Phone cards, Mobiles and ringtones
Phone Cards
A telephone card, calling card or phone card for short, is a small card, usually resembling a credit card, used to pay for telephone services. Such cards can either employ a prepaid credit system or a credit-card-style system of credit. The exact system for payment, and the way in which the card is used to place a telephone call, depend on the overall telecommunication system. Currently, the most common types of telephone cards involve pre-paid credit (stored-value) in which the card is purchased with a specific balance, from which the cost of calls made is deducted. Pre-paid phone cards are disposable. When the balance is exhausted you simply buy a new card. In some countries, cards purchased can be refilled. The other main type of card involves a card with a special PIN printed on it that allows one to charge calls to a land-line telephone account. These are known as remote memory cards.
Mobiles
A mobile phone or mobile (also called cellphone and handphone, as well as cell phone, wireless phone, cellular phone, cellular device, cell, cellular telephone, mobile telephone or cell telephone) is a long-range, electronic device used for mobile telecommunications (mobile telephony, text messaging or data transmission) over a cellular network of specialized base stations known as cell sites.
Most current cell phones connect to a cellular network consisting of switching points and base stations (cell sites) owned by a mobile network operator (the exception is satellite phones, which are mobile but not cellular). In addition to the standard voice function, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video, MP3 player, radio and GPS.
As opposed to a radio telephone, a cell phone offers full duplex communication, automatised calling to and paging from a public switched telephone network (PSTN), and handoff (American English)/handover (British/European English) during a phone call when the user moves from one cell (base station coverage area) to another. A mobile phone offers wide area service, and should not be confused with a cordless telephone, which also is a wireless phone, but only offer telephony service within a limited range, e.g. within a home or an office, through a fixed line and a base station owned by the subscriber
Ring Tones
A ringtone or ring tone is the sound made by a telephone to indicate an incoming call or text message. Not literally a tone, the term is most often used today to refer to customizable sounds used on mobile phones.
Contents [hide]
1 Background
2 History
3 Ringtone makers
4 Ringtone business
4.1 Billing controversies
5 Types of ring tones
6 Ring tone encoding formats
7 See also
8 References
9 External links
[edit]Background
A phone "rings" when its network indicates an incoming call and the phone thus alerts the user. For landline telephones, the call signal can be an electric current generated by the switch to which the telephone is connected. For mobile phones, the network sends the phone a message indicating an incoming call.
A telephone "ring" is the sound generated when there is an incoming telephone call. The term originated from the fact that early telephones had a ringing mechanism consisting of a bell and an electromagnetically-driven hammer, producing a ringing sound. The aforementioned electrical signal powered the electromagnet which would rapidly move and release the hammer, striking the bell. This "magneto" bell system is still in widespread use. The ringing signal sent to a customer's telephone is AC at 90 volts and 20 hertz in North America. In Europe it is around 60-90 volts AC at a frequency of 25 hertz
While the sound produced is still called a "ring", more-recently manufactured telephones electronically produce a warbling, chirping, or other sound. Variation of the ring signal can be used to indicate characteristics of incoming calls (for example, rings with a shorter interval between them might be used to signal a call from a given number)