PROPAGATION CHARACTERISTICS\ Sky wave Ground wave Direct wave Wired Communication Cable TV uses coaxial cable as a transmission medium Coaxial cable is capable of transmitting a large number of channels through the wire – so-called guided wave system Addressability - the ability to send a program to some households but not others. used for pay-per-view (PPV) TV Still a form of appointment TV Downloads offer flexibility, time-shifting Fiber Optics uses digital technology - almost unlimited bandwidth Not encumbered by limited transmission frequencies The Growth of New Wireless Services Cellular services In 2010, more than 70% of Americans had access to broadband services in the home; 90% use a cell phone In 2009, Americans traded 822 billion text messages 3G (3rd generation) 4G (4th generation) Two different systems: Global System Mobile (GSM) and Code Division Multiple Access (CDMA) The Growth of New Wireless Services Wireless Services two-way systems that receive and transmit on different frequencies Often transmit on 2.4 GHZ or 5 GHZ Range is usually limited to a given area—Hot Spot Wireless uses a standard know as 802.11 WiMax: newer, long-range high speed networks LTE Storage technology Storage and Retrieval Transition is near complete in the industry from tape to digital (tapeless). Analog Video First VTR, designed for commercial use was Ampex’s quadruplex VTR. Replaced the kinescope. This eventually gave way to the slant track or helical scan system. Digital Video Recording DVC-Pro and other formatsSomewhat a hybrid systemTapeless
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