1、 ETSI TS 125 462 V15.0.0 (2018-07) Universal Mobile Telecommunications System (UMTS); UTRAN Iuant interface: Signalling transport (3GPP TS 25.462 version 15.0.0 Release 15) TECHNICAL SPECIFICATION ETSI ETSI TS 125 462 V15.0.0 (2018-07)13GPP TS 25.462 version 15.0.0 Release 15Reference RTS/TSGR-03254
2、62vf00 Keywords UMTS ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice The present document can b
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7、ut the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media. ETSI 2018. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTMand the ETSI logo are trademarks of ETSI registered for the benefit of its Members. 3GPPTM and LTETMare trademarks of ETSI
8、 registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M logo is protected for the benefit of its Members. GSMand the GSM logo are trademarks registered and owned by the GSM Association. ETSI ETSI TS 125 462 V15.0.0 (2018-07)23GPP TS 25.462 version 15.0.0 Release 15
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13、t document does not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks. Foreword This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP). The present document may refer to technical specifications or
14、 reports using their 3GPP identities, UMTS identities or GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables. The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under http:/webapp.etsi.org/key/queryform.asp. Modal verbs ter
15、minology In the present document “shall“, “shall not“, “should“, “should not“, “may“, “need not“, “will“, “will not“, “can“ and “cannot“ are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). “must“ and “must not“ are NOT allowed
16、in ETSI deliverables except when used in direct citation. ETSI ETSI TS 125 462 V15.0.0 (2018-07)33GPP TS 25.462 version 15.0.0 Release 15Contents Intellectual Property Rights 2g3Foreword . 2g3Modal verbs terminology 2g3Foreword . 5g31 Scope 6g32 References 6g33 Definitions and abbreviations . 6g33.1
17、 Definitions 6g33.2 Abbreviations . 7g34 Iuant data link layer 7g34.1 Invalid receptions . 7g34.2 Frame lengths . 7g34.3 Default address . 7g34.4 Window size . 8g34.5 Message timing 8g34.6 State model . 8g34.7 Device types . 8g34.8 XID negotiation 8g34.8.1 HDLC parameters . 9g34.8.2 Protocol version
18、 9g34.8.3 Address assignment 9g34.8.4 Device scan . 10g34.8.5 Reset device 10g34.9 Link establishment . 10g34.10 Link timeout . 10g3Annex A (informative): HDLC description 11g3A.1 Basic structure 11g3A.2 UNC commands . 12g3A.2.1 Set Normal Response Mode (SNRM) . 12g3A.2.2 Disconnect (DISC) 12g3A.2.3
19、 Unnumbered Acknowledge (UA) . 12g3A.2.4 Disconnected Mode (DM) 12g3A.2.5 Receiver Ready (RR) 12g3A.2.6 Receiver Not Ready (RNR) 12g3A.2.7 Information (I) 12g3A.2.8 Frame Reject (FRMR) 12g3A.3 Option 1 13g3A.4 Option 4 13g3A.5 Option 15.1 . 13g3A.6 Link safety 13g3A.7 Full duplex link 13g3Annex B (i
20、nformative): HDLC parameter negotiation 15g3Annex C (informative): HDLC parameter negotiation example 16g3Annex D (informative): Address assignment example 17g3D.1 Address assignment command 17g3D.2 Address assignment response . 17g3Annex E (informative): Device scan example 19g3Annex F (informative
21、): Change History 21g3ETSI ETSI TS 125 462 V15.0.0 (2018-07)43GPP TS 25.462 version 15.0.0 Release 15History 22g3ETSI ETSI TS 125 462 V15.0.0 (2018-07)53GPP TS 25.462 version 15.0.0 Release 15Foreword This Technical Specification has been produced by the 3rdGeneration Partnership Project (3GPP). The
22、 contents of the present document are subject to continuing work within the TSG and may change following formal TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an identifying change of release date and an increase in version number as
23、follows: Version x.y.z where: x the first digit: 1 presented to TSG for information; 2 presented to TSG for approval; 3 or greater indicates TSG approved document under change control. y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections, updates,
24、etc. z the third digit is incremented when editorial only changes have been incorporated in the document. ETSI ETSI TS 125 462 V15.0.0 (2018-07)63GPP TS 25.462 version 15.0.0 Release 151 Scope The present document specifies the signalling transport related to RETAP and TMAAP signalling to be used ac
25、ross the Iuant interface. The logical Iuant interface is a Node B/eNB internal interface between the implementation specific O - The “U” means Unbalanced operation (master slave operation); - The “N” means Normal response mode (sequence numbers used in data frames); - The “C” means Class. - Options
26、supported; - “1” means use of XID negotiation; - “15.1” means use of start/stop transmission with basic transparency; - Two Way Alternate (TWA) is the HDLC term for half duplex. A.1 Basic structure In unbalanced operation, there is one primary station (master) which controls the bus and a number of
27、secondary stations (slaves) which only are allowed to transmit when the primary station gives them permission to do so. All messages are transmitted as frames with the layout shown in table A.1.1: Table A.1.1: Format of an HDLC frame Flag 1 octet ADDR 1 octet Control 1 octet INFO N octets FCS 2 octe
28、ts Flag 1 octet 0x7E Secondary Station Address Control bits Variable length CRC 0x7E HDLC frames begin and end with a Flag (0x7E) (see A.5 for details). The transmitting station calculates a Frame Check Sequence (CRC16) on all octets which follow the starting flag but not including the FCS octets. T
29、he checksum is transmitted as FCS in little endian order and is followed by the closing flag. The receiving station calculates the checksum on all octets between the flags. When it finds the closing flag, it compares the checksum to 0xF0B8. If it is a match, the HDLC frame is processed. The address
30、field contains the HDLC address of the secondary station. If the primary station sends the message, it is called a command and the address field contains the address of the secondary station as destination. If the secondary station sends the message, it is called a response and the address field con
