Blu-ray is a DVD format for storing high-definition video. Blu-ray is one of the two new emerging high definition formats, the other is HD DVD. Blu-ray gets its name from the blue laser it users. Standard DVD uses a red laser to read discs. Blu-ray is designed to replace standard DVD’s. A Blu-ray disk can hold up to 25 GB per layer as opposed to HD DVD which holds on 15 GB per layer. Blu-ray development was spear-headed by Sony, the original developer of Beta-Max. Other companies that support Blu-ray include Apple, Dell and Panasonic. Blu-ray implements DRM with a scheme called BD+. Currently the PlayStation 3 has a Blu-ray drive.

Association of Public Safety Communications Officials A set of standards for private radio networks designed specifically for public safety (police, fire, emergency services) applications in North America It includes standards for common air access, encryption, over the air reprogramming, data port interface, host data interface, trunking, inter-connection to PSTN and network management. APCO-25 was adopted in 1995 and is a digital standard, as compared to APCO-16 that was analog.

Metropolitan Area Exchange or Metropolitan Area Ethernet. A major Internet Network Access Point (NAP) where different providers and networks hand off traffic to each other. The two main MAEs in the United States are MAE East in Washington, DC and MAE West in Silicon Valley.

There are many hoaxes continually popping up on the nets. False viruses are the most common of these with names like "Join the Crew" or "PenPal Greetings", but there are many more themes that keep recurring. Appeals to charity is a common theme for a hoax, sometimes partially based in fact. If you get a chain letter appeal about Jessica Mydek or Craig Shergold or anything involving the Make A Wish Foundation, please check it out first before spreading it. There are also lots of stories going around about Bill Gates and money-making schemes and expensive cookie recipes and stolen kidneys, all of which are interesting stories, but usually false or even fraudulent. You can read more about hoaxes in our feature article, Hoaxes and Urban Legends. When in doubt, never spread a story around. Instead, check the Department of Energy's Computer Incident Advisory Committee (CIAC) Hoaxes Page or ask us here in the NavNet Forum or check out our glossary items for virus or for the taller tales, urban legends.

The ratio of the lengths of the positive to negative halves of a waveform expressed in percentages.

The ability of an oscilloscope to display just one window of time, thus preventing unwanted multiple displays. Useful for trace photography.

The decrease in signal amplitude during its transmission from one point to another

An electric current whose instantaneous value and direction change periodically. The term usually refers to sinusoidally shaped current or voltage waves.

The time variant portion of a voltage or current.

The unit of electric potential difference that and electromotive force equal to the difference of potential between two points on a conductor carrying a constant one-ampere current when the power dissipated between these two points is equal to one watt.