4G 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 delivers high-reliability, ultra-low latency handovers with seamless mobility management, ensuring optimal Quality of Experience (QoE) across enterprise, private, and mission-critical networks where connection loss can impact operations or safety. GXC's 4G architecture supports both intra-Access Point (AP) and inter-AP handovers using an optimized “make-before-break” approach. This design reduces interference between cells, improves spectral efficiency, minimizes signaling overhead, and enables precise mobility control. As a result, critical applications can operate without interruption, even in complex RF environments with overlapping coverage areas.
Neighbor cell relationships are configured in the Onyx Portal, providing operators with complete control over handover topology. The system automatically generates an initial all-to-all neighbor configuration that can be customized with prioritized neighbor lists for each cell. This approach ensures predictable, reliable handover behavior tailored to your specific network topology and operational requirements.
Supported Handover Types
The 4G Onyx solution supports multiple handover mechanisms designed to ensure seamless mobility and service continuity as UE move across cells.
Intra-AP Handovers
An intra-AP handover occurs when a UE moves between cells managed by the same AP. These handovers are internal to the AP, allowing for faster execution, reduced signaling delays, and minimal service impact. Intra-AP handovers are optimized for high-density environments where multiple cells per AP provide overlapping coverage.
Inter-AP Handovers
An inter-AP handover occurs when a UE moves between cells managed by different APs. This process, requiring precise neighbor cell configuration and robust measurement reporting, involves coordination between APs via the Onyx Edge over the S1 interface. Inter-AP handovers ensure service continuity across wider coverage areas, supporting uninterrupted mobility as UE move between different coverage zones.
GXC employs a "make-before-break" handover strategy that enhances spectral efficiency by establishing the new connection before terminating the existing one. This approach reduces interference and signaling overhead while providing more predictable network behavior. The method is particularly valuable in private and industrial networks, where efficient radio resource management and consistent performance are essential for service continuity.
Neighbor Relation Tables
GXC APs maintain two types of neighbor relation tables:
Neighbor Frequency Table – Contains the list of frequencies that UE should measure to detect neighboring cells. This table is automatically populated by the Onyx Edge based on Spectrum Access System (SAS) grants received by associated APs and cannot be edited manually.
Neighbor Cell Table – Contains detailed information about neighboring APs and cells, including cell IDs, PCI, signal strengths, signal quality metrics, and other parameters necessary for handover decisions. This table is populated based on the neighbor relationships manually configured in the Onyx Portal.
Special Configuration Cases
Dual-Carrier and Carrier Aggregation APs require specific neighbor table considerations when configuring handovers.
Dual-Carrier (DC) APs – In DC APs, each cell maintains its own "Neighbor Frequency Table" and "Neighbor Cell Table". One cell's frequency is listed as a neighbor for the other cell within the same AP, enabling seamless intra-AP handovers. Neighbor relationships and advanced handover parameters must be configured for each cell independently.
Carrier Aggregation (CA) APs – In CA APs, only the primary frequency is advertised to other APs. For example, if AP 1 uses frequency A as primary and B as secondary, and AP 2 uses X and Y respectively, then frequency X is included as a neighbor for AP 1, and frequency A as a neighbor for AP 2.
Neighbor Relationship Configuration Modes
The Onyx Portal offers two modes for configuring neighbor relationships. Choose the mode that best fits your network topology and operational requirements.
Automatic Neighbor Configuration (Default) – In this mode, the system automatically manages neighbor relationships.
All cells associated with the same Onyx Edge are configured as neighbors to each other
The system automatically assigns priority order
No manual neighbor selection required
Ideal for networks where all cells need connectivity to all other cells
Simplifies deployment and reduces configuration overhead
Use this mode when:
Your network has 16 or fewer cells per Onyx Edge. The AP “Neighbor Frequency Table” has a limit of eight unique frequencies. If the AP has more than eight neighbors with different frequencies, priority determines which frequencies are included.
You want to minimize manual configuration
Manual Neighbor Configuration (Explicit Neighbors) – In this mode, you have full control over neighbor relationships.
