Category
page 1ITU-T G Series Recommendations

VDSL
Very high-speed digital subscriber line (VDSL) and very high-speed digital subscriber line 2 (VDSL2) are digital subscriber line (DSL) technologies providing data transmission faster than the earlier standards of asymmetric digital subscriber line (ADSL) G.992.1, G.992.3 (ADSL2) and G.992.5 (ADSL2+).
synchronous optical networking
standardized protocol that transfers multiple digital bit streams synchronously over optical fiber
G.729
G.729 is a royalty-free narrow-band vocoder-based audio data compression algorithm using a frame length of . It is officially described as Coding of speech at 8 kbit/s using code-excited linear prediction speech coding (CS-ACELP), and was introduced in 1996. The wide-band extension of G.729 is called G.729.1, which equals G.729 Annex J.
G.711
G.711 is a narrowband audio codec originally designed for use in telephony that provides toll-quality audio at 64 kbit/s. It is an ITU-T standard (Recommendation) for audio encoding, titled Pulse code modulation (PCM) of voice frequencies released for use in 1972.
High-bit-rate digital subscriber line
telecommunications protocol standardized in 1994, developed to transport DS1 services at 1.544 Mbit/s and 2.048 Mbit/s over telephone local loops without a need for repeaters
single-pair high-speed digital subscriber line
technology for broadband Internet
G.726
G.726 is an ITU-T ADPCM speech codec standard covering the transmission of voice at rates of 16, 24, 32, and 40 kbit/s. It was introduced to supersede both G.721, which covered ADPCM at 32 kbit/s, and G.723, which described ADPCM for 24 and 40 kbit/s. G.726 also introduced a new 16 kbit/s rate. The four bit rates associated with G.726 are often referred to by the bit size of a sample, which are 2, 3, 4, and 5-bits respectively. The corresponding wide-band codec based on the same technology is G.722.
G.984
ITU-T G.984 is the series of standards that define the architecture and operation of gigabit-per-second–capable passive optical network (GPON). It is commonly used to implement the link to the customer (the last kilometre, or last mile) of fibre-to-the-premises (FTTP) services, using a point-to-multipoint design. GPON supporting a shared bandwidth of downstream data rates of up to 2.4 Gbit/s and normally upstream rates of up to 1.2 Gbit/s.
ADSL2+
G.992.5 (also referred to as ADSL2+, G.dmt.bis+, and G.adslplus) is an ITU-T standard for asymmetric digital subscriber line (ADSL) broadband Internet access. The standard has a maximum theoretical downstream sync speed of 24 megabits per second (Mbit/s). Utilizing G.992.5 Annex M upstream sync speeds of 3.3 Mbit/s can be achieved.

G.722
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.
G.992.3
ITU G.992.3 is an ITU (International Telecommunication Union) standard, also referred to as ADSL2 or G.dmt.bis. It optionally extends the capability of basic ADSL in data rates to 12 Mbit/s downstream and, depending on Annex version, up to 3.5 Mbit/s upstream (with a mandatory capability of ADSL2 transceivers of 8 Mbit/s downstream and 800 kbit/s upstream). ADSL2 uses the same bandwidth as ADSL but achieves higher throughput via improved modulation techniques. Actual speeds may decrease depending on line quality; usually the most significant factor in line quality is the di
G.723
G.723 is an ITU-T standard speech codec using extensions of G.721 providing voice quality covering 300 Hz to 3400 Hz using Adaptive Differential Pulse Code Modulation (ADPCM) to 24 and 40 kbit/s for digital circuit multiplication equipment (DCME) applications. The standard G.723 is obsolete and has been superseded by G.726.
G.728
G.728 is an ITU-T standard for speech coding operating at 16 kbit/s. It is officially described as Coding of speech at 16 kbit/s using low-delay code excited linear prediction.
G.992.1
In telecommunications, ITU-T G.992.1 (better known as G.dmt) is an ITU standard for ADSL using discrete multitone modulation (DMT). G.dmt full-rate ADSL expands the usable bandwidth of existing copper telephone lines, delivering high-speed data communications at rates up to 8 Mbit/s downstream and 1.3 Mbit/s upstream.
G.723.1
G.723.1 is an audio codec for voice that compresses voice audio in frames. An algorithmic look-ahead of duration means that total algorithmic delay is . Its official name is Dual rate speech coder for multimedia communications transmitting at 5.3 and . It is sometimes associated with a Truespeech trademark in coprocessors produced by DSP Group.
G.fast
alt=Sckipio 24port DPU|thumb|Sckipio 24-port DPU (Distribution point unit), provides G.fast service.
G.fast is a digital subscriber line (DSL) protocol standard for local loops shorter than 500 meters, with performance targets between 100 Mbit/s and 1 Gbit/s, depending on loop length. High speeds are only achieved over very short loops. Although G.fast was initially designed for loops shorter than 250 meters, Sckipio in early 2015 demonstrated G.fast delivering speeds over 100 Mbit/s at nearly 500 meters and the EU announced a research project.

