LCD BRIEFLY EXPLAINED

In color LCDs each individual pixel is divided into three cells, or subpixels, which are colored red, green, and blue, respectively, by additional filters (pigment filters, dye filters and metal oxide filters). Each subpixel can be controlled independently to yield thousands or millions of possible colors for each pixel. CRT monitors employ a similar 'subpixel' structures via phosphors, although the electron beam employed in CRTs do not hit exact 'subpixels'.

Color components may be arrayed in various pixel geometries, depending on the monitor's usage. If the software knows which type of geometry is being used in a given LCD, this can be used to increase the apparent resolution of the monitor through subpixel rendering. This technique is especially useful for text anti-aliasing.

To reduce smudging in a moving picture when pixels do not respond quickly enough to color changes, so-called pixel overdrive may be used.


[edit] Passive-matrix and active-matrix addressed LCDs

A general purpose alphanumeric LCD, with two lines of 16 characters.LCDs with a small number of segments, such as those used in digital watches and pocket calculators, have individual electrical contacts for each segment. An external dedicated circuit supplies an electric charge to control each segment. This display structure is unwieldy for more than a few display elements.

Small monochrome displays such as those found in personal organizers, or older laptop screens have a passive-matrix structure employing super-twisted nematic (STN) or double-layer STN (DSTN) technology—the latter of which addresses a color-shifting problem with the former—and color-STN (CSTN)—wherein color is added by using an internal filter. Each row or column of the display has a single electrical circuit. The pixels are addressed one at a time by row and column addresses. This type of display is called passive-matrix addressed because the pixel must retain its state between refreshes without the benefit of a steady electrical charge. As the number of pixels (and, correspondingly, columns and rows) increases, this type of display becomes less feasible. Very slow response times and poor contrast are typical of passive-matrix addressed LCDs.

High-resolution color displays such as modern LCD computer monitors and televisions use an active matrix structure. A matrix of thin-film transistors (TFTs) is added to the polarizing and color filters. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is activated, all of the column lines are connected to a row of pixels and the correct voltage is driven onto all of the column lines. The row line is then deactivated and the next row line is activated. All of the row lines are activated in sequence during a refresh operation. Active-matrix addressed displays look "brighter" and "sharper" than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images.


[edit] Active matrix technologies

A Casio 1.8" color TFT liquid crystal display which equips the Sony Cyber-shot DSC-P93A digital compact camerasMain articles: Thin film transistor liquid crystal display and Active-matrix liquid crystal display

[edit] Twisted nematic (TN)
Twisted nematic displays contain liquid crystal elements which twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, the light is polarized to pass through the cell. In proportion to the voltage applied, the LC cells twist up to 90 degrees changing the polarization and blocking the light's path. By properly adjusting the level of the voltage almost any grey level or transmission can be achieved.

For a more comprehensive description refer to the section on the twisted nematic field effect.


[edit] In-plane switching (IPS)
In-plane switching is an LCD technology which aligns the liquid crystal cells in a horizontal direction. In this method, the electrical field is applied through each end of the crystal, but this requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. This results in blocking more transmission area, thus requiring a brighter backlight, which will consume more power, making this type of display less desirable for notebook computers.


[edit] Advanced Fringe Field Switching (AFFS)
Advanced Fringe Field Switching is a similar technology to IPS or S-IPS offering superior performance and color gamut besides high luminosity. AFFS is developed by Boe Hydis Displays, Korea.

AFFS-applied notebook applications minimize color distortion while maintaining its superior wide viewing angle for a professional display. Color shift and deviation caused by light leakage is corrected by optimizing the white gamut which also enhances white/grey reproduction.

In premium IBM ThinkPad series notebooks, Boe Hydis AFFS displays are used to provide higher resolutions up to 1600x1200 in a relatively small 15 inch display setting. IBM also advertised these high end panels under their FlexViewTM label. AFFS panels are mostly classified under the VIEWIZTM name by Boe Hydis resembling premium performance.

As of 2008, Hitachi acquired AFFS license to manufacture high end panels in their product line. Boe Hydis suspended their production of high quality displays however the company still advertises the benefits of the superior technology.


[edit] Vertical alignment (VA)
Vertical alignment displays are a form of LC displays in which the liquid crystal material naturally exists in a horizontal state removing the need for extra transistors (as in IPS). When no voltage is applied the liquid crystal cell, it remains perpendicular to the substrate creating a black display. When voltage is applied, the liquid crystal cells shift to a horizontal position, parallel to the substrate, allowing light to pass through and create a white display. VA liquid crystal displays provide some of the same advantages as IPS panels, particularly an improved viewing angle and improved black level.


[edit] Blue Phase mode
Main article: Blue Phase Mode LCD
Blue phase LCDs do not require an LC top layer. Blue phase LCDs are relatively new to the market,and very expensive because of the low volume of production. They provide a higher refresh rate than normal LCDs, but normal LCDs are still cheaper to make and actually provide better colors and a sharper image.[citation needed] .


