Introduction to Mobile Telephone System


Cellular, personal communication service (PCS), and third generation 3G mobile radio systems are all cellular wireless communication networks that provide for voice and data communication throughout a wide geographic area. Cellular systems divide large geographic areas area into small radio areas (cells) that are interconnected with each other. Each cell coverage area has one or several transmitters and receivers that communicate with mobile telephones within its area. image shows a basic cellular system. The cellular system connects mobile radios (called mobile stations) via radio channels to base stations. Some of the radio channels (or portions of a digital radio channel) are used for control purposes (setup and disconnection of calls) and some are used to transfer voice or customer data signals. Each base station contains transmitters and receivers that convert the radio signals to electrical signals that can be sent to and from the mobile switching center (MSC). The MSC contains communication controllers that adapt signals from base stations into a form that can be connected (switched) between other base stations or to lines that connect to the public telephone network. The switching system is connected to databases that contain active customers (customers active in its system). The switching system in the MSC is coordinated by call processing software that receives requests for service and processes the steps to setup and maintain connections through the MSC to destition communication devices such as to other mobile telephones or to telephones that are connected to the public telephone network.
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When linked together to cover an entire metro area, the radio coverage areas (called cells) form a cellular structure resembling that of a honeycomb. Cellular systems are designed to overlap each cell border with adjacent cell borders to enable a “hand-off” from one cell to the next. As a customer (called a subscriber) moves through a cellular system, the mobile switching center (MSC) coordinates and transfers calls from one cell to another and maintains call continuity.

Market Growth
Key drivers for the mobile telephone market growth include new wireless technology (3G) service availability and the replacement market for mobile phones with new capabilities such as camera phones, color displays, and increased accessory capabilities. The mobile phone industry is transitioning from first-generation analog technology (1st generation – 1G), through second-generation digital technology (2nd generation – 2G), to high-capacity third-generation digital systems (3G). Because mobile telephone service providers gain increased system efficiency (more customers per tower) and have the ability to offer new and advanced service (that can be billed), this is resulting in aggressive offers from carriers to upgrade existing customers and add new customers to the new high-capacity systems. The number of mobile users reached 1.3 billion in 2003 [i]. As manufacturers offer mobile phones that have new capabilities that offer significantly improved lifestyles, customers will upgrade their mobile telephones to devices with these increased capabilities. Some of the key capabilities include camera phones, color displays, and wireless personal area network (WPAN) communications ability. The market for camera phones reached 3 million units in 2001, achieved 17 million units in 2002, and it should reach 60 million units by the end of 2003, and predictions show that camera phones will reach 165 million units by 2006 [ii]. The leading WPAN system in 2003 is Bluetooth. The upgrade or inclusion of Bluetooth with mobile telephone devices allows the connection of mobile telephones with many service-enhancing accessories such as wireless headsets, data transfer to PDAs and laptops, and printing. Figure shows the number of subscribers (left axis) and the growth in percentage right (axis) of the worldwide mobile telephone industry. This graph shows during the early 1990s, the industry growth had exceeded more than 30% each year. In the 2000’s, the growth had begun to decrease due to the high percentage of global market penetration (almost 25% of all people in the world had mobile telephones in 2003).
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