Huawei MU509 At Command Interface Specification page 90

HUAWEI MU509 HSDPA LGA Module
AT Command Interface Specification
Bit7...bit4
1111
<VP>: indicates the validity period, which starts from the message being received by
the SC. If VPF=00, this field is lacking. The duration is expressed as follows:
Table 6-12 The description of <VP>
VP value
0 to 143
144 to 167
168 to 196
197 to 255
<UDL>: length of user data. The value of UDL depends on the specific coding mode.

In case of default 7-bit coding, it indicates there are a total of how many septets.

In case of 8bit coding, it indicates there are a total of how many Octets.

In case of UCS2 coding, UDL indicates there are a total of how many Octets.

In case of compressed 7-bit or 8bit or UCS2 coding, UDL indicates there are a
total of how many Octets after compression.
For the compressed message codes, the data length of <UD> should not be more
than 160septets; for the message of uncompressed codes, the <UD> length should
not be more than 140Octets.
<UD>: user data. The data validity depends on the parameter UDL.
Issue 04 (2013-01-28)
Data coding/message
class
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Short Message Service Commands
Bit3.....bit0
Bit2 Reserved. The value is 0.
Bit2 Coding mode of message. The values are
as follows:
0: GSM 7 bit default code
1: 8bit data
Bit1 bit0 message type indication
0 0 : Class 0, providing display and reply
to the SC that the message is received but not
stored.
0 1 : Class 1, stored to the NV (or SIM
card if the NV is full)
1 0 : Class 2, for use of SIM only. After
the message is stored, the storage state will be
replied to the SC. If the SIM card is full, the SC
failure and the reasons will be reported.
1 1 : Class 3, stored to the TE. When the
MS receives the message, but has not
transmitted it to the TE, it will give a response
to the SC.
Description
(VP + 1) x 5 minutes
12 hours + ((VP–143) x 30 minutes)
(VP–166) x 1 day
(VP–192) x 1 week
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