Manually select which specific cells should be neighbors for each cell
Define priority order by arranging neighbors in your preferred sequence (Priority 1 = highest)
Add or remove neighbor relationships as needed
Control handover topology precisely
Use this mode when:
Your network has more than 16 cells (only 16 neighbors can be configured per cell). The AP “Neighbor Frequency Table” has a limit of eight unique frequencies. If the AP has more than eight neighbors with different frequencies, priority determines which frequencies are included.
You need to optimize handover paths based on physical layout or UE movement patterns
You want to prevent handovers to certain cells
You need asymmetric neighbor configurations (different neighbors for different cells)
Notes and Limitations
Handovers are supported only between APs associated with the same Onyx Edge or the same Onyx Edge Pool.
Manual neighbor configuration requires GXC APs running software version 3.1.14 or later.
Onyx Edge running pre-3.1.3 release version will have ANR enabled. To manage neighbor relations, upgrade to Onyx Edge release 3.1.3 or later.
The AP “Neighbor Frequency Table” is automatically populated by the Onyx Edge based on SAS grants and cannot be edited manually.
The AP “Neighbor Frequency Table” has a limit of eight unique frequencies. If the AP has more than eight neighbors with different frequencies, priority determines which frequencies are included. Contact GXC Technical Support for assistance with multi-frequency deployments.
The AP “Neighbor Cell Table” has a limit of 16 cell entries, with a constraint that the corresponding frequencies do not exceed eight. Priority order determines which neighbors are added when the limit is reached.
If the full list of configured neighbors cannot be applied due to table limits, an alert is generated for the affected cell.
UE must support the necessary hardware and software capabilities for handover functionality. Older or lower-end UE may lack adequate support.
Changes to neighbor frequency or cell tables reboots the APs, resulting in service disruption during configuration updates. Plan all neighbor table changes during scheduled maintenance windows.
How it Works
This section describes how inter-AP handovers work in conjunction with Onyx Portal-configured neighbor relationships for successful UE handovers.
Inter-AP handovers follow a two-phase process:
Neighbor Relationship Configuration
Before handovers can occur, the Onyx Portal and Onyx Edge must establish which cells are neighbors and what frequencies they use, for each AP.
Neighbor Relationship Configuration Call Flow
Configure Neighbor Cell Relationships — An Onyx Portal Administrator configures AP neighbor cell relationships using automatic or manual configuration modes. For more information, see Configuration Workflow.
Populate Neighbor Tables — When a TR-069 session is established with an AP, the Onyx Edge applies the neighbor cell and frequency table configurations:
The Onyx Edge populates each AP’s “Neighbor Cell Table” based on the neighbor relationships and priorities configured in the Onyx Portal. Priority order determines which neighbors are included when the 16-cell table limit is reached (with the constraint that corresponding frequencies do not exceed eight).
The Onyx Edge automatically populates each AP’s “Neighbor Frequency Table” based on SAS grants assigned to the neighbor cells.
Changes to the neighbor tables result in AP reboot.
UE Handover Execution
With neighbor tables in place, the network continuously monitors UE signal quality and executes handovers based on LTE measurement events: A1, A2, and A5.
For a description of each measurement event, the signal-level timeline, and a worked example, see Sample Handover Walkthrough. For detailed parameter definitions, default values, and tuning guidance, see Handover Parameters Reference.
The following call flow diagram summarizes the end-to-end UE handover execution sequence.
UE Handover Call Flow
Send A1 Measurement Configuration — The serving AP delivers a measurement configuration message to the UE containing the A1 RSRP threshold parameters. When the serving cell’s RSRP exceeds this threshold (Event A1), the UE stops measuring neighbor cells, reducing power consumption and measurement overhead.
Send A2 Measurement Configuration — The serving AP delivers a measurement configuration message to the UE containing the A2 RSRP threshold parameters. When the serving cell’s RSRP falls below this threshold (Event A2), the UE begins measuring neighbor cells to identify candidate target cells for handover.
Trigger Neighbor Measurements (A2 Event Report) — When the serving cell’s signal quality falls below the configured A2 threshold, the UE reports the condition to the serving AP.
