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collapse/expand 10Base2
  • An earlier Ethernet cabling standard where data is transmitted in baseband spectrum of a thin 50-Ohm coaxial cable with data rate of 10 Mbps. Here is the clue: 10 for 10Mbps, Base for baseband, 2 for 200 meters (actually 185 meters).
    10Base2 implementation uses bus topology. There can be 30 nodes per segment with maximum 3 segments populated with nodes. Maximum length of a cable segment is 185 meters. Minimum distance between nodes is 0.5 m (excluding drop cables).
    10Base2 is also known as Thin Ethernet, Thinnet, or Cheapernet.

collapse/expand 10Base5
  • An earlier Ethernet cabling standard where data is transmitted in baseband spectrum of a thick 50-Ohm coaxial cable with data rate of 10 Mbps. Here is the clue: 10 for 10Mbps, Base for baseband, 5 for 500 meters. 10Base5 is also known as Thick Ethernet or Thicknet.
    10Base5 implementation uses bus topology. There can be 100 nodes per segment with maximum 3 segments populated with nodes.  Maximum length of a cable segment is 500 meters. Minimum distance between nodes is 2.5 m (excluding drop cables).
    10Base5 is also known as Thick Ethernet or Thicknet.

collapse/expand 10BaseT
  • An Ethernet cabling standard where data is transmitted in baseband spectrum of a twisted pair cable (i.e. Cat 3 or better, Cat 5 in most networks) with data rate of 10 Mbps. Here is the clue: 10 for 10Mbps, Base for baseband, T for twisted pair.
    10BaseT implementation uses star topology with a hub as a central connection point. There can be 12 nodes per hub. Several hubs can be connected together so up to 1024 nodes are supported. Minimum distance between nodes is 2.5 m. Maximum length of a cable segment (from a node to the hub) is 100 meters.

collapse/expand 10BaseF
  • An Ethernet cabling standard where data is transmitted in baseband spectrum of a fiber optic cable with data rate of 10 Mbps. It can reach distance up to 2 kilometers.
    Here is the clue: 10 for 10Mbps, Base for baseband, F for fiber optic. 10BaseF is often used for connection between buildings.

collapse/expand 100BaseT
  • An Ethernet cabling standard where data is transmitted in baseband spectrum of a twisted pair cable (i.e. Cat 5 or better), with data rate of 100 Mbps. 100BaseT implementation uses star topology.
    100BaseT is also known as Fast Ethernet.

collapse/expand 100VG-AnyLAN
  • A LAN architecture conforming to the IEEE 802.12 standard where data is carried over Voice Grade twisted pair cable (Cat 3) with data rate of 100 Mbps. Maximum cable segment is 100 meters.
    Compared with 802.3 (Ethernet), 100VG-AnyLAN employs a different media access method that is called demand priority and uses all four pairs of the UTP copper wires.
    Also see demand priority.

collapse/expand 1000BaseT
  • An Ethernet cabling standard where  data is transmitted in baseband spectrum of a twisted pair cable (Cat 5e or better), with data rate of 1000 Mbps. 1000BaseT implementation uses star topology. 1000BaseT is also known as Gigabit Ethernet.

collapse/expand 2B1Q
  • Two (2) Binary One (1) Quaternary. The line coding technique used in ISDN, using 4 voltage levels (1Q) to represent 2 bits (2B).

collapse/expand 3DES
  • Triple DES. A three step Data Encryption Standard, where the key is 168 bits long, 3 times longer than a 56-bit DES key. 3DES is more secure than DES.

