> For the complete documentation index, see [llms.txt](https://docs.gxc.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.gxc.io/docs/application-notes/5g-handovers.md).

# 5G Handovers

## Introduction

Handovers are a core capability in mobile networks, enabling uninterrupted service continuity as active User Equipment (UE) move between cells. For mission-critical applications, such as autonomous systems, industrial automation, and enterprise communications, seamless handovers are essential to prevent service disruptions and maintain safety and operational standards.

GXC's Onyx solution provides a high-reliability, ultra-low-latency handover framework for 5G New Radio (NR). The Onyx Edge is deployed in an NR+Core configuration (gNB + 5G Core functions co-located at the edge). 5G NR handovers follow a measurement-based approach: the UE monitors the signal quality of the serving cell, and begins actively measuring neighboring cells once the A2 event triggers and reports these measurements to the network, which then makes the handover decision using a make-before-break approach — the target cell connection is established before the source connection is released, minimizing interruption and signaling overhead.

The system supports both an automatic all-to-all neighbor configuration and a manually curated, explicit neighbor list.

### Supported Handover Types

The 5G Onyx solution supports multiple handover mechanisms designed to ensure seamless mobility and service continuity as UE move across cells.

#### Intra-gNB / Intra-DU Handovers

{% columns %}
{% column %}
An intra-DU handover occurs when a UE moves between cells within the same Distributed Unit (DU) of a gNB. This is the simplest case — both source and target cells are controlled by the same DU, so the handover is handled entirely within the gNB and the core network (AMF) is not involved in the handover signaling or user-plane switching. Intra-DU handovers apply whenever a DU serves multiple cells — in high-density deployments with overlapping coverage, and equally in single-Onyx-Edge deployments using an FHM for additional coverage.
{% endcolumn %}

{% column %}

<figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2Fp2u6gpUh5GTFGCWGVWuP%2F5g-handover-intra-gnb-intra-du-handovers.png?alt=media&amp;token=bdbf204a-6406-4e8c-b329-ee00302d5548" alt="" width="375"><figcaption></figcaption></figure>
{% endcolumn %}
{% endcolumns %}

#### Inter-gNB (Xn) Handovers

{% columns %}
{% column %}
An inter-gNB handover occurs when a UE moves between cells belonging to different gNBs, using the Xn interface for direct gNB-to-gNB context transfer and data forwarding. The core network (AMF) is only minimally involved — it is notified after the handover to update the path, but does not participate in the handover decision or preparation. If an Xn interface is not available between the two gNBs, the core network facilitates the handover over the N2 interface instead, with the AMF actively managing handover signaling, context transfer, and user-plane path switching.
{% endcolumn %}

{% column %}

<figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FpgGu8fZBSjIXwFfFlH8O%2F5g-handover-inter-gnb-xn-handovers.png?alt=media&amp;token=e0a43c18-6a2a-4d09-8450-9fd9dd8d486a" alt="" width="375"><figcaption></figcaption></figure>
{% endcolumn %}
{% endcolumns %}

{% hint style="info" %}
**NOTE**: Deployment scope for this release: mobility is supported within a single DU, and Inter-gNB Xn handover is implemented between gNBs of the same radio family. Handovers spanning multiple CUs, multiple AMFs, and inter-RAT handovers between 5G and 4G (via the N26 interface) are not part of this release — see [*Notes and Limitations*](#notes-and-limitations).
{% endhint %}

GXC employs a make-before-break handover strategy: the new radio connection is established ahead of releasing the old one, improving spectral efficiency and providing predictable behavior — particularly valuable in private and industrial 5G networks where consistent performance is critical.

### Neighbor Relationships

GXC 5G cells maintain neighbor relationships that define which cells a UE should consider for handover. Each relationship carries the neighbor cell's PCI, frequency, and the signal thresholds used for handover decisions. Neighbor frequency information is populated automatically from SAS grants when SAS is enabled; the relationships themselves come from the neighbor configuration set in the Onyx Portal (Automatic or Explicit mode).

Underlying this data, each NR cell holds one or more cell relation entries — one per neighbor — each carrying per-neighbor RSRP/RSRQ/SINR offsets and handover-allowed/removal-allowed flags, and each referencing a shared frequency relation and frequency definition for the neighbor's carrier. This is the configuration data model behind the Onyx Portal's Handover tab and Edit Cell dialog.