Configure Neighbor Cell Measurements (A5 Measurement Configuration) — Upon receiving the A2 report, the serving AP configures the UE to perform neighbor cell measurements on frequencies listed in the AP’s “Neighbor Frequency Table”. The AP uses A5 event triggers to control when measurements are reported.
Evaluate Handover Conditions (A5 Event Report) — As the UE moves and signal strength changes, the UE continuously monitors both serving and neighbor cell signal levels. Event A5 is triggered when both A5 conditions are met simultaneously:
The serving cell’s RSRP drops below the A5 threshold, and
A configured neighbor cell’s RSRP exceeds the A5 threshold.
This dual-condition approach ensures handovers occur only when the current cell is genuinely degrading and a stronger alternative is available. For a detailed example of how A5 conditions play out in practice, see Sample Handover Walkthrough.
Execute Handover — The serving AP initiates the handover procedure over the S1 interface. The Onyx Edge coordinates the handover between the serving and target APs using a make-before-break approach. The UE disconnects from the serving cell and connects to the target cell, maintaining service continuity.
For detailed parameter definitions, default values, and tuning guidance for each event's thresholds, see Handover Parameters Reference.
Sample Handover Walkthrough
This section walks through an example of a UE moving from AP-1 (serving cell) toward AP-2 (neighbor cell) in a typical deployment scenario, illustrating how each measurement event is triggered as signal conditions change."
Example Threshold Values
A1 Threshold
−82 dBm
A2 Threshold
−92 dBm
A5 Threshold 1 (serving cell)
−100 dBm
A5 Threshold 2 (neighbor cell)
−96 dBm
The following diagram illustrates how RSRP levels drive each measurement event as the UE moves away from the serving AP and toward a neighbor AP.
LTE Handover Measurement Events — Signal Level Timeline
Initially, while the serving cell’s RSRP remains above the A1 threshold (−82 dBm), Event A1 is triggered, and the UE suspends neighbor cell measurements.
As the UE moves farther away from the serving cell, the serving cell signal level gradually decreases.
When the serving cell RSRP falls below the A2 threshold (−92 dBm), Event A2 is triggered, and the UE begins actively measuring neighbor cells. This measurement phase is represented by the shaded region.
Measurements continue until both A5 conditions are satisfied simultaneously:
The serving cell RSRP drops below A5 Threshold1 (−100 dBm), and
The neighbor cell RSRP exceeds A5 Threshold2 (−96 dBm).
At this point, Event A5 is triggered, and the serving AP initiates the handover procedure.
Event A1: UE Close To Serving AP
Event A1 - Serving Cell Becomes Better Than Threshold
The UE is in close proximity to AP-1, and the serving cell RSRP is above A1 threshold (−82 dBm), which satisfies the A1 threshold condition. Event A1 is triggered, and the UE stops neighbor cell measurements. Signal conditions are strong; no handover is needed.
Event A2: UE Moves Away, Signal Degrades
Event A2 — Serving Cell Becomes Worse Than Threshold
As the UE moves away from AP-1, serving cell RSRP gradually decreases. When it drops below the A2 threshold (−92 dBm), Event A2 is triggered. The UE reports this condition to AP-1, which instructs the UE to begin measuring neighbor cells on the frequencies listed in its “Neighbor Frequency Table”. During this phase, the UE actively evaluates AP-2 and other configured neighbors. This measurement process continues until either the serving signal exceeds the A1 threshold (thereby triggering Event A1) or a suitable handover candidate is identified, thereby triggering Event A5.
Event A5: Both A5 Conditions Are Met, Handover Triggered
Event A5 — Handover Triggered (Dual Threshold Condition Met)
As the UE continues moving towards AP-2, Event A5 is triggered when both of the following conditions are met simultaneously:
The serving cell (AP-1) RSRP drops below A5 Threshold1 (−100 dBm)
The neighbor cell (AP-2) RSRP rises above A5 Threshold2 (−96 dBm)
This dual-condition mechanism ensures that handover occurs only when the current connection is clearly degrading and a better target cell is available.