[edit] Quality control
Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are commonly referred to as stuck pixels or dead pixels respectively. Unlike integrated circuits (ICs), LCD panels with a few defective pixels are usually still usable. It is also economically prohibitive to discard a panel with just a few defective pixels because LCD panels are much larger than ICs. Manufacturers have different standards for determining a maximum acceptable number of defective pixels. The maximum acceptable number of defective pixels for LCD varies greatly. At one point, Samsung held a zero-tolerance policy for LCD monitors sold in Korea.[18] Currently, though, Samsung adheres to the less restrictive ISO 13406-2 standard.[19] Other companies have been known to tolerate as many as 11 dead pixels in their policies.[20] Dead pixel policies are often hotly debated between manufacturers and customers. To regulate the acceptability of defects and to protect the end user, ISO released the ISO 13406-2 standard.[21] However, not every LCD manufacturer conforms to the ISO standard and the ISO standard is quite often interpreted in different ways.


Examples of defects in LCDsLCD panels are more likely to have defects than most ICs due to their larger size. In the example to the right, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the LCD panel would be a 0% yield. The standard is much higher now due to fierce competition between manufacturers and improved quality control. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one. Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have "zero defective pixel guarantee", which is an extra screening process which can then determine "A" and "B" grade panels. Many manufacturers would replace a product even with one defective pixel. Even where such guarantees do not exist, the location of defective pixels is important. A display with only a few defective pixels may be unacceptable if the defective pixels are near each other. Manufacturers may also relax their replacement criteria when defective pixels are in the center of the viewing area.

LCD panels also have defects known as mura, which look like a small-scale crack with very small changes in luminance or color.[22] It is most visible in dark or black areas of displayed scenes. Defects in various LCD panel components can cause mura effect.[clarification needed]


[edit] Zero-power (bistable) displays
The zenithal bistable device (ZBD), developed by QinetiQ (formerly DERA), can retain an image without power. The crystals may exist in one of two stable orientations (Black and "White") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufacture both grayscale and color ZBD devices.

A French company, Nemoptic, has developed another zero-power, paper-like LCD technology which has been mass-produced since July 2003. This technology is intended for use in applications such as Electronic Shelf Labels, E-books, E-documents, E-newspapers, E-dictionaries, Industrial sensors, Ultra-Mobile PCs, etc. Zero-power LCDs are a category of electronic paper.

Kent Displays has also developed a "no power" display that uses Polymer Stabilized Cholesteric Liquid Crystals (ChLCD). The major drawback to the ChLCD is slow refresh rate, especially with low temperatures.

In 2004 researchers at the University of Oxford demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.[23]

Several bistable technologies, like the 360° BTN and the bistable cholesteric, depend mainly on the bulk properties of the liquid crystal (LC) and use standard strong anchoring, with alignment films and LC mixtures similar to the traditional monostable materials. Other bistable technologies (i.e. Binem Technology) are based mainly on the surface properties and need specific weak anchoring materials.

See Ferro Liquid Display for more information about ferro fluid based bistable displays.

LCD SPECIFICATION

Specifications
Important factors to consider when evaluating an LCD monitor:
Resolution: The horizontal and vertical size expressed in pixels (e.g., 1024x768). Unlike CRT monitors, LCD monitors have a native-supported resolution for best display effect.
Dot pitch: The distance between the centers of two adjacent pixels. The smaller the dot pitch size, the less granularity is present, resulting in a sharper image. Dot pitch may be the same both vertically and horizontally, or different (less common).
Viewable size: The size of an LCD panel measured on the diagonal (more specifically known as active display area).
Response time: The minimum time necessary to change a pixel's color or brightness. Response time is also divided into rise and fall time. For LCD Monitors, this is measured in btb (black to black) or gtg (gray to gray). These different types of measurements make comparison difficult. A response time of <16ms title="" href="http://en.wikipedia.org/wiki/LCD#cite_note-0">[1], and the difference between response times once they're below 10ms begin becoming imperceptible due to limitations of the human eye [2] [3]
Refresh rate: The number of times per second in which the monitor draws the data it is being given. Since activated LCD pixels do not flash on/off between frames, LCD monitors exhibit no refresh-induced flicker, no matter how low the refresh rate. [4] Many high-end LCD televisions now have a 120 Hz (current and former NTSC countries) or 200 Hz (PAL/SECAM countries) refresh rate. The rate of 120 was chosen as the least common multiple of 24 frame/s (cinema) and 30 frame/s (NTSC TV), and allows for less distortion when movies are viewed due to the elimination of telecine (3:2 pulldown). For PAL/SECAM at 25 frame/s, 200 Hz is used as a compromise of one-third the least common multiple of 600 (24 x 25). This is most effective from a 24p-source video output (available on Blu-ray DVD).
Matrix type: Active TFT or Passive.
Viewing angle: (coll., more specifically known as viewing direction).
Color support: How many types of colors are supported (coll., more specifically known as color gamut).
Brightness: The amount of light emitted from the display (coll., more specifically known as luminance).
Contrast ratio: The ratio of the intensity of the brightest bright to the darkest dark.
Aspect ratio: The ratio of the width to the height (for example, 4:3, 5:4, 16:9 or 16:10).
Input ports (e.g., DVI, VGA, LVDS, DisplayPort, or even S-Video and HDMI).
Displays that have built-in TV Tuners or decoders may feature
Gamma correction