### Special Configuration Cases

Onyx 5G does not currently support Dual-Carrier (DC) or Carrier Aggregation (CA) modes.

In this release, every 5G cell is Single Carrier only. The per-cell neighbor relationships described above still apply. See [*Notes and Limitations*](#notes-and-limitations).

### Neighbor Relationship Configuration Modes

The Onyx Portal offers two modes for 5G neighbor relationships:

#### Automatic Neighbor Configuration (Default)

* All cells of the same radio family associated with the same Onyx Edge are configured as neighbors to each other automatically.
* No manual neighbor selection required; Desired and Configured neighbor fields both display "All."
* Recommended for networks where all cells should be reachable from all others, and to minimize configuration overhead.

#### Manual Neighbor Configuration (Explicit Neighbors)

* Operator manually selects which cells are neighbors of each cell, via the Explicit Neighbors toggle.
* Supports asymmetric relationships and deliberate exclusion of certain cells.
* Limited to at most four explicit neighbors per cell. Neighbors must be of the same radio hardware family as the cell itself (gNB-to-gNB or O-RAN AP-to-O-RAN AP, never mixed).

{% hint style="info" %}
Neighbor configuration is directional. Adding Cell-2 as a neighbor of Cell-1 does not automatically make Cell-1 a neighbor of Cell-2. If bidirectional handovers are needed, both relationships must be configured explicitly.
{% endhint %}

### Notes and Limitations

* Handovers are supported only within a single DU for intra-gNB mobility, and only between gNBs/APs of the same radio family for inter-gNB (Xn) mobility — gNB-to-gNB (currently G227, G228, G244) or O-RAN AP-to-O-RAN AP, never mixed.
* A maximum of four explicit neighbors can be configured per cell.
* Handovers spanning multiple CUs, multiple AMFs (N14), and inter-RAT handovers between 5G and 4G (via N26) are not part of this release.
* Dual-Carrier (DC) and Carrier Aggregation (CA) modes are not supported for 5G in this release.
* Manual (Explicit) neighbor configuration and per-cell advanced handover thresholds require Onyx Edge running 4.1.0 or later.
* Changes to neighbor tables are expected to be service-disrupting, since they modify configuration across associated equipment; plan changes during maintenance windows.
* If the full list of configured explicit neighbors cannot be applied due to the four-neighbor limit, an alert is expected to be generated for the affected cell.

### How it Works

This section describes how 5G inter-gNB handovers work in conjunction with Onyx Portal-configured neighbor relationships for successful UE handovers.

#### Neighbor Relationship Configuration

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2Fr3Iyc4Zle8epUN63nz4I%2F5g-handover-call-flow-phase-1.png?alt=media&amp;token=8aa1c5eb-8234-4c8b-8430-f23caaffd09e" alt=""><figcaption></figcaption></figure></div>

Before handovers can occur, the Onyx Portal and Onyx Edge must establish which cells are neighbors and what frequencies they use, for each cell.

* An Onyx Portal Administrator configures cell neighbor relationships using Automatic or Explicit configuration modes.
* The Onyx Edge populates each cell's neighbor relationships based on the neighbor(s) configured in the Onyx Portal, subject to the four-neighbor limit.
* The Onyx Edge automatically populates each cell's neighbor frequency information based on SAS grants assigned to the neighbor cells, when SAS is enabled.

#### UE Handover Execution

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2F6OdMaUWjW2pxs814yYvf%2F5g-handover-call-flow-phase-2.png?alt=media&amp;token=19fb19fa-f969-4278-b9eb-8cf1815e6c64" alt=""><figcaption></figcaption></figure></div>

With neighbor tables in place, the network continuously monitors UE signal quality and executes handovers based on NR measurement events A1, A2, A3, and A5, applied to NR RSRP measurements.

For the simplest case — an intra-frequency handover between two cells on the same DU — the call flow runs as follows:

* The UE detects a neighboring cell meeting the A3 measurement event criteria and sends an RRC Measurement Report to the gNB-CU via the source DU.
* The CU initiates the handover by sending a UE Context Modification Request naming the target cell to the DU over the F1AP interface.
* The DU allocates a new C-RNTI for the target cell, along with the target cell's Physical Cell ID (PCI) and updated RLC/MAC configuration, and returns these to the CU.
* The CU builds an RRCReconfiguration message carrying the new C-RNTI, target PCI, and RLC/MAC configuration, and forwards it to the UE via the DU.
* The UE performs Random Access on the target cell, then sends RRCReconfiguration Complete back through the target DU to the CU, completing the handover.

