What Is a Firewire® to USB Adapter

Firewire® (IEEE 1394) and USB (Universal Serial Bus) are two separate high-speed bus technologies that allow multiple devices to be connected to a computer. The two technologies are not integrated, and it is not possible to connect a USB device to a Firewire® port either directly. A Firewire® to USB adapter cable for transferring digital video (DV) is available from at least one manufacturer, but it can be expensive and difficult to find.

Even if you don't have a Firewire® to USB adapter cable, it doesn't mean that your Firewire® devices are useless if you have a USB port, or vice versa. Several companies do provide dual hubs. This type of device has two ports in a single hub, which may be either external or internal; one port is used Firewire® and one for USB, allowing either type of device to function. The combination hub is actually two separate ports combined into a single form factor for convenience; there is no conversion between Firewire® and USB taking place when you use one of these hubs.

Another alternative is simply to add two separate cards, assuming your computer has enough available slots. Firewire® and USB cards are both coming down in price, and adding whichever one is missing should not represent a major expense.

Both Firewire® and USB are efficient, high-speed bus standards. A Firewire® hub can support a data transfer rate of up to either 400Mbps or 800Mbps, depending on the standard, and a single Firewire® port can connect up to 63 devices and deliver a guaranteed rate of speed to each one. Firewire® is often used for devices that require real-time operation such as audio and video systems because of this guarantee, and it is also used frequently in storage area networks.

USB can connect more devices (up to 127), but supports data transfer rates of only up to 12Mbps. It is more often used for standard peripherals, such as mice, modems, and keyboards. The USB 2.0 standard supports speeds of up to 480Mbps, which makes it more competitive with Firewire®. On 17 November 2008, USB 3.0 specifications were released, with a transfer rate 10 times that of USB 2.0; consumer devices that use this standard were expected to be available by 2010.

If you cannot purchase a Firewire® to USB adapter, using a hub allows you to use devices that are compatible with either technology. Both technologies support Plug-and-Play and hot-plugging (hot-swappable).

What is the Difference Between GSM and CDMA

In cellular service there are two main competing network technologies: Global System for Mobile Communications (GSM) and Code Division Multiple Access (CDMA). Cellular carriers including Sprint PCS, Cingular Wireless, Verizon and T-Mobile use one or the other. Understanding the difference between GSM and CDMA will allow you to choose a carrier that uses the preferable network technology for your needs. 

The GSM Association is an international organization founded in 1987, dedicated to providing, developing, and overseeing the worldwide wireless standard of GSM. CDMA, a proprietary standard designed by Qualcomm in the United States, has been the dominant network standard for North America and parts of Asia. However, GSM networks continue to make inroads in the United States, as CDMA networks make progress in other parts of the world. There are camps on both sides that firmly believe either GSM or CDMA architecture is superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful.

Coverage: The most important factor is getting service in the areas you will be using your phone. Upon viewing competitors' coverage maps you may discover that only GSM or CDMA carriers offer cellular service in your area. If so, there is no decision to be made, but most people will find that they do have a choice.

Data Transfer Speed: With the advent of cellular phones doing double and triple duty as streaming video devices, podcast receivers and email devices, speed is important to those who use the phone for more than making calls. CDMA has been traditionally faster than GSM, though both technologies continue to rapidly leapfrog along this path. Both boast "3G" standards, or 3rd generation technologies.

EVDO, also known as CDMA2000, is CDMA's answer to the need for speed with a downstream rate of about 2 megabits per second, though some reports suggest real world speeds are closer to 300-700 kilobits per second (kbps). This is comparable to basic DSL. As of fall 2005, EVDO is in the process of being deployed. It is not available everywhere and requires a phone that is CDMA2000 ready. 

GSM's answer is EDGE (Enhanced Data Rates for GSM Evolution), which boasts data rates of up to 384 kbps with real world speeds reported closer to 70-140 kbps. With added technologies still in the works that include UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access), speeds reportedly increase to about 275—380 kbps. This technology is also known as W-CDMA, but is incompatible with CDMA networks. An EDGE-ready phone is required. 

In the case of EVDO, theoretical high traffic can degrade speed and performance, while the EDGE network is more susceptible to interference. Both require being within close range of a cell to get the best speeds, while performance decreases with distance. 

Subscriber Identity Module (SIM) cards: In the United States only GSM phones use SIM cards. The removable SIM card allows phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself is tied to the network, rather than the actual phone. Phones that are card-enabled can be used with any GSM carrier. 

The CDMA equivalent, a R-UIM card, is only available in parts of Asia but remains on the horizon for the U.S. market. CDMA carriers in the U.S. require proprietary handsets that are linked to one carrier only and are not card-enabled. To upgrade a CDMA phone, the carrier must deactivate the old phone then activate the new one. The old phone becomes useless.

