Blame - docs/Transport-Layer-and-ORAN-Fronthaul-Protocol-Implementation_fh.rst - oransc/o-du/phy

Luis Farias

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2020-05-28 19:01:58 -0700

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..

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.. Licensed under the Apache License, Version 2.0 (the "License");

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.. you may not use this file except in compliance with the License.

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.. You may obtain a copy of the License at

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..

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.. http://www.apache.org/licenses/LICENSE-2.0

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..

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.. Unless required by applicable law or agreed to in writing, software

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.. distributed under the License is distributed on an "AS IS" BASIS,

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.. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

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.. See the License for the specific language governing permissions and

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.. limitations under the License.

.. |br| raw:: html

<br />

Transport Layer and ORAN Fronthaul Protocol Implementation

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==========================================================

.. contents::

:depth: 3

:local:

This chapter describes how the transport layer and ORAN Fronthaul

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protocol are implemented.

.. _introduction-2:

Introduction

------------

Figure 8 presents an overview of the ORAN Fronthaul process.

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.. image:: images/ORAN-Fronthaul-Process.jpg

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:width: 600

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:alt: Figure 8. ORAN Fronthaul Process

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Figure 8. ORAN Fronthaul Process

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The XRAN library provides support for transporting In-band and

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Quadrature (IQ) samples between the O-DU and O-RU within the RAN

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architecture based on functional split 7.2x. The library defines the

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xRAN packet formats to be used to transport radio samples within Front

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Haul according to the ORAN Fronthaul specification. It provides

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functionality for generating xRAN packets, appending IQ samples in the

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packet payload, and extracting IQ samples from xRAN packets. The Bronze release version

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of the library supports U-plane and C-plane only. It is ready to

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be used in the PTP synchronized |br|

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environment.

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Regarding the clock model and synchronization topology, configurations

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C1 and C3 of the connection between O-DU and O-RU are the only

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configurations supported in this release of the xRAN implementation.

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Quality of PTP synchronization with respect to S-plane of ORAN Fronthaul

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requirements as defined for O-RU is out of the scope of this document.

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PTP master and PTP slave configuration are expected to satisfy only the

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O-DU side of |br|

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requirements and provide the “best-effort” PTP master for

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O-RU. This may or may not be sufficient for achieving the end to end

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system requirements of S-plane. Specialized dedicated NIC card with

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additional HW functionality might be |br|

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required to achieve PTP master

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functionality to satisfy O-RU precision requirements for RAN deployments

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scenarios.

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.. image:: images/Configuration-C1.jpg

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:width: 600

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:alt: Figure 9. Configuration C1

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Figure 9. Configuration C1

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.. image:: images/Configuration-C3.jpg

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:width: 600

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:alt: Figure 10. Configuration C3

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Figure 10. Configuration C3

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Supported Feature Set

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---------------------

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The ORAN Fronthaul specification defines a list of mandatory

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functionality. Not all features defined as Mandatory for |br|

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O-DU are

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currently supported to fully extended. The following tables contain

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information on what is available and the level of validation performed

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for this release.

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2. Cells with a red background are listed as mandatory in the

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specification but not supported in this implementation of xRAN.

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Table 7. ORAN Mandatory and Optional Feature Support

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+-----------------+-----------------+-----------+----------------+

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+=================+=================+===========+================+

+-----------------+-----------------+-----------+----------------+

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| | Support for | | N |

+-----------------+-----------------+-----------+----------------+

| | RU) | | |

+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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| | Real-Time | | N |

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+-----------------+-----------------+-----------+----------------+

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| | UE Channel Info | | N |

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+-----------------+-----------------+-----------+----------------+

| Saving | s | | |

+-----------------+-----------------+-----------+----------------+

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| | Real-time | | Y |

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| | var | | |

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+-----------------+-----------------+-----------+----------------+

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| | Compressed IQ | | Y |

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+-----------------+-----------------+-----------+----------------+

