RAD - G

Gateway - Gateways are points of entrance and exit from a communications network. Viewed as a physical entity, a gateway is that node that translates between two otherwise incompatible networks or network segments. Gateways perform code and protocol conversion to facilitate traffic between data highways of differing architecture.

Grooming - In telecommunications, the process of separating and segregating channels by combing, such that the broadest channel possible can be assembled and sent across the longest practical link. The aim is to minimize de-multiplexing traffic and reshuffling it electrically.

G.SHDSL - G.SHDSL, or SHDSL, is a standardized method (ITU-T G.991.2) to transport symmetrical data rates on copper pair access lines. G.SHDSL offers bitrates from 192 kbps to 2.3 Mbps over a 2-wire single pair and up to 9.2 Mbps over four bonded pairs.

G.SHDSL Modem- A G.SHDSL modem is a customer located transceiver, connecting users to a G.SHDSL service via the local DSLAM.

GSM (Global System for Mobile communications) - A second generation digital cellular telecommunication system originating in Europe, but now considered the international standard.

GSM Abis - The Abis channel is an internal interface connecting the Base Transceiver Station (BTS) and the Base Station Controller (BSC) in GSM cellular networks. The GSM Abis interface is used to control the radio equipment and to allocate radio frequency in the BTS

HSDPA (High Speed Downlink Packet Access) - High Speed Downlink Packet Access (HSDPA) is an upgrade to WCDMA technology that provides high speed downlinks of up to 14 Mbps over a 5 MHz bandwidth in WCDMA downlink. HSDPA, also known as 3.5G, is an improvement to UMTS networks.

Idle Disconnects - The breaking or release of a circuit connecting two telephones or data devices that occurs when no data is transmitted on a link in a specified amount of time.

IEEE (Institute of Electrical and Electronic Engineers) - An international professional society issuing its own standards. The IEEE is a member of ANSI and ISO.

IETF (Internet Engineering Task Force) - Body which was initially responsible for developing the specifications required for the interoperable implementation of IP.

IMA (Inverse Multiplexing over ATM) - A method to pass ATM traffic over multiple E1/T1 links while keeping the ATM’s quality of service and optimization of bandwidth usage.

In-band Signaling - The transmission of signaling information over the same path as data and/or voice information. Another term for in-band signaling is robbed-bit signaling. Robbed-bit refers to the 8 kbps of each channel used for signaling. T1 access lines containing one or more switched channels, and switched-56 lines use in-band signaling.

Integrated Access Devices - Integrated access devices (IAD) deliver voice and data services from user equipment to metro or wide area networks, over a shared xDSL access line.

Inverse Multiplexing - A method in which the inverse multiplexer slices the data stream into equal portions and transmits each portion over an available circuit. The receiving end adjusts for network-induced delay and reassembles the data packets into their proper order. Therefore, an inverse multiplexer allows lower speed channels across a network to be combined into a single, higher speed data stream.

IP (Internet Protocol) - A networking protocol for providing a connectionless service to the higher transport protocol. It is responsible for discovering and maintaining topology information and for routing packets across homogeneous networks. Combined with TCP, it is commonly known as the TCP/IP platform.

ITU (International Telecommunication Union) - A European-based, international advisory committee recommending worldwide standards for transmission.

Jitter - The deviation of a transmission signal in time or phase. It can introduce errors and loss of synchronization in high speed synchronous communications.

Jitter Buffer - Variation in the arrival times between packets, also called jitter, causes unnatural-sounding voice instead of a smooth voice stream. If a packet does not arrive in time to fit into the voice stream, the previous packet is replayed. This can seriously detract from voice quality. Since the jitter buffer adds to the overall delay of voice transmissions, the optimal jitter buffer should fit the network's differential delay. Adaptive jitter buffering continuously monitors the network delay and adjusts the queuing period accordingly.