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.

What Is Microfiche

A microfiche is a four by five-inch (10.2 by 15.2 cm) piece of photographic film, used to store printed information in miniaturized form. To read a microfiche, a user places the film card under the lens of a microform reader, magnifying it greatly. Its thinness and small size enables it to be stored very easily and efficiently, allowing libraries, museums and businesses to increase their resource collections without the need for additional space. While many libraries and businesses now store records digitally, microform records are still in use and, in fact, have some advantages over digital storage options.

How it Works

Microfiche is a subtype of microform, a term used to describe several mediums that provide storage for exact, miniaturized copies of documents. Unlike microfilm, which producers spin into a reel, microfiche is a flat sheet of film. These thin, flat cards take up less space than microfilm and do not require a separate canister for storage.

It is impossible for the human eye to read microform as is, one must use a specially designed machine. These machines include a magnifier and a simple projector that allows the user to read the greatly magnified image or document on a screen. These machines are usually expensive and can be found in institutions that use microform documents, such as libraries or government offices.

Advantages

The advantages of microfiche include its storability: Even a small storage cabinet could hold thousands of cards which, in turn, contain tens of thousands of pages of material. In addition, computers or specialized software is not required to read a microform document. Unlike some digital storage methods, such as CD-ROMs, microform is also remarkably stable and, if kept in a temperature controlled environment, can last as long as 500 years.

Libraries, museums and businesses that own valuable or important documents also value this data storage method as a way of providing researchers with access to important records and archives without significant risk of loss or damage. Since it is impossible to read without a special machine and has no aesthetic value of its own, microform data is of little interest to thieves. If a card becomes damaged, the organization that owns the original document can have a new one created.

Disadvantages

Microfiche lacks the portability of digital files: Special equipment is needed to both read and duplicate the cards. Microform readers, for example, are bulky and aren’t as accessible as personal computers. Making a paper copy of a microfiche also requires using a special printer integrated into the machine. It is usually impractical to use color ink in microform, meaning that documents are usually stored only in black and white.

Researchers may also have difficulty using microform documents. For example, if a needed document is only in microfilm or microfiche, a researcher may have to travel to the physical location where the record is actually stored. If the data was in digital form, the researcher could receive the data via email or a document sharing system and then read it on his or her personal computer. Machines used to read microforms are also cumbersome to use, sometimes requiring the user to scroll through the documents in order to find needed information. Digital data, on the other hand, is easily and quickly searched through the use of specialized software.

What Are LED Christmas Lights

Stringing up Christmas lights has traditionally been one of the most tortuous of holiday tasks. Untangling wires, balancing on a ladder and attaching them to the house are all chores associated with this endeavor, but the biggest problem for many people is finding that mysterious broken bulb. Hours are lost and tempers flare, but this is where LED Christmas lights can show their true benefit.

LED Christmas lights use light emitting diodes rather than the traditional miniature incandescent bulbs. LEDs are much like incandescent bulbs except that they do not have a filament inside that can burn out and take the entire string of bulbs with it. Instead, they are illuminated by the movement of electrons in a semi-conductor material. Another benefit of this light source is the absence of excessive heat and wasted electricity.

LEDs have been around for a long time, but only caught on for use as Christmas lights in recent years. One reason is that older LEDs originally came in only red. Incandescent bulbs, on the other hand, emit only white light but are encased in colored glass. Another problem was a lack of brightness of LEDs. The potential was there however, and advanced LEDs solved these problems. Today you can find LED christmas lights in all kinds of shapes and sizes. They can blink just like the regular incandescent varieties and come in a wide range of colors.

The end result is a string of lights that use about one-tenth of the electrical current of the more commonly used incandescent lights. They are also encased in thick plastic rather than flimsy glass, so broken bulbs and mistakenly stepping on one won't result in a holiday tragedy. As mentioned, the life of LEDs are extremely long-they are used often in the dashboards of jet planes-so burn out after one season is highly unlikely. One last benefit is the relative thickness of the wires used for these lights, making wires less likely to get tangled in the closet or garage.

Caring for LED lights is simple with such a long life and tough casing. Users can simply roll them up and store them at the end of the holiday and fully expect to come back next year and find them still functioning.