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Below is the site layout for the VOCAL Technologies website.

• Systems
  • Overview
  • VoIP Systems
  • V²oIP Systems
  • RoIP Systems
  • RASoIP Systems
  • Cryptographic Systems
  • Facsimile Lawful Interception
  • T.38 FoIP Lawful Interception
  • Hardware
    • ATA
      • Features
      • Specifications
      • Reference Designs
      • Interoperability
      • Provisioning
      • 1x1+1
      • 2x1+1
      • 2x2+1
      • 3x2+1
      • 8x1+1
    • HPNA Home PBX
      • Features
      • Specifications
      • VPBX Gateway Unit
      • VPBX Extension
    • Video PBX
      • Features
      • Specifications
    • FPGA/PLD/ASIC Cores
      • Advanced Encryption Standard (AES) IP Core
      • Counter with Cipher Block Chaining-Message Authentication Code (CCM) IP Core
  • T.38 Real-Time Fax Relay Over IP
  • Platforms
  • Operating Systems
• Software
  • Overview
  • Modules
  • VoIP
    • Overview
    • V²oIP
    • MGCP
    • SIP
    • SDP
    • RTP
    • SRTP
    • T.38 Real-Time Fax Relay Over IP
    • Comparison of T.38 Transmission Over UDPTL or RTP
    • T.38 Transmission Over SRTP
    • Current Proposed Modifications to T.38
    • T.38 Prioritization in a Universal Gateway
    • T.38 Image Extraction from Captured Network Data
    • Comparison of Facsimile Transmission over T.38 and V.152
    • VoIP Vocoders
  • SIP
    • Overview
    • SIP Calling
    • SIP Conferencing
    • SIP Call Forwarding
    • SIP Call Transferring
    • Locating SIP Servers
    • SIP Message Routing
    • SIP PRACK
    • SIP Presence and Instant Messaging
    • SIP Registration
    • Secure SIP
    • SIP Session Timers
  • Voice Codecs
    • Overview
    • Efficient Implementation of LPC Analysis Filters
    • Wideband Energy Detection in Scalable Speech Coding
    • PSQM
      • PSQM Values
      • Resource Requirements
    • ITU Speech Coders
      • ITU G.711 - 64k bps PCM (A-law or μ-law form)
      • ITU G.722 - 7 kHz audio coding within 64 kbit/s (SB-ADPCM)
      • ITU G.722.1 - 24k and 32k bps, 7 kHz audio
      • ITU G.722.2 - Adaptive Multi-Rate Wideband (GSM AMR-WB)
      • ITU G.723.1 - 5 1/3k and 6.4k bps ACELP/MP-MLQ
      • ITU G.726 - 16k, 24k, 32k and 40k bps ADPCM
      • ITU G.727 - 5, 4, 3 and 2-bits sample Embedded ADPCM
      • ITU G.728 - 16k bps LD-CELP
      • ITU G.729/G.729A - 8k bps CS-ACELP
      • ITU G.729 Annex B - Silence Detection
    • GSM Speech Coders
      • GSM Full Rate
      • GSM Half Rate
      • GSM Enhanced Full Rate
      • GSM Adaptive Multi-Rate
      • GSM Adaptive Multi-Rate Wideband (G.722.2)
    • Other Speech Coders
      • iLBC
      • LPC-10
      • MELP
      • MELPe
      • Speex
    • Wideband Speech Coders
      • ITU G.722
      • ITU G.722.1
      • ITU G.722.2 (GSM WB-AMR)
      • ITU Speex
    • Evaluating Voice Coders
  • Audio Examples
    • Echo Cancellation
    • Noise Cancellation
    • Speech Coders
    • Wideband Speech Coders
  • Video Codecs
    • Overview
    • Still Picture
      • JPEG
      • JPEG2000
        • Wavelet Transform for Sparsity in JPEG2000
        • JPEG2000 Rate and Quality Scalability
        • Secure JPEG2000 (JPSEC) Images
        • Wireless JPEG2000 Transmission and Unequal Error Protection using JPWL
        • JPEG2000 Image Transmission using JPIP
    • Motion Picture
      • MJPEG
      • MPEG-2
      • MPEG-4
    • Video Conference
      • H.261
      • H.263
      • H.264
  • Echo Cancellation
    • Acoustic Echo Cancellers
      • Two-Path Method for Acoustic Echo Cancellation
      • The Affect of Convergence Speed in the Two-Path Method
      • Robust Adaptive Algorithms for Echo Cancellation
      • The Combination of Adaptive Filters
      • The Challenges of Stereophonic\Multichannel Echo Cancellation's
      • Subband Acoustic Echo Cancellation
      • Wideband Acoustic Echo Cancellation
      • Frequency Domain Adaptive Filtering in Echo Cancellation
      • Handling of Nonlinearities in Echo Cancellation
      • Double-Talk Detection in Echo Cancellation
      • Variable Step-size and Regularization Parameters for NLMS
      • Post Filtering for Residual Echo Control
      • The Perception of Echo
      • The Combined Reduction of Echo and Noise
      • Echo Control on Codec Parameters
      • Echo Cancellation in Cellular Networks
      • Estimating Echo Return Loss and Echo Return Loss Enhancement
      • Statistical Joint Control of Acoustic Echo Canceller and Post-Filter
      • Frequency Offset Compensation in Echo Cancellation
      • Echo Cancellation in IP Networks
