Archive for May, 2008
:: The Definition of Backbone Cabling
Backbone cabling may be within one building or between buildings on a campus. All wiring between telecommunication rooms is called as backbone cabling.
In many cases, backbone cabling is actually between wiring closets on the same floor of a building, but the more typical case is the floor to floor wiring in a multi-floor building. Many call it vertical cabling in contrast to horizontal cabling.
:: How are backbone wiring implemented?
Typically all hubs, concentrators and switches are placed in the telecom rooms which serve all workstations on that same floor. Backbone wiring then connects the hubs, on to another on different floors.
• Daisy Chain wiring. In a daisy chain wiring, the back bone wiring connects from hub to hub to hub. Daisy chain is a good choice for Token-Ring topology, since it provides convenient ring-in and ring-out connections.
• Star wiring: In a star wiring, the back bone wiring connects all hubs from different floors to a center hub. Star wiring is a good choice for Ethernet which must limits repeater jumps.
For large buildings, telecom rooms are often placed in services shaft, one above the other, distances between telecom rooms are minimal. Thus the backbone wiring from each floor may be concentrated in a single master telecom room and the number of repeater jumps minimized.
:: How is backbone wiring capacity implemented?
Backbone wiring should be terminated in the same manner as horizontal cabling. The backbone cabling should be of same or higher category and type that meets your performance requirements and the safety and fire protection requirements for your installation.
For example, for Cat 5e horizontal wiring, you should use Cat 5e cable or even higher category such as Cat 6 and Cat 7. If you anticipate using your wiring system for multiple applications, double or even triple each backbone wiring run. This will give you ample room for growth and the ability to rapidly respond to new requirements.
:: Fire Safety
Most standard require that all riser cable (cable that goes vertically between floors) be riser rated for its fire and smoking rating. Some even require plenum rated cables.
But one most important thing is – you must properly install fire-stop material on all openings you make between floors, no matter those are cable ports or direct openings.
If you backbone wiring actually involves floor-to-floor cabling in vertical shafts or cable ports, you may need to use special riser cable that has a fire-retardant sheath, certified to meet NEC low-flame requirements. The NEC requires that riser cable meet UL flammability tests to be used in high-rise buildings.
:: Grounding requirement
When pulling cables between far flung telecom rooms or between floors, electrical grounding and bonding requirements must be observed. You can refer to EIA/TIA standards for the proper practices.
:: Advantages of fiber optic cable
Fiber optic cable provides significant advantages over copper cable. Fiber optic cable is not subject to electrical or magnetic interference, and thus may be run in locations, such as elevator shafts or alongside power lines.
In addition, a cabling system may be electrically isolated between buildings or between floors of the same building by using fiber optic cable.
Colin Yao is an expert on fiber optic networking technologies and products. Learn even more ribbon fiber cable, bulk fiber optic cables, multimode fiber optic cable on Fiber Optics For Sale Co. web site.
Have you ever experienced an annoying problem with your computer that you just could not get sorted out on your own? Most people have, and it can be completely frustrating when you are on a schedule trying to meet a deadline. Computer consultants/technicians are expensive even for the most basic of tasks, and calling one each time you have a simple problem can break the bank pretty quickly. However, if you can read simple directions and follow instructions, then it is likely that you can get all the help you need with your computer problems just for the asking.
So how is this possible and where do you need to go? Just visit one of the thousands of computer forums online and you will have hundreds or thousands of people willing to help you out with whatever problem you may have. Most of the minor issues or concerns that you have can be solved by posing a simple question to the many willing participants of the forum. Despite the cynical thinking of some, people are naturally helpful and computer forums are a great place to get help. Even if you have a major issue, there are some participants on forums who will go out of their way to help you get it resolved.
Considering the helpfulness of many of the participants on computer forums, you may be wondering why these individuals choose to help others who need it. There are probably thousands of reasons, but some of the main reasons computer forum participants are willing to help are:
1. People generally like to help others – it gives them a sense of purpose and usefulness
2. They may be “paying it forward” – someone helped them out when they needed it
3. They may have a type of symbiotic relationship with the computer forum – they provide help in exchange for advertising their business and gaining new clients
The third reason is the probably main reason that many users frequent computer forums and provide help. In addition to generally feeling good about helping others, they are afforded the opportunity to promote their business in the process. This works for you and the person providing the help.
