8 General message format and information elements coding
24.2443GPPRelease 17Stage 3TSWireless LAN control plane protocol for trusted WLAN access to EPC
8.1 General
The least significant bit of a field is represented by the lowest numbered bit of the highest numbered octet of the field. When the field extends over more than one octet, the order of bit values progressively decreases as the octet number increases.
Figure 8.1.1 shows an example of a field where the most significant bit of the field is marked MSB and the least significant bit of the field is marked LSB.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
|
MSB |
x |
x |
x |
x |
x |
x |
x |
octet 1 |
|
x |
x |
x |
x |
x |
x |
x |
x |
|
|
x |
x |
x |
x |
x |
x |
x |
LSB |
octet N |
Figure 8.1.1: Example of bit ordering of a field
Within the protocols defined in the present document, the WLCP message consists of the following parts:
a) Message type;
b) Procedure transaction identity;
c) other information elements, as required.
The organization of a message is illustrated in the example shown in figure 8.1.2.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
|
Message type |
octet 1 |
|||||||
|
Procedure transaction identity |
octet 2 |
|||||||
|
octet 3 |
||||||||
|
Other information elements as required |
||||||||
|
octet n |
||||||||
Figure 8.1.2: General message organization example for a WLCP message
Unless specified otherwise in the message descriptions of clause 7, a particular information element shall not be present more than once in a given message.
8.2 Message type
The message type octet is the first octet in a WLCP message. Table 8.2.1 defines the value part of the message type IE used in the WLCP protocol. Bit 6 to 7 are coded as "01" indicating it is a WLCP message.
Table 8.2.1: Message types for WLCP
|
Bits |
|||||||||
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
||
|
1 |
0 |
– |
– |
– |
– |
– |
– |
WLCP messages |
|
|
1 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
PDN connectivity request |
|
|
1 |
0 |
0 |
0 |
0 |
0 |
1 |
0 |
PDN connectivity accept |
|
|
1 1 |
0 0 |
0 0 |
0 0 |
0 0 |
0 1 |
1 0 |
1 0 |
PDN connectivity reject PDN connectivity complete |
|
|
1 |
0 |
0 |
0 |
0 |
1 |
0 |
1 |
PDN disconnect request |
|
|
1 |
0 |
0 |
0 |
0 |
1 |
1 |
0 |
PDN disconnect accept |
|
|
1 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
PDN disconnect reject |
|
|
1 |
0 |
0 |
0 |
1 |
0 |
0 |
0 |
PDN modification request |
|
|
1 |
0 |
0 |
0 |
1 |
0 |
0 |
1 |
PDN modification accept |
|
|
1 |
0 |
0 |
0 |
1 |
0 |
1 |
0 |
PDN modification reject |
|
|
1 |
0 |
0 |
0 |
1 |
0 |
1 |
1 |
PDN modification indication |
|
|
1 |
0 |
0 |
1 |
0 |
0 |
0 |
1 |
WLCP bearer setup request |
|
|
1 |
0 |
0 |
1 |
0 |
0 |
1 |
0 |
WLCP bearer setup accept |
|
|
1 |
0 |
0 |
1 |
0 |
0 |
1 |
1 |
WLCP bearer setup reject |
|
|
1 |
0 |
0 |
1 |
0 |
1 |
0 |
1 |
WLCP bearer modify request |
|
|
1 |
0 |
0 |
1 |
0 |
1 |
1 |
0 |
WLCP bearer modify accept |
|
|
1 |
0 |
0 |
1 |
0 |
1 |
1 |
1 |
WLCP bearer modify reject |
|
|
1 |
0 |
0 |
1 |
1 |
0 |
0 |
1 |
WLCP bearer release request |
|
|
1 |
0 |
0 |
1 |
1 |
0 |
1 |
0 |
WLCP bearer release accept |
|
|
1 |
0 |
0 |
1 |
1 |
0 |
1 |
1 |
WLCP bearer release reject |
|
|
1 |
0 |
1 |
0 |
1 |
0 |
0 |
0 |
Status |
|
8.3 Procedure transaction identity
The procedure transaction identity (PTI) octet is the second octet in a WLCP message. The PTI allows distinguishing up to 254 different bi-directional messages flows for a given message type. Such a message flow is called a transaction. The procedure transaction identity is released when the procedure is completed. Table 8.3.1 defines the value part of the Procedure transaction identity IE used in the WLCP.
Table 8.3.1: Procedure transaction identity
|
Bits |
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|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
||
|
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
No procedure transaction identity assigned |
|
|
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
\ |
|
|
to |
} Procedure transaction identity value |
||||||||
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
0 |
/ |
|
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
Reserved |
|
|
In this version of the protocol the sending entity shall not set the PTI to the value 0. Any entity receiving a request with a PTI set to the value 0 shall consider that as a syntactical error (see subclause 6.5.1). |
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8.4 Request type
See subclause 10.5.6.17 in 3GPP TS 24.008 [4].
8.5 PDN type
See subclause 9.9.4.10 in 3GPP TS 24.301 [5].
8.6 Access point name
See subclause 10.5.6.1 in 3GPP TS 24.008 [4].
8.7 Protocol configuration options
See subclause 10.5.6.3 in 3GPP TS 24.008 [4].
8.8 PDN address
See subclause 9.9.4.9 in 3GPP TS 24.301 [5].
8.9 PDN connection ID
The purpose of the PDN connection ID is to identify the PDN connection between the UE and the TWAG.