Roaming: For the most part, both networks have fairly concentrated coverage in major cities and along major highways. GSM carriers, however, have roaming contracts with other GSM carriers, allowing wider coverage of more rural areas, generally speaking, often without roaming charges to the customer. CDMA networks may not cover rural areas as well as GSM carriers, and though they may contract with GSM cells for roaming in more rural areas, the charge to the customer will generally be significantly higher. 

International Roaming: If you need to make calls to other countries, a GSM carrier can offer international roaming, as GSM networks dominate the world market. If you travel to other countries you can even use your GSM cell phone abroad, providing it is a quad-band phone (850/900/1800/1900 MHz). By purchasing a SIM card with minutes and a local number in the country you are visiting, you can make calls against the card to save yourself international roaming charges from your carrier back home. CDMA phones that are not card-enabled do not have this capability, however there are several countries that use CDMA networks. Check with your CDMA provider for your specific requirements.

According CDG.org, CDMA networks support over 270 million subscribers worldwide, while GSM.org tallies up their score at over 1 billion. As CDMA phones become R-UIM enabled and roaming contracts between networks improve, integration of the standards might eventually make differences all but transparent to the consumer. 

The chief GSM carriers in the United States are Cingular Wireless, recently merged with AT&T Wireless, and T-Mobile USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin Mobile. There are also several smaller cellular companies on both networks.

What Are Unlocked Cell Phones

Unlocked cell phones are mobile phones that can be used on any GSM network with interchangeable SIM cards. No matter which carrier makes the card, the phone will be able to recognize it and send voice and data over the network. This contrasts with a locked phone, which is bound to a specific cell phone service provider (or carrier) network with software settings, and is typically offered with a contract when someone starts mobile service.

Potential Advantages

One advantage to buying an unlocked cell phone is the ability to buy almost any GSM (Global System for Mobile Communications) phone, rather than being restricted to a limited selection offered by a specific carrier. This can include phones only distributed in certain countries, or with features that are not available on all carriers. People also don't need to wait for a contract to expire to buy a new phone; they can remove the SIM (Subscriber Identification Module) card from an existing phone and insert it into a new one when they are ready for a replacement. This allows them to keep their number while upgrading the phone, without having to go through the carrier.

Additionally, the ability to use an unlocked cell phone with a variety of SIM cards can be convenient for travelers. Most carriers only supply service to a particular country or area; when traveling outside the coverage zone, the mobile phone user will have to "roam" on another carrier's network, which often comes with a high fee. To avoid roaming fees, a person can buy a SIM card from a local carrier at his destination and insert it, preserving all his existing phone settings but getting a new number and a local calling plan. In addition to less expensive calling rates, this provides the added benefit of having a local number while in the area.

Potential Disadvantages

Not all unlocked phones have all the same features as their locked counterparts even when the provider is the same. Carriers may include such features only on locked phones, which use their proprietary software and settings. Some carriers offer free calling to a number of contacts or one-button access to certain features that can only be used on locked phones. Consumers concerned about specific features may want to check with a carrier to see if they are available on unlocked cell phones. 

In addition, such phones tend to be more expensive. Locked phones are often costly because they usually come with phone service contracts that commit the consumer to that service provider for a certain period of time (like two years). Unlocked phones typically sell at or close to retail price because the buyer can use the phone with a number of different carriers.

Another issue with unlocked cell phones is that they may not work on all GSM bands; as of 2012, a quadband phone could operate anywhere in the world with a GSM network, but other phones could not. This may be a concern for international travelers especially, since not all bands are used in all countries. For example, in South America, the 850 MHz band is in common use, but others may not be available. It is advisable to check on which bands the phone uses, and which bands are available in given travel destinations.

Getting an Unlocked Phone

One way to get a phone without proprietary settings is to buy it new from a third party vendor in its original, unlocked state. Third party services are also available to unlock a person's cell phone for a fee, usually by attaching it to a special piece of hardware specially designed for this purpose. This doesn't guarantee the phone will always work correctly, as carrier settings might remain in the software. 

There are also instructions online to unlock most models. In many cases, unlocking a phone is just a matter of activating the phone and entering a specific code; some phones, however, require a series of steps before the code can be entered. Not all codes work, and trying to enter codes that are incorrect can cause the phone to "hardlock" and prevent it from being unlocked. Certain models of cell phones can only be unlocked using the hardware method, which may also worked for hardlocked phones.

Some cell carriers sell unlocked phones at full price, usually allowing consumers to pick a flexible plan such as month-to-month or pay-as-you-go billing. This can provide access to carrier-specific features with the flexibility of an unlocked phone. If a customer has been with a carrier for some time — sometimes for as little as 90 days — the carrier may even be willing to supply an unlock code for a locked phone, although they may charge a fee.

