Product manual

System description, DECT air interface

Technical Product Manual - DCT1800-GAP

TD 92093 (1/LZBNB 103 108 R4D) / 2006-03-09/ Ver.C

If K is derived from UAK and an UPI then in the portable part the UAK and the manually entered UPI

are both associated with either an IPUI or an IPUI/PARK pair.

Fig. 37 Derivation of K from UAK and UPI

6.9.3 Authentication Code (AC)

The AC is used to derive K when authentication of the portable part or authentication of an fixed part

service is applied. It is usually a short value (e.g. 16 to 32 bits). The AC may be stored in non-volatile

memory within the portable part or it may be manually entered by the user when required for an

authentication service. This depends upon the application.

There is no conceptual difference between UAK and an AC. AC is intended to be used only for those

applications which require a temporary or short term key for the portable part or fixed part

authentication. For all other applications a UAK is more appropriate.

If K is derived from UAK, then in the portable part the UAK is associated with either an IPUI or an

IPUI/PARK pair.

Fig. 38 Derivation of K from AC

6.10 Authentication algorithms

Another important part of the security services is the authentication algorithm. The following

authentication algorithms can be used:

• DECT standard authentication algorithm 1 (DSAA)

• GSM authentication algorithm

• Proprietary algorithm

These algorithm are only available on a restricted basis (only for the party that needs them, for instance,

manufacturers of DECT equipment).

6.11 Detailed feature description

The paragraphs below give a detailed explanation of some of the mandatory GAP features. DECT

describes all the possible messages and information elements that can exist in a DECT system. GAP

not only specifies which features are mandatory but also which mandatory/optional procedures and

information elements must be implemented in the Fixed radio Termination (FT) and the Portable radio

Termination (PT). To avoid describing all the possible procedures, messages and information elements

(it makes the description unnecessary long without adding any conceptual knowledge) only the

procedures, messages and information elements mandatory in GAP will be described.

UAK

B2 process

UPI

023

B1 process

024