Tech Industry Articles

As Wi-Fi spots are popping up all over the country and our digital lives are becoming a 24/7 extension of our existence, many manufacturers are venturing deeper into the world of fully functional ultraportable laptops that can be used anywhere, stored anywhere and perform whatever tasks are required of them. This, of course, poses a number of challenges to manufacturers; weight, size, ease of use, ergonomics… and how to fit all of the power the market demands into such a small chassis.

The general criteria used to determine what is an ultraportable laptop and what is not requires that they weigh less than or about 4 lbs and that they be compact enough to be taken anywhere. Almost every manufacturer offers some version of an ultraportable laptop, though some are better and more competitively priced than others. Dell, Lenovo, Sony, Compaq, Fujitsu, Apple, IBM, HP, ASUS and others all offer ultraportable laptops. Below are a few picks from some of the better brand names on the market:

HP tx2000

CPU: 2-GHz Turion 64 X2 TL-60 • Display Size (inches): 12.1 • Wide Screen: Yes • Total HD Size (GB): 160 • Min. Weight (lbs.): 4.26 • Price (at time of review): $899

This ultraportable laptop is very well equipped for its price and offers all of the standard amenities that its larger HP counterparts have such as 3 USB ports, a dual-layer DVD burner, built in webcam and so on. Its weight puts it a little on the heavy side for an ultraportable, but it still is quite manageable. The 12.1” screen is difficult to see if you are used to viewing a larger laptop all day, but it does have the benefit of being a convertible, which means the screen can be flipped and used as a tablet PC with ease.

Asus W5Fe-2P025E

CPU: 2-GHz Core 2 Duo T7200 • Display Size (inches): 12.1 • Wide Screen: Yes • Total HD Size (GB): 160 • Min. Weight (lbs.): 4 • Price (at time of review):$2800

Sturdy, powerful and attractive; this ultraportable laptop is sure to please. A handsome magnesium alloy case gives this machine a very solid feel that won’t leave you scared to take it out on the road. The powerful Intel Core 2 Duo processor makes this a powerful tool for anything most business men (and woman) can throw at it. It also boasts a 2.25-by-2.75-inch “Windows SideShow LCD” that is molded directly into the lid, a very unique feature. This little screen allows you to view emails, check calendar appointments, as well as browse pictures or music, all without opening the main screen.

Sony VAIO VGN-TZ150N

CPU: 1.06-GHz Core 2 Duo U7500 • Display Size (inches): 11.1 • Wide Screen: Yes • Total HD Size (GB): 100 • Min. Weight (lbs.): 2.7 • Price (at time of review):$2100

Weighing in at just less than 3 lbs, this ultraportable is about as light as they come. Of course, this makes for a considerable decrease in performance, so don’t expect to be running very demanding programs with this machine. Some key strengths of this laptop are its ability to play DVDs without actually booting up Windows, dual operable SD and memory stick readers, over a 5 hour run time and a stylish carbon fiber case. Though it is not a monster performer, this machine will still keep you up and running when you are out of the office.

As can be seen from these three examples, ultraportable laptops range all over the place in terms of features and ability. This makes it very important to have a good vision in your head of what you want out of your ultraportable laptop before you start shopping. This will allow you to get all of the features you need and avoid the ones that will just make your laptop heavier.

Christophe Catesson - Communication Manager for http://www.bestlaptopsreviews.com Laptop and notebook reviews and ratings, most popular laptops, industry news, Forum, Q/A.

The structure of an optical receiver is simple: consisting of just a photodiode to produce the electrical current and an amplifier. But do not be fooled: it is far more complex to design a really high performance optical receiver. So we will talk about some of the criteria of actual receivers.

The are a bunch of factors involved in the process. You have to take into count of signal current noise, noise from the photodiode such as from an avalanche diode, noise from the amplification electronics, thermal noise, dark current and signal to noise ratio for high data bit rate.

How to choose the correct photodiode?