They will provide a detailed response addressing your concern; and in return, they are allowed to place a small two to three sentence ad, also called a “signature”, at the end of their post advertising their business. If they are really helpful, many times people will become regular customers/clients and consult them for future issues.
You should be aware that on any forum you visit, there are rules regarding acceptable behavior; and these rules will vary across the different computer forums. So when you join, be sure to read all the rules regarding forum etiquette before you even place your first post.
Computer forums are an excellent way to get the help you need at either no cost or a reduced rate. In addition to getting help, you benefit from becoming a member of a community. And once you have your issue sorted out, hopefully in the future, you will return the favor and lend a hand to another.
Visit Computer Juice computer forums for computer forum computer repairs.
Wireless networks have become incredibly popular – so much so that virtually all new laptop computers have wireless network cards included as part of a set of standard features. As a matter of fact, customers will offer salespeople a strange, blank look if wireless networking is not included as one of the standard features. People love the convenience of being able to boot up the laptop and surf the net wherever they may be.
Wireless networks have become so popular and affordable that many people are now opting to include this convenience in their homes also. If you happen to be one of the thousands of people who choose to install wireless networking in your home, then there are a few things that you will need to understand about how wireless networks work.
One of the best and most appealing features of wireless networks is the fact that they are wireless. This makes installation incredibly simple and affords you the freedom to roam about in your home with your laptop untethered. Wireless networks eliminate the need for the wires associated with traditional Ethernet networks.
Installing wireless networking in your home is a rather painless process. Plus, in comparison to traditional wired, or Ethernet, networking, it is relatively cost effective. Many times, you can set up a wireless network in your home for less than a hundred dollars. The only disadvantage to wireless networks is that they are slightly slower than Ethernet networks. However, the average consumer will never even notice the difference.
Most wireless networking technology available for home use operates on what is called 802.11g technology. What this means is that the data sent over the network is transmitted at 2.4 GHz at a speed of 54 megabits. For non-technical folks, that means the data is moving pretty fast. Newer technology is currently in the works for wireless networks (802.11n), but it is still in the beta, or testing, phase.
Wireless networks operate by using either modulating radio waves or pulsing infrared light. They include a router that is hardwired to your Internet connection and transmits data via these radio or light waves. Your computer receives the information via either an internal or external wireless adapter, which acts as a receiver.
If you are thinking of installing a wireless network in your home, you will need a high speed Internet connection, a router, and wireless adapters for each computer you wish to access the network. Most basic wireless routers only have a range of about 100 feet, so if you live in a larger home, you may need to also purchase a range extender or repeater for your network. And that is pretty much it.
Wireless networks are easy to install and convenient. If you have not already decided to bite the bullet and install one in your home, you are missing out. The installation process only requires reading and following a few simple instructions. Do this and you will have a wireless network that the entire family can enjoy.
Visit Computer Juice computer forums for computer forum computer help.
The two most common outdoor fiber optic cable installations are pole line aerial installation and underground cable installation. Underground cable installation can be buried directly underground or placed into a buried duct.
Direct burial installation:
Direct burial installations are most common for long cross-country installations. The cables are plowed in or buried in a trench; the installation process can be very quick. The most common cables used for direct burial are steel armored outdoor fiber cables.
Underground duct installation:
Fiber optic cables can also be pulled through underground ducts, which protect the cables from harsh environment. Underground duct installation also provides opportunity for future expansion without the need to dig. This is the most common practice in urban areas. Another benefit is that fiber cables without armor can be used which makes the installation even easier.
Preparation before underground cable installation:
1. Obtain proper right-of-way permits
2. Identify existing underground utilities such as buried cables, pipes
3. Investigate the soil condition in order to determine the installation depth, whether duct should be used, the type of fiber cable should be used and plowing equipment needed
Cable Burial techniques:
1. Plowed under
Plowing in a fiber cable is faster than trenched. But this process has to be carefully monitored to prevent from damaging the cable.
2. Trenched
The fiber cable can also be trenched. This process is slower than plowing in; however, it allows a much more controlled cable installation. Trenches can be dug by hand or by machine.
3. Directional boring
Directional boring technique is used where the surface cannot be worked on such as high, railway crossings, etc. Instead, a boring machine is used to bore a several inches diameter hole underneath the surface, a duct is pulling through the hole and then fiber cables pulled into the duct.
