Motorola Horizon macro » History » Revision 13
Revision 12 (laforge, 02/19/2016 10:47 PM) → Revision 13/16 (laforge, 02/19/2016 10:47 PM)
[[PageOutline]] = Motorola Horizon macro BTS = The Motorola Horizon macro BTS is a BTS model manufactured by Motorola in the late 1990ies. It can support up to 6 TRX, typically in a configuration of 3 sectors. There is currently no support for it in OpenBSC, but we are working on it. == Hardware == [[Image(horizonmacro_cabinet_door_open.jpg, 50%)]] [[Image(horizonmacro_cabinet_top.jpg, 33%)]] === CTU === The up to 6 CTU modules are the individual transceivers (TRX) of the BTS cabinet. transceivers. They plug into the SURF RF backplane and have a front-accessible DB9 serial port, as well as a SMA connector for the TX PA output. This TX PA output is normally wired using a ~10cm semi-rigid SMA cable to the TX input port of a combiner/duplexer. combiner. The CTU is of course fully shielded. But if you remove the shielding cover, it looks like this: [[Image(horizonmacro_ctu_pcb.jpg, 50%)]] You can see * two diversity receivers in the top left part * digital section in the top right part * transmit section (exciter) in the center * RF power amplifier in the bottom right part ==== digital part ==== The CTU digital part has the following connections * backplane connector for * power supply (27V DC) * two redundand 2048 Mbps TDM links with MCUF, manchester-encoded, 32 timeslots * three coaxial backplane connectors with SURF * Rx side A (diversity) * Rx side B (diversity) * Rx loopback (for transmitting into Rx path, loopback testing) The CTU digital part consists of three main processors: * RSS (Radio Subsystem) * communicates with MCUF via dedicated 64kbps timeslots in TDM link * communicates via dual-ported ram with CCCP * Flash EEPROM for boot loader and 8 MByte DRAM * EQCP (Equalizer and Control Processor) * DSP for radio control and channel equalization * alarm management * downlink burst building and modulator control * tx power control * synthesizer channel control * rf frequency hopping * receiver front-end and remote tune combiner control * uplink synchronziation and equalization * diversity receiver control * automatic gain control * receiver signal sthrength calculation * CCCP (Channel Coder Control Processor) * DSP for channel coding, data routing and baseband hopping * uplink channel decoding * downlink channel encoding * A5 encryption * baseband frequency hopping * TRAU frame collection and synchronization The CTU has a three serial consoles routed to the same DB-9 plug. We console, we describe it in [wiki:Motorola_Horizon_macro/CTU_Console] === Combiner === The combiner / duplexer combines the TX signal of two CTU and duplexes it with the Rx path in order to be able to have two TRX attached to one antenna === MCUF === The MCUF is a full-size digital board and contains the BTS controller [[Image(horizonmacro_mcuf_pcb_top.jpg, 33%)]] [[Image(horizonmacro_mcuf_front.jpg, 33%)]] === NIU === The NIU is a E1 interface card for up to two E1 lines. Multiple NIU boards can be plugged into the rack [[Image(horizonmacro_niu_pcb.jpg, 50%)]] === BPSM === The BPSM is a small power supply for the NIU, MCUF and other digital boards [[Image(horizonmacro_bpsm_pcb.jpg, 50%)]] === ALARMS === The ALARMS board is monitoring FAN and other alarms in the cabinet. [[Image(horizonmacro_alarms_pcb.jpg, 50%)]] === A-bis interface === The A-bis interface is via classic E1 lines. The Horizon indoor cabinet supports up to 6 E1 ports. Each NIU module serves 1 or 2 E1 ports. The E1 ports are physically routed to the BIB (Balanced Interface Board) module on top of the cabinet. The pinout of the 37pin D-Sub connector on top of the BIB board has been reversed as: ||Pin ||Transformer||Usage|| ||1 ||T1.1 ||NIUA0 Port 0 (Tx)|| ||2 ||T2.1 ||NIUA0 Port 0 (Rx)|| ||3 ||GND || ||4 ||T4.1 || ||5 ||T5.1 || ||6 ||GND || ||7 ||T7.1 || ||8 ||T8.1 || ||9 ||GND || ||10 ||T10.1 || ||11 ||T11.1 || ||12 ||GND || ||13 ||T13.1 || ||14 ||T14.1 || ||15 ||GND || ||16 ||T16.1 || ||17 ||T17.1 || ||18 ||GND || ||19 ||GND || ||20 ||T1.8 ||NIUA0 Port 0 (Tx)|| ||21 ||T2.8 ||NIUA0 Port 0 (Rx)|| ||22 || || ||23 ||T4.8 || ||24 ||T5.8 || ||25 || || ||27 ||T7.8 || ||28 ||T8.8 || ||29 ||T10.8 || ||30 ||T11.8 || ||31 || || ||32 ||T13.8 || ||33 ||T14.8 || ||34 || || ||35 ||T16.8 || ||36 ||T17.8 || == Software == === MCUF === There is a 20MByte Intel Series2 Flash PCMCIA card inside the MCUF. It contains software + configuration for the BTS. [[Image(horizonmacro_pcmcia_iflash2.jpg, 33%)]] There once has been a mtd_iflash2.c driver for Linux 2.4.x, but apparently it has never been merged mainline before the big CardServices API redesign happened in 2.6.x. So unfortunately it's not straight-forward to read them out :( The MCUF is able to run without the PCMCIA card. In this case, it will download all software + config via E1 from the BSC. The MCUF has a very extensive command line interface (MMI), for more information check [wiki:Motorola_Horizon_macro/MCUF_Console] === CTU === It is assumed that the CTU only contains a boot loader to download the real software from the MCUF. == Further reading == * Motorola BSS11 Base Station Operational Aspects (Describes BTS hardware) * http://wenku.baidu.com/view/da379c82d4d8d15abe234e32.html * Motorola SYS01 GSM SYSTEM INTERFACES (Chapter 5: Mobis) * http://read.pudn.com/downloads61/ebook/212957/SYS01.pdf