Two major types of photodiodes are commercially available for optical receiver applications: PIN photodiode and Avalanche photodiode.

PIN photodiode

PIN photodiode is an extension of PN diode. But PN diode has many vital flaws. PN diode has too small depletion region which makes the received optical power must be fairly high to generate sufficient current. The second flaw is PN diode’s slow response which limits it only to kilohertz applications.

PIN photodiode solved these limitations on PN diode. The depletion region has been made as large as possible and most of the photons absorbed within the depletion region. And the inclusion of the intrinsic layer decreases the function capacity which raises the switching speed and the photon capture area.

The benefit of the improved design is a more efficient opto-electro conversion and faster speed.

Avalanche photodiode (APD)

In a PIN photodiode, each absorbed photon produces one electron hole pair which sets one electron flowing in the external circuit.

But in a Avalanche photodiode, a few incident photons result in many carriers being produced and an increased external current. How does an Avalanche diode achieve this?

This is produced by the phenomenon called avalanche multiplication. What this does is a strong electric field will accelerate current carriers so much that they knock valence electrons out of the semiconductor lattice and with a high enough bias voltage an avalanche of carriers will result.

While all those are good, there are also a dark side on this. While the carriers are amplified, the uneven nature of the multiplication introduces noise as well.

As a conclusion, although avalanche photodiodes are non-linear and fairly unstable, they are very similar to normal silicon photodiodes except that they require a slightly lower operation voltage to achieve good multiplication.

Other critical performance parameters of a photodiode

For your reference, some of the most critical parameters are listed below.

Responsivity

Photodiode responsivity is the ratio of generated current to incident light power. This is usually expressed in Amp/Watt. Sometimes this is also referred to as quantum efficiency.

Dark Current

Dark current is the current produced by the photodiode when there is no incident light at all. The dark current includes current generated by background radiation and the saturation current of the semiconductor junction. Dark current is a source of noise when it is being used in optical communication systems.

Noise-equivalent power

Noise equivalent power is the minimum input optical power needed to generate photocurrent. This equals to the rms noise current in a 1Hz bandwidth.

Colin Yao is an expert on fiber optic communication technologies and products. Learn about corning fan bt25, ribbon fan out, Spider fan out on Fiber Optics For Sale Co. web site.

What happens if a major fiber optic cable is cut or a major hubbing location is destroyed in a fiber network? Will the whole system be brought down?

That is the subject of this article: the survivability of a well designed fiber network.

Modern fiber optic transmission systems have provided tremendous capacity for voice, video and data traffic. At the same time, the fiber network needs to be designed to take the full advantage of this economies of scale while minimizes maintenance cost.

The main design goal is to utilize cost-effective interoffice (facilities between buildings) to maximize the number of circuits remaining intact after a worst-case failure while minimizing the ongoing maintenance cost associated with this survivability.

Conventional (existing) network architecture and design methods as well as future technologies can both be used to achieve this goal to some different degrees.

The principles in designing a survivable fiber network

Put simply, the basic principle behind the design of efficient fiber networks is “demand aggregation”. Demand aggregation makes use of facility hubbing and facility hierarchies to optimize facility networks.

What is facility hubbing?

Facility hubbing depends on the fact that fiber optic equipment occupies the majority cost in a fiber network. A fiber optic network’s total cost is not very sensitive to the network’s distance. In the mean time, fiber’s capacity is too much for building to building data traffic. As a result, it is conclude that routing traffic from each building into a building selected as its “hub” is the most efficient network design.

In this way, traffic is aggregated into the largest possible bundle to take advantage of economies of scale of fiber technology.

At the hub, all traffic is sorted and properly assigned to get to its destination. Digital Cross-Connect (DCS) is used at the hub to rearrange lower rate traffic into higher rate traffic. Thus all traffic is concentrated into high capacity routes to a central location where the demands are sorted according to destination.

What is facility hierarchy?

Facilty hierarchy is the extension of facility hubbing. The concept of facility hubbing is brought a step further.

