Product manual

System description, DECT air interface
Technical Product Manual - DCT1800-GAP
TD 92093 (1/LZBNB 103 108 R4D) / 2006-03-09/ Ver.C
© 2006
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6.11.3 Authentication of portable part
This paragraph describes the sequence in which procedures are executed to support the feature
‘Authentication of portable part’ (see figure
41). It is implemented by a mandatory procedure for the
Portable radio Termination (PT) and the Fixed radio Termination (FT) as shown in table 7.
The authentication of a portable part can be initiated by the fixed part either when the portable part
requests for a call set-up or when there is an incoming call to the portable part. Authentication can
also be requested during a call (in-call authentication).
The ‘Authentication of portable radio termination’ procedure consists of the ‘Authentication request’
and the ‘Authentication reply’ message.
Authentication request
The ‘Authentication request’ message contains the following information elements:
• Authentication algorithm type: specifies that the DECT standard authentication algorithm 1 must
be used.
• Authentication key type: specifies that the UAK must be used.
• RAND: specifies that random number RAND-F must be used in authentication algorithm. RAND-
F is issued by fixed radio termination.
• RS: the number to be used together with RAND-F and the authentication key to calculate the
authentication response (RES1).
Authentication reply
The ‘Authentication reply’ message contains the following information elements:
• RES1: authentication response calculated in PT
Process description of authentication of portable part
The authentication protocol is graphically represented in figures 41 and 42 and follows the following
steps:
1. The fixed part sends an authentication request message to the portable part. The message
contains the random numbers RAND-F and RS. It also identifies the authentication algorithm and
the authentication key to be used by the portable part.
2. The fixed part computes the authentication key K based on the selected authentication process
(B1) and UAK (stored during subscription in portable part) (see paragraph
6.9). Based on K, RS,
RAND-F the fixed part computes XRES1 based on authentication algorithms A11 and A12.
3. The portable part computes the authentication key K based on the selected authentication process
(B1) and UAK (stored during subscription in portable part).
4. Based on K, RAND-F, RS the portable part computes RES1 based on authentication algorithms
A11 and A12.
Feature Procedure
Status
PT FT
Authentication of Portable Part (PP) M M
Authentication of portable radio termination M M
Table 7 Mandatory procedures to support the ‘Authentication of portable part’ feature