Archive for February, 2009
The present communication revolution is in the nature of a race from wire to unwire medium. This has led to a significant shift in the area of broadcasting and communication. In this decade, we witnessed widespread growth in the area of terrestrial wireless services (Mobile Communication), particularly in China and South-east Asia. The upgradation in terms of speed and range of these services would lead to significant interference with ‘C’ band satellite communication services because WiMAX wireless services being developed lately are using the same frequency spectrum as allotted to C band satellite link. Satellite link providers would encounter this interference after implementation of WiMAX technology by terrestrial telecommunication operators.
The radio frequency spectrum is a limited natural resource and is a part of the electromagnetic spectrum extending up to approximately 3000 GHz. ‘C’ band is a portion of the electromagnetic spectrum in the microwave range of frequency. Theoretically the band extends from 4 to 8 GHz. It was the first frequency band allocated for commercial ground to satellite communication and vice versa.
A typical ‘C’ band satellite uses 3.7 – 4.2 GHz for downlink and 5.925 to 6.425 for uplink. ‘C’ band is primarily used for open satellite communication and is highly associated with satellite reception systems. There are slight variations in the ‘C’ band frequency and these are approved by ITU for usage in different parts of the world.
Source: Science Reporter, January 2009 issue.
A disk drive can be used to store data externally and provide flexibility to any system. The enclosure connects the computer through a universal serial bus (USB) or Fire wire port, making it a plug-and-play device. Turning Off and On can be done even when the system is running. Hard drive enclosure can be used for providing portability between desktop and laptop, or home and office and also for many other purposes.
As carrying signal between different connector types is a trivial conversion. To require a separate embedded system to retransmit data over connector and signal of a different standard is so complicated in others. All built around disk enclosures includes factory assembled external hard disk drives, external DVD-ROM drives and others.
External hard drive enclosure’s main advantage is security. Hacking, Spyware, Viruses, Poorly written software, Trojan horses and hateful script is the major concern for online threats.
Pre-made external hard drive cost much less than a drive and enclosure. An internal IDE hard drive can turn into an external one due to the external enclosures. To get a external USB 2.0 or IEEE 1394 (Fire wire) Hard drive, External Enclosures are the best way.
To keep key information or software private from the several family members when they share the computer can be possible by external drive. To ensure they stay safe is by installing financial data or sensitive programs on a external hard drive. When online if the user is not accessing the programs or data then the hard drive enclosure can be left off.
External hard disk is the perfect one for storing system back ups or ghost images of the main hard disk. In mere minutes the ghost image on the external drive can re-create the main disk if the main drives fails. Acronis True Image is the popular software which can make a bootable carbon copy of the main disk on the external disk. From the Enclosure and installed into the system for an instant fix, the external disk can be removed.