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Diffstat (limited to 'doc/manuals/abis/rsl.adoc')
| -rw-r--r-- | doc/manuals/abis/rsl.adoc | 238 |
1 files changed, 233 insertions, 5 deletions
diff --git a/doc/manuals/abis/rsl.adoc b/doc/manuals/abis/rsl.adoc index 331ccb3e..b1b49641 100644 --- a/doc/manuals/abis/rsl.adoc +++ b/doc/manuals/abis/rsl.adoc @@ -7,7 +7,7 @@ grouped by their level of compliance with 3GPP TS 08.58. ==== Messages Compliant With TS 08.58 -Specific limitations apply, see the linked sections. +Specific additions and limitations apply, see the linked sections. .Messages compliant with TS 08.58 [options="header",cols="10%,20%,45%,5%,20%"] @@ -26,9 +26,9 @@ Specific limitations apply, see the linked sections. | 8.3.10 | - | UNIT DATA REQUEST | <- | Received | 8.3.11 | - | UNIT DATA INDICATION | -> | Sent 5+<| *DEDICATED CHANNEL MANAGEMENT MESSAGES* -| 8.4.1 | - | CHANNEL ACTIVATION | <- | Received -| 8.4.2 | - | CHANNEL ACTIVATION ACKNOWLEDGE | -> | Sent -| 8.4.3 | - | CHANNEL ACTIVATION NEGATIVE ACKNOWLEDGE | -> | Sent +| 8.4.1 | <<CHANNEL_ACTIVATION>> | CHANNEL ACTIVATION | <- | Received +| 8.4.2 | <<CHANNEL_ACTIVATION>> | CHANNEL ACTIVATION ACKNOWLEDGE | -> | Sent +| 8.4.3 | <<CHANNEL_ACTIVATION>> | CHANNEL ACTIVATION NEGATIVE ACKNOWLEDGE | -> | Sent | 8.4.4 | - | CONNECTION FAILURE INDICATION | -> | Sent | 8.4.5 | - | DEACTIVATE SACCH | <- | Received | 8.4.6 | - | ENCRYPTION COMMAND | <- | Received @@ -71,6 +71,13 @@ Specific limitations apply, see the linked sections. | <<rsl_dlcx_msg_ack>> | RSL Delete Connection (DLCX) ACK | -> | Sent | <<rsl_dlcx_msg_nack>> | RSL Delete Connection (DLCX) NACK | -> | Sent | <<rsl_dlcx_ind>> | <<rsl_dlcx_ind_msg>> | RSL Delete Connection (DLCX) Indication | -> | Sent +5+<| *IPA style PDCH Management* (<<ipa_style_pdch_mgmt>>) +.3+.| <<pdch_act>> | <<rsl_pdch_act>> | RSL PDCH Activation | <- | Received + | <<rsl_pdch_act_ack>> | RSL PDCH Activation ACK | -> | Sent + | <<rsl_pdch_act_nack>> | RSL PDCH Activation NACK | -> | Sent +.3+.| <<pdch_deact>> | <<rsl_pdch_deact>> | RSL PDCH Deactivation | <- | Received + | <<rsl_pdch_deact_ack>> | RSL PDCH Deactivation ACK | -> | Sent + | <<rsl_pdch_deact_nack>> | RSL PDCH Deactivation NACK | -> | Sent |=== ==== Messages Not Implemented by OsmoBTS @@ -110,6 +117,16 @@ Specific limitations apply, see the linked sections. === Message Limitation Details +[[CHANNEL_ACTIVATION]] + +When used on a timeslot using the non-standard channel combination +'NM_CHANC_OSMO_TCHFull_TCHHalf_PDCH' as configured by OML, the regular +RSL channel activation procedures can not only be used for activation +of circuit-switched channels, but also for activation of a PDCH. + +NOTE:: Do not confuse this with the ip.access style _PDCH ACT_ type +dynamic PDCH protocol employed by nanoBTS devices. + [[MEASUREMENT_RESULT]] ==== Measurement Result @@ -330,6 +347,41 @@ non-acknowledged *RSL Delete Connection (DLCX) Indication* to the BSC. See <<rsl_dlcx_ind_msg>> +[[ipa_style_pdch_mgmt]] +=== IPA style PDCH Management + +When using an IPA-style dynamic TCH/F+PDCH channel type on an +on-air timeslot, there are a couple of non-standard RSL messages used +in order to activate or deactivate this timeslot in PDCH mode. + +When the channel is used as TCH/F, regular circuit-switched activation +is