Cell Phone Carriers

The majority of the world — 99% — uses the GSM network, and numerous carriers use it for their services. The competing network is CDMA, or code division multiple access. Most carriers on the CDMA network do not, as of 2012, use card-enabled phones; instead, subscriber information is stored in the cell phone's memory, which means it cannot be transferred to another phone. The CDMA equivalent of the SIM card — the R-UIM — is likely to be used by these carriers in the future, and is already in use in some parts of Asia. This card contains software that allows it to be used in GSM phones as well.

Jailbroken Phones

A jailbroken phone is not exactly the same as an unlocked phone. Most often used in reference to Apple's iPhone®, when a phone is jailbroken, it has been modified to allow it to download applications (apps) not approved or sold by the carrier, such as the Apple App Store. A phone that has been jailbroken is not unlocked, although it may be necessary to jailbreak a phone before unlocking it is possible. Jailbreaking a phone is considered legal in the US, although it may violate the warranty.

Why Can't You Use Your Cell Phone on an Airplane

In 1991, the Federal Communications Commission (FCC) banned passengers from using their cell phones while on board an airplane that is in flight. The ban was instituted because the FCC suspected that the radio frequency emitted by cell phones could malfunction an airplane's equipment systems. In complying with this rule, different airlines have instituted different policies about when phones can be turned on and off. In 2005, the FCC announced that it might consider lifting the ban on the use of cell phones on airplanes, with certain restrictions. 

The FCC regulates the use of all electronic devices, including cell phones, on airplanes under the assumption that they may affect the communication systems on board. The Federal Aviation Administration (FAA) agrees with the FCC that cell phones may cause substantial interference with aircraft systems and supports the ban for all commercially operated airplanes. The use of cell phones on private or charter planes is not regulated, however, and many private flights permit passengers to use cell phones while in flight. 

Lots of debate has surrounded the use of cell phones on airplanes. The primary concern is that cell phones may interfere with the navigation and communication systems of the plane, potentially resulting in devastating failure. Numerous airlines have reported disruptions in cabin pressure, compass function, and wireless navigation systems associated with the use of cell phones on board. The FCC, it seems, erred on the side of caution when it enforced an outright ban on the use of radio frequency emitting devices which could potentially cause an aircraft to crash. 

There have also been some reports that the use of cell phones on planes may cause disruptions in ground communications because of interference. Others claim that the airlines and the FCC would simply prefer that consumers use the telecommunications systems mounted on most seat backs in commercial airplanes, because these phones are said to be highly profitable. Newer cell phones are capable of operating on very low power settings, which may not interfere with the aircraft as much. The FCC is attempting to establish an acceptable threshold of radio frequency emissions, so that cell phones could be used on airplanes without any fear of the navigation system failing or service on the ground being disrupted.

How can I Make a Room Soundproof

There are many times when a person might want to reduce the amount of sound coming into or leaving a room. Making a room soundproof involves stopping or reducing sound waves by using certain building techniques or materials. There are many methods available, and choosing one will depend on the room itself and the amount of money that you are willing to spend. To make a room soundproof, you might have to make changes to the walls, ceiling, windows, doors and any cracks or openings. A few things that will help make a room soundproof include using a double layer of sheetrock on walls, with a layer of silicone or another sticky sound-dampening compound in between them; installing double- or triple-hung windows; installing a drop ceiling; and installing carpet padding and carpet on the floors.

The best way to prevent a noise problem is to construct the room with building materials and techniques that will reduce the noise that enters or leaves a room. Pre-planning in this way is not always possible, however, especially for renters. In those cases, soundproofing a room centers on how to absorb unwanted noise after the walls already are in place.

Soundproofing Walls

If you are building the walls or are willing to re-do existing walls, consider using two layers of sheetrock with a small amount of space in between. They can be glued together using a layer of silicone or a special type of sound-dampening glue. For existing walls, a layer of sheetrock can be added over the wall. Sounds waves are reduced as they travel through mass and as they go from substances of different densities, which is why two layers of sheetrock that are slightly separated are better than one layer that is twice as thick. Various sound-reducing materials also can be added to the interior of walls, such as fiberglass insulation, rockwool insulation, mass-loaded vinyl or certain types of soundproofing foam panels.

Doors and Windows

Doorways and windows can also contribute to unwanted noise problems. Thick, solid doors and double- or triple-paned vinyl-framed windows will block more sound than thin doors and single-paned windows. Also, just like the way that a draft of air can travel through leaks around a door or window, sound can enter or leave a room through them. Weatherstrips or caulk can be applied to the gaps around door frames and windows to reduce the amount of sound that sneaks through the gaps.

Floors and Ceilings

Floors and ceilings can be soundproofed as well. Carpet can be installed over carpet padding on floors. Special sound-reducing mats also can be laid under the carpeting. A ceiling can be soundproofed by adding a drop ceiling, which is sometimes called a false ceiling or suspended ceiling. This type of ceiling consists of special panels hung from the ceiling.

