| [[smscb]] |
| == SMSCB (Cell Broadcast) |
| |
| OsmoBSC supports SMS Cell Broadcast (SMSCB) services (CBS). This |
| includes the CBSP protocol to interact with a CBC (Cell Broadcast |
| Centre) such as OsmoCBC, as well as the scheduling of SMSCB messages on |
| both the BASIC and EXTENDED CBCH and transmission of related RSL |
| messages to the attached BTS. |
| |
| More high-level information can be found at |
| https://en.wikipedia.org/wiki/Cell_Broadcast and the related |
| specification is <<3gpp-ts-23-041>>. |
| |
| In order to use SMSCB with OsmoBSC, you will need to |
| |
| * Configure the CBSP server and/or client |
| * Use a channel combination including a CBCH on the BTSs |
| |
| === Enabling a CBCH channel combination |
| |
| On the Um interface, SMSCB are transmitted via the CBCH (Cell Broadcast |
| Channel). The CBCH is a separate downlink-only logical channel which |
| must be activated on any of the BTSs requiring CBSP support. |
| |
| The channel combination is configured in the `timeslot` node of each TRX. |
| |
| The two `phys_chan_config` supporting CBCH are `CCCH+SDCCH4+CBCH` and |
| `SDCCH/8+CBCH`. Please note that the CBCH steals one of the SDCCH, so |
| a SDCCH/4 will only have three remaining SDCCH, and a SDCCH/8 will |
| have only seven remaining SDCCH. |
| |
| === Configuring the CBSP connection |
| |
| CBSP is the protocol between BSC and CBC. It operates over TCP. |
| |
| According to 3GPP TS 48.049, a BSC typically operates as a TCP server, |
| and the CBC connects as TCP client. This would require the CBC to have |
| out-of-band knowledge of all the BSCs in the network (and their IP |
| addresses). |
| |
| In order to comply with the specifications, OsmoBSC supports this mode |
| of operation as CBSP TCP server. However, to make network operation and |
| configuration more simple, it also can operate in TCP client mode, |
| connecting to the CBC. This way the all the BSCs need to know is the CBC IP |
| address, but not vice-versa. |
| |
| The BSC can operate both CBSP TCP server and CBSP TCP client mode in |
| parallel. |
| |
| The CBC related configuration of OsmoBSC can be found in the `cbc` configuration |
| node of the VTY interface. |
| |
| .Example: Configure CBSP TCP client to connect to CBC at 1.2.3.4:48049 |
| ---- |
| OsmoBSC> enable |
| OsmoBSC# configure terminal |
| OsmoBSC(config)# cbc |
| OsmoBSC(config-cbc)# remote-ip 1.2.3.4 |
| OsmoBSC(config-cbc)# remote-port 48049 |
| OsmoBSC(config-cbc)# end |
| ---- |
| |
| .Example: Disable CBSP TCP client |
| ---- |
| OsmoBSC> enable |
| OsmoBSC# configure terminal |
| OsmoBSC(config)# cbc |
| OsmoBSC(config-cbc)# no remote-ip |
| OsmoBSC(config-cbc)# end |
| ---- |
| |
| .Example: Configure CBSP TCP server to listen for CBC at 127.0.0.2:9999 |
| ---- |
| OsmoBSC> enable |
| OsmoBSC# configure terminal |
| OsmoBSC(config)# cbc |
| OsmoBSC(config-cbc)# listen-ip 127.0.0.2 |
| OsmoBSC(config-cbc)# listen-port 9999 |
| OsmoBSC(config-cbc)# end |
| ---- |
| |
| For more details on the available configuration commands, please check the OsmoBSC VTY Reference. |