Lantronix
SESPM1040-541-LT-xx Install Guide
33772 Rev. F
Page
61
of
64
Glossary of Terms
Note
that the mention or definition of a term here does not imply that the switch supports that particular
feature.
802.11b
standard has a maximum raw data rate of 11 Mbit/s and uses the same media access method defined
in the original standard. 802.11b products appeared on the market in early 2000, since 802.11b is a direct
extension of the modulation technique defined in the original standard. The dramatic increase in throughput of
802.11b (compared to the original standard) along with simultaneous substantial price reductions led to the
rapid acceptance of 802.11b as the definitive wireless LAN technology. Devices using 802.11b experience
interference from other products operating in the 2.4 GHz band. Devices operating in the 2.4 GHz range include
microwave ovens, Bluetooth devices, baby monitors, cordless telephones, and some amateur radio equipment.
802.11g
modulation standard was ratified in June 2003. This works in the 2.4 GHz band (like 802.11b) but uses
the same OFDM based transmission scheme as 802.11a. It operates at a maximum physical layer bit rate of 54
Mbit/s exclusive of forward error correction codes, or about 22 Mbit/s average throughput. 802.11g hardware is
fully backward compatible with 802.11b hardware, and therefore is encumbered with legacy issues that reduce
throughput by ~21% when compared to 802.11a.
802.11n
is an amendment that improves upon the previous 802.11 standards by adding multiple-input multiple-
output antennas (MIMO). 802.11n operates on both the 2.4 GHz and the 5 GHz bands. Support for 5 GHz bands
is optional. Its net data rate ranges from 54 Mbit/s to 600 Mbit/s. The IEEE has approved the amendment, and it
was published in October 2009. Prior to the final ratification, enterprises were already migrating to 802.11n
networks based on the Wi-Fi Alliance’s certification of products conforming to a 2007 draft of the 802.11n
proposal.
BLE
(Bluetooth Low Energy): Bluetooth® Low Energy (LE) enables short-burst wireless connections and uses
multiple network topologies. The Bluetooth LE broadcast topology supports localized information sharing and is
well suited for beacon solutions, such point-of-interest (POI) information and item-finding and way-finding
services. Bluetooth Low Energy (Bluetooth LE, BLE, formerly marketed as “Bluetooth Smart” is a wireless
personal area network technology designed and marketed by the Bluetooth Special Interest Group (
) aimed at novel applications in the healthcare, fitness, beacons, security, and home entertainment
industries. Compared to Classic Bluetooth, Bluetooth Low Energy is intended to provide considerably reduced
power consumption and cost while maintaining a similar communication range. BLE broadcasting can be
disabled via the CLI or the Web UI.
Endspan
: PSE type located at the end of the twisted-pair channel. For example, a switch.
IEEE 802.3bt
: Trade names of PoE++, 4PpoE. Types 1, 2, 3, and 4. Max speed of 10GBASE-T. Power on 4 out of 4
pairs, up to 960mA / pair (480mA / wire); PSE: Max of 99.9 W, PD: Max of 71 W.
IP 66
: IP (Ingress Protection) ratings are defined in international standard EN 60529 (British BS EN 60529:1992,
European IEC 60509:1989). IP ratings are used to define levels of sealing effectiveness of electrical enclosures
against intrusion from foreign bodies (tools, dirt, etc.) and moisture. The numbers that follow IP each have a
specific meaning. The first indicates the degree of protection (of people) from moving parts, as well as the