A3 is an intra-frequency measurement event and can apply within a single gNB or across gNBs — it is not limited to intra-DU deployments.

For inter-frequency handovers, the same A2/A5 measurement-event logic governs when the handover is triggered — these events can likewise apply within a single gNB or across gNBs — with the Xn (or N2 fallback) interface carrying the context transfer between source and target gNBs instead of the intra-DU F1AP exchange described above whenever the handover crosses gNBs.

#### Sample Handover Walkthrough

This section walks through the measurement events using the default threshold values.

{% hint style="info" %}
Threshold values in this section reflect the portal defaults verified for this note. Actual trigger timing depends on the thresholds, hysteresis, and time-to-trigger configured for your deployment.
{% endhint %}

**Example Threshold Values**

| Threshold                      | Verified Value               |
| ------------------------------ | ---------------------------- |
| A1 Threshold                   | 71 (report level) / −85 dBm  |
| A2 Threshold                   | 66 (report level) / −90 dBm  |
| A5 Threshold 1 (serving cell)  | 56 (report level) / −100 dBm |
| A5 Threshold 2 (neighbor cell) | 59 (report level) / −97 dBm  |

<p align="center"><strong>5G Handover Measurement Events — Signal Level Timeline</strong></p>

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FEDuomuvASkIYdBxurRhk%2F5g-handover-measurement-events-signal-level-timeline.png?alt=media&amp;token=54b3a992-3b6c-47bd-9b71-7d07cdf3bf18" alt=""><figcaption></figcaption></figure></div>

By default, the UE watches only Event A2 on the serving cell — no inter-frequency neighbor measurement, and no measurement gap, so the UE pays no throughput cost. Once the serving cell's RSRP falls below the A2 threshold, Event A2 fires: the network installs the A5 neighbor report and the corresponding measurement gap, and the UE begins actively measuring neighbor cells (a \~15% airtime cost while this is active). If the serving cell's RSRP then drops below A5 Threshold 1 while a neighbor cell's RSRP exceeds A5 Threshold 2, Event A5 fires and handover evaluation begins. If instead the serving cell recovers above the A1 threshold before A5's conditions are met, Event A1 fires: neighbor measurement and the measurement gap are removed, and the cell returns to the default A2-only state.

## Configuring Handovers

In the 5G Onyx architecture, handover configuration requires planning of neighbor relations, adjustment of mobility parameters, and testing to ensure seamless transitions. This section outlines the steps for configuring handovers in the Onyx Portal.

### Configuration Workflow

{% stepper %}
{% step %}
Add the AP / gNB hardware entry.

See [*Add Access Points*](#add-access-points).
{% endstep %}

{% step %}
Associate the AP with a cell under an Onyx Edge (NR+Core).

See [*Associate Access Points with an Onyx Edge*](#associate-access-points-with-an-onyx-edge).
{% endstep %}

{% step %}
Configure neighbor relationships and handover parameters for each cell.

* Configure all cells associated with the Onyx Edge as the cell's prospective neighbors and allow Automatic Neighbor Configuration. See [*Configure Cells to Use Automatic Neighbor Configuration*](#configure-cells-to-use-automatic-neighbor-configuration).
* Configure specific cells as explicit neighbors. See [*Configure Cells to Use Manual Neighbor Configuration*](#configure-cells-to-use-manual-neighbor-configuration).
* Optionally edit the default advanced handover threshold values. See [*Configure Advanced Handover Parameters*](#configure-advanced-handover-parameters).
  {% endstep %}
  {% endstepper %}

#### Add Access Points

Add the AP here before referencing it from a cell.

#### Associate Access Points with an Onyx Edge

This section describes how to add a new cell and associate an AP with it. If the cell already exists, you can edit it to associate the AP with it.

**To associate an AP with an Onyx Edge (NR+Core):**

{% stepper %}
{% step %}
Navigate to **Equipment** > **Onyx Edge (NR+Core)** tab / **Onyx Edge** tab.