[edit] Brief history

1888: Friedrich Reinitzer (1858-1927) discovers the liquid crystalline nature of cholesterol extracted from carrots (that is, two melting points and generation of colors) and published his findings at a meeting of the Vienna Chemical Society on May 3, 1888 (F. Reinitzer: Beiträge zur Kenntniss des Cholesterins, Monatshefte für Chemie (Wien) 9, 421-441 (1888)).[5]
1904: Otto Lehmann publishes his work "Flüssige Kristalle" (Liquid Crystals).
1911: Charles Mauguin first experiments of liquids crystals confined between plates in thin layers.
1922: George Friedel describes the structure and properties of liquid crystals and classified them in 3 types (nematics, smectics and cholesterics).
1936: The Marconi Wireless Telegraph company patents the first practical application of the technology, "The Liquid Crystal Light Valve".
1962: The first major English language publication on the subject "Molecular Structure and Properties of Liquid Crystals", by Dr. George W. Gray.[6]
1962: Richard Williams of RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what is now called “Williams domains” inside the liquid crystal.[7]
1964: In the fall of 1964 George H. Heilmeier, then working in the RCA laboratories on the effect discovered by Williams realized the switching of colors by field-induced realignment of dichroic dyes in a homeotropically oriented liquid crystal. Practical problems with this new electro-optical effect made Heilmeier to continue work on scattering effects in liquid crystals and finally the realization of the first operational liquid crystal display based on what he called the dynamic scattering mode (DSM). Application of a voltage to a DSM display switches the initially clear transparent liquid crystal layer into a milky turbid state. DSM displays could be operated in transmissive and in reflective mode but they required a considerable current to flow for their operation.[8][9][10] George H. Heilmeier was inducted in the National Inventors Hall of Fame and credited with the invention of LCD.[11]
1960s: Pioneering work on liquid crystals was undertaken in the late 1960s by the UK's Royal Radar Establishment at Malvern. The team at RRE supported ongoing work by George Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals (which had correct stability and temperature properties for application in LCDs).
1970: On December 4, 1970, the twisted nematic field effect in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.[8] Hoffmann-La Roche then licensed the invention to the Swiss manufacturer Brown, Boveri & Cie who produced displays for wrist watches during the 1970s and also to Japanese electronics industry which soon produced the first digital quartz wrist watches with TN-LCDs and numerous other products. James Fergason at the Westinghouse Research Laboratories in Pittsburgh while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute filed an identical patent in the USA on April 22, 1971.[12] In 1971 the company of Fergason ILIXCO (now LXD Incorporated) produced the first LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption.
1972: The first active-matrix liquid crystal display panel was produced in the United States by T. Peter Brody.[13]
2007: In the 4Q of 2007 for the first time LCD televisions surpassed CRT units in worldwide sales.[14]
2008: LCD TVs become the majority with a 50% market share of the 200 million TVs forecast to ship globally in 2008 according to Display Bank.[15]
A detailed description of the origins and the complex history of liquid crystal displays from the perspective of an insider during the early days has been published by Joseph A. Castellano in "Liquid Gold, The Story of Liquid Crystal Displays and the Creation of an Industry".Another report on the origins and history of LCD from a different perspective has been published by Hiroshi Kawamoto, available at the IEEE History Center.

LIQUID CRYSTAL DISPLAY

A liquid crystal display (LCD) is an electronically-modulated optical device shaped into a thin, flat panel made up of any number of color or monochrome pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector. It is often utilized in battery-powered electronic devices because it uses very small amounts of electric power.
A comprehensive classification of the various types and electro-optical modes of LCDs is provided in the article LCD classification.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, and two polarizing filters, the axes of transmission of which are (in most of the cases) perpendicular to each other. With no actual liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer.
The surface of the electrodes that are in contact with the liquid crystal material are treated so as to align the liquid crystal molecules in a particular direction. This treatment typically consists of a thin polymer layer that is unidirectionally rubbed using, for example, a cloth. The direction of the liquid crystal alignment is then defined by the direction of rubbing. Electrodes are made of a transparent conductor called Indium Tin Oxide (ITO).
Before applying an electric field, the orientation of the liquid crystal molecules is determined by the alignment at the surfaces. In a twisted nematic device (still the most common liquid crystal device), the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This reduces the rotation of the polarization of the incident light, and the device appears grey. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

LCD with top polarizer removed from device and placed on top, such that the top and bottom polarizers are parallel.
The optical effect of a twisted nematic device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, these devices are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). These devices can also be operated between parallel polarizers, in which case the bright and dark states are reversed. The voltage-off dark state in this configuration appears blotchy, however, because of small variations of thickness across the device.
Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).
When a large number of pixels are needed in a display, it is not technically possible to drive each directly since then each pixel would require independent electrodes. Instead, the display is multiplexed. In a multiplexed display, electrodes on one side of the display are grouped and wired together (typically in columns), and each group gets its own voltage source. On the other side, the electrodes are also grouped (typically in rows), with each group getting a voltage sink. The groups are designed so each pixel has a unique, unshared combination of source and sink. The electronics, or the software driving the electronics then turns on sinks in sequence, and drives sources for the pixels of each sink.