In this concept, buildings are grouped into “clusters”, with each cluster having one hub building. This approach considers such factors as community of interest and geographic area.

The clusters can then be regrouped into “sectors”, with each sector having a “gateway”. The gateway is actually a hub building designated to handle inter-cluster traffic demand. A gateway can then aggregate demand from several cluster hubs to form a large demand to be routed to another gateway in much the same way as demand is aggregated to a hub building.

Actually the concept of facility hierarchy can be extended to an arbitrary number of levels.

Conclusion

Current fiber optic technology trends have forced a radical change in the structure of networks and the way in which networks are designed. The large capacity of fiber optic systems have resulted in efficient networks having large aggregations of demand in a few facilites.

Properly designed network architecture can increase network cost slightly but increase network survivability greatly.

Colin Yao is an expert on fiber optic communication technologies and products. Learn about break out kits, breakout kits, fiber optic breakout on Fiber Optics For Sale Co. web site.

What are fiber optic sensors?

The fundamental characteristic of all fiber optic sensors is that they depend on some optical properties, such as intensity, phase, state of polarization and wavelength, to be modulated by measurands. Measurands could be pressure, temperature, electromagnetic field or displacement.

All fiber optic sensors have an optical element that is sensing these property changes. For most sensors, this element is the optical fiber itself or a non-fiber optical element.

Fiber optic sensors with optical fiber as sensor element are called “intrinsic fiber sensor” and sensors with a non-optical fiber sensing element are called “extrinsic fiber sensor”.

1. Intrinsic Fiber Sensors

In the intrinsic fiber sensor, external measurands such as pressure, vibration, temperature interact with optical fiber element and cause fiber bending, fiber distortion and a change in the refractive index of the sensing fiber.

Because of the refractive index change, lights that travel through the fiber are affected accordingly. The changes in light properties, such as light intensity, light wavelength and light phase are then detected. The magnitude of measurands interacting with the fiber can then be determined.

2. Extrinsic Fiber Sensors

Birefringent crystal, intensity mask or thin film absorbers are most often used as sensor elements in extrinsic fiber sensors. Usually they are integrated into the optical path.

When the external force interacts with the sensing element, the light properties are modulated as well. The sensor has light source, optical path and photo detector parts. The magnitude of measurands is detected similar to intrinsic fiber sensors.

The Applications of Fiber Optic Sensors

Wide Area Sensing and Monitoring

Because of optical fiber’s immune to electromagnetic field, fiber sensors have a big potential in these areas. They are widely used in temperature sensing in building, leakage monitoring along oil pipelines and so on.

The above mentioned applications are called wide area sensing or monitoring. The name means that the sensing covers a wide area. In this area, fiber sensors are divide into two categories: distributed sensor and quasi-distributed sensor.

1. Distributed Sensor

Distributed sensors sense measurands continuouly over the entire length of the fiber. The most important criteria is that sensor fibers must be very sensitive to measurands.

A typical example of distributed sensors is a temperature sensor utilizing Raman scattering effect in optical fibers. Another example is OTDR (Optical Time Domain Reflectometer) which senses signal reflection in the whole length of an optical path.

2. Quasi-Distributed Sensor

Quasi-distributed sensors use discrete sensor elements that are carefully arranged in the fiber network. This type if sensor needs to be small size, low cost and high reliability.

High Sensitivity Measurements

Another area for fiber sensors is the high sensitivity measurement applications. This type of sensors typically utilize light interference’s extremely high sensitivity property.

A number of interferometric fiber sensors have been used for measurement of temperature, pressure, vibration and so on. The fiber optic gyroscope is one typical example of this type of applications.

Harsh Environment Measurement

Some extreme environment has no choice but fiber optic sensors. This kind of applications include high temperature, immersion into chemical reagents, radioactive rays factories and so on. The fiber optic sensor’s resistant to this type of harsh environment is extremely important.

Colin Yao is an expert on fiber optic communication technologies and products. Learn about fiber optic ST, ST connectors, ST fiber connector on Fiber Optics For Sale Co. web site.