{% hint style="info" %}
**NOTE:** If a 5G network includes both Onyx Edge (NR+Core) and Onyx Edge (Core), the summary details for all Onyx Edge (NR+Core) configured in the network are displayed in the **Equipment** page > **Onyx Edge (NR+Core)** tab. If the network includes only Onyx Edge (NR+Core), the summary details are displayed in the **Equipment** page > **Onyx Edge** tab.
{% endhint %}
{% endstep %}

{% step %}
For the Onyx Edge that you want to configure, in the **Onyx Edge (n)** panel > **Actions** column, click the corresponding **⋮** (options) icon, then click **Edit**.

The **Edit Onyx Edge (*****\<onyx edge name>*****)** page is displayed.
{% endstep %}

{% step %}
Click the **RAN** tab.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FdFAP7dIEaZTz6yjiIGrA%2Fimage.png?alt=media&amp;token=35daf780-6f4d-4f8f-b9f7-51656730701b" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
To add a cell, click **Add Cell**.

The **Add Cell** dialog box is displayed.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2F3QHxiyHtPYntuu9wsi51%2Fimage.png?alt=media&amp;token=96cc7f62-c015-4ef9-b485-b1635d64a4bc" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
In the **General** tab, enter a name for the cell, and the bandwidth, frequency, and PSS (for PCI) values. In the **Associated AP/FHM** dropdown, select the AP/FHM to associate with the cell.
{% endstep %}

{% step %}
Proceed to the **Handover** step to configure neighbor relationships, then click **Submit**.
{% endstep %}
{% endstepper %}

#### Configure Cells to Use Automatic Neighbor Configuration

{% hint style="info" %}
This is the default behavior. All cells associated with the Onyx Edge are configured as prospective neighbors of each other automatically; Desired and Configured neighbor fields display "All."
{% endhint %}

To configure a cell to use Automatic Neighbor Configuration:

{% stepper %}
{% step %}
Navigate to **Equipment** > **Onyx Edge (NR+Core)** tab / **Onyx Edge** tab.
{% endstep %}

{% step %}
For the Onyx Edge that you want to edit, in the **Onyx Edge (n)** panel > **Actions** column, click the corresponding **⋮** (options) icon, then click **Edit**.

The **Edit Onyx Edge (*****\<onyx edge name>*****)** page is displayed.
{% endstep %}

{% step %}
Click the **RAN** tab.
{% endstep %}

{% step %}
For the cell that you want to edit, in the **Action** column, click the options menu (⋮), then click **Edit**.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FMfbdZYg6khEfE7GCaJZf%2Fimage.png?alt=media&amp;token=43f58a3d-74d9-448e-915a-46756ef32f4b" alt=""><figcaption></figcaption></figure></div>

The **Edit Cell** dialog box is displayed.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FNHFuzxa7uHsPg50OSTdH%2Fimage.png?alt=media&amp;token=62dc43d5-bca0-49e9-b9d2-c87c712b65d3" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Click the **Handover** tab.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FhTl7jC7fgV2W0XhLWpGD%2Fimage.png?alt=media&amp;token=6d66a742-cb57-4ceb-a5ee-1fa7285bd265" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Leave the **Explicit Neighbors** toggle off (as seen in the above screenshot).
{% endstep %}

{% step %}
To edit advanced handover parameters, see [*Configure Advanced Handover Parameters*](#configure-advanced-handover-parameters).
{% endstep %}

{% step %}
Click **Save**, then click **Save Onyx Edge**.
{% endstep %}
{% endstepper %}

#### Configure Cells to Use Manual Neighbor Configuration

{% hint style="warning" %}
Adding or editing neighbor tables can restart affected equipment since tables are modified across units. Plan neighbor table changes as a service-disrupting operation.
{% endhint %}

To configure a cell to use Manual (Explicit) Neighbor Configuration:

{% stepper %}
{% step %}
Navigate to **Equipment** > **Onyx Edge (NR+Core)** tab / **Onyx Edge** tab.
{% endstep %}

{% step %}
For the Onyx Edge that you want to edit, in the **Onyx Edge (n)** panel > **Actions** column, click the corresponding **⋮** (options) icon, then click **Edit**.

