| Harald Welte | 6d839f5 | 2019-12-01 14:19:54 +0100 | [diff] [blame^] | 1 | [[overview]] |
| 2 | == Overview |
| 3 | |
| 4 | |
| 5 | [[intro_overview]] |
| 6 | === About OsmoHNBGW |
| 7 | |
| 8 | OsmoHNBGW implements the Home NodeB Gateway function in the 3G network architecture. It serves |
| 9 | as a gateway between the classic 3G core network (CN) domain with its IuCS and IuPS interface |
| 10 | and the femtocell based RAN. |
| 11 | |
| 12 | A typical 3G network consisting of Osmocom components will look as illustrated in the following |
| 13 | diagram: |
| 14 | |
| 15 | [[fig-3g]] |
| 16 | .Typical 3G network architecture used with OsmoHNBGW |
| 17 | ---- |
| 18 | +------------+ +--------+ +----------+ +---------+ |
| 19 | UE <-->| hNodeB |<--Iuh---->| HNB-GW |<--IuCS-->| OsmoMSC |<--GSUP-->| OsmoHLR | |
| 20 | UE <-->| femto cell | ...-->| | ...-->| | | | |
| 21 | | | | | +----------+ +---------| |
| 22 | +------------+<--GTP-U | | |
| 23 | \ | | +------+ +------+ |
| 24 | | | |<--IuPS-->| SGSN |<--GTP-C-->| GGSN | |
| 25 | | +--------+ ...-->| | GTP-U-->| | |
| 26 | | +------+ / +------+ |
| 27 | \_______________________________/ |
| 28 | ---- |
| 29 | |
| 30 | The HNB-GW performs a translation interface between the IuCS/IuPS interfaces on the one hand |
| 31 | side, and the Iuh interface on the or ther hand: |
| 32 | |
| 33 | ---- |
| 34 | Iuh IuCS/IuPS |
| 35 | |
| 36 | NAS +----+----+ +----+----+ |
| 37 | Non-Access Stratum | CC | MM | | CC | MM | |
| 38 | - - - - - - - - - - - +----+----+-------+ +----+----+ |
| 39 | | RANAP | | H | RANAP | |
| 40 | Access Stratum +---------+ HNBAP | N +---------+ - - SCCP USER SAP |
| 41 | | RUA | | B | SUA | \ |
| 42 | +---------+-------+ - +---------+ | |
| 43 | | SCTP | G | SCTP | } SIGTRAN |
| 44 | +-----------------+ W +---------+ | |
| 45 | | IP | | IP | / |
| 46 | +-----------------+ +---------+ |
| 47 | ---- |
| 48 | |
| 49 | On the femtocell (Home NodeB) side, OsmoHNBGW implements the Iuh interface as specified by 3GPP. |
| 50 | |
| 51 | === The Iuh interface |
| 52 | |
| 53 | Iuh consists of the following sub-layers: |
| 54 | |
| 55 | - HNBAP (Home NodeB Application Part) |
| 56 | - RUA (RANAP User Adaptation, between RANAP and SCTP |