Rapid Developments

The decade of the 1980s saw a big increase in the number of satellites and satellite operators. The GEO began to become crowded in sectors serving North America, Europe, and East Asia. Applications in TV, private data and voice networks, and mobile communications established themselves as the ground segments mushroomed. Private commercial operators such as RCA Americom (now GE Americom), Hughes Communications, and Pan A Sat (now combined as a result of a merger in 1997) grew to profitability onthe foundation of the cable and broadcast TV industry. Television signals relied on these satellites to serve thousands of locations in North America.

Cable TV systems in local communities created the demand for specialized and high-value programming from HBO, Turner Broadcasting (now part of AOL /Time Warner), Disney, and ESPN. Cable networks numbered more than 100 by 1985 and continue to be delivered through 3-to-5-m C-band dishes at the head ends of local cable TV (CATV) systems. Origination of the network feeds requires extensive studio facilities. Ku-band satellites and ground segments also appeared in the 1980s to take advantage of
the smaller dish sizes that this band allows. As a result, VSAT user terminals like that in Figure 1.7 became popular with major retailers like Wal-Mart, Rite Aid, and Kmart, and oil companies like Chevron, Mobile, and Texaco.

The first real DBS system was introduced in Japan in the late 1970s and became very popular by 1985. While offering only two TV channels, the NHK DBS project resulted in several million home DBS installations throughout Japan. The United Kingdom and continental Western Europe saw the explosion of commercial satellite TV during the late 1980s. One could argue that this expansion came about through News Corp's Sky TVand the Astra satellites operated by Société Européene des Satéllites. This powerful combination delivered an attractive programming package directly to subscribers, who bought and installed their own DBS receivers. There is little doubt that this established the viability of direct-to-home (DTH) satellite TV, an application which DIRECTV subsequently took to new heights (but still at GEO altitude).

Inmarsat became the foundation of commercial mobile communications as defense applications of satellite mobile services were already established but with space and ground segments owned and controlled by governments. Several proposals were put forth in the United States and Europe for innovative satellite services using new frequency bands. One was intended for tracking trucks on intercity routes, so that dispatchers knew where their drivers were even if they could not call in. Even though there was a serious shakeout in these early systems, they nevertheless represent an important precursor for the global mobile satellite systems of the next
decade.

We cannot forget to mention the cellular telephone networks, which began to reach critical mass during this same decade. While relying completely on local base stations and switching systems, cellular radio proved the value and reliability of automated radio frequency channel assignment, cell-to-cell handover, and intersystem roaming. Similar capabilities were

Figure 1.7 Examples of VSAT earth stations for two-way communications: (a) 1.2-m data application (photo courtesy of Hughes Electronics); (b) 1-m video-data terminal(photo courtesy of STM Wireless).

demonstrated on the INTELSAT system with the pioneering SPADE SCPC DA system of the early 1970s and the DA system installed in Indonesia in 1977 for Palapa A. These technologies provided a basis for large global mobile personal communications services (GMPCS) projects like Iridium, Globalstar, and ICO.