      • Cross-Correlations in Echo Cancellation
    • G.165 Echo Cancellers
    • G.168 Echo Cancellers
  • Speech & Audio Enhancement
    • De-reverberation of Speech Signals
    • Scalable Audio Coding
    • Scalable Speech Coding
    • Error Concealment for Speech Transmission
    • Independent Component Analysis (ICA)-Based Speech Enhancement
    • Dual Channel Noise Estimation for Speech Enhancement
    • Speech Enhancement and Speech Intelligibility
    • Standard Methods of Voice Activity Detection (VAD)
  • Noise Reduction
    • Overview
    • Noise Reduction of Non-stationary Noise Sources
    • Monaural Speech Segregation
    • The Artifacts of Spectral Subtraction
  • Compressed Sensing
    • Recovery of Audio Signals with Compressed Sensing
    • Compressed Sensing of Images
    • Background Subtraction using Compressed Sensing
    • Noise Resiliency with Compressed Sensing
    • Interference Cancellation in Compressed Sensed Signals
    • Adaptive Parity Error Detection for Compressive Imaging
    • Multipath Channel Estimation with Compressed Sensing
    • Single Pixel Camera
    • Terahertz Imaging for Security using Compressed Sensing
    • Overview of Encryption of Compressed Sensed Images
    • Compressed Sensing in Secure JPEG2000 (JPSEC)
    • Secrecy of Cryptography With Compressed Sensing
    • Gradient Projection Reconstruction of Compressed Sensing Signals
    • Error Correction Using Compressed Sensing Techniques
    • Enhanced Security Based on Under-Determination in Compressed Sensing
    • Compressed Sensing for Error Protection in JPWL
  • Beamforming
    • Acoustic Beamforming
      • Beamforming for Voice Quality Enhancement
      • Microphone Array and Remote Capture Beamforming
      • Sound Capture Model for Beamforming
      • Microphone Array for Source Location
      • Microphone Array in Conference Environment
      • Speech Separation with Microphone Array
      • Beamforming Combined with Acoustic Echo Cancellation
      • Acoustic Beamforming in a Dispersive Environment
      • Direction of Arrival Estimation Algorithms in Array Signal Processing
    • Wireless Beamforming
      • Beamforming for Wireless MIMO Communications
      • Beamforming for Space Division Multiple Access
      • Beamforming for MIMO-OFDM with Limited Feedback
      • MIMO Techniques in 3GPP LTE
      • MIMO Techniques in WiMAX Networks
      • Joint Transceiver Beamforming Design for Multiuser MIMO Systems
      • Grassmannian Beamforming for MIMO Wireless Systems
      • Beamforming for Wireless Sensor Networks
      • Beamforming for Low Probability of Interception
      • Adaptive Modulation for 802.11n Beamforming Systems
      • Transmit Beamforming in 802.11n
      • Coordinated Linear Beamforming
      • User Selection for Multiple Antenna Broadcast Channel
      • Opportunistic Scheduling and Beamforming for MIMO-OFDMA
      • Transmit Beamforming Schemes for Time-Selective Fading Multi-antenna Systems
      • An Optimized Unitary Beamforming Technique for MIMO Broadcast Channels
      • Relay Beamforming Strategies for Physical-Layer Security
      • A Competitive Mean-Squared Error Approach to Beamforming
      • A Smart Antenna Receiver Array Using a Single RF Channel and Digital Beamforming
      • Exploiting Spacial Diversity in Single Antenna Systems using Cooperative Communications
    • Image Beamforming
      • Beamforming for Ultrasonic Imaging
  • Blind Signal Separation
    • Underdetermined Blind Signal Separation
    • Blind I/Q Signal Separation for Receiver Signal Processing
    • Blind Separation of Co-Channel Signals Using an Antenna Array
    • Separation of Overlapping Radio Frequency Identification (RFID) Signals by Antenna Arrays
  • Advanced Error Coding
    • Overview
    • Reed Solomon
    • Turbo Code
    • LDPC
  • Stochastic Resonance (SR)
    • Weak Signal Detection using Particle Swarm Optimization (PSO) and Stochastic Resonance
  • Swarm Coding
    • Particle Swarm Optimization in the Design of Adaptive FIR Filters
    • Particle Swarm Optimization in the Design of Adaptive IIR Filters
    • Particle Swarm Optimization in Acoustic Echo Cancellation
    • Adaptive Antenna Arrays using Particle Swarm Optimization
    • Blind Signal Separation (BSS) using Particle Swarm Optimization (PSO)
    • Particle Swarm Optimization on FPGA
    • Motion Tracking using Particle Swarm Optimization
    • Image Compression using Compressed Sensing (CS) and Particle Swarm Optimization (PSO)
    • Particle Swarm Optimization in the RWA Process for All-Optical WDM Networks
    • Particle Swarm Optimization (PSO) in Speech Enhancement