Important factors:
1. Cable installation depth: up to 40 inches
The depth that fiber cables should be buried is determined by the soil conditions and surface usage. In colder areas, fiber cables are typically buried below the frost line to prevent the cables from being damaged by ground frost heaves.
2. Keep the trenches as straight as possible
Fiber cable trenches should be straight, and the trench bottom should be flat and level. Backfill can also be used to distribute the cable load evenly and protect the cables.
3. Fiber cable warning labels should be buried directly above the cable
Fiber optic warning cables are typically buried directly above the cables to warn future digging operations. Or concrete slabs can be buried below the warning label but above the cables to provide even more protection.
4. Whenever conducting armored fiber cables are used, they should be properly grounded
In direct burial installations, steel armored fiber cables are often chosen for their strength and protection from rodent bites. A very important thing to keep in mind is to properly ground the cables. They should be grounded at all termination points, splices and building entrances. The cable steel armor should be connected to a ground wire using a compression-type clamp. The cable ground wire is then bolted to a nearby ground terminal strip.
5. Fiber optic cable minimum bending radius should always be observed during installation.
Colin Yao is an expert on fiber optic technologies and products. Learn even more about fiber distribution cable, fiber optic distribution cable, indoor fiber cable on Fiber Optics For Sale Co. web site.
:: Duct/Innerduct materials and colors:
Fiber ducts are usually made from HDPE (high-density polyethylene), PVC or other compound. They are usually in black or gray. Fiber innerduct is usually orange or yellow.
:: Why usually fiber ducts and innerducts are corrugated?
Fiber ducts and innerducts are corrugated to provide the following benefits:
1. Decreasing pulling tensions during installation
2. Very flexible and can be used in installation locations where many turns are involved
3. After installation, corrugated innerduct should be left for a day to allow the innerduct to retreat back into the duct through its corrugated spring action
:: The use of pulling tape
Fiber optic cable pulling tape is preinstalled in fiber duct and innerduct in the factory. This saves significant time during the installation process. Duct and innerduct can also be pre-lubricated in the factory, thus significantly reduces pulling tensions.
:: Never bend over its minimum bend radius
Just like fiber optic cable, fiber duct and innerduct also have a minimum bend radius spec. Never ever should the duct or innerduct be bent tighter than its minimum bend radius.
:: What is supported radius?
The supported radius is the minimum bend radius when the duct is bent around a supporting structure such as in another duct or on a reel.
:: What is unsupported radius?
The unsupported radius is the minimum bend radius when the duct has no supporting structure in the bend.
:: Benefits of using fiber duct
Fiber duct protects the fiber cable and also provides an opportunity for future cable access and expansion. Fiber optic cable can be pulling into existing duct. The duct should usually be oversized to allow future cables be pulled in.
:: Benefits of using fiber innerduct
Fiber innerduct provides protection for the fiber cable from being disturbed by other companies’ cable installation operation. It also provides extra protection from the environment. Or fiber innerduct can be used in old duct installation.
:: Things to keep in mind
1. Install end plugs
After the fiber optic cable is installed into a duct or innerduct, end plugs should be installed to provide a water seal. No debris should be able to enter the duct or innerduct, and watertight should always be maintained for the duct or innerduct.
2. Duct and innerduct should be properly sized for future expansion possibility
As always, planning for future expansion is crucial for real successful projects. A maximum of 40% fill ratio is a good practice to follow. The duct size should be increased for long installation lengths with many turns. A larger duct can help to reduce cable-pulling tensions. Standard duct sizes vary from 3 to 8 inch ID and innerduct sizes vary from 0.75 to 2 inch.
:: The benefit of using duct lubricant
Duct lubricant can significantly reduce the cable’s coefficient of friction, thus lessening the pulling tension during cable pulling process. This is especially important in long cable duct pulls and pulls with many turns.
Duct lubricant spillage should be cleaned up as soon as possible to prevent accident since it is very slippery. Manufactures’ recommended procedure for cleaning lubricant provides good instruction on how to do the cleaning.
Colin Yao is an expert on fiber optic networking technologies and products. Learn even more about outdoor fiber cable,outdoor fiber optic cable, outdoor multimode fiber on Fiber Optics For Sale Co. web site.