Call Management Personal Communication System (PCS) A system where wired and wireless networks are integrated for establishing communication.PCS technologies have grown rapidly in the telecommunications industry. PCS refers to varietyof wireless access (communication) and personal mobility services provided through a smallterminal at any place, and in any form. Business opportunities (E-commerce) for such servicesare tremendous, since every person, every organization, etc., could be equipped. Several PCsystems have been developed to meet rapid growth prompted by market demand. Most ofthem are connected to Public Switched Telephone Network (PSTN) to integrate with the wiredservice. Two of the most popular are cellular telephony and Cordless and low-tier PCS telephony. Radio Network: PCS users carry mobile stations (MSs) to communicate with the base stations (BSs) in a PCS network. MS is also referred to as handset, mobile phone, subscriber unit orpotable, the term mobile station is used in GSM system. Different types of MSs have variouspower ranges and radio coverages. For example, hand-held MSs have a lower output power(where the maximum output power can be low as 0.8 watts for GSM 900) and shorter rangecompared with antennas (where the maximum output power can be as high as 8 watts inGSM900). The radio coverage of a base station is called cell.The name cellular system emerged from this. The shape of the cell is considered as hexagonal.This is to overcome the disadvantages of other shapes like circle, rectangle etc. Hexagon hasmore similar shape to circle. It will not give void when three hexagon connected together.The following figure shows PCS architecture PSTN- public switching telephone networkMSC- Mobile switching center
BSC – Base station controllerBS- Base stationIt consists of radio network between each module. Wireline Transport Network: The mobile switching center (MSC) connected to the base station is a special switch tailored to mobile applications. For example, the Lucent 5ESS MSC 2000 is an MSC modified from Lucent Technologies 5ESSswitching system. The MSC is connected to the PSTN to provide services between the PCS users and the wirelineusers. MSC also communicates with mobility databases to track the locations of mobile stations.