lATEST PDA'S

A personal digital assistant (PDA) is a handheld computer, also known as a palmtop computer. Newer PDAs also have both color screens and audio capabilities, enabling them to be used as mobile phones, (smartphones), web browsers, or portable media players. Many PDAs can access the Internet, intranets or extranets via Wi-Fi, or Wireless Wide-Area Networks (WWANs). Many PDAs employ touch screen technology.
The first[vague] PDA is considered to be the CASIO PF-3000 released in May 1983. GO Corp. was also pioneering in the field. The term was first used on January 7, 1992 by Apple Computer CEO John Sculley at the Consumer Electronics Show in Las Vegas, Nevada, referring to the Apple Newton. In 1996 Nokia introduced the first mobile phone with full PDA functionality, the 9000 Communicator, which has since grown to become the world's best-selling PDA and which spawned a category of phones called the smartphone. Today the vast majority of all PDAs are smartphones, selling over 150 million units while non-phone ("stand-alone") PDAs sell only about 3 million units per year. The RIM Blackberry, the Apple iPhone and the Nokia N-Series are typical smartphones.

Typical features
Currently, a typical PDA has a touch screen for entering data, a memory card slot for data storage and at least one of the following for connectivity: IrDA, Bluetooth and/or WiFi. However, many PDAs (typically those used primarily as telephones) may not have a touch screen, using softkeys, a directional pad and either the numeric keypad or a thumb keyboard for input.
Software typically required to be a PDA includes an appointment calendar, a to-do list, an address book for contacts and some sort of note program. Connected PDAs also typically include E-mail and Web support.

[edit] Touch screen
Many original PDAs, such as the Apple Newton and Palm Pilot, featured touch screens for user interaction, having only a few buttons usually reserved for shortcuts to often used programs. Touch screen PDAs, including Windows Pocket PC devices, usually have a detachable stylus that can be used on the touch screen. Interaction is then done by tapping the screen to activate buttons or menu choices, and dragging the stylus to, for example, highlight. Text input is usually done in one of four ways:
Using a virtual keyboard, where a keyboard is shown on the touch screen. Input is done by tapping letters on the screen.
Using external keyboard or corded keyboard connected by USB, IR or Bluetooth.
Using letter or word recognition, where letters or words are written on the touch screen, and then "translated" to letters in the currently activated text field. Despite rigorous research and development projects, end-users experience mixed results with this input method, with some finding it frustrating and inaccurate, while others are satisfied with the quality.[1] Recognition and computation of handwritten horizontal and vertical formulas such as "1 + 2 =" was also under development.
Stroke recognition (termed Graffiti by Palm). In this system a predefined set of strokes represents the various characters needed. The user learns to draw these strokes on the screen or in an input area. The strokes are often simplified character shapes to make them easier to remember.
PDAs for business use, including the BlackBerry and Treo, have full keyboards and scroll wheels or thumb wheels to facilitate data entry and navigation, in addition to supporting touch-screen input. There are also full-size foldable keyboards available that plug directly, or use wireless technology to interface with the PDA and allow for normal typing. BlackBerry has additional functionality, such as push-based email and applications.
Newer PDAs, such as the Apple iPhone and iPod touch include new user interfaces using other means of input. The iPhone and iPod touch uses a technology called Multi-touch.

[edit] Memory cards
Although many early PDAs did not have memory card slots now most have either an SD (Secure Digital) and/or a Compact Flash slot. Although originally designed for memory, SDIO and Compact Flash cards are available for such things as Wi-Fi and Webcams. Some PDAs also have a USB port, mainly for USB flash drives. Some PDAs are now compatible with micro SD cards, which are physically much smaller than standard SD cards.

[edit] Wired connectivity
While many earlier PDAs connected via serial ports or other proprietary format, many today connect via USB cable. This served primarily to connect to a computer, and few, if any PDAs were able to connect to each other out of the box using cables, as USB requires one machine to act as a host - functionality which was not often planned. Some PDAs were able to connect to the internet, either by means of one of these cables, or by using an extension card with an ethernet port/RJ-45 adaptor.

[edit] Wireless connectivity
Most modern PDAs have Bluetooth wireless connectivity, an increasingly popular tool for mobile devices. It can be used to connect keyboards, headsets, GPS and many other accessories, as well as sending files between PDAs. Many mid-range and superior PDAs have Wi-Fi/WLAN/802.11-connectivity, used for connecting to Wi-Fi hotspots or wireless networks. Older PDAs predominantly have an IrDA (infrared) port; however fewer current models have the technology, as it is slowly being phased out due to support for Bluetooth and Wi-Fi. IrDA allows communication between two PDAs: a PDA and any device with an IrDA port or adapter. Most universal PDA keyboards use infrared technology because many older PDAs have it, and infrared technology is low-cost and has the advantage of being permitted aboard aircraft.

