CORDLESS SYSTEMS: CORDLESS SYSTEMS Cordless system: Cordless system What is cordless system? History of cordless system. Frequencies Performance Wireless phone handsets Types of cordless system ● Analog ● Digital What is cordless system? : What is cordless system? Cordless system is basically general term of cordless telephones and cordless telecommunication systems. Cord means “wire” , so cordless system means wireless system. Slide 4: Cordless telephone with base Definition:: Definition: A cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station (which has the handset cradle). The base station is on the subscriber premises, and attaches to the telephone network the same way a corded telephone does. Slide 6: Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handover, various advanced features, such as data-transfer and even, on a limited scale, international roaming. Slide 7: Unlike a corded telephone, a cordless telephone needs mains electricity to power the base station. The cordless handset is powered by a rechargeable battery, which is charged when the handset sits in its cradle. Limitations:: Limitations: Residential – a single base station can provide in-house voice and data support Office A single base station can support a small office Multiple base stations in a cellular configuration can support a larger office Telepoint – a base station set up in a public place, such as an airport History of Cordless System: History of Cordless System A jazz musician named Teri Pall invented a version of the cordless phone in 1965 but could not market her invention as its two-mile range caused radio signals to interfere with aircraft George Sweigert , an radio operator and inventor from is largely recognized as the father of the cordless phone. He submitted a patent application in 1966 for a "full duplex wireless communications appartus". Sweigert, a radio operator in World War II stationed at the South Pacific Island developed the full duplex-concept for untrained personnel, to improve battlefield communications for senior commanders. History (cont.): History (cont.) In the 1980s, a number of manufacturers, including Sony , introduced cordless phones for the consumer market. Since the 1980s, several companies have entered the cordless-phone market: VTech , Uniden , Philips , Gigaset and Panasonic . They advertise many new features,a few provided by the phone and most provided by the network. which also do not use traditional mobile (cellular) phone networks. Frequencies: Frequencies In the US, seven frequency bands have been allocated by the FCC for uses that include cordless phones. These are: 1- 1.7 MHz (1.64 MHz to 1.78 MHz & up to 5 Channels, AM System) 2- 43–50 MHz (Base: 43.72-46.97 MHz, Handset: 48.76-49.99 MHz, allocated in 1986 for 10 channels, and later 25 Channels, FM System) 3- 900 MHz (902–928 MHz) (allocated in 1990) 4- 1.9 GHz (1880–1900 MHz) (used for DECT communications outside the U.S.) 5- 1.9 GHz (1920-1930 MHz) (developed in 1993 and allocated U.S. in October 2005) : 5- 1.9 GHz (1920-1930 MHz) (developed in 1993 and allocated U.S. in October 2005) 6- 2.4 GHz (allocated in 1998) 7- 5.8 GHz (allocated in 2003 due to crowding on the 2.4 GHz band). usually within a limited range of its base station (which has the handset cradle). The base station is on the subscriber premises, and attaches to the telephone network the same way a corded telephone does. : usually within a limited range of its base station (which has the handset cradle). The base station is on the subscriber premises, and attaches to the telephone network the same way a corded telephone does. Current cordless telephone standards, such as PHS and DECT, have blurred the once clear-cut line between cordless and mobile telephones by implementing cell handover, various advanced features, such as data-transfer and even, on a limited scale, international roaming. Performance : Performance Manufacturers usually advertise that higher frequency systems improve audio quality and range. Higher frequencies actually have worse propagation in the ideal case. More important influences on quality and range are signal strength, antenna quality, the method of modulation used, and interference, which varies locally. Many cordless phones in the early 21st century are digital. Digital technology has helped provide clear sound and limit eavesdropping. Many cordless phones have one main base station and can add up to 3 or 4 additional bases. This allows for multiple voice paths that allow 3-way conference calls between the bases. This technology also allows multiple handsets to be used at the same time and up to 2 handsets can have an outside conversation.: This allows for multiple voice paths that allow 3-way conference calls between the bases. This technology also allows multiple handsets to be used at the same time and up to 2 handsets can have an outside conversation . Types (standards) of Cordless telephone : Types (standards) of Cordless telephone Digital cordless phones (i) Digital Enhanced Cordless telecommunication(DECT) (ii)Personal Handy-Phone System(PHS) Analog cordless phones The main distinction among types of cordless phones is the way to