N-GEN Communications Web-based Seminars ©NGCS

Seminar - An Overview of Communications Technologies

Module 9 - Wireless Systems and Technologies                                                                                 Slide 59 of 80                                                                                                    ________________

WLL Technologies

                                        Analogue Cellular

                                        Digital Cellular

                                        Personal Communications Network (PCN) / 
                                          Personal Communications Services (PCS)

                                        Cordless Telephones 2nd Generation (CT-2) /
                                          Digital European Cordless Telecommunications (DECT)

                                        Personal Handyphone System (PHS)

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Vendors are faced with a choice of fixed-acces, mobile and digital cordless technologies. The appropriate WLL technology will depend on an array of applications considerations such as the size and population density of the geographic area, rural vs. urban, and the service needs of the subscriber base (residential vs. business; POTS vs. data access). WLL will be implemented across five categories of wireless technologies: Analogue Cellular, Digital Cellular, Personal Communications Network (PCN) / Personal Communications Service (PCS), Cordless Telephones 2nd generation (CT-2) / Digital European Telecommunications (DECT), and Proprietary Implementations. Each of these technologies have strengths and weaknesses for WLL applications.

Analogue Cellular - Given that analogue cellular is widely used to serve the mobile markets, there is significant momentum to use it for WLL. There are at present three main analogue cellular system types operating in the World: Advanced Mobile Phone System (AMPS), Nordic Mobile Telephone (NMT) and Total Access Communications Systems (TACS). As a wLL platform analogue cellular has limitations regarding capacity and functionality.

Digital Cellular - Digital systems are outpacing analogue systems in growth. Major worldwide digital cellular standards include Global System for Mobile Communications (GSM), Time-Division Multiplexing Access (TDMA) and Code-Division Multiple Access (CDMA). GSM dominates the digital cellular market. Digital Cellular has the benefit of wide availability and can support a higher capacity of subscribers than Analogue Cellular. It is forecasted that most of the installed base will use digital cellular technology. CDMA offers higher capacity than other digital standards, high-quality voice and a high-level of security. 

PCN / PCS - incorporates digital cellular and cordless standards. PCN is seen as a city communications system with far less range than cellular systems. PCS is a broad range of individualized telecommunications service that let people or devices communicate regardless of where they are. PCN/PCS are not seen as potential WLL technologies.

CT-2 / DECT - Cordless technology was developed to provide wireless access within a residence or business between a base station and a handset. The base station is connected to the PSTN therefore CT-2 is not considered WLL. DECT is considered WLL when a public network operator provides wireless service directly to the user via this technology. DECT is capable of carrying higher levels of traffic, provides good quality of voice and can transmit data at higher rates.

Proprietary Systems - are positioned to provide fixed wireless telephony in low and medium demand density applications.

PHS - This standard was developed in Japan to provide basic telephony service. This standard has been adopted by many countries.