Once both conditions are satisfied:
The UE reports the measurement to AP-1
AP-1 forwards the request to the Onyx Edge
The Onyx Edge coordinates a make-before-break handover
The UE transitions to AP-2 without service interruption
Configuring Handovers
In the 4G Onyx architecture, handover configuration requires careful planning of neighbor relations, precise adjustment of mobility parameters, and thorough testing to ensure seamless transitions. While actual parameter ranges and GUI steps may vary based on the specific GXC equipment and network environment, this section outlines the foundational steps for configuring reliable handovers.
Configuration Workflow
Add the APs. See Add APs.
Associate the APs with an Onyx Edge or an Onyx Edge Pool. See Associate APs with Onyx Edge or Pool.
Configure neighbor relationships and handover parameters for each AP. Choose the configuration approach that best suits your network topology and mobility requirements:
Configure all cells associated with the Onyx Edge as the AP’s prospective neighbors and allow the Onyx Edge to decide on the neighbors. See Edit APs to Use Automatic Neighbor Configuration.
Keep the default advanced handover parameter configurations.
Edit the default advanced handover parameter configurations to configure optimal threshold values for the given radio environment. See Configure Advanced Handover Parameters.
Configure specific cells as the AP’s neighbors. See Edit APs to Use Manual Neighbor Configuration.
Keep the default handover advanced parameter configurations.
Edit the default advanced handover parameter configurations to configure optimal threshold values for the given radio environment. See Configure Advanced Handover Parameters.
Add APs
This section describes the high-level steps to add an AP.
For detailed instructions, see 4G Onyx Portal Operations Guide > Add APs.
To add an AP:
In the Onyx Portal’s navigation pane, click Equipment > Access Points tab.
The Equipment page > Access Points tab displays the summary details of all APs configured in the network.
In the upper-right corner of the page, click Add Node > Add Access Point.
The Create Access Point page > Access Point tab is displayed.
Enter the AP's details.
For detailed instructions, see 4G Onyx Portal Operations Guide > Add APs.
In the lower-right corner of the page, click Configure RAN.
The RAN tab is displayed.
Enter the RAN details.
For detailed instructions, see 4G Onyx Portal Operations Guide > Add APs.
To save the AP, in the upper-right corner of the page, click Save Access Point.
Associate APs with an Onyx Edge or Onyx Edge Pool
After you add the APs, you must associate them with an Onyx Edge or an Onyx Edge Pool.
Associate APs with an Onyx Edge
To associate APs with an Onyx Edge:
In the navigation pane, click Equipment.
The Equipment page > Onyx Edge tab displays the summary details of all Onyx Edge configured in the network.
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 displays the Onyx Edge’s details.
Click the RAN tab.
Click the Associated Access Point dropdown and select the APs to associate with the Onyx Edge.
To save your edits, in the upper-right corner of the page, click Save Onyx Edge.
Associate APs with an Onyx Edge Pool
To associate APs with an Onyx Edge pool:
In the navigation pane, click Equipment.
The Equipment page > Onyx Edge tab displays the summary details of all Onyx Edge configured in the network. At the bottom of the page, the Onyx Edge Pool panel lists the available pools.
For the pool that you want to edit, in the Onyx Edge Pool (n) panel > Actions column, click the corresponding ⋮ (options) icon, then click Edit.
The Edit Onyx Edge Pool page is displayed.
Click the Associated Access Points dropdown and select the APs to associate with the Onyx Edge pool.
To save your edits, click Save Onyx Edge Pool.
Edit APs to Use Automatic Neighbor Configuration
This section describes how to edit an AP to configure every cell as a neighbor and allow the Onyx Edge to decide on a cell’s neighbors. Note that this is the default behavior.
To edit an AP to configure every cell as a neighbor to the AP:
In the Onyx Portal’s navigation pane, click Equipment > Access Points tab.
The Equipment page > Access Points tab displays the summary details of all APs configured in the network.
In the Actions column, for the AP that you want to edit, click the corresponding ⋮ (options) icon, then click Edit.
The Edit Access Point page displays the AP’s details.
Navigate to the Handover tab and configure the following details:
Explicit Neighbors – When disabled, all cells associated with the Onyx Edge are automatically configured as the AP’s neighbors.
