Hi Experts,
Quick question on VoNR muting in Ericsson.
From what I can see, most of the controls look to be node-level.
Is there any way to handle muting at cell level, or any parameters/workarounds people have used for more granular control?
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In the Ericsson ecosystem, you are correct that most high-level VoNR (Voice over New Radio) features—particularly those related to SIP timers, IMS registration, and AMR codec handling—are managed at the Node level (gNodeB or ManagedElement) or within the Core (IMS/5GC).
However, for granular control over “muting” (often referring to silence suppression, DTX, or specific radio resource muting to prevent interference), there are a few cell-level mechanisms and common workarounds.
1. Cell-Level Discontinuous Transmission (DTX)
While the decision to use DTX is typically a UE-driven or Core-negotiated setting, the RAN can influence its behavior via QCI/5QI-specific parameters.
* Logical Channel Config: You can modify the LogicalChannelConfig for 5QI1 (the dedicated voice bearer) at the cell level.
* Workaround: By adjusting the Periodic BSR (Buffer Status Report) timers or the SR (Scheduling Request) periodicity specifically for the voice bearer on a per-cell basis, you can indirectly control how “aggressive” the cell is in allowing or muting silent periods during a call.
2. Interference-Based Muting (Radio Resource Muting)
If your “muting” refers to the radio-level blanking of Resource Blocks (RBs) to protect neighboring cells (a common 5G optimization), this is handled at the cell level.
* RadioNinja / Interference Coordination: Ericsson features like “RadioNinja” allow for the muting of specific RBs at Cell C1 to ensure that users at neighboring cells don’t experience interference.
* Cell Individual Offsets (CIO): While not a “mute” button, adjusting the CIO or QrxlevminNR at the cell level can force UEs in “problematic” areas of a cell to handover rather than persisting in a muted or high-interference state.
3. Service-Based Handover (The “Fallback” Workaround)
If a specific cell is experiencing high VoNR mute rates (audio gaps), a common granular workaround is to disable VoNR on that specific cell while keeping it active on the rest of the node.
* Parameter: NrCellCu::epsFallbackOrder or voiceServicePolicy.
* Action: You can set a cell to EPS Fallback (EPSFB) mandatory. This effectively “mutes” the VoNR capability for that specific cell, forcing the UE to use the more stable VoLTE layer without affecting the whole gNodeB.
Check also the document I shared in the group
Yes, check VoLTE license features