98 Glossary of TermsGlossary of TermsAPN Access Point Name. Directs the user to the gateway or the required service.CHAP Challenge Handshake Authentication Protocol. A security feature for the GPRS network.CSD Circuit Switched Data. A communication method used to transmit data over telephone connections.DTMF Tones Dual Tone Multi-Frequency tones allow you to communicate with computerised phone systems, voice mailboxes,etc.GPRSGeneral Packet Radio Service. A GSM transmission technique that transmits and receives data in packets ratherthan setting up a continuous channel. It makes very efficient use of available radio spectrum and users pay onlyfor volume of data sent and received.GSM Global System for Mobile communications. The name given to the advanced digital technology that your phoneuses.Network Operator The organization responsible for operating a GSM network.PAP Password Authentication Protocol. A security feature in the GPRS network.Password Used for the control of Call Bar. Supplied by your service provider.PIN Personal Identification Number used for SIM security. Supplied by your service provider. If the PIN is enteredincorrectly 3 times, the PIN will be blocked.PIN2 Personal Identification Number used for the control of Fixed Dial Store and Call Charge metering. If the PIN2is entered incorrectly 3 times, the PIN2 will be blocked.PUK/PUK2 PIN/PIN2 Unblocking Key. Used to unblock the PIN/PIN2. Supplied by your service provider. If the PUK/PUK2 is enteredincorrectly 10 times, the PUK/PUK2 will be blocked.Registration The act of locking on to a GSM/GPRS network. This is usually performed automatically by your phone.Roaming The ability to use your phone on networks other than your Home network.