Alcatel 3EM04001AA Signal Processing Unit – with 2 Accessory Cards
The Alcatel 3EM04001AA is a dedicated signal processing unit (SPU) designed for voice‑centric telecom platforms such as media gateways, softswitches, and integrated access devices. This module, identified by the full code 3EM04001AAAC and hardware revision MREV:01, includes two companion accessory cards that expand its I/O and processing capabilities. It handles intensive real‑time DSP tasks including voice coding, echo cancellation, tone generation/detection, and conferencing bridging.
Product Architecture
The SPU is based on a high‑density array of programmable DSPs, capable of processing up to 256 simultaneous voice channels. The accessory cards typically provide additional TDM (E1/T1) or packet (Ethernet) interfaces, enabling the unit to connect to both circuit‑switched and packet‑switched networks. The module communicates with the host system via a high‑speed backplane bus and is managed through a control processor running real‑time firmware.
The MREV:01 revision includes improved DSP algorithms for enhanced voice quality, reduced latency, and support for wideband codecs such as G.722 and AMR‑WB. It also features hardware acceleration for fax and modem relay, essential for legacy enterprise services.
Technical Specifications
Product Type: Signal Processing Unit
Part Number: 3EM04001AA / 3EM04001AAAC
Hardware Revision: MREV:01
DSP Chips: 8 x dual‑core DSPs (500 MHz each)
Voice Channels: Up to 256 (full‑duplex)
Supported Codecs: G.711, G.729A/B, G.723.1, G.726, G.722, AMR, AMR‑WB
Echo Cancellation: G.168 compliant, up to 128 ms tail
Conference Capacity: 64 participants per conference bridge (multiple bridges)
Tone Functions: DTMF, MF, call progress tones (programmable)
Accessory Cards (included): 1 x TDM interface (8 E1/T1 ports) + 1 x Gigabit Ethernet (2 ports) with RTP processing
Memory: 2 GB DDR2 (shared)
Power Consumption: 45 W (with accessory cards)
Operating Temperature: 0°C to 55°C
Dimensions: Single‑slot (proprietary) + 2 accessory slots
Key Features and Benefits
High channel density reduces the number of SPUs needed per chassis.
Advanced echo cancellation ensures clean audio for VoIP and cellular interworking.
Flexible codec support enables seamless interoperability between TDM and IP networks.
Integrated conference bridging eliminates the need for external conference servers.
Redundant power and clock inputs for carrier‑grade availability.
Deployment Scenarios
This SPU is used in Alcatel‑Lucent media gateways and softswitch platforms to interconnect PSTN trunks with IP‑based core networks. It processes voice channels for residential, business, and wholesale termination services. The accessory cards provide direct connectivity to E1/T1 lines from legacy PBXs or to IP uplinks for SIP trunking.
In contact centre applications, the SPU handles audio mixing for agent conferences and recording.
Management and Maintenance
The unit is managed via the host system's OAM, with performance monitoring per DSP and per channel. Firmware upgrades are performed remotely. The accessory cards are hot‑swappable for field expansion or replacement.
Reliability
MTBF exceeds 180,000 hours. The module includes ECC memory and self‑diagnostic tests.
Conclusion
The Alcatel 3EM04001AA signal processing unit with its two accessory cards offers a comprehensive, high‑capacity solution for voice‑processing needs in next‑generation networks, bridging legacy and IP domains with exceptional quality and reliability.




