VOIP GATEWAYS FOR CELLULAR TOWERS

Sigpro designed the transcoder architecture for a VoIP gateway that allows Ethernet-based communication between cellular stations in a campus environment.

Customer Requirement
One of the world leaders in CDMA equipment was seeking to link "mini" cellular base stations in an enterprise campus with inexpensive IP-based Ethernet. Sigpro was tasked with specifying the gateway functionality that would transcode between the CDMA IS-95 protocols and VoIP H.323 protocols.

Sigpro Approach

• Systematically match signaling, registration, addressing, etc., protocols from IS-95 to H.323.
  
  
• Use H.323 GateKeeper as the MSC function (address, location, and presence switch).
  
  
• Produce detailed specification for the customer's internal team to code and implement.
  
  
• Maintain voice payload in Q-CELP format to avoid conversion latency.

Key Results:

• Software coded from specification directly by internal customer team.
  
  
• Demonstration was the world's first CDMA-VoIP gateway.
  
  
• Successful prototype led to technology spin-off in a new company, which has since been acquired by the leading network service provider of VoIP communications.