[edit] Synchronization
An important function of PDAs is synchronizing data with a PC. This allows up-to-date contact information stored on software such as Microsoft Outlook or ACT! to update the database on the PDA. The data synchronization ensures that the PDA has an accurate list of contacts, appointments and e-mail, allowing users to access the same information on the PDA as the host computer.
The synchronizing also prevents the loss of information stored on the device in case it is lost, stolen, or destroyed. Another advantage is that data input is usually a lot quicker on a PC, since text input via a touch screen is still not quite optimal. Transferring data to a PDA via the computer is therefore a lot quicker than having to manually input all data on the handheld device.
Most PDAs come with the ability to synchronize to a PC. This is done through synchronization software provided with the handheld, such as HotSync Manager, which comes with Palm OS handhelds, Microsoft ActiveSync for older versions of Windows or Windows Mobile Device Center on Windows Vista, which comes with Windows Mobile handhelds.
These programs allow the PDA to be synchronized with a Personal information manager. This personal information manager may be an outside program or a proprietary program. For example, the BlackBerry PDA comes with the Desktop Manager program which can synchronize to both Microsoft Outlook and ACT!. Other PDAs come only with their own proprietary software. For example, some early Palm OS PDAs came only with Palm Desktop while later Palms such as the Treo 650 has the built-in ability to sync to Palm Desktop and/or Microsoft Outlook, while Microsoft's ActiveSync and Windows Mobile Device Center only synchronize with Microsoft Outlook or a Microsoft Exchange server.
Third-party synchronization software is also available for many PDAs from companies like Intellisync and CompanionLink. This software synchronizes these handhelds to other personal information managers which are not supported by the PDA manufacturers, such as GoldMine and Lotus Notes.

IPOD NANOO

The iPod Nano (marketed lowercase as iPod nano) is a portable media player designed and marketed by Apple Inc. It is the midrange model in Apple's iPod family. The first generation was introduced in 2005.[1] It uses flash memory, like the iPod Shuffle, but with a 2-inch (diagonal) QVGA display and the "click wheel" found on the iPod Classic. The iPod nano has gone through four models, or generations, since its introduction.

Instead of the hard disk which is used in the iPod Classic, the Nano uses flash memory.
The first, second, third, and fourth generation iPod Nano include some pre-installed games: Brick, Music Quiz, Parachute, Maze (an accelerometer game), Vortex and Solitaire. The third generation iPod Nano included pre-installed games, but can also run games which Apple makes available for purchase in the iTunes Store. [2]
Unlike the preceding iPod Mini, its battery is soldered to the printed circuit board of the device, making it harder to replace manually,[3] although replacement batteries are readily available.[citation needed] The flash memory chips used are surface mount devices, making any attempt to upgrade the Nano's storage capacity impractical. It has 24 hours of power when fully charged.
The lack of the remote connector found on the top of many previous models means that a number of third-party accessories do not work with the iPod Nano; newer versions using the dock connector have been made. The first and third generation iPod Nano did not support voice recording; the second and fourth generation Nanos function with third-party recording attachments.[4] It did not function with either Apple's iPod Camera Connector or other camera connectors from third-party manufacturers.

Advertising emphasized the iPod Nano's small size: it is 1.6 in (40 mm) width, 3.5 in (90 mm) length, 0.27 in (6.9 mm) thick and weighs 1.5 ounces (42 grams). Its stated battery life is up to 14 hours. The screen is 176x132 pixels, 1.5 in (38 mm) diagonal, and can display 65,536 colors (16-bit color).[1]

[edit] History
Development work on the design of the iPod Nano started only nine months before its launch date.[8] The Nano was launched in two colors (black and white) with two available sizes: 2 GB (roughly 500 songs) for US$199 and 4 GB (1000 songs) for US$249.[1] On February 7, 2006, Apple updated the lineup with the 1 GB model (240 songs) sold at US$149.[9] Apple also released some accessories, including armbands and silicone "tubes" designed to bring color to the Nano and protect it from scratches, as well as a combination lanyard-earphone accessory that hangs around the neck, and avoids the problem of tangling earphone cords.

[edit] Electronics
The iPod Nano uses general-purpose integrated circuits (IC) instead of smaller, low-cost custom-developed chips, possibly to reduce time-to-market. This design, however, increases the number of electronic components and increases the cost. Japanese engineers estimated the component cost of the 2 GB Nano as between JP¥22,000 and JP¥27,000 (US$185-US$227), which was high compared to the retail price of JP¥21,800 (US$183) at the time. The cost of 2 GB NAND flash memory was about JP¥14,000 (US$118). Apple also opted for the 0603 (1.6x0.8 mm) surface mount technology which was just beginning widespread use in mobile phones in 2005.[10] The iPod Nano uses a PortalPlayer PP5021C "system on a chip" with dual embedded 80 MHz ARM 7TDMI processors