In the last decade, a wide variety of applications have been developed that covers a dozen of datacom networking technologies. The transmission speed ranges from 10Mbits up to 10Gbit/s and growing.

High distance-bandwidth product is the major selling point for fiber optic transceivers. Another major benefit of fiber optic systems is their high reliability compared to other media.

Now fiber optic transceivers are commercially available for almost all international and industrial standards, including Ethernet, Fast Ethernet, Gigabit Ethernet, 10Gbit Ethernet.

So let’s review the the bunch of industry standards and inspect the various applications that fiber optic transceivers provide.

There are two classifications for optical fiber: single-mode (SMF) and multi-mode (MMF). SMF is used for long distance communication and MMF is used for distances of less than 300 m. SMF has a narrower core (6.3 ?m) which makes it difficult to connect. MMF has a wider core (50 or 62.5 ?m) and is more expensive than SMF.

Ethernet

Ethernet is the result of research done at Xerox Corporation in the early 1970s. It has evolved into the most popular physical and link layer protocol today. Up until late 1980s, 10Mbit/s Ethernet had the largest installed base and was the most popular networking standard.

Fast Ethernet

By the mide of 1990s, all 10Mbit/s Ethernet installation base have been upgraded to 100Mbit/s Fast Ethernet. The fiber standards for Fast Ethernet includes 100Base-FX, 100Base-SX and 100Base-BX.

100Base-FX uses a 1300nm multimode light. The maximum length is 2 kilometers for full duplex over multimode optical fiber.

100Base-SX is the lower cost alternative to 100Base-FX. It uses 850nm light and can only operate at distance up to 300 meters.

100Base-BX is version of Fast Ethernet over a single strand of optical fiber. (Both 100Base-FX and 100Bse-SX use two strands of optical fibers). It uses WDM (wavelength division multiplexing) technology to separate the transmission and receiving signals.

Gigabit Ethernet

By the end of 1990s and early 2000s, most 100Mbit/s Fast Ethernet installation base have been upgraded to 1000Mbit/s Gigabit Ethernet. In the same process, fiber is increasingly the transmission medium of choice when copper reaches its fundamental limits for high speed transmission.

For fiber optic transceivers, the related industry standards include 1000Base-SX, 1000Base-LX, 1000Base-LH, 1000Base-BX10 and 1000Base-ZX.

1000Base-SX uses 850nm multimode light over multimode fibers. Its spec says the maximum operation length is 500 meters but usually it can reach much longer than that.

1000Base-LX uses 1300 or 1310nm single mode fiber and laser. Its specification says the maximum operation length is 5km. But manufacturers often guarantee over 10km working length.

1000Base-LH is not a standard but accepted by the industry. It is backward compatible with 1000Base-LX but its specification is 10km over single mode fiber. This is actually achieved by using high quality fiber optic components.

1000Base-BX10 operates over a single strand of single mode fiber. Similar to 100Base-BX, this is achieved by using WDM technology. Its specification is 10km.

1000Base-ZX is also not a industry standard by accepted by the industry. It uses 1550nm single mode fiber and laser to operate over 70km.

10Gbit Ethernet

10Gbit Ethernet is also called 10GigE. This was first published in 2002 and is still the fastest Ethernet standard, although 100Gbit Ethernet is under development. The standard includes 10GBase-SR, 10GBase-LR, 10GBase-LRM, 10GBase-ER, 10GBase-ZR and 10GBase-LX.

Colin Yao is an expert on fiber optic communication technologies and products. Learn about fiber fan out kits, fiber optic fan out, fiber optic fanout on Fiber Optics For Sale Co. web site.

Do you know why it is so expensive to install Fiber To The Home? Why Bell companies are reluctant to deploy fiber optic network directly to consumers in a large scale?

It’s not the material cost. It’s the labor! The introduction of fiber into the subscriber loop has increased the installation of short cable lengths with large number of splices. The speed at which the cables can be placed, spliced, accessed and reconfigured are becoming extremely important.