collapse/expand 3G
  • 3rd Generation mobile communications. 3G refers to broadband mobile communications with maximum data rate of 2 Mbps for stationary user and 384 kbps for mobile user. With 3G, bandwidth-intensive and latency-sensitive applications can be delivered to mobile devices, e.g. mobile TV broadcast, video streaming, video conferencing, VoIP, and interactive gaming.
    3G standard is developed on the basis of earlier technologies, i.e. 1G (analog PCS), 2G (digital PCS), and 2.5G (enhanced 2G). UMTS-WCDMA is the preferred 3G access technology for GSM-based service providers. Meanwhile non-GSM (CDMA) carriers mostly choose CDMA2000.
    3G has been a much hyped technology for years. Its mounting license fee and the politics around its auction added flare to the hype. Despite that fact, many cellular operators around the world have started commercial 3G network deployment using either technology. And some operators offer seamless interoperability between their 3G networks and Wi-Fi hotspots.
    While 3G services are still in the introductory phase, users and operators alike feel the need for faster download/upload speed and less dead spots. That is the reason for the emergence of 3G enhancement technologies known as 3.5G, i.e. HSPA (HSDPA and HSUPA) for WCDMA-based network and EV-DO (Rev 0, Rev A, and Rev B) for CDMA2000 network.
    Also see EV-DO, HSDPA, and HSUPA.

collapse/expand 3GPP
  • 3rd Generation Partnership Project. A global initiative supported by national and regional standardization bodies to coordinate works on  global 3G technical specifications.

collapse/expand 3GPP2
collapse/expand 4G
  • Fourth Generation. Refers to the future wireless telecommunication systems that will deliver multimedia services (VoIP, video, Internet) at high speed (100 Mbps or more) over end-to-end IP network infrastructure and enable seamless handoff between mobile wireless WAN and fixed wireless LAN. Among popular techniques that will most likely make 4G a reality are OFDM, MIMO, adaptive modulation coding (AMC), and software defined radio.

collapse/expand 5-4-3 rule
  • A rule in Ethernet design saying that in a LAN there can be no more than 5 segments with no more than 4 repeaters between any two nodes. Only 3 of the 5 segments can contain nodes.

collapse/expand 54g
  • Refers to Broadcom s standards-based 802.11g technology, with maximum performance speed, reach, and security. 54gTM equipment has been tested to reach the 802.11g maximum speed of 54 Mbps.

collapse/expand 802.11a
  • A Wireless LAN technology conforming to the IEEE 802.11a standard that operates at the UNII band (5.15 - 5.35 GHz and 5.725 - 5.825 GHz) and uses OFDM technology. Its maximum data rate is 54 Mbps.
    Because the UNII band is less populated than the ISM, 802.11a risks less interference from other wireless systems but its coverage is smaller than 802.11b/g. The 802.11a system is not compatible with the popular 802.11b. 802.11a is also known as Wireless A.

collapse/expand 802.11b
  • A Wireless LAN technology conforming to the IEEE 802.11b standard that operates at the ISM band (2.4 - 2.497 GHz) and uses DSSS technology. Its maximum data rate is 11 Mbps.
    Most hotspots at public places use 802.11b access points. Wi-Fi is the popular nickname of the 802.11b system and often used to refer to all wireless LAN standards (802.11 a/b/g). It is actually a trademark that is owned by the Wi-Fi Alliance. 802.11b is also known as Wireless B.

collapse/expand 802.11g
  • A Wireless LAN technology conforming to the IEEE 802.11g standard that operates at the ISM band (2.4 - 2.497 GHz) and uses OFDM technology. Its maximum data rate is 54 Mbps.
    The 802.11g system is backward compatible with the 802.11b system. 802.11g is also known as Wireless G.

collapse/expand 802.15
  • IEEE standards that define PHY (physical layer) and MAC sublayer specifications of Wireless Personal Area Network (WPAN). It includes Bluetooth (802.15.1), UWB (802.15.3) and ZigBee (802.15.4) specifications.
    Also see Bluetooth, UWB and ZigBee.

collapse/expand 802.16
  • IEEE standards that define PHY (physical layer) and MAC sublayer for Wireless Metropolitan Area Network (Wireless MAN). The technology that is developed based on subsequent 802.16 standards is popularly known as WiMAX.

collapse/expand 802.3
  • An IEEE standard that specifies CSMA/CD access method and physical layer of Local Area Network (LAN). Popularly known as Ethernet, because it was originally developed based on earlier Ethernet standard that was invented in the late 1970 by Xerox and then promoted by DEC, Intel, Xerox (DIX) in 1980s.
    Today, when people talk about Ethernet, it refers to the IEEE 802.3 standard. Ethernet has become the most widely used LAN technology, replacing older LAN technologies, such as Token Ring, FDDI, and ArcNet.