write a short essay report to describe a topic of your inter

write a short essay report to describe a topic of your interest related to the past, or current, or future technologies of cellular communications, bandwidths, antennas or their impact to the human society

Solution

past, or current, or future technologies of cellular communications:

Mobile computing is to describe technologies that enable people to access network services anyplace, anytime, and anywhere.

past,present technologies of cellular communications:

1896 Guglielmo Marconi,First demonstration of wireless telegraphy.Based on long wave, requiring very large transmitters

1907 Commercial Trans-Atlantic Wireless Service.Huge ground stations: 30 x 100m antenna masts

1920 Discovery of short waves by Marconi.Cheaper, smaller, better quality transmitters by vacuum tube

1982 Start of GSM in Europe (1G analog)

1983 Start of AMPS in America (1G analog)

1992 Start of GSM (2G digital)

1997 Wireless LAN - IEEE802.11

1998 Iridium satellite system.

1999 Standardization of additional wireless LANs

2000 GSM with higher data rates (2.5G digital).HSCSD offers up to 57,6kbit/s.First GPRS trials with up to 50 kbit/s

2001 Start of 3G systems.IMT - 2000, several “members” of a “family”, CDMA2000 in Korea, UMTS tests in Europe.

GPRS: General Packet Radio Service

It is a mobile data service available to users of GSM mobile phones. It is often described as \"2.5G“.

GPRS is packet-switched which means that multiple users share the same transmission channel, only transmitting when they have data to send.

GPRS provides moderate speed data transfer, by allocating unused cell bandwidth to transmit data.Poor bit rate in busy cells.Usually, GPRS data is billed per kilobytes of information transceived.

future technologies of cellular communications:

Improved radio technology and antennas.smart antennas, beam forming, multiple-input multiple-output (MIMO) 802.11N.dynamic spectrum allocation.Core network convergence.IP-based, quality of service, mobile IP.Ad-hoc technologies.spontaneous communication, power saving, redundancy.Simple and open service platform.intelligence at the edge, not in the network (as with IN).more service providers, not network operators only.

Impact on Society:

Since the introduction of mobile phones, concerns (both scientific and public) have been raised about the potential health impacts from regular use.But by 2008, American mobile phones transmitted and received more text messages than phone calls.Numerous studies have reported no significant relationship between mobile phone use and health, but the effect of mobile phone usage on health continues to be an area of public concern.

For example, at the request of some of their customers, Verizon created usage controls that meter service and can switch phones off, so that children could get some sleep.There have also been attempts to limit use by persons operating moving trains or automobiles, coaches when writing to potential players on their teams, and movie theater audiences. By one measure, nearly 40% of automobile drivers aged 16 to 30 years old text while driving, and by another, 40% of teenagers said they could text blindfolded.

Environmental impacts:Like all high structures, cellular antenna masts pose a hazard to low flying aircraft. Towers over a certain height or towers that are close to airports or heliports are normally required to have warning lights. There have been reports that warning lights on cellular masts, TV-towers and other high structures can attract and confuse birds. US authorities estimate that millions of birds are killed near communication towers in the country each year.