The narrowband SIP phone, based on the Internet Protocol voice session control protocol, can make and receive calls over LAN/WAN without the need for a SIM card. Users can build a toll-free IP network intercom system for real-time full-duplex communication. This solution is suitable for various industries such as coal mining, finance, and healthcare.

 

 

The principle of the narrowband SIP phone solution is shown in the diagram below. The audio processing part incorporates multiple processing algorithms such as ANS (background noise suppression), AGC (automatic gain control), and AEC (acoustic echo cancellation). The MCU uses a high-performance embedded processor, ensuring high speed, stability, and smooth operation. Paired with large memory, it enables various functions such as outgoing/incoming call logs and contact storage. The voice coding section supports multiple types of digital vocoders including G.722, G.723, G.729A, AMBE, and AHELP.

 

 

The narrowband SIP phone solution supports standard SIP protocol, enabling high-quality voice calls and digital broadcasting over LAN/WAN. The product supports handset and hands-free speakerphone modes.

This solution can achieve protocol conversion between SIP and CAN bus, expanding coverage in industrial sites and making it suitable for underground operation scenarios such as coal mines.

One-touch Call, One-touch DND                Noise Suppression, Echo Cancellation

One-touch Broadcast, Real-time Paging         SIP to Bus Conversion, Full Coverage

Call Hold, Call Transfer                          Supports Multi-party Conference Function