Abis Interface » History » Version 3
laforge, 02/19/2016 10:47 PM
add reference to 04.08
1 | 1 | laforge | The Abis protocol is the protocol spoken between the BSC (Base Station Controller) and BTS (Base Transceiver Station). |
---|---|---|---|
2 | |||
3 | It is specified in the following GSM standards: |
||
4 | * 3GPP TS 08.51 : BSC-BTS Interface General Aspects |
||
5 | * 3GPP TS 08.52 : BSC-BTS Interface principles |
||
6 | * 3GPP TS 08.54 : BSC-BTS Layer 1: Structure of Physical Circuits |
||
7 | * 3GPP TS 08.56 : BSC-BTS Layer 2: Specification |
||
8 | * 3GPP TS 08.58 : BSC-BTS Layer 3: Specification |
||
9 | * This contains the specification of the RSL (Radio Signalling Link) on SAPI 0 |
||
10 | * 3GPP TS 21.21 : Network Management procedures and messages on the A-bis interface |
||
11 | * This basically describes the OML (Organization and Maintenance Layer) on SAPI 62 |
||
12 | 3 | laforge | * 3GPP TS 04.08 : Mobile radio interface layer 3 specification |
13 | * Description of the on-air (BTS-MS) layer 3, as carried in "DATA INDICATION" and other Abis messageS |
||
14 | 1 | laforge | |
15 | == RSL (Radio Signalling Link) == |
||
16 | |||
17 | The RSL contains two types of messages |
||
18 | 2 | laforge | * transparent messages (forwarded by BTS without interpretation or changes). T-bit in message discriminator == 1 |
19 | 1 | laforge | * non-transparent messages (messages sent between BSC and BTS) |
20 | |||
21 | furthermore, the messages are grouped into four main groups (see below). |
||
22 | 2 | laforge | |
23 | All messages are transmitted using LAPD I frames, except for MEASUREMENT RESULT (UI). T-bit in message discriminator == 0 |
||
24 | 1 | laforge | |
25 | === Radio Link Layer Management === |
||
26 | 2 | laforge | |
27 | All messsages are prefixed by 6-byte header: |
||
28 | * 1 byte message discriminator |
||
29 | * 1 byte message type |
||
30 | * 2 byte channel number |
||
31 | * 2 byte link identifier |
||
32 | |||
33 | The actual message types are: |
||
34 | 1 | laforge | * EST_IND: Link establishment indication (BTS->BSC) |
35 | * EST_REQ: Link establishment request (BSC->BTS) |
||
36 | * EST_CONF: Link establishment Confirmation (BTS->BSC) |
||
37 | * REL_IND: Link release indication (BTS->BSC) |
||
38 | * REL_REQ: Link release request (BSC->BTS) |
||
39 | * REL_CONF: Link release confirmation (BTS->BSC) |
||
40 | * DATA_REQ: Transmission of transparent L3 message in acknowledged mode (BSC->BTS) |
||
41 | * DATA_IND: Reception of transparent L3 message in acknowledged mode (BTS->BSC) |
||
42 | * UNIT_DATA_REQ: Transmission of transparent L3 message in unacknowledged mode (BSC->BTS) |
||
43 | * UNIT_DATA_IND: Reception of transparent L3 message in unacknowledged mode (BTS->BSC) |
||
44 | * ERROR_IND: Link error indication (BTS->BSC) |
||
45 | |||
46 | === Dedicated Channel Management === |
||
47 | 2 | laforge | |
48 | All messsages are prefixed by 4-byte header: |
||
49 | * 1 byte message discriminator |
||
50 | * 1 byte message type |
||
51 | * 2 byte channel number |
||
52 | |||
53 | The actual message types are: |
||
54 | 1 | laforge | * CHAN_ACTIV: Channel activation (BSC->BTS) |