transmit their signals. Digital Enhanced Cordless Telecommunications : Digital Enhanced Cordless Telecommunications Digital Enhanced Cordless Telecommunications, usually known by the acronym DECT. Beyond Europe, it has been adopted by Australia, and most countries in Asia and South America . Slide 18: DECT is used primarily in home and small office systems, but is also available in many PBX systems for medium and large businesses. Application of DECT: Application of DECT Domestic cordless telephony, using a single base station to connect one or more handsets to the public telecoms network. Enterprise premises cordless PABXs and wireless LANs, using many base stations for coverage. Calls continue as users move between different coverage cells, through a mechanism called handover. Calls can be both within the system and to the public telecoms network. Public access, using large numbers of base stations to provide high capacity building or urban area coverage as part of a public telecoms network. “Fido” Slide 20: DECT has also been used for Fixed Wireless Access as a substitute for copper pairs in countries such as India and South Africa. By using directional antennas and sacrificing some traffic capacity, coverage could extend to over 10 km. The standard is also used in electronic cash terminals, traffic lights, and remote door openers Technical development and adoption of DECT: Technical development and adoption of DECT The DECT standard was developed by ETSI in several phases, the first of which took place between 1988 and 1992 when the first round of standards were published. Initially named "Digital European Cordless Telephone" at its launch by CEPT in November 1987 . At suggestion by Enrico Tosato of Italy , its name was soon changed to "Digital European Cordless Telecommunications" to reflect its broader range of application, including data services . In 1995, due to its more global usage, the name was changed from "European" to "Enhanced." Slide 22: Digital Enhanced Cordless Telecommunications is an ETSI standard for digital portable phones (cordless home telephones), commonly used for domestic or corporate purposes. DECT was developed by ETSI but has since been adopted by many countries all over the world . The original DECT frequency band (1880 MHz–1900 MHz) is used in all countries in Europe . Outside Europe, it is used in most of Asia, Australia and South America . In the United States, the Federal Communications Commission in 2005 changed channelization and licensing costs in a nearby band (1920 MHz–1930 MHz, or 1.9 GHz), known as Unlicensed Personal Communications Services (UPCS), allowing DECT devices to be sold in the U.S. with only minimal changes Features of DECT : Features of DECT Typical abilities of a domestic DECT Generic Access Profile (GAP) System include: Multiple handsets to one base station and one phone line socket. This allows several cordless telephones to be placed around the house, all operating from the same telephone jack. Interference-free wireless operation to around 100 metres (109 yards) outdoors, much less indoors when separated by walls . - For instance, generally immune to interference from other DECT systems, Wi-Fi networks, video senders, Bluetooth technology, baby monitors and other wireless devices. Slide 24: Talk time several hours and standby time of several days on one battery charge. Some systems offer: ● A longer range between the telephone and base station (usable further from the base). ● Extended battery talk-time, sometimes up to 24 hours. Analog phones : Analog phones Features of analog phones These are least expensive Better voice quality than digital phones Use 5.8 GHz frequency band Slide 26: Drawbacks of analog phones Are of shorter rang than digital phones This is not a secure transmission We can listen voices by using RF scanner (Radio Frequency) or any comparable device Conference calls are not allowed (2)PHS (personal handy-phone system): (2)PHS (personal handy-phone system) Developed in Japan as a cordless telecommunication system Operates on 1895 MHz-1918MHz Slide 28: Features of PHS PHS is Light weight PHS is Portable Handle voice,fax, and vedio sigals PHS system (cont.): PHS system (cont.) In mid 1990s, UTStarcom introduce IP-based personal access system(iPAS) iPAS network is i) Low-cost ii) Easy to deploy iii) Wireless alternative of copper wire iv) Portable v) Support 55 million subscribers globally PHS systems (cont.): PHS systems (cont.) “providing wireless local loop connectivity” Services provided by PHS system City wide mobility Email Mobile internet access (MIA) Short messaging Location based services iPAS (IP-based personal access solution): iPAS (IP-based personal access solution) iPAS (IP-based personal access solution): iPAS (IP-based personal access solution) Features of using iPAS Ensure rapid wireless deployment Ideal for large installation Support 10,000-5,000,000 Subscribers on single installation Bypass the time consumming process of copper infrastructure installation Based on Radio Frequency(RF) mechanism Deliver voice services more efficiently and cost-effectively than traditional cellular phones. ANY QUESTION?????: ANY QUESTION?????