Differentiate the generations in the cordless phones and cellular phones?
10. Differentiate the generations in the cordless phones and cellular phones?
Cellular Phones: In 1945 the Zero Generation (0G) of mobile telephones was introduced. 0G mobile phones like mobile telephone service, were not cellular, and so did not feature ‘handover’ from one base station to the next and reuse of radio frequency channels. Like other technologies of the time it involved a single powerful base station covering a wide area and each telephone would effectively monopolize a channel over that whole area while in use. The concepts of frequency reuse and hand off as well as a number of other concepts that formed the basis of modem cell phone technology arc first described in U.S. patent 4.152.647 issued on May 1. 1979 to Charles A Gladden and Marlin H Parelman, and assigned by them to the United States Government. This is the first embodiment of all the concepts that formed the basis of the next major step in mobile telephony, the analog cellular telephone.
The first commercial city wide cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation). The Nordic Mobile Telephone (NMT) system went on-line in Denmark, Finland, Norway and Sweden in 1981.
Personal Handy phone system and modems used in Japan around 1997-2003. In 1983, Motorola DynaTAC was the first approved mobile phone by FCC in the United States. In 1984, Bell Labs developed modern commercial cellular technology, which employed multiple, centrally controlled base stations (cell sites), each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system a signal between a base station (cell SIC) and a terminal phone) only need, be s[ring enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells. The first “modern’ network technology on digital 20 (Second Generation) cellular technology was launched by Radiolinja in 199) in Finland on the OSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland who ran a 1-G NMT network.
The first data services appeared on mobile phones starting with person-to-person SMS text messaging in Finland in 1993. First trial payments using a mobile phone to pay for a Coca Cola vending machine were set in Finland in 1998. The first commercial payment system to mimic banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Glove and Smart. The first content sold to mobile phones was the ringing tone, first launched in 1998 in Finland. The first full Internet service on mobile phones was i-mode introduced by NTT’s DoCoMo in Japan in 1999. In 2001 the first commercial launch of 3G (third generation) was again in Japan by NTT DoCoMo on the WCDMA standard.
Until the early 1990’s, most mobile phones were too large to be carried in a Jacket pocket, so they were typically installed in vehicles as car phones. With the miniaturisation of digital components and development of more sophisticated batteries, mobile phones have become smaller and lighter.
Cordless phones: George Sweigert an amateur radio operator and inventor from Cleveland Ohio, is largely recognized as the father of the cordless phone. He submitted a patent application in 1966 for “full duplex wireless communication apparatus’. The U.S. patent and trademark office awarded him a patent in June of 1969. Sweigert a radio operator in World War II stationed at the south pacific islands of Guadalcanal and Bougainville, developed the full duplex-concept for untrained personnel, to improve battlefield communications for senior commanders. He was also licensed as W8ZIS and N9LC in the amateur radio service. He also held a first class radio telephone operator’s permit issued by the Federal Communication Commission.
In the 1980s a number of manufacturers including Sony introduced cordless phones for the consumer market. They used a base station that was connected to a telephone line and a handset with a microphone, speaker, keypad and telescoping antenna. The handset contained a rechargeable battery typically NiCd. The base unit is powered by household current via a wall socket. The base included a charging cradle, which as generally a form of trickle charger, on which the handset rested when not in use. Some cordless phones now utilize two rechargeable AA or AAA batteries in place of the more expensive traditional proprietary telephone batteries.
