You're reading an older article from ELECTRICAL CONTRACTOR. Some content, such as code-related information, may be outdated. Visit our homepage to view the most up-to-date articles.
Wireless devices—including laptops, netbooks (the smaller, less powerful and cheaper PCs), iPhones, Blackberrys and regular cell phones—now dominate the news. Wireless is everywhere. I even hiked recently in a 4,500 acre nature preserve that had full Wi-Fi coverage at 50 megabits per second! In many offices, mobility is replacing unshielded twisted pair (UTP) cable to the desktop. Contractors installing cabling need to know about wireless, so let’s test your knowledge. Answers and explanations are in red.
1. Today, mobile devices, such as laptops, netbooks and phones, can be purchased with connections for which of the following network types?
A. Wi-Fi
B. WiMax
C. Cellular data
D. All of the above
Wireless connections are desired for mobility so mobile equipment offers these and sometimes more options.
2. Some of these devices offer more than one wireless connection type, e.g., Wi-Fi and cellular.
True
False
Many devices are now offering two options, for example the iPhone offers Wi-Fi and cellular to ensure maximum coverage.
3. Wireless access points (APs) can be connected to the network by _________.
A. Copper cables
B. Fiber optic cables
C. Wireless links
D. Any of the above
APs are available with interfaces for most link types for most flexible installation.
4. The advantage of using UTP copper for wireless access points is _________.
A. You have more bandwidth than other methods
B. You can power most APs over the UTP cable using power over Ethernet (PoE)
C. The AP can accommodate more users
D. Interference is reduced
All 802.11a, b, g and some n versions can be powered by POE over Cat 5e/6 cable.
5. In order to get the full benefit of the latest, highest speed Wi-Fi (802.11n), it is necessary to have a reliable gigabit Ethernet connection to the AP.
True
False
802.11n can have as much as 600 Mb/s throughput under ideal conditions so it needs a reliable Gigabit Ethernet connection to the network.
6. In order to properly power the newest, fastest version of Wi-Fi (802.11n), _________.
A. Access points may be powered by the current version of PoE (802.3af)
B. Access points may require next-generation PoE (802.3at now under development) for power
C. Access points may require a separate UTP or electrical cable for power
D. Specifications should be checked carefully for power requirements, as any of the above can be true on some equipment
802.11n power requirements vary by AP manufacturer, so it’s important to check the specifications before installation.
7. WiMax is a developing standard that is intended to _________.
A. Be cheaper than other wireless schemes
B. Replace cellular data systems
C. Act as a repeater for Wi-Fi
D. Deliver broadband connections competitive with telco DSL and CATV modem service
WiMax is a fast, high power wireless system that was originally developed to compete with telco DSL or CATV hybrid fiber-coax cable modem systems.
8. Cellular, metropolitan Wi-Fi and WiMax systems generally have antennas connected to their respective networks using _________.
A. Copper cables
B. Fiber optic cables
C. Wireless links
D. Broadband over power cables
Distances require fiber for most antenna systems, generally singlemode fiber, often part of other phone or metropolitan OSP systems.
9. Cellular systems providing coverage in poor signal areas, such as tunnels, or large buildings, such as convention centers, usually have antennas connected by _________.
A. UTP cables
B. Coax cables
C. Multimode fiber optic cables
D. Single-mode fiber optic cables
Most commercial cellular antenna systems use singlemode cabling to allow them to be sited in remote, sometimes distant areas.
10. Creating a secure wireless network may require _________.
A. Installing all equipment on shielded coax
B. Using only fiber cabling because it cannot be tapped
C. Scrambling all wireless communications
D. Installing enough cabling for a separate wireless backbone and AP connections
A secure wireless network uses separate cables to create an independent network that connects only to the Internet, not the company servers.
Answers can be found in “Cabling for Wireless” and in the section on Premises Cabling/Wireless in the new FOA Online Fiber Optic Reference Guide .
HAYES is a VDV writer and educator and the president of The Fiber Optic Association. Find him at www.jimhayes.com.
About The Author
HAYES is a VDV writer and educator and the president of the Fiber Optic Association. Find him at www.JimHayes.com.