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| | Block floating | | Y |

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+-----------------+-----------------+-----------+----------------+

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| | Block scaling | | N |

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+-----------------+-----------------+-----------+----------------+

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| | u-law | | N |

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+-----------------+-----------------+-----------+----------------+

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| | modulation | | N |

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+-----------------+-----------------+-----------+----------------+

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| | beamspace | | N |

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+-----------------+-----------------+-----------+----------------+

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| | Variable Bit | | Y |

+-----------------+-----------------+-----------+----------------+

| | Static | | N |

+-----------------+-----------------+-----------+----------------+

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| | Use of “symInc” | | N |

+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

+-----------------+-----------------+-----------+----------------+

| | Measured | | N |

| | Msg 5) | | |

+-----------------+-----------------+-----------+----------------+

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| | | | |

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+-----------------+-----------------+-----------+----------------+

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| | G.8275.2 | | N |

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+-----------------+-----------------+-----------+----------------+

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| | GNSS based sync | | N |

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+-----------------+-----------------+-----------+----------------+

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| | SyncE | | N |

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+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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| | L3 : IPv4, IPv6 | | N |

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+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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| | Prioritization | | N |

+-----------------+-----------------+-----------+----------------+

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| | Support of | | N |

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+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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| | support of | | N |

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+-----------------+-----------------+-----------+----------------+

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| | IEEE 1914.3 | | N |

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+-----------------+-----------------+-----------+----------------+

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+-----------------+-----------------+-----------+----------------+

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| | Transport | | N |

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+-----------------+-----------------+-----------+----------------+

+-----------------+-----------------+-----------+----------------+

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| | LAA LBT RU | | N |

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+-----------------+-----------------+-----------+----------------+

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Details on the subset of xRAN functionality implemented are shown in

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Table 8.

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Level of Validation Specified as:

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- C: Completed code implementation for xRAN Library

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- I: Integrated into Intel FlexRAN PHY

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- T: Tested end to end with O-RU

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Table 8. Levels of Validation

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+------------+------------+------------+------------+-----+-----+---+

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+============+============+============+============+=====+=====+===+

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| | | Status | C | I | T | |

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+------------+------------+------------+------------+-----+-----+---+

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| General | Radio | NR | N/A | N/A | N/A | |

+------------+------------+------------+------------+-----+-----+---+

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| | Nominal | 15 | Y | Y | N | |

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| | s\ | /30/120KHz | | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | FFT size | 512/1024 | Y | Y | N | |

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| | | /2048/4096 | | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Channel | 5/10 | Y | Y | N | |

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| | bandwidth | /20/100Mhz | | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Number of | 12 | Y | Y | N | |

| | the | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | RU | A | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | TDD Config | Supporte\ | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | FDD | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Tx/Rx | Supported | Y | Y | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | IP version | N/A | N/A | N/A | N/A | |

| | for | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| PRACH | One Type 3 | Supported | Y | Y | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | Type 3 | 1 | Y | Y | N | |

| | per | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | timeOffset | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Supported | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | PRACH | Supported | Y | Y | N | |

| | the | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| Delay | Network | Supported | Y | Y | N | |

| | det\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | lls-CU | Supported | Y | Y | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | Non-delay | Not | N | N | N | |

+------------+------------+------------+------------+-----+-----+---+

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| C/U-plane | Transport | Ethernet | Y | Y | N | |

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| Transport | enc\ | | | | | |

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| | / IP) | | | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Jumbo | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Transport | eCPRI | Y | Y | N | |

| | RoE) | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | IP version | N/A | N/A | N/A | N/A | |

+------------+------------+------------+------------+-----+-----+---+

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| | eCPRI | Not | N | N | N | |

