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In the 1980s, before the advent of GSM phones, beepers (aka pagers) were used to alert important people about conditions they had to attend to. The pager users carried a small receiver in a pouch attached to their belts. A radio transmitter would dial the pager’s call number, and the pager would emit a crisp audible sound that drew the attention of the intended person (Fig. 15.1).

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DTMF Pager

  • 章节

  • 发表日期：

    2025年

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  • Orhan Özhan

摘要

In the 1980s, before the advent of GSM phones, beepers (aka pagers) were used to alert important people about conditions they had to attend to. The pager users carried a small receiver in a pouch attached to their belts. A radio transmitter would dial the pager’s call number, and the pager would emit a crisp audible sound that drew the attention of the intended person (Fig. 15.1).