The PDN connection ID information element is coded as shown in figure 8.9.1 and table 8.9.1.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
||||
|
PDN connection ID IEI |
octet 1 |
||||||||||
|
0 |
0 |
0 |
0 |
PDN connection ID |
octet 2 |
||||||
|
Spare |
value |
||||||||||
Figure 8.9.1: PDN connection ID information element
Table 8.9.1: PDN connection ID information element
|
PDN connection ID (bits 1-4) |
||||
|
3 |
2 |
1 |
0 |
|
|
0 |
0 |
0 |
0 |
|
|
to |
Reserved |
|||
|
0 |
1 |
0 |
0 |
|
|
0 |
1 |
0 |
1 |
PDN connection ID value 5 |
|
0 |
1 |
1 |
0 |
PDN connection ID value 6 |
|
0 |
1 |
1 |
1 |
PDN connection ID value 7 |
|
1 |
0 |
0 |
0 |
PDN connection ID value 8 |
|
1 |
0 |
0 |
1 |
PDN connection ID value 9 |
|
1 |
0 |
1 |
0 |
PDN connection ID value 10 |
|
1 |
0 |
1 |
1 |
PDN connection ID value 11 |
|
1 |
1 |
0 |
0 |
PDN connection ID value 12 |
|
1 |
1 |
0 |
1 |
PDN connection ID value 13 |
|
1 |
1 |
1 |
0 |
PDN connection ID value 14 |
|
1 |
1 |
1 |
1 |
PDN connection ID value 15 |
8.10 User plane connection ID
The purpose of the user plane connection ID is to identify the user plane for
– one PDN connection between the UE and the TWAG when multiple WLCP bearers are not supported; or
– the WLCP bearer of the PDN connection between the UE and TWAG when multiple WLCP bearers are supported.
The user plane connection ID value is the MAC address of the TWAG with a length of 6 octets. The MAC address is defined in subclause 8 of IEEE Std 802 [6].
The user plane connection ID information element is coded as shown in figure 8.10.1.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
|
User plane connection ID IEI |
octet 1 |
|||||||
|
User plane connection ID value |
octet 2 |
|||||||
|
octet 7 |
||||||||
Figure 8.10.1: User plane connection ID information element
8.11 Cause
See subclause 9.9.4.4 in 3GPP TS 24.301 [5].
8.12 GPRS timer 3
See subclause 10.5.7.4a in 3GPP TS 24.008 [4].
8.13 NBIFOM container
See subclause 10.5.6.21 in 3GPP TS 24.008 [4].
8.14 UE N3G capability
The purpose of the UE N3G capability information element is to provide the network with information concerning aspects of the UE capabilities related to trusted non-3GPP access. The contents might affect the manner in which the network handles the operation of the UE.
The UE N3G capability information element is coded as shown in figure 8.14.1 and table 8.14.1.
The UE N3G capability is a type 1 information element.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
|
UE N3G capability IEI |
0 spare |
0 spare |
0 spare |
MBCI value |
octet 1 |
|||
Figure 8.14.1: UE N3G capability information element
Table 8.14.1: UE N3G capability information element
|
MBCI (Multiple bearer capability indicator) |
||||
|
0 |
Multiple WLCP bearers not supported |
|||
|
1 |
Multiple WLCP bearers supported |
|||
8.15 WLCP bearer identity
The purpose of the WLCP bearer identity is to identify the WLCP bearer (default or dedicated) with which one or more packet filters specified in a traffic flow aggregate are associated.
The WLCP bearer identity information element is coded as shown in figure 8.15.1 and table 8.15.1.
The WLCP bearer identity is a type 1 information element.
|
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
|
|
WLCP bearer identity IEI |
WLCP bearer identity value |
octet 1 |
||||||
Figure 8.15.1: WLCP bearer identity information element
Table 8.15.1: WLCP bearer identity information element
|
WLCP bearer identity (bits 0-3) |
||||
|
0 |
0 |
0 |
0 |
|
|
to |
Reserved |
|||
|
0 |
1 |
0 |
0 |
|
|
0 |
1 |
0 |
1 |
WLCP bearer identity value 5 |
|
0 |
1 |
1 |
0 |
WLCP bearer identity value 6 |
|
0 |
1 |
1 |
1 |
WLCP bearer identity value 7 |
|
1 |
0 |
0 |
0 |
WLCP bearer identity value 8 |
|
1 |
0 |
0 |
1 |
WLCP bearer identity value 9 |
|
1 |
0 |
1 |
0 |
WLCP bearer identity value 10 |
|
1 |
0 |
1 |
1 |
WLCP bearer identity value 11 |
|
1 |
1 |
0 |
0 |
WLCP bearer identity value 12 |
|
1 |
1 |
0 |
1 |
WLCP bearer identity value 13 |
|
1 |
1 |
1 |
0 |
WLCP bearer identity value 14 |
|
1 |
1 |
1 |
1 |
WLCP bearer identity value 15 |
8.16 EPS quality of service
See subclause 9.9.4.3 in 3GPP TS 24.301 [5].
8.17 Traffic flow template
See subclause 10.5.6.12 in 3GPP TS 24.008 [4].
8.18 Spare half octet
See subclause 9.9.2.9 in 3GPP TS 24.301 [5].
8.19 APN aggregate maximum bit rate
See subclause 9.9.4.2 in 3GPP TS 24.301 [5].