The **Edit Onyx Edge (*****\<onyx edge name>*****)** page is displayed.
{% endstep %}

{% step %}
Click the **RAN** tab.
{% endstep %}

{% step %}
For the cell that you want to edit, in the **Action** column, click the options menu (⋮), then click **Edit**.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FMfbdZYg6khEfE7GCaJZf%2Fimage.png?alt=media&amp;token=43f58a3d-74d9-448e-915a-46756ef32f4b" alt=""><figcaption></figcaption></figure></div>

The **Edit Cell** dialog box is displayed.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FNHFuzxa7uHsPg50OSTdH%2Fimage.png?alt=media&amp;token=62dc43d5-bca0-49e9-b9d2-c87c712b65d3" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Click the **Handover** tab.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FhTl7jC7fgV2W0XhLWpGD%2Fimage.png?alt=media&amp;token=6d66a742-cb57-4ceb-a5ee-1fa7285bd265" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Enable the **Explicit Neighbors** toggle (as seen in the following screenshot).

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FhncHS3hv9QQNBbGlvvmc%2Fimage.png?alt=media&amp;token=e93a4c7f-7136-463f-9a1b-a335d8cc10be" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Click the **Select Neighbor Cell (Priority Order)** dropdown, and under **Available Neighbors**, select the explicit neighbors for the cell. You can choose up to four neighbor cells. Only cells of the same radio family (gNB or O-RAN AP) appear as candidates.
{% endstep %}

{% step %}
To edit advanced handover parameters, see [*Configure Advanced Handover Parameters*](#configure-advanced-handover-parameters).
{% endstep %}

{% step %}
Click **Save**, then **Save Onyx Edge**.
{% endstep %}
{% endstepper %}

#### Configure Advanced Handover Parameters

Advanced handover parameters control the RSRP threshold values that govern when measurements are triggered and when handovers execute.

**Configure Advanced Parameters**

To configure Advanced Handovers parameters, in the **Add Cell**/**Edit Cell** dialog box > **Handover** tab, click the **Show Advanced Configuration** button.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FbqFlvGSbSNxNE8nVln6i%2Fimage.png?alt=media&amp;token=c13bb825-b59e-48c4-b50a-d14c7d1db5fe" alt=""><figcaption></figcaption></figure></div>

#### Onyx Portal Power Measurement Value Conversion

Power measurements are referred to on the dBm scale in the field, but the Onyx Portal displays and accepts a positive "report level" integer instead of a negative dBm value. For 5G NR, the conversion is:

```
dBm = report level − 156 (e.g. report level 71 = −85 dBm)
```

The read-only **Handover** tab displays both the report level and its dBm equivalent together (e.g. "71/-85 dBm"); the Edit Cell > Advanced Configuration form currently accepts only the bare report-level integer — see [*Notes and Limitations*](#notes-and-limitations).

**Portal Power Measurement Value Conversion**

| Threshold             | Power Level          | Onyx Portal Value (dBm + 156) |
| --------------------- | -------------------- | ----------------------------- |
| A1 RSRP               | -85 dBm              | 71                            |
| A2 RSRP               | -90 dBm              | 66                            |
| A5 RSRP Neighbor Cell | -97 dBm              | 59                            |
| A5 RSRP Serving Cell  | -100 dBm             | 56                            |
| A3 Offset RSRP        | N/A (relative value) | 10 dB                         |
| Hysteresis            | N/A (relative value) | 1 dB                          |

#### Handover Parameters Reference

The following table describes the handover parameters along with tuning guidance.

| Parameter                   | Default       | Purpose / Tuning                                                                                                                                                                                                                                                                                                                         |
| --------------------------- | ------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **A1 RSRP**                 | 71 (−85 dBm)  | <p>Serving cell threshold above which the UE stops measuring neighbors, saving battery.</p><p>Decrease in strong-coverage/stationary scenarios, so the UE stops measuring neighbors sooner and saves battery; increase for high-mobility or high-reliability UE that should keep measuring neighbors longer and stay handover-ready.</p> |
| **A2 RSRP**                 | 66 (−90 dBm)  | <p>Serving cell threshold below which the UE starts measuring neighbors.</p><p>Decrease to avoid triggering measurements too early (wait until the signal is weaker); increase to start monitoring earlier in high-mobility or interference-prone areas.</p>                                                                             |
| **A5 RSRP — Serving Cell**  | 56 (−100 dBm) | Serving cell must fall below this to qualify for handover. Increase if UE linger too long on poor signal; decrease to avoid premature/ping-pong handovers.                                                                                                                                                                               |
| **A5 RSRP — Neighbor Cell** | 59 (−97 dBm)  | Neighbor cell must exceed this to be a valid target. Increase to ensure only strong target cells are used; decrease to allow handover to weaker cells rather than dropping service.                                                                                                                                                      |
| **A3 Offset RSRP**          | 10 dB         | Margin by which neighbor RSRP must exceed serving RSRP. Increase to reduce ping-pong handovers in stable/high-density environments; decrease for faster reaction to genuinely better cells.                                                                                                                                              |
| **Hysteresis**              | 1 dB          | Buffer preventing handover flapping from small fluctuations. Increase in highly variable RF conditions; decrease if handovers are delayed too long.                                                                                                                                                                                      |
| **Time to Trigger**         | 480 ms        | Duration a qualifying condition must persist before handover fires. Increase to avoid reacting to short fades; decrease for faster reaction in high-speed mobility scenarios.                                                                                                                                                            |