10G-PON
10G-PON (also known as XG-PON or G.987) is a 2010 computer networking standard for data links, capable of delivering shared Internet access rates up to 10 Gbit/s (gigabits per second) over optical fibre. This is the ITU-T's next-generation standard following on from GPON or gigabit-capable PON. Optical fibre is shared by many subscribers in a network known as FTTx in a way that centralises most of the telecommunications equipment, often displacing copper phone lines that connect premises to the phone exchange. Passive optical network (PON) architecture has become a cost-effective way to m
G.719
G.719 is an ITU-T standard audio coding format providing high quality, moderate bit rate (32 to 128 kbit/s) wideband (20 Hz - 20 kHz audio bandwidth, 48 kHz audio sample rate) audio coding at low computational load. It was produced through a collaboration between Polycom and Ericsson.
Adaptive Multi-Rate Wideband
audio data compression scheme optimized for speech coding
ITU G.992.5 Annex M
Internet specification primarily used in Australia
G.729.1
G.729.1 is an 8- embedded speech and audio codec providing bitstream interoperability with G.729, G.729 Annex A and G.729 Annex B. Its official name is G.729-based embedded variable bit rate codec: An 8- scalable wideband coder bitstream interoperable with G.729. It was introduced in 2006.
G.hn
Gigabit Home Networking (G.hn) is a specification for wired home networking that supports speeds up to 2 Gbit/s and operates over four types of legacy wires: telephone wiring, coaxial cables, power lines and plastic optical fiber. Some benefits of a multi-wire standard are lower equipment development costs and lower deployment costs for service providers (by allowing customer self-install).
G.992.2
In telecommunications, ITU G.992.2 (better known as G.lite) is an ITU standard for ADSL using discrete multitone modulation. G.lite is designed to not require the use of a DSL filter.
G.722.1
G.722.1 is a licensed royalty-free ITU-T standard audio codec providing high quality, moderate bit rate (24 and 32 kbit/s) wideband (50 Hz – 7 kHz audio bandwidth, 16 ksps (kilo-samples per second) audio coding. It is a partial implementation of Siren 7 audio coding format (which offers bit rates 16, 24, 32 kbit/s) developed by PictureTel Corp. (now Polycom, Inc.). Its official name is Low-complexity coding at 24 and 32 kbit/s for hands-free operation in systems with low frame loss. It uses a modified discrete cosine transform (MDCT) audio data compression algorithm.
G.703
G.703 is a ITU-T standard originally written in 1972 but subsequently revised a number of times since. It defines a physical and electrical interface used for encoding voice or data over 75 ohm co-axial cable terminated in BNC or Type 43 connectors or 120 ohm twisted pair cables terminated in RJ48C jacks. The choice is carrier- and region-dependent.