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| | Con\ | supported | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | eAxC ID | 4 \* | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | eAxC ID | 4 \* | Y | Y | N | |

| | Ban\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | eAxC ID | 4 \* | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | eAxC ID | 4 \* | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Fra\ | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Transport | N/A | N | N | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | Separation | Supported | Y | Y | N | |

| | of | | | | | |

| | and | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | Separation | VLAN ID | Y | Y | N | |

| | and | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | Max Number | 4 | Y | Y | N | |

| | per | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| Reception | Rx_on_time | Supported | Y | Y | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | Rx_early | Supported | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Rx_late | Supported | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Rx_corrupt | Supported | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | R\ | Supported | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Total | Supported | Y | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| B\ | RU | Index and | Y | N | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | B\ | C-plane | Y | N | N | |

+------------+------------+------------+------------+-----+-----+---+

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| | Number of | No-re | Y | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| IQ | U-plane | Supported | Y | N | N | |

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| c\ | data | | | | | |

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| ompression | c\ | | | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | U-plane | BFP: | Y | N | N | |

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| | data IQ | 8,9,12,14 | | | | |

| | co | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | Static | Supported | Y | Y | N | |

| | con\ | | | | | |

| | and | | | | | |

| | c\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| eCPRI | ec\ | 001b | Y | Y | Y | |

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+------------+------------+------------+------------+-----+-----+---+

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| | ecp\ | Supported | Y | Y | Y | |

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+------------+------------+------------+------------+-----+-----+---+

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| | ecpriCon\ | Not | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | ec\ | U-plane | Supported | Y | Y | Y |

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+------------+------------+------------+------------+-----+-----+---+

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| | | C-plane | Supported | Y | Y | Y |

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+------------+------------+------------+------------+-----+-----+---+

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| | | Delay | Not | N | N | N |

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| | | m\ | supported | | | |

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+------------+------------+------------+------------+-----+-----+---+

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| | ec\ | Supported | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

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| | ecpriRtcid | Supported | Y | Y | Y | |

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+------------+------------+------------+------------+-----+-----+---+

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| | e\ | Supported | Y | Y | Y | |

| | ID | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | e\ | Supported | Y | Y | Y | |

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+------------+------------+------------+------------+-----+-----+---+

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| | e\ | Not | N | N | N | |

| | S\ | | | | | |

| | ID | | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| C-plane | Section | Not | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Section | Supported | Y | Y | Y | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Section | Supported | Y | Y | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Section | Not | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Section | Not | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| | Section | Not | N | N | N | |

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+------------+------------+------------+------------+-----+-----+---+

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| C-plane | *Coding of | dat\ | Supported | Y | Y | N |

| | A\ | (gNB | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | payl\ | 001b | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | f\ | Supported | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | frameId | Supported | Y | Y | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | subframeId | Supported | Y | Y | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | slotId | Supported | Y | Y | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | sta\ | Supported | Y | Y | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | number | up to the | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | s\ | 1 and 3 | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | udCompHdr | Supported | N | N | N |

| | | c\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | n\ | Not | N | N | N |

| | | UEs) | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | timeOffset | Supported | Y | Y | N |

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+------------+------------+------------+------------+-----+-----+---+

597

| | | fram\ | mu=0,1,3 | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | cpLength | Supported | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

607

| | *Coding of | sectionId | Supported | Y | Y | N |

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| | I\ | (section | | | | |

609

| | nformation | i\ | | | | |

| | A\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

616

| | | rb | 0 | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | symInc | 0 or 1 | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

627

| | | startPrbc | Supported | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

633

| | | reMask | Supported | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | numPrbc | Supported | Y | Y | N |

+------------+------------+------------+------------+-----+-----+---+

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| | | numSymbol | Supported | Y | Y | N |

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+------------+------------+------------+------------+-----+-----+---+

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| | | ef | Supported | Y | Y | N |

650

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+------------+------------+------------+------------+-----+-----+---+

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| | | beamId | Support | Y | Y | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

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| | | ueId (UE | Not | N | N | N |

659

| | | i\ | supported | | | |

660

661

+------------+------------+------------+------------+-----+-----+---+

662

| | | freqOffset | Supported | Y | Y | N |

663

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665

+------------+------------+------------+------------+-----+-----+---+

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| | | regulariza\| Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

