Signaling
Protocol type: Packet oriented
Packet format:
| Name | Description | Length | Presence | Note |
|---|---|---|---|---|
| Primitive | Packet description | 1 | Mandatory | The most significant bit will indicate if the packet is connection related If not set the packet header will contain the connection id field If set the packet will not contain the connection id field |
| Info | Extended info | 1 | Mandatory | Interpreted according to primitive and packet data |
| ConnectionId | Unsigned integer in network byte order | 2 | Conditional | Present only if primitive most significant bit is not set |
| Data | Packet data | 0-n | Optional |
Primitives with code 0-127 are associated with a communication channel and its ID is presen after the Info field. Primitives with code 128-255 are not associated with a channel and Data (if present) follows immediately after the Info field.
Primitive
| Value | Name | Sender | Description | Note | Available in release |
|---|---|---|---|---|---|
| L3Message | Both | Connection related L3 message | The packet carries a connection related L3 message | 1 | |
| 1 | ConnLost | Connection abnormally released | The notifies about connection lost No response is required | 1 | |
| 2 | ConnRelease | YBTS | Request connection release | YBTS requests a connection release No response is required | 1 |
| 3 | StartMedia | YBTS | Request media channel | YBTS requests changing the channel mode to allow traffic On success MediaStarted is notified, on error a MediaError is reported | 1 |
| 4 | StopMedia | YBTS | Request stopping media | YBTS requests media traffic to stop No response is required | 1 |
| 5 | AllocMedia | YBTS | Request reservation of a traffic channel | YBTS requests having a traffic channel allocated In case of error a MediaError is reported | 1 |
| 6 | MediaError | <YBTSPeer> | Notifies about a traffic channel error | This is sent in case of allocation failure or channel mode change failure | 1 |
| 7 | MediaStarted | <YBTSPeer> | Notifies that the traffic channel has started | This is sent to confirm a StartMedia request | 1 |
| 8 | EstablishSAPI | Both | Request or notification for SAPI establishment | This should be used for SAPI 1-3, SAPI 0 is established by default | 1 |
| 9 | PhysicalInfo | <YBTSPeer> | Physical channel information report | Provides information about uplink physical channel | 4 |
| 10 | HandoverRequired | <YBTSPeer> | Outbound handover required | Provides list of candidate cells and MS measured levels | 4 |
| 11 | HandoverAck | <YBTSPeer> | Inbound handover acknowledge | Confirms resource allocation, carries RR HANDOVER COMMAND | 4 |
| ? | StartCiphering | YBTS | Request ciphering start | To be discussed: The message may carry a RR CIPHERING MODE COMMAND | |
| 64 | GprsAttachReq | <YBTSPeer> | GPRS Attach Request from MS | This message is repeated as attach procedure progresses | 4 |
| 65 | GprsAttachLBO | YBTS | Attach Accept with Local Breakout | Attach procedure continues with locally provided connectivity | 4 |
| 66 | GprsAttachOk | YBTS | Attach Accept through core network | Attach procedure continues with data going through the core network | 4 |
| 67 | GprsAttachRej | YBTS | Attach is rejected by network | The connection is closed when this message is sent or received | 4 |
| 68 | GprsIdentityReq | YBTS | The MS is requested to send the IMSI identity | A new GprsAttachReq is expected after receiving IMSI | 4 |
| 69 | GprsAuthRequest | YBTS | The MS is requested to authenticate | A new GprsAttachReq is expected after successful authentication | 4 |
| 70 | GprsDetach | Both | GPRS is being detached either by MS or by network | The connection is closed when this message is sent or received | 4 |
| 71 | PdpActivate | Both | PDP Context creation is requested or acknowledged | The reply parameter indicates a response | 4 |
