Nokia AirScale: What is the Relationship Between AMIA and ASIB?
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When deploying and maintaining Nokia AirScale 4G/5G indoor BBU systems, network engineers and procurement teams often encounter the terms AMIA and ASIB. Understanding their relationship is essential for correct hardware configuration, slot planning, and spare‑part replacement.

What is Nokia AMIA?
Nokia AMIA is the AirScale indoor BBU subrack or chassis. It provides the physical enclosure, backplane connectivity, and power infrastructure for plug‑in boards.

Technically, AMIA itself does not perform baseband processing. It acts as a carrier for:
- ASIB / ASIK common control boards
- ABIO / ABIL capacity boards
Based on the slot architecture:
- C1 and C2 slots are dedicated to common control boards, such as ASIB
- B1 to B6 slots are dedicated to baseband capacity boards, such as ABIO
What is Nokia ASIB?
Nokia ASIB is a control and capacity-integrated module that plugs into the AMIA subrack. It is usually installed in slot C1 or C2.
ASIB is responsible for:
- System management and configuration
- Clock synchronization
- Backhaul interface processing
- Communication with radio units
- Integrated baseband processing capability (in combination with capacity boards)
- Active‑standby redundancy when two ASIB boards are installed
An AMIA subrack can typically host up to two ASIB boards for redundancy.
The Relationship Between AMIA and ASIB
The relationship can be summarized as follows:
However, AMIA and ASIB alone are not enough for a fully operational BBU. A typical AirScale indoor BBU also requires baseband capacity boards.
The basic configuration is:
Slot Allocation in the AMIA Subrack
| Slot | Board Type | Quantity |
|---|---|---|
| C1, C2 | ASIB Common Control Board | Up to 2 |
| B1‑B6 | ABIO Baseband Capacity Board | Up to 6 |
ASIB vs ASIK, ABIO vs ABIL
In addition to ASIB and ABIO, Nokia also offers newer generations such as ASIK and ABIL.

- ASIB is a control and capacity-integrated module, typically paired with ABIA capacity cards
- ASIK is a newer pure common control unit, typically paired with ABIL capacity cards
- ASIB and ASIK cannot normally be mixed in the same AMIA chassis
- ABIO and ABIL also belong to different generations
Practical Implications for Procurement and Maintenance
-
Maintenance replacement
If ASIB fails, it can often be replaced separately while the existing AMIA chassis remains on site. -
Redundancy configuration
Installing two ASIB boards in C1 and C2 provides active‑standby redundancy. -
Capacity expansion
Additional ABIO or ABIA boards can be added into B1‑B6 slots to increase baseband capacity. -
Generation matching
Always check whether the system is using ASIB+ABIA or ASIK+ABIL before purchasing replacement parts.
Sourcing Nokia AirScale Spare Parts
Skyward Telecom supplies original and fully tested Nokia AirScale BBU spare parts, including AMIA subracks, ASIB common control boards, ABIO capacity boards, and related radio units.
For technical enquiries or replacement‑part sourcing, please contact our team for configuration support.