* HISTORY REVIEW. * The paging system consists. * The paging system components. * The advantages of paging. * Disadvantages of Paging. *BASIC PARTS OF PAGING SYSTEM. *PAGING TERMINAL. * TRANSMISSION NETWORK. * TRANSMITTER EQUIPMENT. * SYSTEM CAPACITY. * The capacity of any paging system is effected. *FREQUENCY BANDS. * paging systems in Saudi Arabia. * The ERMES paging system.

Paging is a one - way broadcast signaling system. It can send data only, data and voice messages, numeric displays, and/or alphanumeric displays. Alphanumeric message paging system became available in the mid s. Paging is a mobile communication service without two -way speech Facilities. Paging systems are designed as extensions of the telephone network. The first land mobile radio system, the one - way information broadcast concept was pioneered by the The term paging, in general, refers to sending short messages to some one in the move with some defined coverage The paging system is a simple application of mobile radio systems, where we send the signal from the transmitter without assurance that the message has actually, arrived at (or acknowledged by) the intended receiver Paging is a ''one - way'' system.

The caller network, and Paging service. The caller network connects into the paging service via the normal local telephone exchange (Public Switched) Telephone Network (PSTN) or Mobile Network (MN)

[Paging control units, Area controllers, Modems, and Transmitters (TX)]. Each paging terminal receiver in this system is uniquely identified by an address code. For example: when a caller needs to send a message through this system to a subscriber, he will use the telephone terminal and enter the code number (paging number) of the subscriber, this message is routed by the switched telephone network to a central server of the paging network, and is then transmitted on a radio channel into a given region.

1-communication services lies in the simplicity of its concept. 2-messages are sent via a radio channel to a receiving terminal situated within a given area. 3-The receiver is very simple. 4-This reflects on cheaper cost of paging services and terminals compared to other more powerful communication services. 5-Paging has limited capabilities allowing only one. 6-way store and-forward data transmission.

1-extra resource consumption. 2-memory overhead for storing page tables The worst cases are when page table may take up a significant portion of virtual memory. 3-Other disadvantage is translation overhead.

The basic parts of paging system are:. Access / Voice Messaging Units 'Caller Network'.. Paging Terminal. Transmission Network.. Transmitter Equipment. ''The last three can be called Paging Service''

The paging terminal consists of two units: a) Paging Network Controller (PNC) : Paging Network Controller (PNC) communicates with the access devices stores, and handles customer messages. The PNC - OMC inter working is managed by PNC. b) Operation and Maintenance Center (OMC). The paging system operation and maintenance functions are concentrated on the OMC. This means all network management, administration and maintenance functions. The OMC provides traffic and quality of service statistics. From the OMC we can load to all network elements new software without physically visiting the different sites.

The transmission network consists of : a) Paging Area Controller (PAC). b) Network Router (NR).

The transmitter equipment used consists of : a) Base Station Controller (BSC) b) Transmitters (TX) c) Antenna System.

Paging systems capacity can be divided in four different kinds, as follows : 1 ) Air-time capacity ''output capacity''. 2) Access capacity ''input capacity''. 3) Processing capacity ''for paging and voice messaging''. 4) Database capacity ''for paging and voice messaging''.

* Number and characteristics of the radio channels used. * The number of times each channel is re-used within the system. * The peak information (address and message) requirements in a location or locations. *Tolerable paging delay. *Data transmission rate. *Code efficiency. *Method of using the total code capacity throughout the system. *Any inefficiencies introduced by battery - saving provisions. *Possible telephone system input restriction ns.

Allocated frequency bands for paging systems vary from country to country The ITU specify the following frequency bands for mobile services.

Point leaders are considered as sufficient information to you

Saudi Arabia is among the first countries in the Middle East that started public paging services. Saudi PTT planned the paging network to initially cover the major cities like Riyadh, Jeddah, and Dammam. It then developed this network to cover other large towns - in the Kingdom of Saudi Arabia. Firstly, in A.H. (1992) Saudi PTT adopted the POCSAG standard as the Public Radio Paging System (PRPS) to operate in its region. This network operated in 16 cities. After initial service offering and the resulting high demand, Saudi PTT decided to increase the paging network capacity by high speed and large capacity new paging standard.

1. Paging Network Controller (PNC). 2. Paging Area Controller (PAC). 3. Paging Area Controller - Network (PAC-NR). 4. Tele Access Units (TAU). 5. Data Access Units (DAU). 6. Operation and Maintenance Center (OMC). 7. Network Router (NR) 8. Base Stations (BS).

This new system is applied in the hospital system for the convenience of patients and reviewers using a pager. A00 _______________________________________