- 125 High Speed Mode
125 High Speed Mode (or 125HSM) is
Broadcom 's proprietary frame-bursting and compressiontechnology to improve 802.11gwireless LAN performance. Thethroughput transmission speed limit when using 125HSM is claimed to be up to 35%-40% higher than standard 802.11g.The "125" in "125 High Speed Mode" refers to performance at a theoretical signaling rate of 125 Mbit/s: a 125HSM device can actually achieve a maximum throughput of up to (or greater than) 34.1 Mbit/s, which is the equivalent throughput of a system strictly following all 802.11g protocols and operating at a signaling rate of 125 Mbit/s.
When 125HSM was originally announced in 2004, it was called Afterburner. It's currently marketed as a proprietary extension of Broadcom's
Xpress technology , their standards-based frame-bursting approach that is supported by their 54gWi-Fi chipset s. Other vendors have marketed 125HSM products under a variety of names:* g+ SuperSpeed (
ZyXEL )
* G Plus or HSM (Belkin )
* 125* High Speed or Turbo G ( Buffalo)
* SpeedBooster (Linksys )
* 125 Mbit/s 802.11g(It is not the same as "Super-G" or "108 Mbit/s" technology.) [http://www.techworld.com/mobility/features/index.cfm?FeatureID=641]
Manufacturers that have licensed 125HSM technology from Broadcom include
Belkin ,Buffalo Technology ,Dell , Gateway,Hewlett-Packard ,Asus ,Linksys (now part ofCisco Systems ),Motorola , andU.S. Robotics . In general, 125HSM products from different vendors are all interoperable in 125HSM mode.125HSM is one of several competing proprietary approaches that were developed to increase 802.11g performance of wireless devices, such as MIMO-based extensions from
Airgo Networks , Nitro fromConexant , and Super G fromAtheros . 125HSM can be more successful in radio-dense environments than non-standardchannel bonding approaches to enhance 802.11g performance. Broadcom claims that in the real-world, 125HSM provides up to 17% better performance over channel bonding approaches such as Super G because otherISM band devices—such as neighboringwireless network s,cordless telephone s,baby monitor s, andBluetooth devices—can interfere with channel bonding atdistance s of up to convert|150|ft|m.External links
* Press release announcing 125HSM as [http://www.broadcom.com/press/release.php?id=507846 Afterburner]
* [http://www.54g.org/about_54g_speed.php 125 High Speed Mode] page within the [http://www.54g.org/ 54g Wi-Fi technology] site
* [http://www.usr.com/download/whitepapers/maxg-keylabs.pdf KeyLabs benchmark comparison] of 125 Mbit/s products by US Robotics, Linksys, Netgear, Belkin, and DLink. Also comparisons to some "Draft 802.11n" competitors.
* Article at SmallNetBuilder (formerlyTom's Hardware Guide ) [http://www.smallnetbuilder.com/content/view/24649/96/1/9/ testing 125HSM performance]
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