672

| | | ciIsample, | Not | N | N | N |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

680

| | | laaMsgType | Not | N | N | N |

681

| | | (LAA | supported | | | |

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683

684

+------------+------------+------------+------------+-----+-----+---+

685

| | | laaMsgLen | Not | N | N | N |

686

| | | (LAA | supported | | | |

687

688

689

+------------+------------+------------+------------+-----+-----+---+

690

| | | lbtHandle | Not | N | N | N |

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692

+------------+------------+------------+------------+-----+-----+---+

693

| | | lbtD\ | Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

700

| | | lbtBack | Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

707

| | | lbtOffset | Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

712

| | | MCOT | Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

718

| | | lbtMode | Not | N | N | N |

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720

+------------+------------+------------+------------+-----+-----+---+

721

| | | l\ | Not | N | N | N |

+------------+------------+------------+------------+-----+-----+---+

726

| | | sfStatus | Not | N | N | N |

727

728

729

+------------+------------+------------+------------+-----+-----+---+

730

| | | lbtDrsRes | Not | N | N | N |

731

732

733

+------------+------------+------------+------------+-----+-----+---+

734

| | | initia\ | Not | N | N | N |

| | | SF) | | | | |

+------------+------------+------------+------------+-----+-----+---+

740

| | | lbtBufErr | Not | N | N | N |

741

| | | (LBT | supported | | | |

742

743

744

+------------+------------+------------+------------+-----+-----+---+

745

| | | sfnSf | Not | N | N | N |

746

747

| | | End) | | | | |

748

+------------+------------+------------+------------+-----+-----+---+

749

| | | lbt | Not | N | N | N |

| | | for | | | | |

| | | m | | | | |

+------------+------------+------------+------------+-----+-----+---+

759

| | | lbt | Not | N | N | N |

| | | (TB | | | | |

| | | for | | | | |

| | | m | | | | |

+------------+------------+------------+------------+-----+-----+---+

769

| | | lbtTr\ | Not | N | N | N |

| | | for | | | | |

| | | m | | | | |

+------------+------------+------------+------------+-----+-----+---+

780

| | | lbtCWR_Rst | Not | N | N | N |

781

| | | (No | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

789

| | | reserved | 0 | N | N | N |

| | | use) | | | | |

+------------+------------+------------+------------+-----+-----+---+

+------------+------------+------------+------------+-----+-----+---+

798

| | | extType | Supported | Y | N | N |

799

800

801

+------------+------------+------------+------------+-----+-----+---+

802

| | | ef | Supported | Y | N | N |

803

804

805

+------------+------------+------------+------------+-----+-----+---+

806

| | | extLen | Supported | Y | N | N |

807

808

809

+------------+------------+------------+------------+-----+-----+---+

| | I\ | | | | | |

| | A\ | | | | | |

| | E\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

821

| | *ExtType=1:| bfwCompHdr | Supported | Y | N | N |

822

| | B\ | (beam\ | | | | |

823

824

825

| | Extension | c\ | | | | |

826

827

828

+------------+------------+------------+------------+-----+-----+---+

829

| | | bf | Supported | Y | N | N |

| | | (b\ | | | | |

| | | c\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

838

| | | bfwl | Supported | Y | N | N |

| | | (b\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

845

| | | bfwQ | Supported | Y | N | N |

| | | (b\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

852

| | | bfaCompHdr | Not | Y | N | N |

853

854

| | B\ | eamforming | | | | |

855

856

| | Attributes | c\ | | | | |

857

858

859

+------------+------------+------------+------------+-----+-----+---+

860

| | | bfAzPt | Not | Y | N | N |

861

| | | (b\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

867

| | | bfZePt | Not | Y | N | N |

868

| | | (b\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

874

| | | bfAz3dd | Not | Y | N | N |

875

| | | (b | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

881

| | | bfZe3dd | Not | Y | N | N |

882

| | | (b\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

888

| | | bfAzSl | Not | Y | N | N |

889

| | | (b\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

895

| | | bfZeSl | Not | Y | N | N |

896

| | | (b\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

902

| | | ze\ | Not | Y | N | N |

903

904

+------------+------------+------------+------------+-----+-----+---+