ipods

iPod is a brand of portable media players designed and marketed by Apple Inc. and launched on October 23, 2001 (2001-10-23). The product line-up includes the hard drive-based iPod Classic, the touchscreen iPod Touch, the video-capable iPod Nano, and the compact iPod Shuffle. The iPhone can function as an iPod but is generally treated as a separate product. Former iPod models include the iPod Mini and the spin-off iPod Photo (since reintegrated into the main iPod Classic line). iPod Classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued Mini used a Microdrive miniature hard drive). As with many other digital music players, iPods, excluding the iPod Touch, can also serve as external data storage devices. Storage capacity varies by model.
Apple's iTunes software can be used to transfer music to the devices from computers using certain versions of Apple Macintosh and Microsoft Windows operating systems.[2] For users who choose not to use Apple's software or whose computers cannot run iTunes software, several open source alternatives to iTunes are also available.[3] iTunes and its alternatives may also transfer photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars to iPod models supporting those features. As of September 2008[update], more than 173 million iPods had been sold worldwide, making it the best-selling digital audio player series in history.[

The iPod line came from Apple's "digital hub" category,[5] when the company began creating software for the growing market of personal digital devices. Digital cameras, camcorders and organizers had well-established mainstream markets, but the company found existing digital music players "big and clunky or small and useless" with user interfaces that were "unbelievably awful,"[5] so Apple decided to develop its own. As ordered by CEO Steve Jobs, Apple's hardware engineering chief Jon Rubinstein assembled a team of engineers to design the iPod line, including hardware engineers Tony Fadell and Michael Dhuey,[6] and design engineer Jonathan Ive.[5] The product was developed in less than one year and unveiled on 23 October 2001. Jobs announced it as a Mac-compatible product with a 5 GB hard drive that put "1,000 songs in your pocket."[7]
Apple did not develop the iPod software entirely in-house, instead using PortalPlayer's reference platform based on 2 ARM cores. The platform had rudimentary software running on a commercial microkernel embedded operating system. PortalPlayer had previously been working on an IBM-branded MP3 player with Bluetooth headphones.[5] Apple contracted another company, Pixo, to help design and implement the user interface under the direct supervision of Steve Jobs.[5] As development progressed, Apple continued to refine the software's look and feel. Starting with the iPod Mini, the Chicago font was replaced with Espy Sans. Later iPods switched fonts again to Podium Sans—a font similar to Apple's corporate font, Myriad. iPods with color displays then adopted some Mac OS X themes like Aqua progress bars, and brushed metal meant to evoke a combination lock. In 2007, Apple modified the iPod interface again with the introduction of the sixth-generation iPod Classic and third-generation iPod Nano by changing the font to Helvetica and, in most cases, splitting the screen in half by displaying the menus on the left and album artwork, photos, or videos on the right (whichever was appropriate for the selected item).
In September 2007, during the course of a lawsuit with patent holding company Burst.com, Apple drew attention to a patent for a similar device that was developed in 1979. Kane Kramer patented the idea of a "plastic music box" in 1979, which he called the IXI.[8] He was unable to secure funding to renew the US$ 120,000 worldwide patent, so it lapsed and Kramer never profited from his idea.[8] Kramer is now in talks with the company to discuss how he will be reimbursed.

The name iPod was proposed by Vinnie Chieco, a freelance copywriter, who (with others) was called by Apple to figure out how to introduce the new player to the public. After Chieco saw a prototype, he thought of the movie 2001: A Space Odyssey and the phrase "Open the pod bay door, Hal!", which refers to the white EVA Pods of the Discovery One spaceship.[5] Apple researched the trademark and found that it was already in use. Joseph N. Grasso of New Jersey had originally listed an "iPod" trademark with the U.S. Patent and Trademark Office in July 2000 for Internet kiosks. The first iPod kiosks had been demonstrated to the public in New Jersey in March 1998, and commercial use began in January 2000, but had apparently been discontinued by 2001. The trademark was registered by the USPTO in November 2003, and Grasso assigned it to Apple Computer, Inc. in 2005.

Mobile broadband

Mobile broadband is the name used to describe various types of wireless high-speed internet access through a portable modem, telephone or other device. Various network standards may be used, such as GPRS, 3G, WiMAX, LTE UMTS/HSPA, EV-DO and some portable satellite-based systems.
Devices that provide mobile broadband include: PC data cards, USB modems, USB sticks, phones with data modems and portable devices with built-in support for Mobile Broadband (like notebooks, netbooks and Mobile Internet Devices (MIDs)). Notebooks with built-in Mobile Broadband Modules are offered by all leading laptop manufacturers in Europe and Asia including: Dell, Lenovo (previously IBM), HP, Fujitsu, Toshiba and Acer.
A group of telecommunication manufacturers, mobile phone producers, chipset manufacturers and notebook manufacturers have joined forces to push built-in support for Mobile Broadband technology on notebook computers[1]. The players have established a service mark to identify devices that deliver the highest standard of Mobile Broadband.

