modify README

README.md

-# OpenAirInterface License #
+# OpenXG-RAN
 
-OpenAirInterface is under OpenAirInterface Software Alliance license.
-
- *  [OAI License Model](http://www.openairinterface.org/?page_id=101)
- *  [OAI License v1.1 on our website](http://www.openairinterface.org/?page_id=698)
-
-It is distributed under **OAI Public License V1.1**.
-
-The license information is distributed under [LICENSE](LICENSE) file in the same directory.
-
-Please see [NOTICE](NOTICE.md) file for third party software that is included in the sources.
-
-# Where to Start #
-
- *  [The implemented features](./doc/FEATURE_SET.md)
- *  [How to build](./doc/BUILD.md)
- *  [How to run the modems](./doc/RUNMODEM.md)
-
-# RAN repository structure #
-
-The OpenAirInterface (OAI) software is composed of the following parts: 
-
-<pre>
-openairinterface5g
-├── ci-scripts        : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
-├── cmake_targets     : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
-├── common            : Some common OAI utilities, other tools can be found at openair2/UTILS.
-├── doc               : Contains an up-to-date feature set list and starting tutorials.
-├── executables       : Top-level executable source files.
-├── LICENSE           : License file.
-├── maketags          : Script to generate emacs tags.
-├── nfapi             : Contains the NFAPI code. A local Readme file provides more details.
-├── openair1          : 3GPP LTE Rel-10/12 PHY layer / 3GPP NR Rel-15 layer. A local Readme file provides more details.
-│   ├── PHY
-│   ├── SCHED
-│   ├── SCHED_NBIOT
-│   ├── SCHED_NR
-│   ├── SCHED_NR_UE
-│   ├── SCHED_UE
-│   └── SIMULATION    : PHY RF simulation.
-├── openair2          : 3GPP LTE Rel-10 RLC/MAC/PDCP/RRC/X2AP + LTE Rel-14 M2AP implementation. Also 3GPP NR Rel-15 RLC/MAC/PDCP/RRC/X2AP.
-│   ├── COMMON
-│   ├── DOCS
-│   ├── ENB_APP
-│   ├── F1AP
-│   ├── GNB_APP
-│   ├── LAYER2/RLC/   : with the following subdirectories: UM_v9.3.0, TM_v9.3.0, and AM_v9.3.0.
-│   ├── LAYER2/PDCP/PDCP_v10.1.0
-│   ├── M2AP
-│   ├── MCE_APP
-│   ├── NETWORK_DRIVER
-│   ├── NR_PHY_INTERFACE
-│   ├── NR_UE_PHY_INTERFACE
-│   ├── PHY_INTERFACE
-│   ├── RRC
-│   ├── UTIL
-│   └── X2AP
-├── openair3          : 3GPP LTE Rel10 for S1AP, NAS GTPV1-U for both ENB and UE.
-│   ├── COMMON
-│   ├── DOCS
-│   ├── GTPV1-U
-│   ├── M3AP
-│   ├── MME_APP
-│   ├── NAS
-│   ├── S1AP
-│   ├── SCTP
-│   ├── SECU
-│   ├── TEST
-│   ├── UDP
-│   └── UTILS
-└── targets           : Top-level wrappers for unitary simulation for PHY channels, system-level emulation (eNB-UE with and without S1), and realtime eNB and UE and RRH GW.
-</pre>
+OpenXG-RAN is originally forked from OpenAirInterface, and evolves at its own step.