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WHAT ARE CELLULAR AND PCS <br /> SERVICES AND HOW DO THEY OPERATE? <br /> <br />2elluIar telephone service has been 0~fered commercially for <br />~-more than ten years. Prior to the development and introduction <br /> of cellular phone service, mobile telephone service offerings were <br />imited. The older, non-cellular systems used a single high- <br />-cowered radio transmitter to cover an entire community. With <br /> few allocated frequencies and channels, the old systems could <br /> nly provide service to a limited number of subscribers. <br /> <br />-'Today's cellular systems overcome this limitation by <br /> =,lbdividin~ their service areas into small cells, each with a Iow- <br /> owered radio transmitter. With this design, channels may be <br />Tiused in the service area; the same channels are assigned to <br /> · qultiple, nonadjacent cells, significantly increasing the number <br /> ~calls the system can handle ar any one time and thus the <br /> vrt:mber of subscribers served. A call is automatically <br /> :ransferred from one channel in one cell to another channel in <br /> e next cell as a subscriber moves through the service area. <br /> .-vzost ceIlular systems today use conventional analog <br /> :ransmission technology. <br /> <br /> ,'S is a new technology and a competitor to cellular <br /> '-e-lephone service. The first broadband PCS systems began <br /> .,,~erations in 1996. PCS systems share the same "cell-shaped" <br /> ;ign that characterizes ceIlular service. However, broadband <br /> 7-~C systems may require more antenna sites because PCS - <br /> :ystems operate at higher frequencies than cellular phone <br /> ; vices, frequencies at which the effective coverage area ora <br /> :_l decreases. In this band, PCS systems also may provide <br /> -ther communications services, such as data transmission and <br /> ~ ;lng, over the same frequencies. <br /> <br />PCS systems also differ from cellular telephone systems because <br />they use lower power transmitters and digital transmission <br />technologies. Future PCS services may include computer <br />networking and wireless lnternet access. <br /> <br />Both cellular and broadband PCS subscribers use portable <br />phones to access or receive calls from the public switched . <br />telephone network (PS'i'N) through cell site antenna facilities. <br />Antenna facilities are connected to a Mobile Telephone <br />Switching Office (MTSO) by landline or microwave links. <br />The MTSO is connected by trunks to the PSTN. The MTSO <br />switches calls between the PSTN and the ceil sites. <br /> <br />Cellular and PCS antenna facilities have been installed on <br />communications towers, water tanks, rooftops, and street lights. <br />In some areas, facilities have been installed in church steeples, <br />clock towers, or camouflaged as artificial trees to address <br />aesthetic concerns of the community. <br /> <br />Communications towers take many forms and vai-y significantly <br />in height. A tower may be free standing or "guyed," anchored <br />with cables. A guyed tower needs significantly more land than <br />a free standing tower. Free standing or self-supporting towers <br />include monopoles and three- or four-sided steel-lattice towers. <br />Tower and tower foundation specifications depend on a variety <br />&factors including design load, wind speed, ice load, soil <br />conditions, building code requirements, and antenna loading. <br /> <br /> <br />