned applications.
The number of users to be served by the system must also be determined. Some access points share the available bandwidth among multiple users. Depending on the number of users, this can result in slower performance, so the number of users per access point must be considered. More access points may need to be added as the user count increases. Design of the access point type and placement is a combination of the number of users, application requirements and building structure.
The placement of wireless equipment has traditionally been in or on the ceiling, but sometimes wireless access points are mounted in or on the walls or even on desks. Special ceiling panels are available to house wireless equipment. There are plenum-rated access points and antennae, however these may not be acceptable in all jurisdictions due to fire codes.
Early access points were devices that had to be plugged into main power. These devices are still available. Consequently, the installation of an access point involved having an electrician run a new outlet. There is a system of supplying power to devices over the Ethernet data cable. Extra wires, within the data cable, but not used for data, are used to supply DC power to access points. This is referred to as power over Ethernet (POE). In addition to access points, POE is increasingly being used to power devices such as VOIP phones, web cameras, security devices and building management systems. In this system, there are power supplies in the wiring closet that power the distributed devices. The power supplies are either part of the network devices or external devices, eliminating the need for individual AC power circuits at the access points. This puts a large power load in the wiring closet.
Typically, a survey of wireless coverage must be conducted. Building steel, partitions, furniture and other electric equipment can affect the wireless signal in unpredictable ways. Some material can reflect radio waves and cause interference. There is no practical way to fully figure out the facility impact in advance. Normally, a survey is conducted by temporarily installing access points and then walking around with a test device to determine where there is adequate signal strength. The coverage of each point is mapped and additional points are added until the entire desired area is covered. One must be careful that there are no dead spots between access points. Typically the vendor/installer will perform this survey as part of the installation fee. The steps in this design process are:
Select initial positions for access points, based upon experience.
Test signal strength and move access points or adjust antenna direction as required.
Create map of how each access point covers area.
Consider number of users per point.
Determine if additional points are required.
Assign frequencies to access points.
The actual installation may involve data wiring, electrical outlets, access points and antenna. It could also include the installation of wireless circuits or Network Interface Cards (NIC cards) in computers. This is typically an IT function. Thus, the installation may involve data wiring contractors, electricians, IT and a wireless vendor. The facility manager may be called upon to act as a project manager in such an installation.
It is important to configure security on the wireless system. Without good security, corporate data is at risk to easy access by hackers. This is normally an IT responsibility.
Training will likely be required for several groups. If the IT department has not worked with wireless before, then the network engineers will have to be trained to administer the system. The help desk will have to be trained to answer user questions and users will have to be trained in the use of the system.
An organization with a mobile work force might give their field personnel PDAs or tablet devices to communicate to the office about the status of work orders, parts needed or jobs completed. Such an implementation would be a major project for the IT department and could involve the development of custom software. A PDA system installation may or may not involve the facility manager.
By the nature of a system for a mobile field work force, much of it is used outside of the facility. Usually, such a system would be implemented via the cell phone system, but there could be antennae at the facility in some cases. This antenna and associated transmitters and receivers could be located off-site or could be constructed at the central facility. A system of PDAs within a facility, such as a restaurant or maintenance system could have a central antenna or could be implemented via a series of wireless access points.
Wireless or Satellite Antenna
The facility manager may be called upon to install an antenna or satellite dish. Such systems are usually on the roof, although in a campus setting a ground location may be possible. Mounting the antenna on the roof can be a challenge. Obviously, it must be very physically secure. Fortunately, satellite dishes are getting smaller and there is little need to install the six foot diameter dishes of past years. In multi-tenant buildings, the tenant should negotiate rights to install an antenna as part of the lease, even if none is planned upon move-in.
There are two basic methods to installing an antenna. On a flat roof a weighted sled is sometimes used. A sled simply sits on the flat roof and is sufficiently large to spread the weight out. The sled will have weights to keep it from being blown off of the building by the wind. The antenna is mounted to the sled. Engineering input is required on the design and weight of the sled. The advantage of the sled is that
there are no roof penetrations involved, hence no opportunity for leaks. The other method is to clamp the antenna to a mast or pole or an existing part of the roof structure if there is any. Sometimes a short mast can be mounted to the parapet wall. For vertical or whip type antenna this is the preferred method of mounting. Point to point wireless antennas (i.e. WiMAX) are often boxes about a foot square and are usually mounted to poles.
