THE PAGING SYSTEM

HISTORY

Paging system is a one-way personal wireless alerting and messaging system. Paging was started in the 1960s. The receiver is a tone page (beeper) with a dedicated telephone number to receive the message.

The message primarily is the caller’s phone number. In some tone paging systems, a voice message can be transmitted after the beep. Also, the pager can be an alphanumeric pager, which has a fairly large screen to display several text strings. It was introduced in the late 1970s and became popular in the mid-1990s.


TECHNOLOGY OF PAGING


The bandwidth of the paging channel is 25 kHz. Each paging channel can serve 50,000 pagers. Each paging tower can be 100 m high and can cover an area of 16-km radius. 

Therefore, the paging system is the most spectrally efficient system. Also, the paging frequencies operate at around 35 MHz, 150 MHz, 450 MHz, and 900 MHz. In these low-frequency ranges, the propagation loss is minimal compared to the operation system with frequencies above 1 GHz.


DIFFERENT PAGING SYSTEMS


There are several kinds of paging systems based on their air interfaces. The British Post Office initiated one signal format called the Post Office Code Standardization Advisory Group (POCSAG) during 1970. In early 1990, a high-speed protocol called European Radio Message System (ERMES) was approved by ETSI. Motorola developed FLEX, and Philips Telecom developed Advanced Paging Operations Code (APOC). Therefore, different types of pagers receive different signal formats.

The POCSAGcoding format can be operated at 2400 bps and can accommodate 2 million pagers. The FLEX coding format also can be operated at 2400 bps. 


The ERMES can have an effective transmission rate of 3750 bps. In the 1990s, the paging system was very popular, especially in the Asian region. Many people carried pagers because of its low service charge. Also, the pagers were smaller in size and lighter in weight as compared with cellular phones. 

Motorola was developing Re FLEX two-way paging systems but could not find a market.


WHY DISAPPEARED?


In the year 2000s, the size, weight, and service charge of cellular phones were drastically reduced, and the need of a paging system did not exist. The paging systems disappeared.

 

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