905

| | | cod | Not | N | N | N |

906

907

| | DL | (precoder | | | | |

908

909

910

| | Type* | tra | | | | |

911

912

+------------+------------+------------+------------+-----+-----+---+

913

| | | layerID | Not | N | N | N |

| | | tra\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

919

| | | txScheme | Not | N | N | N |

920

| | | (tr | supported | | | |

921

922

923

+------------+------------+------------+------------+-----+-----+---+

924

| | | numLayers | Not | N | N | N |

| | | DL | | | | |

| | | tra\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

932

| | | crsReMask | Not | N | N | N |

933

| | | (CRS | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

938

| | | c | Not | N | N | N |

| | | (CRS | | | | |

| | | i\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

946

| | | crsShift | Not | N | N | N |

| | | DL | | | | |

| | | tra\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

953

| | | beamIdAP1 | Not | N | N | N |

| | | for | | | | |

+------------+------------+------------+------------+-----+-----+---+

960

| | | beamIdAP2 | Not | N | N | N |

| | | for | | | | |

+------------+------------+------------+------------+-----+-----+---+

967

| | | beamIdAP3 | Not | N | N | N |

| | | for | | | | |

+------------+------------+------------+------------+-----+-----+---+

974

| | | csf | Not | Y | N | N |

975

976

977

| | C\ | shift | | | | |

+------------+------------+------------+------------+-----+-----+---+

983

| | | mod | Not | Y | N | N |

| | | ( | | | | |

| | | c\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

992

| | | mcS\ | Not | Y | N | N |

993

994

| | Modulation | ( | | | | |

995

| | C\ | modulation | | | | |

996

| | ompression | c\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

1002

| | | csf | Not | Y | N | N |

1003

| | | (con\ | supported | | | |

+------------+------------+------------+------------+-----+-----+---+

1008

| | | mcS | Not | Y | N | N |

| | | co\ | | | | |

+------------+------------+------------+------------+-----+-----+---+

1016

| U-plane | dat | Supported | Y | Y | Y | |

| | (gNB | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1023

| | payl\ | 001b | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

1028

| | f\ | Supported | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

1033

| | frameId | Supported | Y | Y | Y | |

| | i\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1038

| | subframeId | Supported | Y | Y | Y | |

| | i\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1043

| | slotId | Supported | Y | Y | Y | |

| | i | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1048

| | symbolId | Supported | Y | Y | Y | |

| | i\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1053

| | sectionId | Supported | Y | Y | Y | |

| | i\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1058

| | rb | 0 | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

1063

| | symInc | 0 | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

1069

| | startPrbu | Supported | Y | Y | Y | |

| | (s\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1076

| | numPrbu | Supported | Y | Y | Y | |

+------------+------------+------------+------------+-----+-----+---+

1082

| | udCompHdr | Supported | Y | Y | N | |

| | c\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1088

| | reserved | 0 | Y | Y | Y | |

| | use) | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1093

| | u\ | Supported | Y | Y | N | |

| | c\ | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1100

| | iSample | 16 | Y | Y | Y | |

1101

1102

1103

+------------+------------+------------+------------+-----+-----+---+

1104

| | qSample | 16 | Y | Y | Y | |

| | ( | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1109

| S-plane | Topology | Supported | N | N | N | |

| | C1 | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1114

| | Topology | Supported | N | N | N | |

| | C2 | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1119

| | Topology | Supported | Y | Y | Y | |

| | C3 | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1124

| | Topology | Supported | N | N | N | |

| | C4 | | | | | |

+------------+------------+------------+------------+-----+-----+---+

1129

| | PTP | Full | Supported | Y | Y | N |

1130

1131

1132

| | | (G.8275.1) | | | | |

1133

+------------+------------+------------+------------+-----+-----+---+

1134

| M-plane | | | Not | N | N | N |

1135

1136

+------------+------------+------------+------------+-----+-----+---+

1137

1138

\* The bit width of each component in eAxC ID can be configurable.

