Product features©2001 Nokia Mobile Phones. All rights reserved. 16means of light indicators and also by means of tone in the telephone set’s re-ceiver. For further information, see “ Short Message Service (SMS)”on page 15.High Speed Circuit Switched Data(HSCSD)The GSM terminal supports High Speed Circuit Switched Data that enables adata transmission speed of up to 43.2 kbps. The High Speed Circuit SwitchedData (HSCSD) relies on the simultaneous use of multiple GSM timeslots.For the terminal data transfer modes, see “7. Technical specifications” on page36. The Nokia 22 Data Packet is required to use this feature.The HSCSD is a network service. For details, contact your service provider.Calling Line Identification (CLI)The Calling Line Identification (CLI) feature displays the caller’s number with anexternal calling line display device.Two signalling methods are available, ETSI FSK (European TelecommunicationsStandards Institute Frequency Shift Keying) and DTMF (Dual Tone Multi Fre-quency).The signalling mode varies depending on the operator and the country. The de-fault mode is ETSI FSK. For information about changing the CLI mode, see “Changing Calling Line Identification (CLI) mode” on page 32.Note: The CLI devices are not provided by Nokia. For details and avail-ability, contact your service provider.Automatic Area Code (AAC) and routingThe Automatic Area Code (AAC) feature allows the user to dial local numberswithout a local area code in the GSM network. Before the number is sent a pre-programmed local area code is added automatically by the Nokia 22.The user can also specify that the terminal changes certain prefixes automati-cally, for example to provide a cost-effective route. The AAC and routing settingscan be modified using the Nokia 22 Configurator Software.