The function of the digital echo canceller is to detect and remove the echo. It does this by estimating the transfer function of the hybrid that produces the echo, which it accomplishes by comparing the echo to the original signal.
Gaithersburg, MD (PRWEB) December 27, 2011
GL Communications Inc. a leader in providing PC-based test, analysis and simulation products and consulting services to the worldwide telecommunications industry, conveyed today the availability of the Digital Echo Canceller software.
Speaking to media persons, Mr. Vijay Kulkarni CEO of the company said, ”The Digital Echo Canceller is a four-port device that supports bi-directional voice traffic between the two ends of a connection. The two ends of the connection are referred to as the far end and the near end. Voice signals from the far end are carried to the near end on the receive path. Voice signals from the near end are carried to the far end on the send path. Note that the signal pathways are labeled from the point of view of the near end.”
He added, “The function of the digital echo canceller is to detect and remove the echo. It does this by estimating the transfer function of the hybrid that produces the echo, which it accomplishes by comparing the echo to the original signal. The process of generating the estimate is normally iterative in nature and more the signal is seen, more refined is the estimate. The estimated transfer function is referred to as the echo path model. The process of refining the echo path model as more and more signal is seen is referred to as adaptation. When adaptation has proceeded to the point that a reasonably good estimate has been calculated, the echo canceller is said to have converged. The speed with which the echo canceller converges, and how accurate the echo path model is, are crucial measures of the echo canceller's performance in a network.”
Mr. Kulkarni further added, “Once a reasonable echo path model has been calculated, the echo canceller can predict the echo that will result from the far end signal that it is monitoring. It can thus remove that echo by subtracting it from the signal on the send path (that is, by subtracting the estimated echo from the actual echo).”
·Allows real-time and offline processing
·Interfaces directly with A-Law or m-Law encoded signals
·G.168-2000 compliant, tests 2A, 2B, 2C, 3A, 3B, 3C, 4, 5, 6, 7
·16, 32, 64 or 128 ms tail length; programmable tail offset
·Comfort noise generator with adaptation to background noise level.
·Echo path visibility
·Continuous reporting of echo path delay, ERL, and dispersion
About GL Communications Inc.,
Founded in 1986, GL Communications Inc. is a leading supplier of test, monitoring, and analysis equipment for TDM, Wireless, IP and VoIP networks. Unlike conventional test equipment, GL's test platforms provide visualization, capture, storage, and convenient features like portability, remotability, and scripting.
GL’s TDM Analysis & Emulation line of products includes T1, E1, T3, E3, OC-3, OC-12, STM-1, STM-4, analog four-wire, and analog two-wire interface cards, external portable pods, and complete system solutions. Capabilities include voiceband traffic analysis and emulation across all traffic types (voice, digits, tones, fax, modem), all protocols (ISDN, SS7, GR-303, Frame Relay, HDLC, V5.X, ATM, GSM, GPRS, LTE, etc.), and with capacities up to thousands of channels. Our newest products provide astonishing capacity and capture capability up to and including gigabit speeds.
GL’s VoIP and IP products generate / analyze thousands of calls and traffic simultaneously with traffic types such as frames, packets, voice files, digits, video, tones, noise, and fax. Almost all codecs are supported including G.711, G.729, AMR, EVRC-A,B,C, GSM, iSAC, and many more. Additional features include visual analysis, real-time listening, and recording. The product line also includes Ethernet / IP Testing capability that simulates and checks frame transport and throughput parameters of Ethernet and IP networks, including delay, errors and other impairments.
GL's Voice Quality Testing (VQT) product line complements all of GL's products. Using ITU-standard algorithms (PAMS, PSQM, and PESQ), GL's VQT provides a widely accepted solution for assessing voice quality in the telecom industry. Voice Quality Testing across multiple networks (T1, E1, T3, E3, OC-3, OC-12, VoIP, Wireless, and Landline) is available.
GL’s Wireless Products perform protocol analysis and voice quality assessment on GSM, CDMA, UMTS, and LTE networks. Connections can be made to any wireless phone with automated call control, GPS mapping and real-time signal measurements.
GL’s Echo Canceller testing solutions provide the broadest range of simulation and analysis, including line and acoustic echo. GL’s compliance testing per G.168. G.167 and P.340 across TDM, IP, VoIP and Wireless networks is widely accepted in the industry.
GL’s wireless VQT solutions help assessing impairments to voice quality such as poor mobile phone quality, voice compression and decompression algorithms, delay, loss and gain in speech levels, noise, acoustic and landline echo, and other distortions are easily assessed and accurately measured.
GL’s Handheld data testers can test a wide variety of communications facilities and equipment including T1, fractional T1, E1, fractional E1, T3 and E3 modems, multiplexers, CSU, DSUs, T1 CSUs, DTUs, NTUs and TIUs and more. The testers provide convenience, economy, and portability for almost any interface, including RS232, RS-422, RS-530, X.21, T1, E1, T3, E3, and many others.
GL’s Network Surveillance and Monitoring products include Probes for TDM, IP, VoIP, ATM, and Wireless networks. An open standards based approach provides a scalable, feature rich, real-time access to network characteristics. Centralized or distributed access, efficient transport and database loading allow compatibility with 3rd party and standards based monitoring systems.