VoIP SLIC Open Platform The Wideband Subscriber Line Interface Circuit for Voice over IP (VoIP) Applications

摘要

The large scale deployment of the voice over IP, or voice over packet technology and the migration of this technology towards the edge of the network stimulates a revival of SLIC and CODEC design. The basics of this existing technology are refreshed and the architecture of a specific implementation is described in this paper.New smart power technologies with single chip low voltage CMOS and high voltage DMOS and bipolar devices allow for full single chip SLIC & CODEC integration. Another option is to put the low voltage CODEC in a deep sub micron system on chip with a mini-SLIC, integrating only the high voltage drivers.In the field new voice circuits get deployed now to bring voice to the phone over the wideband network and do the conversion from wideband IP coded voice to the analogue real world speech signals as close to the phone as possible via an Analogue Telephone Adaptor [ATA]. The conversion can be done in the phone as a real IP-phone, in a PC (Skype) via the audio of the PC or via an ATA, driving a regular phone. The conversion can also be done in the house via a VoIP to POTS converter next to the wideband modem, in your garage e.g. to drive your existing home phone cabling. The conversion can also be done with an ATA in the street cabinets driving only the last kilometer to your home phone.In this paper a Short Haul Line Integrated Circuit [SHLIC] is described, used to transmit Voice over Internet Protocol, also called VoIP, IP Telephony, Internet telephony, wideband telephony, wideband phone, and the routing of voice conversations over the Internet or through any other IP-based network. The SHLIC is a pure analogue circuit processed in a high voltage technology. Also the CODEC, performing the wideband 16Ksamples/s or A/μ law narrow band signal processing, is briefly described.