To edit advanced handover parameters, see Configure Advanced Handover Parameters.
To save your edits, in the upper-right corner of the page, click Save Access Point.
Edit APs to Use Manual Neighbor Configuration
This section describes how to edit APs to configure specific cells as neighbors.
CAUTION: Adding or editing APs restarts all APs, since tables are modified and updated across all units. This is a service-disrupting operation and must be planned accordingly.
To edit an AP to configure specific cells as its neighbors:
In the Onyx Portal’s navigation pane, click Equipment > Access Points tab.
The Equipment page > Access Points tab displays the summary details of all APs configured in the network.
In the Actions column, for the AP that you want to edit, click the corresponding ⋮ (options) icon, then click Edit.
The Edit Access Point (<AP name>) page displays the AP’s details.
Navigate to the Handover tab and configure the following details:
Explicit Neighbors – Enable to manually configure specific neighbor cells for this AP. When enabled, you can explicitly select which cells should be neighbors and specify their priority order.
Select Neighbor Cell (Priority Order) – Click to select the AP’s neighbor cells from the list of cells associated with the Onyx Edge.
The list order determines priority, with the first cell in the list assigned priority 1 (highest), the second cell priority 2, and so on.
To reorder priorities, drag and drop cells up or down in the list as required.
To edit advanced handover parameters, see Configure Advanced Handover Parameters.
To save your edits, in the upper-right corner of the page, click Save Access Point.
Configure Advanced Handover Parameters
Advanced handover parameters control the RSRP threshold values that govern when measurements are triggered and when handovers execute. This section describes how to edit APs to configure advanced handover parameters.
Portal Power Measurement Value Conversion
In practice, power measurements are referred to in the dBm scale, typically ranging from -80 dBm (very good power) to -120 dBm (very poor power). To simplify GUI configuration in the Onyx Portal, these negative dBm values (which are hard to compare intuitively) are converted into positive values by adding an offset of 140. For example, -80 dBm becomes 60 in the Onyx Portal. The following table lists the default values.
Unlike absolute power thresholds (A1, A2, A5), the A3 Offset RSRP and Hysteresis parameters represent relative values measured in decibels (dB), not absolute power levels (dBm). The Onyx Portal values for these parameters are entered directly as dB offsets without the conversion used for absolute power measurements.
Portal Power Measurement Value Conversion
A1 RSRP
-85 dBm
55
A2 RSRP
-90 dBm
50
A5 RSRP Neighbor Cell
-97 dBm
43
A5 RSRP Serving Cell
-100 dBm
40
A3 Offset RSRP
N/A (relative value)
10 dB
Hysteresis
N/A (relative value)
1 dB
Handover Parameters Reference
The following table describes all advanced handover parameters — definitions, defaults, and tuning guidance. The Sample Configurations section provides ready-made profiles for common deployment scenarios.
Handover Parameters Reference
A1 RSRP
55 / −85 dBm
The RSRP threshold above which the serving cell’s signal is considered acceptable. When this threshold is met, the UE is instructed to stop measuring neighbor cells. This optimizes battery life by stopping unnecessary measurements when signal is strong.
In DC mode, configure this parameter for Cell 1 and Cell 2.
Increase
In strong coverage environments, to reduce unnecessary neighbor measurements and improve UE battery life.
When you want to prioritize stability over frequent measurements (e.g., stationary or slow-moving UE).
Decrease
In challenging RF environments with frequent micro-mobility, to keep neighbor measurements active longer.
When UE are moving fast or have high reliability demands (e.g., AGVs or autonomous machines), so they stay ready to handover earlier.
A2 RSRP
50 / −90 dBm
The RSRP threshold below which the serving cell’s signal quality is considered poor. When this threshold is met, the UE is instructed to start measuring neighbor cells in preparation for a potential handover.
In DC mode, configure this parameter for Cell 1 and Cell 2.
Increase
In stable environments with good coverage, to avoid triggering neighbor measurements too early.
When reducing measurement overhead is more important than early preparation.
Decrease
In high-mobility or interference-prone areas, to start neighbor cell monitoring earlier, ensuring smoother handovers.
To improve handover responsiveness for mission-critical applications.
