Computer

Computers are used daily by thousands of people all over the world.

They are machines that manipulates data according to a set of instructions. The first electrical computer were developed in the mid 20th century,they were the size of a large room using hundreds of units of power. Modern computers are now based on intergrrated circuits. Computers have the ability to store many different programmes. When a person uses a computer, they are telling it what to do with their actions.

ADSL modem

An ADSL modem is a device which is used to connect a computer or a router to a DSL phone line, to use ADSL services.

The modem uses high frequency tones for transmission. Most modems are external to the computer & wired to the computers Ethernet port or the usb port. ADSL modems are intended for particular protocols & somtimes dont work on other lines. ADSL modems vary in data speed.

Voice over internet protocol - VoIP

Voice over internet protocol is a general term for a family for a family of transmission technologies for delivery of voice communications over IP networks such as the internet or other packet switched networks. Other things used by VoIP are: IP telephony, Internet telephony, Voice over broadband, Broadband telephony & broadband phone.

Internet telephony refers to communication which are transported through interent.

VoIP use session control protocols to control the set up and tear down of calls also allowing transmission over an IP network.

Broadband

Broadband can refer to broadband networks or broadband internet. It is a way of moving information accross a network and is used for high speed connections. It is much faster then dial up connecting.

Asymmetric digital subscriber line - ADSL

DSL is a family of technologies that provides digital data transmissions over the wire of a local telephone network. ADSL is the most popular version of consumer ready DSL. This can be used at the same time on the same telephone line. DSL works by dividing the frequencies used in a single phone line into two primary bands. The ISP data uses the high frequency band wheras the voice utilizes the lower fequency band. Users install a DSL filter on each phone outlet, which filters out the high frequencies from the phone line so the phone sends or recieves only the lower frequencies. ADSL is useful to me because i use the internet.

Bluetooth.

Bluetooth is an open wireless protocol for exchanging data over short distances using radio waves from fixed and mobile devices. It was originally concieved as a wireless alternative to RS-232 data cables. it can connect several devices overcoming problems of synchronizing. Bluetooth is a standard and a communications protocol primarily designed for lower power consumption with a short range. Bluetooth uses a radio technology called frequency hopping spread spectrum.

general packet radio service - GPRS.

GPRS is a packet oreiented mobile data service available to the users of 2g. GPRS data transfer is charged per megabyte.
It was developed as a GSM response to the earlier CDPD and i-mode packet switched cellular technologies.
GPRS is commonly used in sat navs.

multimedia message service (mms)

Multimedia message service otherwise known as mms, is the standard way to send and recieve messages which includes multimedia items to and from mobile phones. it extends the core of sms which only allows the amount of characters up to 160 per text. The most popular use of mms is to send photos to and from mobiles.

The photo i added shows an example of when mms is used.

3rd generation protocols (3g)

International mobile telecommunications-2000 are better known as 3g or 3rd generation. They are a family standard for mobile telecommunications. 3g allows similatenous speech and data services and higher data rates.

The image i added shows the 3g protocol.

Global System for mobile = (gsm)

GSM is the most popular standard for mobile phones. It has its own personal promoter - GSM associations. They have estimated that 80% of the world uses GSM. GSM is a cellular network, so mobile phones can connect to it by searching for cells in the vicinity. There are 5 different cell sizes in the network, they are: macro, micro, pico, femto & umbrella cells.

macro cells are based on masts or on top of a building.

Micro cells are cells which are antenna height, typically based in urban areas.

pico cells are are mainly used indoors.

femto cells are designed for small buisness or residential areas which connect via broadband.

umbrella cells are used to cover shadowed regions of smaller cells.

wireless access protocol (wap)

Wireless access protocol - wap.

This is an open international standard for application layer network communications in a wireless communication environment. Most use of WAP involves accessing the mobile interweb from either a PDA or a mobile ect. A WAP browser provides all basic services of a computer based web browser but it is simplified. The diagram i added shows the WAP server.

Hypertext transfer protocol - HTTP.

Hypertext Transfer Protocol (http)

This is an application-level protocol for distributed, collobarative hypermedia information systems. Its used for retrieving inter-linked rescouces, called hypertext documents which are from the web.There are two versions of 'http'

HTTP/1.0 and HTTP/1.1

HTTP/1.0 that uses a seperate connection for each document and HTTP/1.1 which can resume the same connection to download HTTP/1.0 is known to be faster.

The image i have shows a HTTP response status.