31、tains the address of the secondary station as source. Secondary stations cannot communicate directly to each other. The control field defines one of three frame types: - I frames contain data as well as a send and receive counter; - S frames contain a receive counter; - U frames contain unnumbered c
32、ommands. The INFO field is only present in I frames and XID frames. The INFO field in an I frame contains the layer 7 payload. ETSI ETSI TS 125 462 V15.0.0 (2018-07)123GPP TS 25.462 version 15.0.0 Release 15A.2 UNC commands According to 6.6.2.1 in ISO/IEC 13239 2 the following commands in shall be s
33、upported in UNC mode: Table A.2.1: Commands supported in UNC mode Commands (Primary Station) Responses (Secondary Station) Frame type I Frame type I Frame type RR Frame type RR Frame type RNR Frame type RNR Frame type SNRM Frame type UA Frame type DISC Frame type DM Frame ty FRMRA.2.1 Set Normal Res
34、ponse Mode (SNRM) This command is used to set the secondary station in connected mode and reset its sequence number variables. A.2.2 Disconnect (DISC) This command is used to terminate the connection. A.2.3 Unnumbered Acknowledge (UA) This response is used to confirm that the secondary station recei
35、ved and acted on an SNRM or DISC command. A.2.4 Disconnected Mode (DM) This response is used to inform the primary station that the secondary station is disconnected. A.2.5 Receiver Ready (RR) This command and response is used to inform the opposite station (primary or secondary) that the transmitti
36、ng station has empty buffers, i.e. is ready to receive an I frame. This aspect is used for flow control. It also contains the sequence number of the next frame the transmitting station expects to see. This works both as an ACK and a NAK depending on the value. A.2.6 Receiver Not Ready (RNR) Just lik
37、e RR, except it informs the opposite station that the transmitting station does not have empty buffers, i.e. that it is not ready to receive an I frame. This aspect is used for flow control. A.2.7 Information (I) This command and response is used to transfer a block of data together with its sequenc
38、e number. The command also includes the sequence number of the next frame the transmitting station expects to see. This way, it works as an RR. Like RR, it enables transmission of I frames from the opposite side. A.2.8 Frame Reject (FRMR) This response is used to indicate an error condition. The two
39、 most likely error conditions are: - Invalid command; - Sequence number problem. The latter is used when the primary station has requested retransmission of a sequence number which it has already acknowledged. ETSI ETSI TS 125 462 V15.0.0 (2018-07)133GPP TS 25.462 version 15.0.0 Release 15A.3 Option
40、 1 Option 1 means the addition of the XID command/response, which is used for parameter negotiation. A.4 Option 4 Option 4 means the addition of the UI command/response, which is used to transfer information without changing the sequence numbers used by I frames. A.5 Option 15.1 Option 15.1 means th
41、at the serial link is not synchronous and start/stop flags are used (asynchronous serial link). The flags are coded as 0x7E and basic transparency is used. This means that all octets between the flags are part of the frame and shall not be transmitted as 0x7E. Since the frame may contain 0x7E, basic
42、 transparency is used, which means that 0x7E is transmitted as 0x7D 0x5E and 0x7D is transmitted as 0x7D 0x5D. The receiving station converts back on reception. All checksum calculations are done on unconverted data. A.6 Link safety HDLC provides the upper layer with a safe link between two stations
43、. Unless excessive frame lengths are used, the CRC16 checksum provides excellent protection against transmission errors. At worst, 105of the bit errors will not be detected. The likelihood of an undetected error in a frame can be calculated by multiplying 105with the Bit Error Rate (at least 109for
44、a reasonable link) and the frame length. The sequence numbers provide protection against: - Message duplication; - Message deletion; - Message re-ordering. Without sequence numbers, the protection is only given by a checksum and some sort of ACK. If the original message is lost, there will be no ACK
45、 and a timeout will cause retransmission which solves the problem. If the original message is not lost, but the ACK is lost, the same timeout will cause a retransmission. With sequence numbers, the message is retransmitted, but the receiving station sees that the sequence number is the same, i.e. th
46、at the message is a retransmission, and throws it away without processing it further. It does send an ACK which informs the transmitting station that the message got through. A.7 Full duplex link The upper layer sees the HDLC link as a full duplex link, although the actual transmissions on layer 1 a
47、re half duplex. The reason for this is that the upper layer is not aware of any restrictions on transmissions or receptions between layer 2 and layer 1 or between the stations. Whenever the upper layer wants to transmit, it places a message on the queue to layer 2. The message will not be transmitte
48、d until the primary station does a poll. NOTE: This applies to both the primary and the secondary station. The same applies to reception. The upper layer will either be told by layer 2 when a message has arrived, or it will periodically check to see if a message has arrived at layer 2. Neither of th
49、ese two methods will in any way influence the reception of a message. That only depends on when the primary does a poll. NOTE This still applies to both the primary and the secondary station. ETSI ETSI TS 125 462 V15.0.0 (2018-07)143GPP TS 25.462 version 15.0.0 Release 15A poll is a command frame from the primary station where the P/F (Poll/Final) bit in the control field is set to 1. This informs the secondary that it is allowed to transmit response frames. U frames set the P/F bit, which means that they are polls. However, since the U frames used in UNC 1,4 require a sp