performed, like on any traditional TCH/F. However, the BSC must +make sure to first disable the PDCH on the timeslot, before activating +it as TCH/F. Likewise, any circuit-switched TCH/F on the channel must +be deactivated using standard RSL signalling, before the specific PDCH +related procedures are used to enable the PDCH. + +[[pdch_act]] +==== PDCH Activate + +This procedure is used by the BSC to request the BTS to activate an +IPA-style dynamic TCH/F+PDCH channel in PDCH mode. + +The operation is not supported on any other physical channel type. + +See <<rsl_pdch_act>>, <<rsl_pdch_act_ack>>, <<rsl_pdch_act_nack>> + +[[pdch_deact]] +==== PDCH Deactivate + +This procedure is used by the BSC to request the BTS to deactivate an +active PDCH on any an IPA-style dynamic TCH/F+PDCH channel. + +The operation is not supported on any other physical channel type. + +See <<rsl_pdch_deact>>, <<rsl_pdch_deact_ack>>, <<rsl_pdch_deact_nack>> + + === Message Formats and Contents [[rsl_crcx_msg]] @@ -524,6 +576,110 @@ Channel number. It is sent in response to the *Delete Connection | Cause | 08.58 9.3.26 | M | TLV | >= 3 |=== +[[rsl_pdch_act]] +==== PDCH Activate + +This message is sent by the BSC to request the activation of a PDCH on +a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels + +[[rsl_pdch_act_ack]] +==== PDCH Activate ACK + +This message is sent by the BTS to confirm the successful activation +of a PDCH on a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +| Frame Number | 08.58 9.3.8 | O | TV | 3 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels + +[[rsl_pdch_act_nack]] +==== PDCH Activate NACK + +This message is sent by the BTS to reject the successful activation +of a PDCH on a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +| Cause | 08.58 9.3.26 | M | TLV | >= 3 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels + +[[rsl_pdch_deact]] +==== PDCH Deactivate + +This message is sent by the BSC to request the deactivation of a PDCH +on a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels + +[[rsl_pdch_deact_ack]] +==== PDCH Deactivate ACK + +This message is sent by the BTS to confirm the successful deactivation +of a PDCH on a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels + +[[rsl_pdch_deact_nack]] +==== PDCH Deactivate NACK + +This message is sent by the BTS to reject the deactivation of a PDCH +on a IPA-style dynamic TCH/F+PDCH channel. + +[options="header"] +[cols="30%,25%,15%,15%,15%"] +|=== +| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH +| Message discriminator | 08.58 9.1 | M | V | 1 +| Message type | <<own_msg_types>> | M | V | 1 +| Channel number | 08.58 9.3.1 | M | TV | 2 +| Cause | 08.58 9.3.26 | M | TLV | >= 3 +|=== + +NOTE:: This message is *not* used by Osmocom style dynamic channels === Information Element Codings @@ -547,17 +703,24 @@ indicated in 3GPP TS 08.58 Section 9.1: | 0x77 | Delete Connection (DLCX) | <<rsl_dlcx_msg>> | 0x78 | Delete Connection (DLCX) ACK | <<rsl_dlcx_msg_ack>> | 0x79 | Delete Connection (DLCX) NACK | <<rsl_dlcx_msg_nack>> +| 0x48 | PDCH Activate | <<rsl_pdch_act>> +| 0x49 | PDCH Activate ACK | <<rsl_pdch_act_ack>> +| 0x4a | PDCH Activate NACK | <<rsl_pdch_act_nack>> +| 0x4b | PDCH Deactivate | <<rsl_pdch_deact>> +| 0x4c | PDCH Deactivate ACK | <<rsl_pdch_deact_ack>> +| 0x4d | PDCH Deactivate NACK | <<rsl_pdch_deact_nack>> |=== ==== A-bis/IP specific RSL IEIs The following Information Element Identifiers (IEIs) are used in -addition to those indicated in 3GPP TS 08.58 Section 9.3.1: +addition to those indicated in 3GPP TS 08.58 Section 9.3: .A-bis/IP specific information elements [options="header",cols="10%,50%,40%"] |=== | IEI | Name | This document ยง +| 0x01 | RSL_IE_CHAN_NR | <<RSL_IE_CHAN_NR>> | 0xf0 | RSL_IE_IPAC_REMOTE_IP | <<RSL_IE_IPAC_REMOTE_IP>> | 0xf1 | RSL_IE_IPAC_REMOTE_PORT | <<RSL_IE_IPAC_REMOTE_PORT>> | 0xf3 | RSL_IE_IPAC_LOCAL_PORT | <<RSL_IE_IPAC_LOCAL_PORT>> @@ -568,6 +731,21 @@ addition to those indicated in 3GPP TS 08.58 Section 9.3.1: | 0xfc | RSL_IE_IPAC_RTP_PAYLOAD2 | <<RSL_IE_IPAC_RTP_PAYLOAD2>> |=== +[[RSL_IE_CHAN_NR]] +==== RSL_IE_CHAN_NR + +This information element is coded like 3GPP TS 08.58 Section 9.3.1, +but in addition supports the following extended coding: + +* C5..C1 bits 0b11000 for PDCH type channels + +The TN-Bits are not re-defined in this case but use the same encoding +as specified in TS 08.58 Section 9.3.1. + +NOTE:: The above extension is only valid on an Osmocom-style dynamic +channel, having configured the 'NM_CHANC_IPAC_TCHFull_PDCH' channel +combination by OML. + [[RSL_IE_IPAC_REMOTE_IP]] ==== RSL_IE_IPAC_REMOTE_IP @@ -679,3 +857,53 @@ illustrated by the differences of <<rsl-msc-pri>> and <<rsl-msc-sec>>. Since the secondary TRX has no BCCH, it does not (need to) receive any 'RSL BCCH INFORMATION' messages from the BSC. +[[rsl-dynamic-channels]] +=== Dynamic Channel Combinations + +In the classic data model established by ETSI/3GPP for A-bis, each +timeslot (channel) is configured using a static channel combination by +means of A-bis OML. Particularly in presence of GPRS services, this +is very unflexible and leads to inefficient use of air interface +resources. + +As such, several methods have been implemented to overcome this +limitation. The fundamental operation can be outlined like this: + +* Configuration of a particular _dynamic_ channel combination via OML +* activation of TCH works like on a classic TCH channel combination +* activation of PDCH requires some specific PDCH activation procedure + +There are two variants implemented in the OsmoBTS A-bis dialect: + +==== ip.access style Dynamic Channels + +This method is used when OML uses 'NM_CHANC_IPAC_TCHFull_PDCH' (0x80) +as channel combination for the given time-slot. + +When the ip.access style dynamic channel combination _TCH/F or PDCH_ +is set, the non-standard 'PDCH ACTIVATE' (<<pdch_act>>) and 'PDCH +DEACTIVATE' (<<pdch_deact>>) procedures are used for switching an idle +channel into PDCH mode and back into idle mode. + +.Example for dynamic channel switchover, for ip.access style dynamic timeslots +["mscgen"] +---- +include::dyn_ts_ipa_style.msc[] +---- + +==== Osmocom style Dynamic Channels + +This method is in use when OML uses +'NM_CHANC_OSMO_TCHFull_TCHHalf_PDCH' (0x90) for the given time-slot. + +The activation of PDCH is performed by using the regular 'RSL CHANNEL +ACTIVATE' procedure according to <<CHANNEL_ACTIVATION>>, with the +exception that the 'cbits' part of the ' + +.Example for dynamic channel switchover, for ip.access style dynamic timeslots +["mscgen"] +---- +include::dyn_ts_osmocom_style.msc[] +---- + + |