So the need for new technologies that promise to reduce the fiber deployment cost are very high. Bell companies are anxious on acquiring these new technologies and products in order to reduce their cost and push the broadband fiber optic network installation.

That is where the high fiber count ribbon cables come to play. These compact, UV epoxy bonded cables are comprised with high precision optical fibers and can be massed fusion spliced with minimum loss. These products have proven to be an excellent platform for FTTH deployment.

Mass fusion splicing machines from Japanese companies are a integrated part of this process. These fusion splicers are used by the fiber installation technicians to splice up to 24 fibers at a time with very low splice loss.

Ribbon Fiber Design

The most basic requirement for any fiber optic cable design is to protect the glass fibers inside from harsh environment. But for ribbon fibers, there is the other vital requirement: organize the fibers for optimum space efficiency and ease of mass fusion splicing and handling. And at the same, they must also be able to maintain the optical performance and mechanical reliability.

This means that ribbon fiber cables must pack high count of glass fibers, organize fibers precisely for mass fusion splicing, provide individual fiber identification, can be divided into single fibers or subunits, mechanically reliable and can be easily accessed from the end or midspan.

These requirements must all be met at the same time which makes the manufacturing of high quality ribbon fibers a tough task.

So fiber cable specialists concluded a excellent design. A color coded array of fibers bonded in a line with fiber coating material. Based on this fundamental structure, two designed emerged: edge bonded or encapsulated.

Edge Bonded Design

The edge bonded design basically bonds the fibers together with only materials in between of each fiber. This design is more popular in the United States. This design is 40% smaller than the encapsulated design.

Encapsulate Design

In encapsulate design, bonding materials extend well beyond the gaps between fibers, it actually encapsulates all fibers inside a rectangular looking tube. This design are more used in Japan.

Ribbon Fiber Mass Fusion Splicing

The time savings for ribbon fiber mass fusion splicing are so big that sometimes in the field individual fibers are ribbonlized to make mass fusion splicings.

However, the success of mass ribbon fiber splicing relies critically on the fiber geometry, the ribbon and the mass fusion splicer. High quality and consistent mass fusion splices can only be produced with ribbons that are made from fibers having stringent geometric tolerances.

These high quality fibers and ribbons are already commercially available. And they make the fiber deployment in FTTH projects a joy for the installers.

Colin Yao is an expert on fiber optic technologies and products. Learn fiber furcation, fiber optic furcation, furcation tubing on Fiber Optics For Sale Co. web site.

The question on many laptop-toting individuals is “Can I watch TV on the computer?” Technology has taken great leaps and bounds, sometimes even more ahead than we have ever mentioned. Gone are the days that we thought television would be the final and only way to broadcast programs and news casts. These days, it’s all about satellite television that streams straight into laptops and computers.

How Is It Better Than TV?

You might be thinking that there is nothing quite like watching TV. Then again, there is nothing quite like surfing the Internet either. But imagine watching television and surfing on the Internet but doing it all on the same platform. Now that is a neat idea. Not only can you watch television on the PC but you can do it while working. This is actually very convenient for people who would like to keep up with the latest news from around the world while working. Satellite television straight to your laptop or your computer is also much better because you are no longer restricted to the limited number of channels that cable TV providers offer you. One can have access to 3000 channels from around the world.

The Price Is Right

Now, you may be enjoying all your television broadcasts on your cable service for a monthly fee. But if you switch to the satellite television on your PC as a solution, it is definitely going to save you more money than you ever dreamed of. Think about it. Sometimes it’s those monthly cable bills that eat up a little more money than you’d like to spend. Satellite TV on your PC solves this problem by offering you software that you can install onto your TV for a one-time, very low price. You can then start enjoying 3000 channels of programming from all around the world and you won’t have to pay a single cent ever. No more monthly bills to worry about, just pure access to all the news and entertainment you can handle. It’s better than free because it’s unlimited!

Can I Watch TV On The Computer Anywhere?