A5 RSRP — Serving Cell
40 / −100 dBm
The serving cell’s signal strength must fall below this threshold to qualify for handover evaluation. Ensures handovers only occur when serving cell signal is genuinely weak.
In DC mode, configure this parameter separately for Cell 1 and Cell 2.
Increase
If UE stay too long on poor signals (delayed handovers), increasing this value will cause them to handover sooner.
Decrease
To avoid unnecessary or premature handovers (ping-pong effect), especially if UE are stationary or moving slowly.
A5 RSRP — Neighbor Cell
43 / −97 dBm
The neighboring cell’s signal strength must exceed this threshold to be considered a valid handover target. This prevents handovers to cells with insufficient signal quality.
In DC mode, configure this parameter separately for Cell 1 and Cell 2.
Increase
To ensure UE only move to strong and stable cells, improving post-handover performance.
In environments where overlapping cells have varying quality, to avoid weak target cells.
Decrease
To allow handovers to weaker cells if no stronger options are available, preventing drops or service interruption.
A3 Offset RSRP
10 dB
The signal strength margin (in dB) by which the neighbor cell's RSRP must exceed the serving cell's RSRP to trigger a handover. This offset helps prevent unnecessary handovers due to minor signal fluctuations.
In DC mode, configure this parameter for Cell 1 and Cell 2.
Increase
In stable RF environments to reduce ping-pong handovers caused by small signal variations.
When prioritizing connection stability over signal optimization, particularly for stationary or slow-moving UE.
In high-density deployments with significant cell overlap where frequent handovers would create excessive signaling overhead.
Decrease
In environments where signal quality changes rapidly and UE need to switch to better cells quickly.
For high-mobility scenarios where faster handover decisions improve service continuity.
When optimizing for maximum signal quality is critical for application performance (e.g., high-throughput data applications).
Hysteresis
1 dB
A buffer value that prevents handover flapping due to small signal fluctuations. The neighbor cell's signal must exceed the serving cell’s signal by this margin (in dB) for the handover to be triggered.
Increase
In highly variable RF conditions to reduce oscillating handovers.
When UE experience frequent rapid changes in signal quality.
Decrease
If handovers are delayed too long despite a neighbor being better, or if service continuity requires faster switching.
Time to Trigger
480 ms
The time duration (in milliseconds) that a qualifying signal condition must persist before a handover is initiated. This prevents unnecessary handovers due to temporary signal variations.
Increase
To avoid unnecessary handovers caused by short-term fading or momentary interference.
Decrease
To make handover reactions faster, especially for high-speed mobility scenarios.
To configure advanced handover parameters:
In the Onyx Portal’s navigation pane, click Equipment > Access Points tab.
The Equipment page > Access Points tab displays the summary details of all APs configured in the network.
In the Actions column, for the AP that you want to edit, click the corresponding ⋮ (options) icon, then click Edit.
The Edit Access Point page displays the AP’s details.
Click the Handover tab.
Click Show Advanced Configuration and configure the following details.
Neighbor Management – Enable to allow Onyx Edge to manage neighbor relationships for this AP. When enabled, the Onyx Edge automatically populates and maintains this AP’s “Neighbor Frequency Table” and “Neighbor Cell Table” based on the other cells associated with it.
Handover Thresholds – Parameters that control the handover process, ensuring smooth transitions between cells when a UE moves out of the serving cell's coverage area.
A5 RSRP – A handover is initiated when both of the following conditions are met simultaneously:
Serving Cell – (Required) When the serving cell RSRP falls below this threshold handover is evaluated. Ensures handovers only occur when the serving cell is genuinely weak. In DC mode, configure this parameter for Cell 1 and Cell 2. Default value: 40 (equivalent to –100 dBm).
Neighbor Cell – (Required) When the neighbor cell RSRP rises above this threshold it is considered a valid handover target. Prevents handovers to cells with insufficient signal. In DC mode, configure this parameter for Cell 1 and Cell 2. Default value: 43 (equivalent to -97 dBm).