55 | * CHAN_ACTIV_ACK: Channel activation acknowledgement (BTS->BSC) |
||
56 | * CHAN_ACTIV_NACK: Channel activation not acknowledged (BTS->BSC) |
||
57 | * MODE_MODIFY: Channel mode modify (BSC->BTS) |
||
58 | * MODE_MODIFY_ACK: Channel mode modify acknowledgement (BTS->BSC) |
||
59 | * MODE_MODIFY_NACK: Channel mode modify not acknowledged (BTS->BSC) |
||
60 | * HANDO_DET: Handover detection (BTS->BSC) |
||
61 | * ENCR_CMD: Start of Encryption (BSC->BTS) |
||
62 | * MEAS_RES: Measurement result (BTS->BSC) |
||
63 | * PREPROC_CONFIGURE: Configure pre-processed measurement report (BSC->BTS) |
||
64 | * PREPROC_MEAS_RES: Preprocessed measurement report (BTS->BSC) |
||
65 | * DEACT_SACCH: Deactivate SACCH (BSC->BTS) |
||
66 | * RF_CHAN_REL: Radio channel release (BSC->BTS) |
||
67 | * RF_CHAN_REL_ACK: Radio channel release ack (BTS->BSC) |
||
68 | * MS_POWER_CONTROL: MS power control (BSC->BTS) |
||
69 | * BS_POWER_CONTROL: Transmission power control (BSC->BTS) |
||
70 | * CONN_FAIL_IND: Connection failure indication (BTS->BSC) |
||
71 | * PHYS_CONTEXT_REQ: Physical context request (BSC->BTS) |
||
72 | * PHYS_CONTEXT_CONF: Physical context confirmation (BTS->BSC) |
||
73 | * SACCH_INFO_MODIFY: SACCH nformation modify (BSC->BTS) |
||
74 | * TALKER_DET: Talker detection (BTS->BSC) |
||
75 | * LISTENER_DET: Listener detection (BTS->BSC) |
||
76 | * REMOTE_CODEC_CONF: Remote codec configuration (BTS->BSC) |
||
77 | * RTD_REP: Round Trip Delay Report (BTS->BSC) |
||
78 | * PRE_HANDO_NOTIF: Pre-handover warning (BSC->BTS) |
||
79 | * CODEC_MOD_REQ: Multirate codec configuration change request (BSC->BTS) |
||
80 | * CODEC_MOD_ACK: Multirate codec configuration change acknowledge (BTS->BSC) |
||
81 | * CODEC_MOD_PERF: Multirate codec change performed (BTS->BSC) |
||
82 | * TFO_REPORT: TFO Report / AMR (BTS->BSC) |
||
83 | * TFO_MODIFICATION_REQ: TFO Modification Request (BSC->BTS) |
||
84 | |||
85 | === Common Channel Management === |
||
86 | 2 | laforge | |
87 | All messsages are prefixed by 4-byte header: |
||
88 | * 1 byte message discriminator |
||
89 | * 1 byte message type |
||
90 | * 2 byte channel number |
||
91 | |||
92 | The actual message types are: |
||
93 | 1 | laforge | * CHAN_RQS: Channel request by MS (BTS->BSC) |
94 | * PAG_CMD: Paging command (BSC->BTS) |
||
95 | * DELETE_IND: Delete indication (BTS->BSC) |
||
96 | * CCCH_LOAD_IND: CCCH load indication (BTS->BSC) |
||
97 | * BCCH_INFO: Broadcast information modify (BSC->BTS) |
||
98 | * SMS_BROADCAST_REQ: Short Message Cell Broadcast (BSC->BTS) |
||
99 | * SMS_BROADCAST_CMD: Short Message Cell Broadcast (BSC->BTS) |
||
100 | * IMM_ASS_CMD: Immediate Assign command (BSC->BTS) |
||
101 | * NOTIF_CMD: Notification (BSC->BTS) |
||
102 | |||
103 | === TRX Management === |
||
104 | 2 | laforge | All messsages are prefixed by 2-byte header: |
105 | * 1 byte message discriminator |
||
106 | * 1 byte message type |
||
107 | |||
108 | The actual message types are: |
||
109 | 1 | laforge | * RF_RES_IND: Radio resource indication (BTS->BSC) |
110 | * SACCH_FILL: SACCH filling information modify (BSC->BTS) |
||
111 | * OVERLOAD: Flow control (BTS->BSC) |
||
112 | * ERROR_REPORT: Error reporting (BTS->BSC) |