Remember that all you need to have in order for this to work is a computer, or a laptop and reasonable Internet access. Of course, having broadband will definitely make the experience much more enjoyable. The point is that is all you need aside from the software that you can buy at a very minimal price. You don’t need any satellite dishes or any special peripherals for your computer. What this means is if you install this into your laptop, you can enjoy television anywhere you can hook up to the Internet. Imagine watching television at all your favorite WIFI hotspots with friends or co-workers. There are even some parks that have free WIFI (depending on the city) so you can also sit in the park and still enjoy watching television.

It may seem that this is all too good to be true. But the truth is that this service does exist and it has been seven years in the making. Programming experts and technicians alike now have an easy-to-use solution for you to be able to enjoy television virtually for free. So if anybody ever asks you, “Can I watch TV on the computer?”, a simpler answer would be, “Why Not?”

Enjoy live tv viewing anywhere. Know more regarding watching live tv on pc now!

Multifunction printers are becoming increasingly popular these days due to their ability to perform many functions at a time. They are not only cost-effective but also space-saving.

If you have a small office or if you are operating from your home office, multifunction printers can be of great solution for your space constraint. It is really exciting for you to find a machine that can print, fax, copy and scan at a time. Many offices that have a shoe-sting budget prefer buying multifunction printers that work for their purpose. Buying a multifunction printer should be an important consideration for you as it involves a lot of research and shopping around as well. Following are a few points that talk about the important aspects of multifunction printers.

Printer resolution:

Printer resolution is important to judge if you are considering about taking picture print-outs. Higher resolution ensures quality prints. For most printing, except photo printing, the resolution of 600*600 will be adequate. However, in multifunction printer the scanner resolution is generally low.

Multitasking ability:

Be sure that the multifunction printer that you are taking truly has multitasking ability. The user should be capable of using it at the same time when the other facets are in use. If all the functions in the machine are not accessible simultaneously, then there is no reason why one should pay for a multifunction printer.

Connection to network:

The multifunction printer needs to have the ability to get integrated into your existing network. If it is easy to deploy with minimum start-up training it is better. While purchasing a multifunction printer, look for the software that comes with it to guide through the process of installation, upgrading or troubleshooting.

Automatic document feeders:

There are some low priced multifunction printers that do not allow automatic document feeder. If your printer does not have that function, you will have to stand by the side of your printer and feed it every single paper. The multifunction printer that holds at least 50 sheets can be considered as a good one.

Total value of the printer and ink cost:

If the printer you buy consumes a large chunk for the ink you will use in it, you will be in a bad deal. A useful multifunction printer can control the cost of your printing and imaging and produce the result effectively and efficiently.

Compatible software and solution:

This is one of the most important aspects that you should consider before buying a multifunction printer. There could be a possibility that the software offered with the multifunction printer may not be compatible. Hence, you should get clear idea about the software that is compatible with the multifunction printer. Your requirements:

Understand your requirements from the printer and buy accordingly. There may be many other things that you want from your multifunction printer beyond printing and copying like reducing paper, managed forms and simplifying work flow. Other requirements like fax, scan, email jobs, number of people sharing the device, color capability, etc are also taken into consideration.

Test before purchasing:

The best thing you can do before buying your multifunction printer is to test it. Make sure that each function works properly in the way they should. There is no harm in asking your dealer for demonstration. Read the instructions carefully before using the device.

Caveat:

Although buying a multifunction printer is a great idea, one should consider individual requirements thoroughly before buy one. If you are running a business where you depend on a photocopy machine quite frequently, you may not benefit much from buying a multifunction printer as it may or may not suit your requirement when it comes to the speed factor. Similarly, if you are looking for high-resolution scanning or cutting-edge faxing features, you have to consider buying a specialized machine instead of going for a multifunction printer.

This article can be accessed in portuguese from the Article section of page www.polomercantil.com.br/impressora.php
Roberto Sedycias works as IT consultant for www.PoloMercantil.com.br