Explore topic-wise fullforms in Telecommunication

Programmable Array Logic (PAL) is a family of programmable logic device semiconductors used to implement logic functions in digital circuits introduced by Monolithic Memories, Inc. (MMI) in March 1978. MMI obtained a registered trademark on the term PAL for use in "Programmable Semiconductor Logic Circuits". The trademark is currently held by Lattice Semiconductor.

PAL devices consisted of a small PROM (programmable read-only memory) core and additional output logic used to implement particular desired logic functions with few components.

Using specialized machines, PAL devices were "field-programmable". PALs were available in several variants:

In most applications, electrically-erasable GALs are now deployed as pin-compatible direct replacements for one-time programmable PALs.

INFO: Full form for OSP is Online Service Provider in Telecommunication category
OSP also has other full forms in other categories mentioned below.

Point coordination function (PCF) is a media access control (MAC) technique used in IEEE 802.11 based WLANs, including Wi-Fi. It resides in a point coordinator also known as access point (AP), to coordinate the communication within the network. The AP waits for PIFS duration rather than DIFS duration to grasp the channel. PIFS is less than DIFS duration and hence the point coordinator always has the priority to access the channel.

The PCF is located directly above the distributed coordination function (DCF), in the IEEE 802.11 MAC Architecture. Channel access in PCF mode is centralized and hence the point coordinator sends CF-Poll frame to the PCF capable station to permit it to transmit a frame. In case the polled station does not have any frames to send, then it must transmit null frame.Due to the priority of PCF over DCF, stations that only use DCF might not gain access to the medium. To prevent this, a repetition interval has been designed to cover both (Contention free) PCF & (Contention Based) DCF traffic. The repetition interval which is repeated continuously, starts with a special control frame called Beacon Frame. When stations hear the beacon frame, they start their network allocation vector for the duration of the contention free period of the repetition period.

Since most APs have logical bus topologies (they are shared circuits) only one message can be processed at one time (it is a contention based system), and thus a media access control technique is required.

Wireless networks may suffer from a hidden node problem where some regular nodes (which communicate only with the AP) cannot see other nodes on the extreme edge of the geographical radius of the network because the wireless signal attenuates before it can reach that far. Thus having an AP in the middle allows the distance to be halved, allowing all nodes to see the AP, and consequentially, halving the maximum distance between two nodes on the extreme edges of a circle-star topology.

PCF seems to be implemented only in very few hardware devices as it is not part of the Wi-Fi Alliance's interoperability standard.

INFO: Full form for NNI is Network Node Interface in Telecommunication category
NNI also has other full forms in other categories mentioned below.

INFO: Full form for NPI is Numbering Plan Identifier in Telecommunication category
NPI also has other full forms in other categories mentioned below.

INFO: Full form for TTP is Third-party Provider in Telecommunication category
TTP also has other full forms in other categories mentioned below.

INFO: Full form for VON is Voice Over Network in Telecommunication category
VON also has other full forms in other categories mentioned below.

Weighted fair queueing (WFQ) is a network scheduling algorithm. WFQ is both a packet-based implementation of the generalized processor sharing (GPS) policy, and a natural extension of fair queuing (FQ). Whereas FQ shares the link's capacity in equal subparts, WFQ allows schedulers to specify, for each flow, which fraction of the capacity will be given.

Weighted fair queuing is also known as packet-by-packet GPS (PGPS or P-GPS) since it approximates generalized processor sharing "to within one packet transmission time, regardless of the arrival patterns."

INFO: Full form for VMWI is Voice Message Waiting Indicator in Telecommunication category
VMWI also has other full forms in other categories mentioned below.

Universal personal telecommunications (UPT) is a special segment of the international telephone number space which has been set aside for universal personal telephone numbers. This service has been allocated country code +87810 and is completed by a 10-digit subscriber number which provides 10 billion unique numbers. The International Telecommunication Union (ITU) introduced this concept in 2001, referring to it as "global number portability". However, number portability normally refers to the service of keeping an existing phone number after moving service to another provider.The delegation of UPT was requested by VisionNG Chairman Herwart Wermescher and was confirmed by Counsellor, SG2 of ITU-TSB Richard Hill on May 21, 2002.

INFO: Full form for TPDU is Transport Protocol Data Unit in Telecommunication category
TPDU also has other full forms in other categories mentioned below.

INFO: Full form for VoX is Voice Exchange in Telecommunication category
VoX also has other full forms in other categories mentioned below.

INFO: Full form for TSA is Terminating Switched Access in Telecommunication category
TSA also has other full forms in other categories mentioned below.

INFO: Full form for UTRAN is Umts (universal Mobile Telecommunication System) Terrestrial Radio Access Network in Telecommunication category
UTRAN also has other full forms in other categories mentioned below.

INFO: Full form for TLP is Transmission Level Point in Telecommunication category
TLP also has other full forms in other categories mentioned below.

