Guest editorial: data communication techniques for storage channels and networks

Since the inception of direct access magnetic storage about 55 years ago, data storage has both benefited from and given rise to extraordinary progress in many technological areas, including materials science, tribology, servo control and actuation, and signal processing and coding. The number of data bits that can be stored in a unit area ¿ the areal recording density ¿ has increased by eight orders of magnitude for harddisk magnetic storage, with compound annual growth rates at times exceeding 100%. Moreover, the cost of this form of storage has dropped by about seven orders of magnitude. For this reason, data storage has been one of the main enablers of the information technology revolution. According to a recent estimation by the technology analysis firm IDC, the amount of data created worldwide has now started to exceed the capacity of storage that is physically available. This so-called digital universe is forecasted to grow explosively and reach more than 1021 bytes (1 ZB) in 2011.