I can now conclude the speech coding that is one of the very important requirements at a reduced bit-rate, with controlled complexity. Complexity of the coders should be very small, as far as possible. Then, advances in speech coding is very important for mobile telephoning, giving us more number of channels. LPC, that is the linear predictive coding bidding the analysis by synthesis, is the dominant technique used in the cellular mobile communication speech coders, but then you have still further challenges, you want to lower the speech coding rates below 8 Kbps and one has to take care of the background noise impairments, the channel errors and the coder complexity. Future important concepts in a speech coding would require variable rate speech coding and adaptive signal processing techniques. Innovations in speech codings is essential for ubiquitous mobile communications too in the future.

---