The Huawei BBU3900, BBU3910 and BBU5900 share the same 2U, 19-inch chassis footprint (86 x 442 x 310 mm), so moving between them rarely changes rack space. What changes is cooling capacity, the power module, backplane switching capability and, most importantly, which main control (UMPT) and baseband (UBBP) boards each frame can host. In short: the BBU3900 is the legacy 2G/3G/4G platform, the BBU3910 adds a faster backplane and support for newer boards (including NR-capable UMPTg and UBBPg2/UBBPg2a), and the BBU5900 is Huawei’s 5G-era BBU with up to 2100 W heat dissipation using the FANf fan module. This guide explains each step of the upgrade path and what to check before you buy replacement hardware.
Why the BBU frame matters in an upgrade
On a Huawei DBS site, the BBU is a chassis: the real processing happens on plug-in boards. A site upgrade usually starts because operators want to add a new RAT or band, add more carriers or cells, or deploy NR. Those features are delivered by newer UMPT and UBBP boards, and newer boards need more power, more cooling and a backplane that can carry the extra traffic. That is why a board that works perfectly in a BBU5900 may not be supported, or may be thermally limited, in an older frame.
Before planning any swap, inventory the site: frame model, fan module, UPEU power module, main control board, every baseband board, and the software release running on the site. Our earlier guide on Huawei BOM codes and serial numbers explains how to read the labels.
BBU3900 vs BBU3910 vs BBU5900 at a glance
| Item | BBU3900 | BBU3910 | BBU5900 |
|---|---|---|---|
| Dimensions (H x W x D) | 86 x 442 x 310 mm | 86 x 442 x 310 mm | 86 x 442 x 310 mm |
| Fan modules | FAN, FANc | FANd, FANe | FANf |
| Heat dissipation | 350 W (FAN) / 650 W (FANc) | 1000 W (FANd or FANe) | 2100 W (FANf) |
| Power module | UPEUa / UPEUb / UPEUc / UPEUd | UPEUd | UPEUe |
| Main control boards | GTMUb/c, UMPTa, UMPTb, UMPTe | GTMUb/c, UMPTb, UMPTe, UMPTg, UMPTga | UMPTe2, UMPTe3, UMPTg2, UMPTg3 (per Huawei product page) |
| Typical baseband boards | WBBP, LBBP, UBBPd, UBBPe, UBBPg1/g1a | UBBPd, UBBPe, UBBPex2, UBBPg2, UBBPg2a and others | UBBPe4, UBBPg1a, UBBPg2 and newer UBBP boards |
| Main role | GSM/UMTS/LTE | Multi-RAT LTE, NR-ready with UMPTg | Multi-RAT including 5G NR |
Board lists are not exhaustive and depend on the hardware and software release; always confirm against the hardware description for the release on your site.
Step 1: BBU3900 to BBU3910
The Huawei BBU 3900 is the classic platform used for GSM, UMTS and LTE. Many older sites still run WMPT/LMPT main control boards and WBBP/LBBP baseband boards, or first-generation UMPT and UBBPd boards. The main limits are cooling (650 W maximum with FANc) and a backplane designed before today’s high-capacity baseband boards.
The Huawei BBU 3910 keeps the same chassis size but uses a backplane with higher switching capability, the FANd or FANe fan modules (1000 W heat dissipation) and the UPEUd power module. It also supports later boards that the BBU3900 does not, such as UMPTg and UBBPg2/UBBPg2a. Huawei documentation also describes mixed configurations: a base station can interconnect two BBU3910s, or one BBU3900 with one BBU3910, which allows operators to add capacity without removing the existing frame immediately.
