Aastra SIP-DECT Installation And Administration Manual page 5

Installation, Administration and Maintenance
GAP
Aastra Telecom
•
The standard (ETS 300 175) essentially specifies the
air interface, known as the radio interface. Voice and
data can both be transmitted via this interface.
•
Its technical key characteristics for Europe are:
•
Frequency range: approx. 1.880 – 1.900 GHz
(approximately 20 MHz bandwidth)
•
10 carrier frequencies (1.728 MHz spacing) with 12
time slots each)
•
Doubling the number of time slots (to 24) using the
TDMA process
•
Net data rate per channel of 32 kbps
(for voice transmission using ADPCM)
•
Voice coding using the ADPCM method
Its technical key characteristics for North American are:
•
Frequency range: approx. 1.920 – 1.930 GHz
(approximately 10 MHz bandwidth)
•
5 carrier frequencies (1.728 MHz spacing) with 12
time slots each)
•
Doubling the number of time slots (to 24) using the
TDMA process
•
Net data rate per channel of 32 kbps
(for voice transmission using ADPCM)
•
Voice coding using the ADPCM method
Generic Access Profile
•
GAP is the abbreviation for Generic Access Profile
•
The GAP standard (ETS 300 444) is based on the
same technology as DECT, but is limited to the most
important basic features. This standard was created in
order to allow telephones of different vendors to be
used on any type of DECT system. It thus represents
the smallest common denominator of all manufacturer-
specific variants of the DECT standard.
•
An important limitation in the GAP standard is that
external handover is not possible. For this reason
connection handover is used, which is supported by
GAP terminals.
•
The operation of GAP-capable telephones is
comparable to that of analogue terminals. For
example, features can be called up via '*' and '#'
procedures.
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