#### Sample Configurations

The following table provides starting configurations for typical deployment environments. The Baseline profile matches the Onyx Portal's default values; the other three are illustrative starting points.

| Parameter             | Conservative  | Baseline (Verified) | Aggressive    | High-Mobility |
| --------------------- | ------------- | ------------------- | ------------- | ------------- |
| A1 RSRP               | 76 (-80 dBm)  | 71 (-85 dBm)        | 71 (-85 dBm)  | 69 (-87 dBm)  |
| A2 RSRP               | 61 (-95 dBm)  | 66 (-90 dBm)        | 66 (-90 dBm)  | 68 (-88 dBm)  |
| A5 RSRP Neighbor Cell | 64 (-92 dBm)  | 59 (-97 dBm)        | 61 (-95 dBm)  | 58 (-98 dBm)  |
| A5 RSRP Serving Cell  | 51 (-105 dBm) | 56 (-100 dBm)       | 54 (-102 dBm) | 56 (-100 dBm) |
| A3 Offset RSRP (dB)   | 12            | 10                  | 6             | 8             |
| Hysteresis (dB)       | 3             | 1                   | 0.5           | 2             |
| Time to Trigger (ms)  | 640           | 480                 | 320           | 240           |

## Testing and Validation

Proper testing is essential to confirm that handover performance meets requirements before full deployment. Use the *Handover Parameters Reference* and *Sample Configurations* tables above as starting points for threshold planning.

### Field Testing

Field testing should track handover success rate, handover failure rate, call drop rate during mobility, time to complete handover, signal strength at trigger points, and application continuity across pedestrian, vehicular, and stationary-to-mobile mobility scenarios.

### Onyx Portal-Based Monitoring

To review the handover configuration for a cell in the Onyx Portal:

{% stepper %}
{% step %}
In the Onyx Portal's navigation pane, click **Equipment** > **Onyx Edge (NR+Core)** tab.
{% endstep %}

{% step %}
Click the Onyx Edge's name to open its details page.
{% endstep %}

{% step %}
Click the **Handover** tab.

<div data-with-frame="true"><figure><img src="https://4071075005-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZc9hpHmiTCrh1sn4mWXn%2Fuploads%2FKPQptXTs8EHsKEmSjYVG%2F5g-oe-handovers-tab---x.png?alt=media&amp;token=e6ff4e92-52c9-4bc9-92ea-d5f834aa8500" alt=""><figcaption></figcaption></figure></div>
{% endstep %}

{% step %}
Review the PCI, Frequency, Explicit Neighbors state, Desired/Configured neighbors, Hysteresis, Time To Trigger, and RSRP thresholds for each cell.
{% endstep %}
{% endstepper %}

## Best Practices and Optimization

1. Plan neighbor relationships based on physical cell locations and expected UE mobility patterns before deployment.
2. Start with Automatic (all-to-all) neighbor configuration, then refine to Explicit mode only where asymmetric or restricted topology is required.
3. Respect the four-neighbor and same-radio-family limits when planning Explicit Neighbor lists.
4. Use GXC default thresholds as your baseline before adjusting based on field test results.
5. Monitor continuously via the Onyx Portal Handover tab to track configuration drift.
6. Document all configuration changes and verification results for future troubleshooting.
7. Contact GXC Technical Support for advanced tuning and optimization guidance.

## Related Documentation

* *GXC Glossary*
* *5G Onyx Portal Operations Guide*
* *4G & 5G Onyx Survey Solution Application Note*

## Contact GXC

To get in touch with GXC, visit [*https://gxc.io/contact-us/*](https://gxc.io/contact-us/).


---

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