Wireless Glossary – I

Internet Assigned Numbers Authority is the entity that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet Protocol-related symbols and numbers.

Inter-Carrier Interference is the interference between symbols transmitted on different subcarriers in OFDM signal.

Inter-Cell Interference Coordination is a set of techniques to reduce the interference between cells.

A Network layer protocol that supplies ping and traceroute functions.

A passive device that listens to network traffic and provides alerts and issues TCP resets if necessary.

Indoor Unit

The IEEE standard that specifies a carrier sense media access control and physical layer specifications for 1 and 2 megabit per second wireless LANs.

802.11a, which has just started to ship, is much faster than 802.11b, with a 54Mbps maximum data rate (actually increased to 72Mbps or 108Mbps in a non-standard double-speed mode depending on the chipset vendor and component manufacturer). 802.11a (and its recently announced interoperability standard called Wi-Fi5) operates in the 5GHz frequency range and allows eight simultaneous channels. One big advantage to 802.11a is that it isn’t subject to interference from Bluetooth or any of the other 2.4GHz frequency denizens. One big disadvantage is that it is not directly compatible with 802.11b, and requires new bridging products that can support both types of networks–although if you don’t mind spending the money for access points for both 11a and 11b, you can plug them into hubs or better yet, switches on your network and they’ll work just fine. Other clear disadvantages are that 802.11a is only available in half the bandwidth in Japan (for a maximum of four channels), and it isn’t approved for use in Europe, where HiperLAN2 is the standard. Another IEEE group, 802.11h, is working on technologies that will tweak 802.11a to work around some of the 5GHz channels used by military in Europe. Like 802.11b, 802.11a has no provisions to optimize voice or multimedia content.

The IEEE standard that specifies a carrier sense media access control and physical layer specifications for 5.5 and 11 megabit per second wireless LANs.
Today 802.11b is the clear winner in business wireless networking. Operating in the 2.4GHz frequency range, 802.11b (aka Wi-Fi) has a nominal maximum data rate of 11Mbps, with the potential of three simultaneous channels. 802.11b has a great advantage in that it is accepted worldwide. One of the more significant disadvantages of 802.11b is that the frequency band is crowded, and subject to interference from other networking technologies, microwave ovens, 2.4GHz cordless phones (a huge market), and Bluetooth. There are drawbacks to 802.11b, including lack of interoperability with voice devices, and no QoS provisions for multimedia content. Interference and other limitations aside, 802.11b is the clear leader in business and institutional wireless networking and is gaining share for home applications as well.

IEEE 802.11d is supplementary to the Media Access Control (MAC) layer in 802.11 to promote worldwide use of 802.11 WLANs. It will allow access points to communicate information on the permissible radio channels with acceptable power levels for user devices. The 802.11 standards cannot legally operate in some countries; the purpose of 11d is to add features and restrictions to allow WLANs to operate within the rules of these countries. Comments: In countries where the physical layer radio requirements are different from those in North America, the use of WLANs is lagging behind. Equipment manufacturers do not want to produce a wide variety of country-specific products and users that travel do not want a bag full of country-specific WLAN PC cards. The outcome will be country-specific firmware solutions.

802.11e is an enhancement to the 802.11 wireless LAN specification that will include quality of service (QoS) features, including the prioritization of data, voice, and video transmissions. 802.11e enhances the 802.11 MAC layer with a coordinated Time Division Multiple Access (TDMA) construct and adds error-correcting mechanisms for delay-sensitive applications such as voice and video.

In early 2000, the IEEE 802.11 Task Group G was given the job of developing a higher-speed, backward-compatible physical-layer extension to the highly successful IEEE 802.11b standard. The new supplement, designated IEEE 802.11g, was to be compatible with the 802.11 media-access control (MAC), implement all mandatory portions of the existing IEEE 802.11b standard to ensure compatibility and interoperability, and include a maximum data rate of at least 20 Mbits/second. The driving forces behind the task group’s work were manifold and significant. Besides the much-needed backward compatibility to 802.11b, they ranged from harmonization of the 2.4- and 5-GHz bands, to applications that stand to benefit from the higher rates at 2.4 GHz. These applications include streaming video in the home and high-speed Internet access and file transfers. After almost a year and a half, the 802.11g group reached a compromise among several proposals, which enabled the adoption of the first 802.11g draft standard last November. The task group made additional technical improvements at its January session and completion of the IEEE 802.11g standard is expected late this year or early in 2003. The IEEE 802.11g draft standard takes the IEEE 802.11b standard requirements and adds extra rate capabilities to extend the data rate in the 2.4-GHz band up to 54 Mbits/s. The mandatory modes of the 802.11b standard-namely, 1- and 2-Mbit/s Barker (code), 5.5- and 11-Mbit/s complementary-code keying (CCK), and a long preamble (192 microseconds)-are required within IEEE 802.11g. In addition, IEEE 802.11g mandates the short preamble (96 microseconds) that is an option in IEEE 802.11b, enabling increased throughput, especially for short packets. The optional 5.5- and 11-Mbit/s packet binary convolutional coding (PBCC) of IEEE 802.11b has been extended in IEEE 802.11g to 22 and 33 Mbits/s. The packet format for the short- and long-preamble modes as well as Barker, CCK and PBCC. To achieve data rates up to 54 Mbits/s, the IEEE 802.11g draft standard has borrowed from IEEE 802.11a. That standard uses orthogonal frequency-division multiplexing (OFDM) in the 5-GHz band to achieve data rates of 6, 9, 12, 18, 24, 36, 48 and 54 Mbits/s. IEEE 802.11g uses the same encoding formatting in the 2.4-GHz band to achieve the same rates, mandating the OFDM rates of 6, 12 and 24 Mbits/s. To compensate for the difference between the 16-microseconds interframe spacing of IEEE 802.11 and the 10-microseconds interframe spacing of IEEE 802.11g, a 6-microseconds virtual-signal extension has been added to the OFDM packets. During this 6 microseconds, no signal is transmitted, but the MAC layer behaves as if there were. This, in effect, enables a longer interframe spacing of 16 microseconds, which is required to decode the OFDM packets.

