Digital Enhanced Cordless Telecommunications (DECT) is a cordless telephony standard maintained by ETSI. It originated in Europe, where it is the common standard, replacing earlier standards, such as CT1 and CT2. Since the DECT-2020 standard onwards, it also includes IoT communication.
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for voice calls for the delivery of voice communication sessions over Internet Protocol (IP) networks, such as the Internet.
A leased line is a private telecommunications circuit between two or more locations provided according to a commercial contract. It is sometimes also known as a private circuit, and as a data line in the UK. Typically, leased lines are used by businesses to connect geographically distant offices.
A cordless telephone or portable telephone has a portable telephone handset that connects by radio to a base station connected to the public telephone network. The operational range is limited, usually to the same building or within some short distance from the base station.
STU-III is a family of secure telephones introduced in 1987 by the NSA for use by the United States government, its contractors, and its allies. STU-III desk units look much like typical office telephones, plug into a standard telephone wall jack and can make calls to any ordinary phone user. When a call is placed to another STU-III unit that is properly set up, one caller can ask the other to initiate secure transmission. They then press a button on their telephones and, after a 15-second delay, their call is encrypted to prevent eavesdropping. There are portable and militarized versions and most STU-IIIs contained an internal modem and RS-232 port for data and fax transmission. Vendors were AT&T, RCA and Motorola.
Secure Terminal Equipment (STE) is the U.S. government's current, encrypted telephone communications system for wired or "landline" communications. STE is designed to use ISDN telephone lines which offer higher speeds of up to 128 kbit/s and are all digital. The greater bandwidth allows higher quality voice and can also be utilized for data and fax transmission through a built-in RS-232 port. STE is intended to replace the older STU-III office system and the KY-68 tactical system. STE sets are backwards compatible with STU-III phones, but not with KY-68 sets.
The Secure Communications Interoperability Protocol (SCIP) is a US standard for secure voice and data communication, for circuit-switched one-to-one connections, not packet-switched networks. SCIP derived from the US Government Future Narrowband Digital Terminal (FNBDT) project. SCIP supports a number of different modes, including national and multinational modes which employ different cryptography. Many nations and industries develop SCIP devices to support the multinational and national modes of SCIP.
VINSON is a family of voice encryption devices used by U.S. and allied military and law enforcement, based on the NSA's classified Suite A SAVILLE encryption algorithm and 16 kbit/s CVSD audio compression. It replaces the Vietnam War-era NESTOR (KY-8/KY-28|28/KY-38|38) family.
Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using a similar methodology to algebraic code-excited linear prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz. AMR-WB was developed by Nokia and VoiceAge and it was first specified by 3GPP.
G.722 is an ITU-T standard 7 kHz wideband audio codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM (SB-ADPCM). The corresponding narrow-band codec based on the same technology is G.726.
Mixed-excitation linear prediction (MELP) is a United States Department of Defense speech coding standard used mainly in military applications and satellite communications, secure voice, and secure radio devices. Its standardization and later development was led and supported by the NSA and NATO. The current "enhanced" version is known as MELPe.
Secure voice is a term in cryptography for the encryption of voice communication over a range of communication types such as radio, telephone or IP.
Bowman is the name of the tactical communications system used by the British Armed Forces.
TSEC/KY-68 DSVT, commonly known as Digital Subscriber Voice Terminal, is a US military ruggedized, full- or half-duplex tactical telephone system with a built-in encryption/decryption module for secure traffic.
The AN/PRC-148 Multiband Inter/Intra Team Radio (MBITR) is the most widely fielded handheld multiband, tactical software-defined radio, used by NATO forces around the world. The radio is built by Thales Communications, a subsidiary of the France-based Thales Group. The designation AN/PRC translates to Army/Navy Portable Radio used for two-way communications, according to Joint Electronics Type Designation System (JETDS) guidelines.
The AN/PRC-152 Multiband Handheld Radio, is a portable, compact, tactical software-defined combat-net radio manufactured by Harris Corporation. It is compliant without waivers to the Joint Tactical Radio System (JTRS) Software Communications Architecture (SCA). It has received NSA certification for the transmission of Top Secret data.
The AN/PRC-150(C) Falcon II Manpack Radio, is a tactical HF-SSB/ VHF-FM manpack radio manufactured by Harris Corporation. It holds an NSA certification for Type 1 encryption. The PRC-150 is the manpack HF radio for the Harris Falcon II family of radios, introduced in the early 2000s.
G.718 is an ITU-T Recommendation embedded scalable speech and audio codec providing high quality narrowband speech over the lower bit rates and high quality wideband speech over the complete range of bit rates. In addition, G.718 is designed to be highly robust to frame erasures, thereby enhancing the speech quality when used in Internet Protocol (IP) transport applications on fixed, wireless and mobile networks. Despite its embedded nature, the codec also performs well with both narrowband and wideband generic audio signals. The codec has an embedded scalable structure, enabling maximum flexibility in the transport of voice packets through IP networks of today and in future media-aware networks. In addition, the embedded structure of G.718 will easily allow the codec to be extended to provide a superwideband and stereo capability through additional layers which are currently under development in ITU-T Study Group 16. The bitstream may be truncated at the decoder side or by any component of the communication system to instantaneously adjust the bit rate to the desired value without the need for out-of-band signalling. The encoder produces an embedded bitstream structured in five layers corresponding to the five available bit rates: 8, 12, 16, 24 & 32 kbit/s.
Victor B. Lawrence is a Ghanaian-American engineer credited with seminal contributions in digital signal processing for multimedia communications. During his 30-plus-year tenure at Bell Laboratories, Dr. Lawrence made extensive and fundamental personal contributions to voice, data, audio and video communications. He led numerous projects that significantly improved or enhanced every phase in the evolution of early low-speed and today's high-speed data communications. He is a Research Professor and Director of the Center for Intelligent Networked Systems (iNetS) at Stevens Institute of Technology, where he also served as Associate Dean. He was inducted into the National Inventors Hall of Fame in 2016. He is a Member of the National Academy of Engineering, a Fellow of the IEEE for contributions to the understanding of quantization effects in digital signal processors and the applications of digital signal processing to data communications, a Fellow of AT&T Bell Labs, and a Charter Fellow of the National Academy of Inventors.