What can usually be reused
- UMPTb and UMPTe main control boards (supported in both frames)
- UBBPd and UBBPe baseband boards
- USCUb satellite/clock cards and the UEIU environment interface unit
- RRUs connected over CPRI, provided the new baseband board supports the RAT and band configuration
What usually has to change
- Fan module (FAN/FANc to FANd or FANe)
- Older-generation boards such as WMPT, LMPT, WBBP and LBBP, which are not on the BBU3910 board list
- UTRP variants other than UTRPa and UTRPc, and UCIU interconnection boards (the BBU3910 uses UCCU)
Step 2: BBU3910 to BBU5900
The Huawei BBU 5900 is the platform Huawei positions for 5G evolution and multi-RAT sites. Its biggest practical advantage over the BBU3910 is thermal headroom: 2100 W heat dissipation with the FANf, roughly double the BBU3910. That matters when a site runs several high-capacity UBBPg boards together with NR.
The BBU5900 uses the UPEUe power module, which accepts -48 V DC input with a range of -38.4 V to -57 V DC. Huawei’s product page lists a full-configuration weight of 18 kg and indoor or outdoor installation (in a suitable cabinet).
For board choice, see our BBU5900 board compatibility guide. Common pairings include a UMPTg main control board with UBBPg-series baseband, for example the Huawei UBBPg2, while LTE-only sites often keep UBBPe boards.
When to skip the BBU3910 entirely
If the goal is NR, or the site needs several new-generation baseband boards, going straight from BBU3900 to BBU5900 is usually simpler. You change the frame, fan and power module once, and you avoid buying an intermediate chassis that may become the next bottleneck.
Upgrade planning checklist
- Define the target configuration: RATs, bands, number of cells and carriers, and whether NR is required.
- Check the software release: new boards need a supporting SRAN release. For example, Huawei documentation lists NR support on UMPTe and UMPTg from SRAN15.1.
- Match main control and baseband boards to the frame’s supported board list.
- Calculate the thermal budget: the total power of installed boards must stay within the frame and fan module’s heat dissipation capability.
- Verify power: the right UPEU model and DC input at the site.
- Review CPRI links: UBBPd, UBBPe and UBBPg boards each provide six CPRI ports; check port count and rates against the RRUs you will connect.
- Plan transmission: confirm which UMPT ports or UTRP boards will carry backhaul.
Buying used frames and boards for the upgrade
Used and refurbished BBU frames are a cost-effective way to upgrade a site or keep spares. When buying, ask for clear label photos showing the BOM code and serial number, confirm the included fan and power modules, and check that slot guides and connectors are undamaged. For boards, check the exact sub-model (for example UBBPg2 vs UBBPg2a), because capabilities differ even when the board looks identical. Browse the full range in our Huawei product category.
FAQ
Can I install a BBU5900 in the same rack space as a BBU3900?
Yes. All three frames measure 86 x 442 x 310 mm (2U, 19-inch), so the BBU5900 fits the same mounting space. Check cabinet airflow and the DC power feed, since the BBU5900 can dissipate much more heat.
Can a BBU3900 support 5G NR?
The BBU3900 is generally treated as a 2G/3G/4G platform. NR deployments are normally done on the BBU3910 with UMPTg or, more commonly, on the BBU5900.
Can I mix a BBU3900 and a BBU3910 at one site?
Huawei documentation describes interconnecting one BBU3900 with one BBU3910, or two BBU3910s, in a single base station. Interconnection uses the UCCU board on the BBU3910.
Do I need to replace my RRUs when I upgrade the BBU?
Not necessarily. RRUs connect over CPRI, so existing radios can often stay in service, as long as the new baseband board and software release support their RAT, band and CPRI rate.
Get the right BBU and boards for your upgrade
We supply used and refurbished Huawei BBU frames, UMPT main control boards and UBBP baseband boards for upgrades, expansions and spares. Every unit is functionally tested before shipment (radio units such as RRUs are also VSWR tested), comes with a 90-day warranty, and we ship worldwide in secure packaging. Send us your part numbers or target configuration via WhatsApp +86 187 3329 4669 / +86 139 3088 8705, email jack@telecombts.com, or use the form at https://telecombts.com/contact-us/.
We also buy surplus Huawei, Ericsson and Nokia equipment. If your upgrade frees up old frames or boards, see sell your equipment.