Transport Layer

---------------

ORAN Fronthaul data can be transported over Ethernet or IPv4/IPv6. In

1144

the current implementation, the xRAN library supports only Ethernet with

1145

VLAN.

1146

1147

.. image:: images/Native-Ethernet-Frame-with-VLAN.jpg

1148

:width: 600

1149

:alt: Figure 11. Native Ethernet Frame with VLAN

1150

1151

Figure 11. Native Ethernet Frame with VLAN

1152

1153

1154

Standard DPDK routines are used to perform Transport Layer

1155

functionality.

1156

1157

VLAN tag functionality is offloaded to NIC as per the configuration of

1158

VF (refer to Appendix Appendix 1).

1159

1160

The transport header is defined in the ORAN Fronthaul specification

1161

based on the eCPRI specification.

1162

1163

.. image:: images/eCPRI-Header-Field-Definitions.jpg

1164

:width: 600

1165

:alt: Figure 12. eCPRI Header Field Definitions

1166

1167

Figure 12. eCPRI Header Field Definitions

1168

1169

Only ECPRI_IQ_DATA = 0x00 and ECPRI_RT_CONTROL_DATA= 0x02 message types

1170

are supported.

1171

1172

Handling of ecpriRtcid/ecpriPcid Bit field size is configurable and can

1173

be defined on the initialization stage of the xRAN |br|

1174

library.

1175

1176

.. image:: images/Bit-Allocations-of-ecpriRtcid-ecpriPcid.jpg

1177

:width: 600

1178

:alt: Figure 13. Bit Allocations of ecpriRtcid/ecpriPcid

1179

1180

Figure 13. Bit Allocations of ecpriRtcid/ecpriPcid

1181

1182

For ecpriSeqid only, the support for a sequence number is implemented.

1183

The subsequent number is not supported.

U-plane

-------

The following diagrams show xRAN packet protocols’ headers and data

1189

arrangement with and without compression |br|

1190

support.

1191

1192

XRAN packet meant for traffic with compression enabled has the

1193

Compression Header added after each Application Header. According to

1194

ORAN Fronthaul's specification, the Compression Header is part of a

1195

repeated Section Application Header. In the xRAN library implementation,

1196

the header is implemented as a separate structure, following the

1197

Application Section Header. As a result, the Compression Header is not

1198

included in the xRAN packet, if compression is not used.

1199

1200

Figure 14 shows the components of an xRAN packet.

1201

1202

.. image:: images/xRAN-Packet-Components.jpg

1203

:width: 600

1204

:alt: Figure 14. xRAN Packet Components

1205

1206

Figure 14. xRAN Packet Components

1207

1208

Radio Application Header

1209

~~~~~~~~~~~~~~~~~~~~~~~~

1210

1211

The next header is a common header used for time reference.

1212

1213

.. image:: images/Radio-Application-Header.jpg

1214

:width: 600

1215

:alt: Figure 15. Radio Application Header

1216

1217

Figure 15. Radio Application Header

1218

1219

The radio application header specific field values are implemented as

follows:

- filterIndex = 0

- frameId = [0:99]

- subframeId = [0:9]

- slotId = [0:7]

- symbolId = [0:13]

Data Section Application Data Header

1233

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1234

1235

The Common Radio Application Header is followed by the Application

1236

Header that is repeated for each Data Section |br|

1237

within the eCPRI message.

1238

The relevant section of xRAN packet is shown in color.

1239

1240

.. image:: images/Data-Section-Application-Data-Header.jpg

1241

:width: 600

1242

:alt: Figure 16. Data Section Application Data Header

1243

1244

Figure 16. Data Section Application Data Header

1245

1246

1247

A single section is used per one Ethernet packet with IQ samples

1248

startPrbu is equal to 0 and numPrbu is wqual to the number of RBs used:

1249

1250

- rb field is not used (value 0).

1251

1252

- symInc is not used (value 0)

Data Payload

~~~~~~~~~~~~

An xRAN packet data payload contains a number of PRBs. Each PRB is built

1258

of 12 IQ samples. The supported IQ bit width is 16. udCompParam is not

1259

included in the data payload as compression currently is not supported.