    • Time Delay of Arrival (TDOA) using Particle Swarm Optimization (PSO)
    • Particle Swarm Optimization (PSO) in the Grassmannian Line Packing Problem for MIMO Beamforming
    • Adaptive Particle Swarm Optimization (APSO)
    • Euclidean Particle Swarm Optimization (EPSO)
    • Gaussian Particle Swarm Optimization (GPSO)
    • Noise Reduction using Singular Value Decomposition (SVD) and Particle Swarm Optimization (PSO)
    • Particle Swarm Optimization (PSO) in Signal Separation
    • Weak Signal Detection using Particle Swarm Optimization (PSO) and Stochastic Resonance
    • Adapting Particle Swarm Optimization (PSO) by Deciding on the State of Convergence
  • Network
    • Network Protocols
      • NAT/Firewall Support
      • Simple Traversal of UDP Through NAT (Classic STUN)
      • Traversal Using Relay NAT (TURN)
      • Interactive Connectivity Establishment (ICE)
      • IEEE802.11
        • 802.11 Distributed Coordination Function (DCF)
        • An introduction to IEEE 802.11e Standard
        • An introduction to IEEE 802.11n Standard
      • Network Utility Maximization for Resource Allocation
    • Ad hoc Networks
      • Distortion Minimizing Rate Control
      • Distortion Based Networking – Ad Hoc Wireless Routing
      • Medium Access Control (MAC) for Distortion Based Networking
    • Network Security
      • CCMP
      • DTLS
      • EAP
      • EAPoL
      • EAPoW
      • HTTPS
      • IPsec
        • IPsec for Blackfin uCLinux
      • Secure SIP
      • SRTP
      • SSLv3/TLSv1
      • S-HTTP
      • WEP
      • WPA
      • WTLS
    • Network Operating Systems
      • LANsEND
    • Cryptography
      • Overview
      • Encryption
        • AES
        • Camellia
        • CAST-128
        • CAST-256
        • CCM
        • DES
        • GCM
        • Rabin
        • RC4
        • RSA
          • RSA Theory
          • User Authentication
          • Key Size Selection
        • SEED
        • TDEA (3-DES)
      • CCM
      • DSA
      • ECDSA
      • GCM
      • GMAC
      • HMAC
      • Keywrap (AESKW, AKW1, AKW2, TDKW)
      • Rabin
      • RIPEMD
      • RSA
        • RSA Theory
        • User Authentication
        • Key Size Selection
      • SHA
      • Whirlpool
    • Security
      • Overview
      • CCMP
      • CMS
      • Data Hiding with Cognitive Imperceptibility
      • Digital Fingerprinting for Multimedia Security
      • Document Signature by Multiple Parties
      • DTLS
      • EAP
        • EAP Types
        • EAPoL
        • EAPoW
      • HTTPS
      • IKEv2
      • IPsec
      • JPSEC
        • JPSEC Authentication Template
        • JPSEC Decryption Template
        • JPSEC Hash Template
        • JPSEC Key Template
        • JPSEC Registration Authority (RA)
        • JPSEC Tools
      • Steganalysis
      • Real-time Video Steganography
      • SDES
      • Secure ACAP
      • Secure IMAP
      • Secure SIP
      • Secure SMTP
      • S-HTTP
      • S/MIME
      • SRTP
      • SSLv3/TLSv1
      • WEP
      • WPA
      • WTLS
    • Lawful Intercept
      • Internal vs External Lawful Interception
      • Lawful Interception for LTE Networks
      • Lawful Interception for WiMax Networks
      • Location-Dependent Lawful Interception
      • Beamforming for Low Probability of Interception
      • Session Initialization Protocol (SIP) and Deep Packet Inspection (DPI)
    • Session Initialization Protocol (SIP) and Deep Packet Inspection (DPI)
    • Telephony
      • Overview
      • Analog Telephony
      • Digital Telephony
      • ISDN
      • Low Speed Digital Carrier Systems (DS1)N
      • Speakerphone
    • Data Modems
      • Overview
      • Data Modulations
        • V.21
        • V.22
        • V.32
        • V.34
        • V.90
        • 56k Modem
        • V.91
        • V.92
        • V.92 Features
      • Data Protocols
        • V.42
        • V.44
      • Modem Command Sets
    • Fax Modems
      • Overview
      • Fax Modulations
        • V.27
        • V.29
        • V.17
        • V.34 Fax
      • Fax Protocols
        • T.30
          • Secure Faxing with JPSEC
        • T.30-E Color
      • Fax Command Sets
    • Soft Radio
    • Products
  • Services
  • Specialties
    • Overview
    • Beamforming
    • Advanced Error Coding
    • Cryptographic Systems
    • Facsimile Lawful Interception
    • T.38 FoIP Lawful Interception
    • Media Gateway
  • Resources
    • Overview
    • Block Diagrams
    • Datasheets
    • Developer
    • Patents
    • White Papers
  • Company Info
    • About Us
    • Press Releases
    • Employment
    • Contact Us