Typically a satellite antenna must point to the equator, in North America most satellite antenna need to point south or southwest, but this must be confirmed with the satellite service provider. A suitable location must be found to give the correct line-of-sight to the satellite. Building owners are usually concerned about minimizing the visibility of antenna for aesthetic reasons. In many areas there are building code restrictions on permanent fixtures on the roof. A movable mount is sometimes preferred for this reason. In Europe, dish antennae cannot be permitted to break the skyline or to have a visual impact on an old or preserved building. Depending on the roof configuration, it is often possible to install an antenna that cannot be seen.
When an antenna is mounted on the roof some provision must be made for the antenna wires to enter the building. It is best not to penetrate the roof membrane if possible for waterproofing reasons. Often a conduit can be installed in the parapet wall or in the wall of a mechanical penthouse. If the antenna is installed on the ground, an underground conduit or aerial cable to the building may be required.
With some systems active electronics must be installed near the antenna. A room or closet may be needed near the roof to house this equipment. Whether or not there is active equipment, there must be a cable pathway for the antenna wire to reach the building communication riser to route it to its final destination, usually the computer room.
Cellular Repeater Systems
Cellular service in certain facilities is poor or non-existent. In these cases a system may be installed to improve service. In multi-tenant buildings, it is often desirable for the repeater system to cover the entire building, rather than just a specific tenant space, although it is possible for an individual tenant to install a repeater system. These systems are fairly expensive and building owners are often reluctant to invest in the systems when no direct revenue will result. Sometimes they try to prorate the cost of the system to the tenants via the lease or a special charge. In these scenarios, the facility manager can become involved in complex negotiations. In single tenant or company-owned facilities the factors involved with installing this type of system are simpler.
There are a number of vendors that supply repeater systems in this rapidly evolving market. Some cell phone companies themselves supply repeater systems. It is usually necessary however, for the system to connect to multiple service providers. An exception might be if an organization has provided cell phones to all employees, in which case there would be a single service provider. Some providers’ systems support more than cell phones including wireless LANs and repeaters for two-way radios, like those used for maintenance or security. With rapid evolution of suppliers, the facility manager must survey the alternatives when an implementation is planned.
The repeater system creates a cell within the building. There may be an antenna on the roof to connect to the service provider or there may be a hard-wired connection to the service providers in the basement NetPOP. In a high-rise building, the antenna typically runs up and down the communication riser to serve the core of the building and elevators. The antenna usually radiates out from the core to cover the floors, typically above the ceiling. Plenum ceilings can be complex and add cost. Active devices are banned in plenum ceilings in some jurisdictions.
There may be active equipment in the riser closets on some floors. This is usually not needed on every floor. If there is a hard-wired connection to the service providers in the NetPOP, there will likely be active equipment. If there is a satellite antenna on the roof, there may be a need for active equipment somewhere on the upper floors to connect the satellite to the internal system. Wherever active equipment is installed, the facility manager should expect to supply power and mounting space.
Maintenance Operations and Support
Maintenance of wireless systems falls heavily on the IT department. Wireless LANs must be maintained in a way similar to other network systems. The IT department must pay particular ongoing attention to security administration. Support for users is generally a training and help desk function which is also typically the role of IT.
As discussed above, the number of users per wireless access point must be limited or bandwidth to each user may be unacceptably reduced. If more users are moved into an area served by wireless, then additional access points may have to be added. The facility manager overseeing the movement of employees within the office should consider the change in user load on the wireless system.
The facility manager needs to be aware that changes in the facility can affect the wireless system. Furniture, partitions, coatings on glass, steel and ceiling tile composition can affect the signal. If a section of the facility is remodeled or changed it is very possible for that remodeling to affect the wireless system. Putting up new partitions, adding heavy equipment, such as air conditioning, adding new furniture and other changes could affect the wireless signal. The facility manager should coordinate with IT before any remodeling begins, so changes to the wireless system can be planned. Although it may not be possible to determine what the impact will be in advance, IT or the wireless vendor should be staged for testing as construction occurs.
Because of the rapid advances in wireless technology, the facility manager should expect to have to change or upgrade their wireless system every few years. It’s somewhat difficult to say what the life cycle will be, but three years is the best estimate at this time. The architecture of the systems may also change. It’s difficult to determine what the architecture may be three to five years from now.
When it is time to change out a system, the facility manager should expect a project that will be somewhat disruptive. This will probably mean a new coverage survey, selectively removing the drop ceilings, installing power, antennas, data cable, new access points and retraining.