Development
On 11 December 2002, the IEEE Standards Board approved the establishment of IEEE 802.20[2], the Mobile Broadband Wireless Access (MBWA) Working Group.
The mission of IEEE 802.20 is to develop the specification for an efficient packet based air interface that is optimized for the transport of IP based services. The goal is to enable worldwide deployment of affordable, ubiquitous, always-on and interoperable multi-vendor mobile broadband wireless access networks that meet the needs of business and residential end user markets.
The main barrier to the take up of mobile broadband will be the coverage the mobile phone networks can provide, in many areas customers will not be able to achieve the speeds advertised due to mobile data coverage limitations.
Demand from emerging markets fuels a large share of growth in Mobile Broadband over the coming years. Without the need to start from the basis of a widespread fixed line infrastructure, many emerging markets leapfrog developed markets and use Mobile Broadband technologies to deliver high-speed internet access to the mass market.
The global Third Generation Partnership Project (3GPP) family of standards - which includes GSM, EDGE, WCDMA, HSPA and LTE – is the most widespread way to deliver mobile broadband. 3GPP standards are serving about 90 percent of the world’s mobile subscribers.
In October 2008, a steering group known as Digital Britain was setup, with the aim of promoting digital telecommunications in the United Kingdom. The conclusion of the steering group was a recommendation that the government took up, namely to have 100% broadband coverage, with a minimum speed of 2mbs in the United Kingdom by the year 2012. Mobile broadband is expected to be utilized to help spread broadband coverage to the more remote areas of the UK.

Air Span Wimax Device

Airspan (NASDAQ: AIRN) is a WIMAX equipment manufacturer founded in 1998 with an R&D facility in the United Kingdom.
The first product, AS4020 platform, was based on CDMA radio technology adapted for fixed wireless access. The company currently provides a wide range of WIMAX base stations and customer premise devices.[1] It won the WIMAX World Best of Show Award for the mobile WIMAX MIMAX device, a miniature WIMAX receiver covering all major licensed and unlicensed WIMAX spectrum.
Airspan has established presence in more than 100 countries and expanded its product lines, both through acquisitions and R&D. In October 2002 it acquired the WiPLL product line from the Israeli branch of Marconi, in December 2004 it took over an Israeli softswitch and VoIP gear maker ArelNet, and in November 2005 it bought out RadioNet, a Finnish maker of WiFi systems. The company currently has over 100 engineers developing Mobile WIMAX solutions.
In 2004, Airspan made an agreement with Neda Telecommunications, a subsidiary of Aspen Wind Corporation, to send radios to Kabul, Afghanistan

NEWS REPORT "WIMAX"

WASHINGTON--WiMax's most prominent supporters are predicting that, despite not exactly stunning support of the wireless technology so far, it will take off this year. Speaking at a conference here hosted by the Wireless Communications Association International, Michael Seymour, vice president of Alcatel-Lucent's North American broadband wireless unit, said WiMax has experienced "tremendous growth" in recent years, even in "emerging markets" like the Dominican Republic, and predicted improvements in the technology would only continue. "WiMax is working, it's ready, it's delivering today," Seymour said, noting that about 110 people at his company's campus are required to use the technology for work every day.Samsung has said it plans to release a WiMax-enabled version of its Q1 Ultra handheld PC (non-WiMax version shown here) in the United States later this year. (Credit: Samsung)Rick Svensson, director of sales for Samsung's WiMax unit, said his company is "very anxious" to show off the technology in 2008. It plans to release a WiMax-enabled version of its Q1 ultramobile PC later this year and to offer support for Sprint Nextel's planned launch of its Xohm WiMax network sometime in 2008. WiMax, of course, refers to a fourth-generation wireless technology that, unlike Wi-Fi, transmits signals that can travel miles, making it more similar to cellular-phone technology--and potentially useful for applications like surfing the Web in a moving vehicle. At the moment, Sprint Nextel is the only major U.S. wireless carrier that has committed to using the technology, picking Samsung, Motorola, and Intel as partners. It has ended a partnership with Clearwire, which runs its own network--at least for now--and has trial networks up and running in the Baltimore/Washington region and Boston so far. Comcast and Time Warner are also reportedly considering offering help in bankrolling a new Sprint and Clearwire venture. The other dominant providers, such as Verizon Wireless and AT&T, and numerous major equipment makers have endorsed an alternative approach known as Long-Term Evolution, or LTE. But it's viewed as being two or three years behind WiMax. Svensson, for his part, said WiMax backers are still optimistic about their prospects. "With the momentum we're seeing around WiMax, we're going to blow them out of the water," he said. Others were more cautious about the future of the technology. "We have a situation today where not a single carrier can implement a nationwide WiMax network today by themselves; they'll either need to partner with someone else or look for additional funding," said Adlane Fellah, co-founder of a Montreal-based analyst firm called Maravedis Research. "From a spectrum footprint perspective, not every carrier has spectrum everywhere, although Sprint has the largest footprint." To be sure, WiMax deployments are still "modest," as are revenues for service and subscriber numbers, Fellah said. According to his firm's analysis, there were 256 WiMax operators in 91 countries and about 1.7 million subscribers as of the fourth quarter of 2007. Of those subscribers, about two-thirds of them are residential customers and a third are business customers. Although most of the WiMax offerings are located in Europe and Asia, the U.S. company Clearwire counts the largest number of subscribers, numbering about 394,000 as of the fourth quarter of 2007, Fellah said. Korea Telecom and Unwired Australia had the next biggest numbers, with about 100,000 and 76,000 subscribers respectively. Alcatel-Lucent, for its part, is participating in more than 70 trials and deployments of WiMax technology around the world, from Brazil to Malaysia to the Netherlands, Seymour said. During tests in Chile in February, he said his company was able to maintain a "stable and correct" 2.3 megabits per second (Mbps) throughput speeds from as far as 43.5 kilometers away from an outdoor base station. In ideal conditions, without "a whole lot of users on the network," WiMax users can expect download speeds of 10 to 11 megabits per second, said Samsung's Svensson. As a general rule, users can expect to get somewhere in the range of 3 to 4Mbps download speeds and 1 to 2Mbps upload speeds, he added. Perhaps the biggest remaining problem for WiMax operators will be managing heavy traffic loads, Seymour said. "Everybody can make it work when there's three guys on (the network)," he said, "but when you're reaching your rate overload, you've got to make sure...the system can properly handle traffic."