1260

The data section is shown in color.

1261

1262

.. image:: images/Data-Payload.jpg

1263

:width: 600

1264

:alt: Figure 17. Data Payload

1265

1266

Figure 17. Data Payload

C-plane

-------

C-Plane messages are encapsulated using a two-layered header approach.

1272

The first layer consists of an eCPRI standard header, including

1273

corresponding fields used to indicate the message type, while the second

1274

layer is an application layer |br|

1275

including necessary fields for control and

1276

synchronization. Within the application layer, a “section” defines the |br|

1277

characteristics of U-plane data to be transferred or received from a

1278

beam with one pattern id. In general, the transport header, |br|

1279

application

1280

header, and sections are all intended to be aligned on 4-byte boundaries

1281

and are transmitted in “network byte |br|

1282

order” meaning the most significant

1283

byte of a multi-byte parameter is transmitted first.

1284

1285

Table 9 is a list of sections currently supported.

1286

1287

Table 9. Section Types

1288

1289

+--------------+--------------------------+--------------------------+

1290

| Section Type | Target Scenario | Remarks |

1291

+--------------+--------------------------+--------------------------+

1292

| 0 | Unused Resource Blocks | Not supported |

1293

| | or symbols in Downlink | |

1294

| | or Uplink | |

1295

+--------------+--------------------------+--------------------------+

1296

| 1 | Most DL/UL radio | Supported |

1297

| | channels | |

1298

+--------------+--------------------------+--------------------------+

1299

| 2 | reserved for future use | N/A |

1300

+--------------+--------------------------+--------------------------+

1301

| 3 | PRACH and | Only PRACH is supported. |

1302

| | mixed-numerology | Mixed numerology is not |

1303

| | channels | supported. |

1304

+--------------+--------------------------+--------------------------+

1305

| 4 | Reserved for future use | Not supported |

1306

+--------------+--------------------------+--------------------------+

1307

| 5 | UE scheduling | Not supported |

1308

| | information (UE-ID | |

1309

| | assignment to section) | |

1310

+--------------+--------------------------+--------------------------+

1311

| 6 | Channel information | Not supported |

1312

+--------------+--------------------------+--------------------------+

1313

| 7 | LAA | Not supported |

1314

+--------------+--------------------------+--------------------------+

1315

| 8-255 | Reserved for future use | N/A |

1316

+--------------+--------------------------+--------------------------+

1317

1318

Section extensions are not supported in this release.

1319

1320

The definition of the C-Plane packet can be found lib/api/xran_pkt_cp.h

1321

and the fields are appropriately re-ordered in |br|

1322

order to apply the

1323

conversion of network byte order after setting values.

Ethernet Header

~~~~~~~~~~~~~~~

Refer to Figure 11.

eCPRI Header

~~~~~~~~~~~~

Refer to Figure 12.

This header is defined as the structure of xran_ecpri_hdr in

1336

lib/api/xran_pkt.h.

1337

1338

Radio Application Common Header

1339

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1340

1341

The Radio Application Common Header is used for time reference. Its

1342

structure is shown in Figure 18.

1343

1344

.. image:: images/Radio-Application-Common-Header.jpg

1345

:width: 600

1346

:alt: Figure 18. Radio Application Common Header

1347

1348

Figure 18. Radio Application Common Header

1349

1350

This header is defined as the structure of

1351

xran_cp_radioapp_common_header in lib/api/xran_pkt_cp.h.