This standard is supplementary to the MAC layer to comply with European regulations for 5GHz WLANs. European radio regulations for the 5GHz band require products to have transmission power control (TPC) and dynamic frequency selection (DFS). TPC limits the transmitted power to the minimum needed to reach the furthest user. DFS selects the radio channel at the access point to minimize interference with other systems, particularly radar.

Supplementary to the MAC layer to improve security. It will apply to 802.11 physical standards a, b and g. It provides an alternative to Wired Equivalent Privacy (WEP) with new encryption methods and authentication procedures. IEEE 802.1x forms a key part of 802.11i.

IEEE 802.16 addresses the “first-mile/last-mile” connection in wireless metropolitan area networks. It focuses on the efficient use of bandwidth between 10 and 66 GHz and defines a medium access control (MAC) layer that supports multiple physical layer specifications customized for the frequency band of use.

The IEEE standard that specifies carrier sense media access control and physical layer specifications for Ethernet LANs.

A routing protocol that functions to advertise networks and metrics within an autonomous system.

The image is the binary executable of the embedded unit software. To update the unit, you must download a new image file.

Integrated Mobile Broadcast (iMB) is a mobile wireless technology that enables broadcast of content (such as live television) at the cellular transmitter level, using the 3G or 4G licenced radio spectrum, and received on mobile terminals.

International Mobile Telecommunications-2000 is a set of specifications by the International Telecommunication Union.

Management signals comprising the data stream which travel over the same networking paths and interfaces.

A type of query that is sent via the Internet to resolve hostnames from IP addresses and/or vice versa.

A wireless technology that utilizes infrared beams to send data across the network. A television remote control uses infrared technology to send requests to the television set, for example. Infrared speeds can reach a maximum of 16Mpbs, and these signals are only used for short distance communications.

Attenuation caused by the insertion of an optical component into an optical transmission path.

A professional society serving electrical engineers through its publications, conferences, and standards development activities. The body responsible for the Ethernet 802.3 and wireless LAN 802.11 specifications.

A circuit-switched network that combines multiple B channels (each of which can handle 64Kbps) with a single signaling (D) channel to form a WAN connection between two locations.

A process which uses an external router or a Layer 3 switch whereby traffic is routed from one VLAN to another.

A configuration mode that sets interface-specific parameters.

Represented by two or more networks that are linked using hardware devices in order to function as a one larger network. It is also known as an internet.

An absolute reversal of the subnet mask. This is principally used when configuring OSPF and access list.

Internet Protocol is the principal communications protocol used for relaying datagrams (also known as network packets) across an internetwork using the Internet Protocol Suite responsible for routing packets across network boundaries. It is the primary protocol that establishes the Internet.

A Network layer protocol that utilizes logical or virtual addressing to move a packet from the source to its destination. Forwarding decisions are made by routers using IP addresses.

Typically used in VPN connections, this protocol framework provides different types of security for network communication.

Internet Protocol Connectivity Access Network. The collection of network entities and interfaces that provides the underlying Internet Protocol (IP) transport connectivity between a UE and the IP Multimedia Subsystem (IMS).

One version of IP addressing that employs 32-bit addresses which are grouped into four octets, and are presented in dotted decimal format. Each octet has a minimum value of 0 and a maximum value of 255.

One version of IP addressing that was created in case the IPv4 address space is exhausted. IPv6 addresses are 128 bits in length and are shown as 32 hexadecimal digits split into eight smaller groups of 4 bits – these are separated by colons.

Industrial, Scientific, and Medical Equipment radio frequency band, in the 900-MHz, 2.4-GHz, and 5.8 GHz ranges.

An antenna (or a theoretic construct of an antenna) that radiates its signal 360 degrees both vertically and horizontally– a perfect sphere.

An electronic device that converts energy from one form to another, producing useful electromagnetic field output in all directions with equal intensity and at 100% efficiency, in threedimensional space.

International Telecommunications Union

International Telecommunication Union (Union internationale des télécommunications, in French), previously the International Telegraph Union, is the specialized agency of the United Nations which is responsible for information and communication technologies. ITU coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world and establishes worldwide standards.