Alternate Line Service

The Alternate Line Service (ALS; . Engl about for AC line service) provides on the basis of CPHS specification, an extension of the GSM standard, a second phone number for outgoing and incoming calls. These can be selected via the mobile phone menu.

Support

Currently, most current devices from all manufacturers support this service. Whether the network to support Alternate Line Service, the SIM card is sharing the terminal via an entry in the Customer Service Profile (CSP ) with.

In Germany, only E-Plus offers this service as a so-called Private Line. The separation of private and business conversations using in First and Second -Line (first and second number) split bills is possible.

In most devices the two lines separate acoustic signaling and call forwarding can be assigned.

In Austria ALS is by the network operator A1 as Xtraline as well as by the operator One / orange as Numbering Plan (formerly One 2 switch) offered.

In Switzerland, the SIM card of the network operator Orange are pre-configured for the ALS service, but an activation of this service is not possible here.

Non -standard implementation and problems with E -Plus simcards

According to CPHS specifications is on the GSM SIM card in a special reserved section, the Customer Service Profile (CSP ) that is stored ALS information. According to this specification should be deposited in the box 6F15 SIM card in the Service Group Code 0x06, the value 0x80, which is then detected and interpreted by the mobile phone so that the necessary menus are displayed on the second line. However, E -Plus SIM cards have the value 0x55, which is interpreted only by Siemens mobile phones as ALS activation in this field. Therefore, the use of E-Plus Private Line only with Siemens phones is possible. Furthermore, can be with some Nokia phones ALS menus using CSP - override enable some Motorola phones display these menus anyway regardless of the SIM card, thus also the use of the service may be possible. Devices with UIQ 3.0 and newer Nokia phones recognize the E-Plus SIM cards correctly and therefore support the service with E -Plus SIM cards. For some devices with Windows Mobile Version 6.1 and the menus using the software can enable Advanced Configuration Tool by Julien Schapman.

With AS - enabled phones from other manufacturers, however, the use of E -Plus Private Line is not possible due to the aforementioned misconfiguration.

Alternative implementation of the second number in Vodafone ( D), O2 (D ) and T- Mobile ( D)

Vodafone, O2 and T -Mobile offer in Germany with Duobill, Dua Line or Twin Bill similar services, but not the AS standard is used, but two distinct SIM card information on a special SIM card, it will be stored, in principle, the switching between the lines is similar to the dual- SIM adapters on the pin number or a SIM Toolkit menu item.

AS vs. alternative implementation

Both solutions offer both advantages and disadvantages:

The ALS solution is technically elegant, so a line choice is for outgoing calls without much effort via context menu possible, and incoming calls can be signaled with different ring tones depending on the line. Disadvantages of this solution are that on the second line no SMS or data transmission is possible is still not possible international roaming to the second line.

The used by T -Mobile and Vodafone solution is technically less elegant, two SIM cards it will only quasi deposited on a map. To change the direction the phone must be switched off and on again at Vodafone. The selection of the active number is when you turn on the input of different PINs. At T -Mobile, a mobile phone menu from which there exists the number can be changed - with this provider you see on the phone screen then what number is active. Mutual forwarding number ( for SMS) are automatically set. Call forwarding are set by the non- each active line on the active line - For Vodafone, however, must - to be accessible on both numbers at the same time.

The signaling of the line for incoming calls using different ring tones is not possible for both parties.

Benefits are virtually unlimited functions of the second line, since it is basically a second SIM card, and SMS and data transfers as well as international roaming on the second line are thus possible.