A1 RSRP – (Required) When the serving cell RSRP rises above this threshold, the signal is considered acceptable. The UE stops measuring neighbors, conserving battery. Default value: 55 (equivalent to -85 dBm). In DC mode, configure this parameter for Cell 1 and Cell 2.
A2 RSRP – (Required) When the serving cell RSRP falls below this threshold, the signal is considered poor. The UE begins measuring neighbors in preparation for handover. Default value: 50 (equivalent to -90 dBm). In DC mode, configure this parameter for Cell 1 and Cell 2.
A3 Offset RSRP – (Required) The margin, in dB, by which the neighbor cell RSRP must exceed the serving cell RSRP to trigger a handover. Prevents unnecessary handovers from minor signal fluctuations. Default value: 10 dB. In DC mode, configure this parameter for Cell 1 and Cell 2.
Hysteresis (dB) – (Required) A buffer value, in dB, that prevents handover flapping from small signal fluctuations. The neighbor cell signal must exceed the serving cell signal by this margin before a handover is triggered. Default value: 1 dB.
Time to trigger (ms) – The duration, in milliseconds, that a qualifying condition must persist before a handover is initiated. Prevents handovers triggered by temporary fading or momentary interference. Default value: 480 ms.
To save your edits, in the upper-right corner of the page, click Save Access Point.
Sample Configurations
The following table provides recommended starting configurations for typical deployment environments. Use these as baselines and adjust based on field testing results and your specific network requirements.
Conservative (Stable Connection) – Designed for stationary or slow-moving devices and mission-critical applications requiring maximum stability. Minimizes handover frequency and reduces ping-pong effects, though devices may stay on weaker signals longer.
Baseline (GXC Default) – GXC-recommended starting point for general enterprise environments with mixed mobility patterns. Provides balanced performance across most scenarios with optimal trade-offs between stability and optimization.
Aggressive (Opportunistic) – Optimized for high-density environments with excellent coverage overlap and performance-critical applications. Maximizes signal quality through quick handovers to better cells but increases handover frequency and signaling overhead.
High-Mobility – Tailored for vehicular applications and fast-moving devices with faster reaction times. Optimized for movement patterns while maintaining reasonable stability but may not suit stationary devices.
Sample Configurations
A1 RSRP
60 (-80 dBm)
55 (-85 dBm)
55 (-85 dBm)
53 (-87 dBm)
A2 RSRP
45 (-95 dBm)
50 (-90 dBm)
50 (-90 dBm)
52 (-88 dBm)
A5 RSRP Neighbor Cell
48 (-92 dBm)
43 (-97 dBm)
45 (-95 dBm)
42 (-98 dBm)
A5 RSRP Serving Cell
35 (-105 dBm)
40 (-100 dBm)
38 (-102 dBm)
40 (-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. The recommended process combines theoretical modeling, field measurement, and portal-based monitoring.
Recommended testing process:
Model parameters using the GXC Handover Visualization Tool. Model parameters using the GXC Handover Visualization Tool to understand how threshold values affect the handover region before deploying to the field. See GXC Handover Visualization Tool.
Plan and configure neighbor relationships. Plan and configure neighbor relationships in the Onyx Portal based on your network topology and expected UE movement patterns.
Apply initial handover parameter configuration. Configure handover parameters in Onyx Portal for initial field testing. Start with model or default threshold values. See Configuring Handovers.
Perform field testing. Use the GXC Onyx Survey Tool across all coverage areas and mobility scenarios. The Onyx Survey Tool is purpose-built for GXC private cellular deployments and provides integrated handover measurement and reporting. For details on using the tool, see the 4G & 5G Onyx Survey Solution Application Note.
Alternatively, professional drive test tools such as TEMS Investigation or Nemo Outdoor may be used. Monitor the performance metrics – track handover success rates, timing, and signal levels to validate real-world performance against expectations. See Field Testing.
Monitor performance in the Onyx Portal. Use Onyx Portal to analyze handover statistics, review neighbor table status, and track overall mobility performance. See Onyx Portal-Based Monitoring.
Adjust and re-test. Based on field test results, refine threshold values and neighbor priorities. Re-test until target performance levels are achieved. See Configure Advanced Handover Parameters.