Less-Expensive Options

If money is a concern or time is limited, a less drastic, inexpensive approach to making a room soundproof might be needed. This might include using a large bookcase or other furniture against a wall, effectively making a thicker wall through which the sound must travel, or using thick curtains over windows to help keep sounds from traveling through the window as easily. Other simple techniques that can reduce the noise in a room involve absorbing the sound that is already in the room, rather than blocking it from entering or leaving the room.

Sound-Absorbing Surfaces

Hard, smooth surfaces in a room typically do nothing to help eliminate sounds, and they might make the noise problem worse. Soft rugs, carpet and curtains can absorb sound. Rough surfaces on walls and ceilings, such as sprayed-on texture, can help reduce the sound waves in a noisy room.

Wall Treatments

Wall treatments or decorations also can help make a room soundproof. This usually involves tacking on or hanging some sort of heavy material that will block sound waves. The material can range from carpeting to blankets to manufactured paneling — even cardboard egg cartons are an option in some situations. As with most soundproofing materials, the thicker, the better.

What is Technology

Technology is a broad term that refers both to artifacts created by humans, such as machines, and the methods used to create those artifacts. More broadly, technology can be used to refer to a way of doing something or a means of organization: for instance, democracy might be considered a social technology. Technology comes from the Greek technologia, which is a combination of “techne”, meaning “craft”, and logia, meaning “saying”. So technology might be considered the articulation of a craft. The word is also used to describe the extent to which a society can manipulate its environment.

When the word “technology” is used today, it is most often used to refer to high technology – computers, cell phones, rockets – rather than technology in general. But when anthropologists use the word “technology,” they go all the way back to the controlled use of fire (from about 500,000 – 1 million years ago), the invention of the wheel (c. 4000 BCE), and beyond. The first technological tools were simple hand-axes made by our hominid ancestors millions of years ago.

The earliest technological divisions are from mankind’s early history, divided into the Stone Age, the Bronze Age, and the Iron Age depending on the primary tool and weapon-making material at the time. Each building material is superior to the one before it, but more difficult to develop requisite metallurgical techniques. The Iron Age began in about 1400 BCE. 

Since the formulation of the scientific method in the 15th century, technological progress has apparently been accelerating. Some technologies developed since then include the telescope, the microscope, the clock, the engine, the electric generator and electric motor, radio, nuclear power and weapons, television, computer, and many others.

Technological development continues strongly today, fueled by the multibillion-dollar economies of the world’s most prosperous nations. The hottest developments in technology today are happening in computers, nanotechnology, materials science, renewable energy, entertainment, space travel, and medicine.

Philosophers as well as laypeople often debate whether or not technological progress is, on the whole, a good thing for humanity. On the pro-technology side of the spectrum are techno-progressivists such as transhumanists, on the anti-technology side are anarcho-primitivists, and Neo-Luddites.

What Is 4G Mobile Technology

4G mobile technology is the name given to the next generation of mobile devices such as cell phones. It became available from at least one provider in several parts of the US in 2009. There is not yet an agreed industry standard for what constitutes 4G mobile, so for now it is merely a marketing term.

The use of G, standing for generation, in mobile technology covers the major advances of the past 20-30 years. 1G technology involved the first widely available mobile phones. 2G technology, which began in the early 1990s, switched to a digital format and introduced text messaging. 3G technology improved the efficiency of how data is carried, making it possible to carry enhanced information services such as websites in their original format. The latest iPhone is the best known example of 3G technology.

4G mobile is not yet established as an agreed set of standards, so its features are currently simply goals rather than requirements. As well as drastically increasing data transfer speeds, 4G mobile should use enhanced security measures. Another goal is to reduce blips in transmission when a device moves between areas covered by different networks. 4G mobile networks should also use a network based on the IP address system used for the internet.

Within the United States, there are two major systems using 4G mobile technology. One is known as WiMax and is backed by Clearwire, a firm whose majority owner is Sprint Nextel. It began testing services in Baltimore in 2008 and was set to expand this into major new markets in 2009. Sprint intended to have 80 cities covered by the end of 2010.

The rival system, Long Term Evolution or LTE, is backed mainly by Verizon. It was expected to be ready for testing in 2010 but not available for widespread use until 2012. LTE's backers hoped to overcome this disadvantage by offering faster speeds and producing cheaper equipment.

Unlike previous generations of mobile technology, 4G mobile will be widely used for internet access on computers as well as carrying cell phone communications. Customers in areas which have strong 4G coverage will be able to use it for a home broadband connection which doesn't require any cabling to their household. It can also be used for accessing the internet on the move without having to be in a wireless hotspot such as those offered by some coffee shops, airports and libraries.