Q: My question is whether or not a specific design meets TIA/EIA requirements. The configuration is as follows: A 48-port Category 6 panel in the telecommunications room (TR). Category 6 cable runs from the TR to a consolidation point (CP). The cable is terminated on the IDC of the panel and on a Cat 6 jack at the CP. From the CP, a single-ended, solid-conductor Category 6 (cable) patch cord is plugged into the jack at the CP and terminated on the IDC of the jack at the workstation. The workstation consists of a Category 6 jack. Category 6-rated patch cords are used at the workstation and panel. The cable and the components are rated to Draft 7, 8, or 9. They do not meet the current component-compliance requirements in Draft 10 of the proposed standard.
Does this configuration meet the standard?
Renee Cook
Network Products Inc.
Gaithersburg, MD
A: The "TIA/EIA standards"-yes. Category 6-not likely. Draft 10 of SP-3-3727-AD1-B includes a tightening of the performance specifications for Category 6 connecting hardware over the previous drafts.
The configuration that you have described is typical and certainly meets TIA/EIA-568B.1 requirements. But it is important to note that TIA/EIA-568B.1 does not include Category 6. The highest category in TIA/EIA-568B.1 is Category 5e.
Will the scenario that you described meet the new Category 6 requirements when they are published? That depends on what, if any, changes the committee makes between Draft 10 and publication. Please remember that there is no "Category 6 standard" until publication. This uncertainty and the very limited number of applications that actually require Category 6 performance is why the industry has not yet made the transition from specifying Category 5e.
As for using a patch panel as a CP, TIA/EIA-568A was worded "intentionally vague" to allow for innovation on the part of the manufacturers, with most manufacturers choosing to focus on the box for housing the CP, rather than the connecting hardware inside. The majority of the CPs that I have seen installed were modular patch panels used as interconnects.
Give a carpenter a hammer, nails, and lumber, and he will frame a house with wood. Give a carpenter a screw-gun, screws, and steel, and he will frame a house with steel. Give the carpenter a choice and he will most likely use what he is most familiar with-usually lumber.
Give a cabling distribution designer or an installer a choice, and they will choose to interconnect with what is most familiar-patch panels to form a plug-and-jack interconnection at the CP.
If I were an end user at the point of post-installation of a better-than-Category 5e (but not quite Category 6) cabling infrastructure, my primary concern would be, "Will the installed cabling system support the applications I will soon be using, or am I facing yet another copper cabling upgrade?"
RG-6 ideal for broadband
The following is an excerpt of a comment that I received from Ed Nielsen, with Wasatch Electric Co. in Salt Lake City, UT. Ed is a member of the Society of Cable Telecommunications Engineers. The comment is in reference to my December 2001 answer to the "RG-6 for cable TV delivery" question:
No, you are not old-fashioned by any means by using RG-6 for cable TV delivery. In fact, with the exception of fiber, no other medium is adequately suited for RF transmission. For baseband, twisted pair is just fine, but broadband requires coaxial cable. If the system you alluded to in your response is similar to the one I became acquainted with a few years ago, the signals are digitized for transmission on the Category 5. While there could be one transmitter, each receiving station had to have its own receiver. At approximately $600 per receiver, this becomes quite pricey. I think the transmitter was around $1,100.
With the cost of good RG-6 being less than that of good Category 5, I don't see why anyone would even think of using anything other than the best-suited medium. There could be exceptions, of course. Certain retrofits might not allow new coaxial cable to be pulled in a hospital, school, or other such building.
I also received a lot of reader mail regarding the link to Magneta Research, which is www.magneta-research.com.
Thanks to everyone for the feedback.
Emergency phones on campus
I have recently received several inquiries regarding where to locate emergency telephone call boxes on a university campus ellipse so there must be grant money out there somewhere.