Validate mission-critical applications. Confirm that applications requiring uninterrupted connectivity maintain acceptable connectivity and performance during handover transitions.
GXC Handover Visualization Tool
GXC provides an interactive web-based tool to help visualize and understand LTE handover behavior before field deployment. Use this tool to understand the relationship between threshold parameters and handover regions before making any configuration changes.
Using GXC’s LTE Handover Region Visualization Tool:
Access the tool at: https://lte-handoff-vfa3mkxapbectiedyiptvj.streamlit.app/
Under Threshold Parameters, use the sliders to adjust the threshold and hysteresis values to observe how changes affect the handover region.
For detailed information on these parameters, see Configuring Handovers.
The green region in the visualization shows where handovers will occur based on the relationship between Serving Cell Power (X-axis) and Neighbor Cell Power (Y-axis).
Experiment with different parameter combinations to understand:
How hysteresis affects handover stability
The relationship between serving and neighbor cell thresholds
Optimal parameter ranges for different deployment scenarios
Use the tool to identify starting parameters and understand parameter interactions before moving to field testing.
Field Testing
After initial parameters are configured, deploy and validate handover performance in the live network environment.
Deploy theoretical parameters in the actual network environment.
Perform field tests using the GXC Onyx Survey Tool to confirm real-world handover performance across your coverage area. The Onyx Survey Tool is purpose-built for GXC private cellular deployments and provides integrated measurement collection, handover event logging, and reporting. For full details on using the tool, see the 4G & 5G Onyx Survey Solution Application Note. Alternatively, use third-party drive test tools such as TEMS Investigation or Nemo Outdoor.
During testing, monitor key performance indicators:
Handover success rate
Handover failure rate
Call drop rate during mobility
Time to complete handover
Signal strength at handover trigger points
Application continuity during handover
Test different mobility scenarios as per deployment requirements:
Pedestrian speed (3 km/h)
Vehicular speed (30-60 km/h)
Stationary to mobile transitions
High-density areas with multiple overlapping cells
Onyx Portal-Based Monitoring
To review and adjust the AP Handover settings in the Onyx Portal:
In the Onyx Portal’s navigation pane, click Equipment > Access Point tab.
The Equipment page > Access Points tab displays the summary details of all APs configured in the network.
To view the details of a particular AP, click its name.
The <AP name> page displays the AP’s details.
Click the Handover tab.
Analyze handover measurements and adjust parameters based on observed performance.
For details, see Configuring Handovers.
Best Practices and Optimization
The following recommendations help ensure reliable handover performance and simplify ongoing network optimization.
Plan before you configure. Plan neighbor relationships based on physical cell locations and expected UE mobility patterns before deployment.
Start all-to-all, then refine. Start with the default all-to-all neighbor configuration and refine based on traffic patterns and field testing.
Use priority ordering to manage table limits. Ensure the most likely handover targets appear within the 16-cell table limit.
Configure bidirectional relationships. Configure bidirectional neighbor relationships for cells where UE movement is expected in both directions.
Start with GXC default thresholds. Use GXC-provided default values as your baseline before adjusting them based on field test results. See Sample Configurations.
Use the Visualization Tool before field testing. Leverage GXC's LTE Handover Region Visualization Tool to understand parameter relationships before field deployment. See GXC Handover Visualization Tool.
Monitor continuously. Track handover success rates, failure patterns, and mobility performance metrics to identify optimization opportunities.
Test iteratively. Combine theoretical modeling, field testing, and Onyx Portal analytics in an iterative cycle to achieve optimal performance.
Validate application performance, not just connectivity. Ensure mission-critical applications maintain service quality during handover transitions.
Schedule table changes during maintenance windows. All neighbor table changes cause AP reboots and service disruption.
Document all changes. Record all configuration changes, performance results, and rationale for future troubleshooting.
Contact GXC Technical Support for advanced tuning and optimization guidance.
Related Documentation
4G Onyx Portal Operations Guide
4G & 5G Onyx Survey Solution Application Note
5G Spectrum Analyzer Application Note
GXC Glossary
Contact GXC
To get in touch with GXC, please visit https://gxc.io/contact-us/.
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