INFO: Full form for TBR is Tagged Bit Rate in Telecommunication category
TBR also has other full forms in other categories mentioned below.

United Telecoms Limited specialising in telecom networks.

INFO: Full form for UTL is United Telecom Limited in Telecommunication category
UTL also has other full forms in other categories mentioned below.

INFO: Full form for VOP is Voice Over Packet in Telecommunication category
VOP also has other full forms in other categories mentioned below.

INFO: Full form for TON is Ieee/acm Transactions On Networking in Telecommunication category
TON also has other full forms in other categories mentioned below.

Telephone User Part (TUP) provides conventional PSTN telephony services across the Signalling System No. 7 (SS7) network. TUP was the first layer 4 protocol defined by the standards bodies and as such did not provision for ISDN services. It has now largely been replaced by ISUP. However, it can still be found in operational use in some parts of the world (e.g., China).

TUP is defined in ITU-T Recommendations Q.721-725. These define the international telephone call control signalling functions for use over SS7.

Various national variants of TUP have evolved, some of which provide varying degrees of support for ISDN. E.g. French SSUTR2 and Chinese TUP (Specification GF001-9001).

Voice activity detection (VAD), also known as speech activity detection or speech detection, is the detection of the presence or absence of human speech, used in speech processing. The main uses of VAD are in speech coding and speech recognition. It can facilitate speech processing, and can also be used to deactivate some processes during non-speech section of an audio session: it can avoid unnecessary coding/transmission of silence packets in Voice over Internet Protocol (VoIP) applications, saving on computation and on network bandwidth.

VAD is an important enabling technology for a variety of speech-based applications. Therefore, various VAD algorithms have been developed that provide varying features and compromises between latency, sensitivity, accuracy and computational cost. Some VAD algorithms also provide further analysis, for example whether the speech is voiced, unvoiced or sustained. Voice activity detection is usually independent of language.

It was first investigated for use on time-assignment speech interpolation (TASI) systems.

INFO: Full form for VCC is Vsat (very-small-aperture Terminal) Control Center in Telecommunication category
VCC also has other full forms in other categories mentioned below.

The 3GPP has defined the Voice Call Continuity (VCC) specifications in order to describe how a voice call can be persisted, as a mobile phone moves between circuit switched and packet switched radio domains (3GPP TS 23.206).

Many mobile phones are becoming available that support both cellular and other broadband radio technologies. For example, the Nokia N Series and E Series devices support both GSM and WiFi. Similar devices from Sony Ericsson, BlackBerry, Samsung, HTC, Motorola and even the Apple iPhone provide comparable dual mode technology. WiMAX support is also being added and further handsets are emerging from Kyocera and other vendors, which provide dual mode technology in CDMA phones. A wide range of Internet applications can then be accessed from mobile devices using wireless broadband technologies like WiFi and WiMAX. For example, VoIP traffic can be carried over these alternative radio interfaces.

Whereas VoIP calls from mobile devices are controlled by IP infrastructure, according to the VCC specifications, calls to and from a cellular phone in the circuit switched domain are also anchored in an IP domain, for example the IP Multimedia Subsystem (IMS). As the handset becomes attached and detached from wireless access points such as WiFi hotspots, a client application in the device provides notifications of the radio conditions to a VCC platform in the network. This allows circuit switched and IP call legs to be originated and terminated such that the speech path is transferred between domains, transparently to the end user.

This technology is of interest to users as an example of the benefits that are achievable through Fixed Mobile Convergence (FMC). Since most WiFi and WiMAX access points will use fixed backhaul technologies, seamlessly moving between for example WiFi and GSM domains allows the best quality and most cost efficient radio to be used at any given point in time, irrespective of the transport technology used for the media. Similarly, service providers are interested in VCC in order to offer FMC products towards specific market segments, such as enterprise users. Cellular operators in particular can offer bundled services that consist of for example, a broadband connection with a WiFi router and a set of dual mode devices. This supports a Fixed Mobile Substitution (FMS) business case where calls from the office can be carried as VoIP over WiFi and a broadband connection, while VCC technology allows these calls to be seamlessly handed over to cellular networks as the device moves to areas of poor WiFi coverage.

One limitation of VCC however, relates to the focus on voice service. In order to preserve the cellular telephony experience while users are WiFi attached, other features need to be replicated in the packet switched domain. For example, the 3GPP has defined SMS over IP specifications (3GPP TS 23.204) in order to describe how messaging functionality can be provided to end users that are present within IP based access networks. However, over several years a range of other business logic, such as GSM Supplementary Services within the Home Location Register (HLR) has been embedded within cellular networks. This functionality must also be realized within the IP domain in order to provide full service continuity between multiple access networks.

INFO: Full form for VCC is Virtual Call Center in Telecommunication category
VCC also has other full forms in other categories mentioned below.