| 72 | PdpModify | Both | PDP Context modification is requested or acknowledged | The reply parameter indicates a response | 4 |
| 73 | PdpDeactivate | Both | A PDP Context is to be deleted | There is no answer, it is assumed to always succeed | 4 |
| 128 | Handshake | Both | Handshake | This is the first message exchanged on signalling interface. Sent by . Response: Handshake | 1 |
| 129 | RadioReady | <YBTSPeer> | Radio ready notification | This message indicates the radio side is functional | 1 |
| 130 | StartPaging | YBTS | Paging start request | This message request paging. It will transport a mobile identity | 1 |
| 131 | StopPaging | YBTS | Paging stop request | This message request paging. It will transport a mobile identity | 1 |
| 132 | NeighborsList | YBTS | Update the list of neighbor cells | The data holds a list of cells ordered by ARFCN | 4 |
| 133 | HandoverRequest | YBTS | Request inbound handover resources | The Handover Reference must be handled by YBTS | 4 |
| 134 | HandoverReject | <YBTSPeer> | Indicates handover allocation failure | 4 | |
| 135 | Stop | <YBTSPeer> | Application stopping notification | YBTS will stop. It may not restart if a non retryable radio error is received | 5 |
| 255 | Heartbeat | Both | Connection idle heartbeat | The packet don't carry data or connection id field It must be sent on idle connection Interval: ? seconds | 1 |
Info
- Bit 7: Set if message is for SACCH
- Bits 0-2 contains the SAPI
- Bits 0-3: Protocol version. Current: 0
- Bit 7: MSC/SGSN identity. This bit must be the same on both ends of a connection
- Bits 4-6: Reserved, must be 0
- Codes the channel traffic type, 0-3 (0 = Signaling only, 1-3 = GSM voice v…)
- Codes the requested paged channel type (0 = Voice, 1 = SMS, 2 = SS)
- L3 CC Cause code (similar to Q.850)
- Handover reference used to match Ack to Request
- Detach reason flags, bit 3 (0x08) indicates power off
- For a routing area update procedure, the message may also contain a pdps parameter detailing the known active PDP contexts from the point a view of the MS. If the MS doesn’t provide the information, the parameter will arrive as 0xffff
- For a routing area update procedure, the message will also contain a pdps parameter listing active PDP contexts, a llcsapis parameter listing used LLC SAPIs and a tids parameter listing transaction IDs used by the MS for each PDP context
- Stopping reason (Normal/ RadioLost/ InternalError/ RadioExiting/ RadioError)
Data
- Mobile identity: TMSIxxxxxxxxxxxxxxxx (hex digits) or IMSIdddddddddddd dddddddddddddddddd (BCD digits) in identity parameter
- if mobile identity is TMSI, StartPaging will also contain the IMSI in imsi parameter
- Human-readable string describing physical level information
- String: BAND ARFCN1:BSIC1:CELLID1 ARFCN2:BSIC2:CELLID2 …
- String: MY_LEVEL LEVEL1:CELLID1 LEVEL2:CELLID2 …
- Binary RR Handover Command
- List of space separated tag=value parameters
- List of space separated tag=value parameters
Media
Protocol type: Packet oriented
Packet format:
2 bytes connection id: unsigned integer in network byte order
0..n bytes media data
Logging
Protocol type: Packet oriented
Packet format:
| Byte 0 | Debug type | Bytes 1..n | Available in release |
|---|---|---|---|
| 0xff | Output | Text | 1 |
| Bits 6-7: 0 | Debug/Alarm with syslog level set in bits 0-5 Output if log level is not 0..7 | Text | 1 |
| Bits 6-7: 3 | Relay Output | Text + 2 * NULL | 4 |
| Bits 6-7: 2 | Relay Debug with level set in bits 0-3 | Text + 2 * NULL | 4 |
| Bits 6-7: 1 | Relay Alarm with level set in bits 0-3 | Text + 3 * NULL + Component + NULL + Alarm Info | 4 |
Command
Protocol type: Packet oriented
Command: 1..n bytes single line of text, up to 1023 characters
Response: 1..n bytes text, may include \n line separators