1352

1353

Please note that the payload version in this header is fixed to

1354

XRAN_PAYLOAD_VER (defined as 1) in this release.

1355

1356

Section Type 0 Structure

1357

~~~~~~~~~~~~~~~~~~~~~~~~

1358

1359

Figure 19 describes the structure of Section Type 0.

1360

1361

.. image:: images/Section-Type-0-Structure.jpg

1362

:width: 600

1363

:alt: Figure 19. Section Type 0 Structure

1364

1365

Figure 19. Section Type 0 Structure

1366

1367

In Figure 18 through Figure 22, the color yellow means it is a transport

1368

header; the color pink is the radio application header; others are

1369

repeated sections.

1370

1371

Section Type 1 Structure

1372

~~~~~~~~~~~~~~~~~~~~~~~~

1373

1374

Figure 20 describes the structure of Section Type 1.

1375

1376

.. image:: images/Section-Type-1-Structure.jpg

1377

:width: 600

1378

:alt: Figure 20. Section Type 1 Structure

1379

1380

Figure 20. Section Type 1 Structure

1381

1382

Section Type 1 message has two additional parameters in addition to

1383

radio application common header:

1384

1385

- udCompHdr : defined as the structure of xran_radioapp_udComp_header

1386

1387

- reserved : fixed by zero

1388

1389

Section type 1 is defined as the structure of xran_cp_radioapp_section1,

1390

and this part can be repeated to have multiple sections.

1391

1392

Whole section type 1 message can be described in this summary:

1393

1394

+----------------------------------+

1395

| xran_cp_radioapp_common_header |

1396

+==================================+

1397

| xran_cp_radioapp_section1_header |

1398

+----------------------------------+

1399

| xran_cp_radioapp_section1 |

1400

+----------------------------------+

1401

| …… |

1402

+----------------------------------+

1403

| xran_cp_radioapp_section1 |

1404

+----------------------------------+

1405

1406

Section Type 3 Structure

1407

~~~~~~~~~~~~~~~~~~~~~~~~

1408

1409

Figure 21 describes the structure of Section Type 3.

1410

1411

.. image:: images/Section-Type-3-Structure.jpg

1412

:width: 600

1413

:alt: Figure 21. Section Type 3 Structure

1414

1415

Figure 21. Section Type 3 Structure

1416

1417

Section Type 3 message has below four additional parameters in addition

1418

to radio application common header.

- timeOffset

- frameStrucutre: defined as the structure of

1423

xran_cp_radioapp_frameStructure

- cpLength

- udCompHdr: defined as the structure of xran_radioapp_udComp_header

1428

1429

Section Type 3 is defined as the structure of xran_cp_radioapp_section3

1430

and this part can be repeated to have multiple sections.

1431

1432

Whole section type 3 message can be described in this summary:

1433

1434

+----------------------------------+

1435

| xran_cp_radioapp_common_header |

1436

+==================================+

1437

| xran_cp_radioapp_section3_header |

1438

+----------------------------------+

1439

| xran_cp_radioapp_section3 |

1440

+----------------------------------+

1441

| …… |

1442

+----------------------------------+

1443

| xran_cp_radioapp_section3 |

1444

+----------------------------------+

1445

1446

Section Type 5 Structure

1447

~~~~~~~~~~~~~~~~~~~~~~~~

1448

1449

Figure 22 describes the structure of Section Type 5.

1450

1451

.. image:: images/Section-Type-5-Structure.jpg

1452

:width: 600

1453

:alt: Figure 22. Section Type 5 Structure

1454

1455

Figure 22. Section Type 5 Structure

1456

1457

1458

Section Type 6 Structure

1459

~~~~~~~~~~~~~~~~~~~~~~~~

1460

1461

Figure 23 describes the structure of Section Type 6.

1462

1463

.. image:: images/Section-Type-6-Structure.jpg

1464

:width: 600

1465

:alt: Figure 23. Section Type 6 Structure

1466

1467

Figure 23. Section Type 6 Structure

1468