Modular design the enabler for WiMAX equipment

The broadband wireless industry is making tremendous progress with the evolution of fixed WiMAX technology and achieving device interoperability testing (IOT). Despite the efforts to develop a large, reliable ecosystem and to align the supply chain for accelerating broad-spread market adoption, volume shipments are not there yet.

WiMAX Antennas

A guide to MIMO and BeamformingWireless operators are increasingly pressured to enhance their networks and service capabilities in order to keep pace with the accelerating growth in wireless utilization and increasing demand for high performing connections.

WiMAX Network Economics

Most of the discussion about WiMAX technology and economics has been centered around the radio access network (RAN) and customer premise equipment (CPE)/handsets. For services to be deployed profitably, however, the economics of the entire network, including backhaul infrastructure, and installation and leasing costs, must be considered. In this larger view, it quickly becomes clear that the RAN is only a portion of the overall picture and costs.

Distributed Network Architecture for WiMAX

The world is moving to IP and service providers in all geographies are embracing the shift. Leveraging the IP foundations of WiMAX technology and the demonstrated benefits of IP systems including rapid cost declines and ease of management, a distributed WiMAX network architecture takes the service provider community one step closer to differentiating their services in a digital, converged, mobile IP world.

Roaming, key to the success of WiMAX- there is no second chanceWhile a significant part of the future success of WiMAX will be dependent on successful roaming, its implementation is complex and challenging to achieve. Bram Jan Streefland, co-founder and managing director of Trustive, Europe's largest wireless hotspot provider explores what it will mean to the industry if we get this wrong, highlights how the industry must learn from the initial mistakes made by WiFi, and proposes that the role of the wireless IP clearinghouse will be fundamental to its successCritical Inputs to a WiMAX Business Case The WiMAX Industry has seen much enthusiasm in the last two years as measured by the number of field trials taking place on a global basis. The industry claims well over 300 trials worldwide. High profile trials and a few early deployments have dominated the media

Critical Inputs to a WiMAX Business Case

The WiMAX Industry has seen much enthusiasm in the last two years as measured by the number of field trials taking place on a global basis. The industry claims well over 300 trials worldwide. High profile trials and a few early deployments have dominated the media.

Wind Telecom and Nortel Get Set to Deploy Nationwide WiMAX in the Dominican RepublicAs one of the first new service providers in the world to launch a nationwide WiMAX network, Wind Telecom is set to bring affordable broadband services to customers in underserved areas of the Dominican Republic as well as the country's major cities.

Optimization and Sensitivity Analysis of a WiMAX Business CaseIn Part 1 of this three part series article, we outlined the process of gathering the input parameters for a comprehensive WiMAX business case. In Part 2 we discussed how to define a variety of service plans and marketing plans in order to build the top line in a WiMAX business case. Here we will focus on the process of selecting the key performance indicators that have the greatest effect on a WiMAX business case, the process of performing sensitivity analysis, and the process of optimizing a WiMAX business case.

Interview with Dragonwave, Inc

DragonWave was founded by a group of people out of Newbridge Networks (which subsequently became Alcatel). They were working in LMDS and decided that they could design and build a better radio than they could buy on the market. They designed a microwave radio solution that can be assembled on a standard surface mount assembly line, reducing cost, improving scalability and reliability and delivering high performance. The company decided rather than to become yet another PDH/SDH radio vendor to concentrate on the emerging high capacity.

WiMAX Opportunities in Africa

The growth and development of WiMAX in Africa has taken place mainly during 2006-2007. At the beginning of 2006, the WiMAX subscribers figure for Africa was just a few thousand. But according to the WiMAX Operator Tracking Service, WiMAXCounts, at the end of 2007 that continent accounts for more than 20,000 WiMAX subscribers Deploying and Managing Femtocells in Today's Mobile NetworksConsumers have begun to demand ubiquitous voice and broadband data connectivity from their mobile networks, from inside buildings and from the convenience of their own homes. Operators can achieve this indoor coverage by deploying more towers with large base stations coupled with paid backhaul links to each tower; however, this approach is prohibitively expensive to deploy and operate. This situation is driving operators to explore alternative, cost-effective solutions for increasing wireless coverage indoors.