Initial minimal OsmoHNBGW user manual
This adds a very basic OsmoHNBGW user manual with an "overview" and
"running" chapter. It still misses any information on configuration.
Change-Id: I54825a4ce5a457f87b0618332347eed8ea54afcb
Closes: OS#2588
diff --git a/doc/manuals/chapters/overview.adoc b/doc/manuals/chapters/overview.adoc
new file mode 100644
index 0000000..2368b4f
--- /dev/null
+++ b/doc/manuals/chapters/overview.adoc
@@ -0,0 +1,56 @@
+[[overview]]
+== Overview
+
+
+[[intro_overview]]
+=== About OsmoHNBGW
+
+OsmoHNBGW implements the Home NodeB Gateway function in the 3G network architecture. It serves
+as a gateway between the classic 3G core network (CN) domain with its IuCS and IuPS interface
+and the femtocell based RAN.
+
+A typical 3G network consisting of Osmocom components will look as illustrated in the following
+diagram:
+
+[[fig-3g]]
+.Typical 3G network architecture used with OsmoHNBGW
+----
+ +------------+ +--------+ +----------+ +---------+
+ UE <-->| hNodeB |<--Iuh---->| HNB-GW |<--IuCS-->| OsmoMSC |<--GSUP-->| OsmoHLR |
+ UE <-->| femto cell | ...-->| | ...-->| | | |
+ | | | | +----------+ +---------|
+ +------------+<--GTP-U | |
+ \ | | +------+ +------+
+ | | |<--IuPS-->| SGSN |<--GTP-C-->| GGSN |
+ | +--------+ ...-->| | GTP-U-->| |
+ | +------+ / +------+
+ \_______________________________/
+----
+
+The HNB-GW performs a translation interface between the IuCS/IuPS interfaces on the one hand
+side, and the Iuh interface on the or ther hand:
+
+----
+ Iuh IuCS/IuPS
+
+NAS +----+----+ +----+----+
+Non-Access Stratum | CC | MM | | CC | MM |
+- - - - - - - - - - - +----+----+-------+ +----+----+
+ | RANAP | | H | RANAP |
+Access Stratum +---------+ HNBAP | N +---------+ - - SCCP USER SAP
+ | RUA | | B | SUA | \
+ +---------+-------+ - +---------+ |
+ | SCTP | G | SCTP | } SIGTRAN
+ +-----------------+ W +---------+ |
+ | IP | | IP | /
+ +-----------------+ +---------+
+----
+
+On the femtocell (Home NodeB) side, OsmoHNBGW implements the Iuh interface as specified by 3GPP.
+
+=== The Iuh interface
+
+Iuh consists of the following sub-layers:
+
+- HNBAP (Home NodeB Application Part)
+- RUA (RANAP User Adaptation, between RANAP and SCTP
diff --git a/doc/manuals/chapters/running.adoc b/doc/manuals/chapters/running.adoc
new file mode 100644
index 0000000..41909e2
--- /dev/null
+++ b/doc/manuals/chapters/running.adoc
@@ -0,0 +1,37 @@
+== Running OsmoHNBGW
+
+The OsmoHNBGW executable (`osmo-hnbgw`) offers the following command-line
+arguments:
+
+=== SYNOPSIS
+
+*osmo-hnbgw* [-h|-V] [-d 'DBGMASK'] [-D] [-c 'CONFIGFILE'] [-s] [-T] [-e 'LOGLEVEL']
+
+=== OPTIONS
+
+*-h, --help*::
+ Print a short help message about the supported options
+*-V, --version*::
+ Print the compile-time version number of the OsmoHNBGW program
+*-d, --debug 'DBGMASK','DBGLEVELS'*::
+ Set the log subsystems and levels for logging to stderr. This
+ has mostly been superseded by VTY-based logging configuration,
+ see <<logging>> for further information.
+*-D, --daemonize*::
+ Fork the process as a daemon into background.
+*-c, --config-file 'CONFIGFILE'*::
+ Specify the file and path name of the configuration file to be
+ used. If none is specified, use `osmo-msc.cfg` in the current
+ working directory.
+*-s, --disable-color*::
+ Disable colors for logging to stderr. This has mostly been
+ deprecated by VTY based logging configuration, see <<logging>>
+ for more information.
+*-T, --timestamp*::
+ Enable time-stamping of log messages to stderr. This has mostly
+ been deprecated by VTY based logging configuration, see
+ <<logging>> for more information.
+*-e, --log-level 'LOGLEVEL'*::
+ Set the global log level for logging to stderr. This has mostly
+ been deprecated by VTY based logging configuration, see
+ <<logging>> for more information.