Planning an emergency telephone system is almost a science unto itself, and the art of choosing where-well, once the word is out that emergency telephones are being installed on your campus, the list of troubled or potentially troubled locations will grow much faster than the budget for procurement and installation. A lot of people will have ideas about where to locate the emergency telephones, but it is best to let the selection committee decide which sites will actually warrant installation. I would offer the following list of questions for consideration when choosing a site:
- What is the population of the area surrounding the site?
- Do the types of services available in the surrounding area attract large numbers of people?
- How remote is the site?
- What are the potential hazards of the site?
- Would the emergency telephone be visible to someone needing help?
- Is there a high potential for vandalism of the emergency telephone at this site?
- Would it be better to install a public pay telephone at this site?
Once you have the estimates prepared for the sites chosen, those sites and priorities will likely change. Why? Cost. It is expensive to push pipe under a street or cut a parking lot to install one telephone. Hence, emergency telephones are most often located near access to an existing duct bank, tunnel or areaway. I suggest that you establish a good rapport with your physical plant staff. If you can get them to contact you whenever they plan to dig a trench, you may be able to get a couple of conduits (one for power and the other for telecom) from a nearby building to a future emergency telephone site without having to reopen the surface later.
From experience, I can assure you that there is a knack to locating emergency telephones close enough to pedestrian traffic to allow convenient use, but not so close that temptation to smack the button and run becomes a "false alarm" problem. Your campus police will soon let you know how well-placed they are.
But "where" is not the only question. What to install is another issue you will have to address.
First rule: all of the emergency telephones should be aesthetically and operationally similar. You don't want someone in urgent need not knowing what to look for or how to summon help. This will also reduce repair and other maintenance costs.
Typically, emergency telephone assemblies consist of a pole with a light at the top, a box for mounting the telephone, and the telephone instrument. In some climates, a thermostatically-controlled heated panel may be required inside the box.
You will need electrical power for lighting, including a light to illuminate telephone user surface, and the top beacon, which usually flashes when activated to assist the emergency response personnel in locating the user's location.
A few well-placed bollards will allow pedestrian access while protecting the pole from damage by vehicular traffic. As with the poles and beacon lights, there will be all sorts of opinions as to exactly which bollards should be used-tall/short, fat/skinny, red/yellow, etc. I suggest that you contact your physical plant and ask that they "standardize" on one choice for each.
When selecting the emergency telephone instruments, choose one that is capable of two-way voice communication. Not everyone who pushes the button needs an ambulance or a police officer. There are three types of instruments that I consider suitable to function as emergency telephones. Pay telephones on which you can lift the receiver and dial 9-1-1 with no coins required, and two types of special emergency telephone instruments. The first is a rather standard-looking telephone; lift the receiver and the auto dialer dials 9-1-1. The second is a hands-free speaker telephone sporting a large button that when depressed causes the auto dialer to dial 9-1-1. In each of these scenarios, the telephone line is POTS and 9-1-1 is being dialed. This eliminates the need for ring-down circuits or special programming in the central office.
In areas where it is difficult (this can also be read as "expensive") to have electrical power installed to the emergency telephone site, solar power is an option; and if the telephone drop cables also prove difficult, cellular can be used.
Once you have completed the bill of materials, sticker shock will begin to set in. Resist the temptation to allow the techs to cobble something together. The first one or two will be fun, but next thing you know, you are a "cottage industry" with no one to call when unforeseen problems begin to cause instrument failures.
To help acquaint your users with their new emergency telephone system, I suggest that a "What to Do if You Need Help" description, and a map indicating the locations of emergency and pay telephones be posted to your university's home page. It can also be printed in your campus telephone directory. To help reduce the number of non-emergency calls, install a sign at each site indicating the location of the nearest pay telephones. Your campus police will thank you.
Donna Ballast is a communications analyst at The University of Texas at Austin and a BICSI registered communications distribution designer (RCDD). Questions can be sent to her at Cabling Installation & Maintenance or at PO Drawer 7580, The University of Texas, Austin, TX 78713; e-mail: [email protected].