125 High Speed Mode
Encyclopedia
125 High Speed Mode is Broadcom
's proprietary frame
-bursting
and compression technology
to improve 802.11g wireless LAN
performance. The throughput
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 achieve a maximum throughput of 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 is currently marketed as a proprietary extension
of Broadcom's Xpress technology
, their standards-based frame-bursting approach that is supported by their 54g Wi-Fi
chipset
s. Other vendors have marketed 125HSM products under a variety of names:
(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 of Cisco Systems
), Motorola
, U.S. Robotics
and Netcomm. 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
from Conexant
, and Super G
from Atheros
. 125HSM can be more successful in radio-dense environments than non-standard channel 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 other ISM band
devices—such as neighboring wireless network
s, cordless telephone
s, baby monitor
s, and Bluetooth
devices—can interfere
with channel bonding at distance
s of up to 150 feet (45.7 m).
Broadcom
Broadcom Corporation is a fabless semiconductor company in the wireless and broadband communication business. The company is headquartered in Irvine, California, USA. Broadcom was founded by a professor-student pair Henry Samueli and Henry T. Nicholas III from the University of California, Los...
's proprietary frame
Data frame
In computer networking and telecommunication, a frame is a digital data transmission unit or data packet that includes frame synchronization, i.e. a sequence of bits or symbols making it possible for the receiver to detect the beginning and end of the packet in the stream of symbols or bits...
-bursting
Burst mode (computing)
Burst mode is a generic computing term referring to any situation in which a device is transmitting data repeatedly without waiting for input from another device or waiting for an internal process to terminate before continuing the transfer of data.In the case of DMA, the DMA controller and the...
and compression technology
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
to improve 802.11g wireless LAN
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
performance. The throughput
Throughput
In communication networks, such as Ethernet or packet radio, throughput or network throughput is the average rate of successful message delivery over a communication channel. This data may be delivered over a physical or logical link, or pass through a certain network node...
transmission speed
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....
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
Data signaling rate
In telecommunication, data signaling rate , also known as gross bit rate, is the aggregate rate at which data pass a point in the transmission path of a data transmission system.Notes:#The DSR is usually expressed in bits per second....
of 125 Mbit/s: a 125HSM device can achieve a maximum throughput of 34.1 Mbit/s, which is the equivalent throughput of a system strictly following all 802.11g protocols
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...
and operating at a signaling rate of 125 Mbit/s.
When 125HSM was originally announced in 2004, it was called Afterburner. It is currently marketed as a proprietary extension
Extension (computing)
Software extension, is a file containing programming that serves to extend the capabilities of or data available to a more basic program. It is a kind of list of commands which are directly included in the program. This term often coincides with the plug-in...
of Broadcom's Xpress technology
Xpress technology
Xpress technology is Broadcom's standards-based frame-bursting approach to improve 802.11g wireless LAN performance. It is a software-based implementation of the frame-bursting originally in the IEEE 802.11e draft specification, and is found in the Wireless Multimedia Extensions ...
, their standards-based frame-bursting approach that is supported by their 54g Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...
chipset
Chipset
A chipset, PC chipset, or chip set refers to a group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.- Computers :...
s. Other vendors have marketed 125HSM products under a variety of names:
- g+ SuperSpeed (ZyXELZyXELZyXEL Communications Corp. , located in Hsinchu, Taiwan, is a manufacturer of DSL and other networking devices. . With headquarters in Taiwan, ZyXEL maintains branch offices in North America, Europe, and Asia...
) (This one uses the G++ Technology solution from Texas Instruments, which uses 125 Mbit/s as well but may or may not be compatible to Broadcom's solution) - G Plus or HSM (BelkinBelkinBelkin International, Inc., is a Californian manufacturer of computer hardware that specializes in connectivity devices, headquartered in Playa Vista, Los Angeles, California...
) - 125* High Speed or Turbo G (BuffaloMelcoMelco Holdings Inc. is a family business founded by Makoto Maki in 1975. The name stands for Maki Engineering Laboratory COmpany...
) - SpeedBooster (LinksysLinksysLinksys by Cisco, commonly known as Linksys, is a brand of home and small office networking products now produced by Cisco Systems, though once a separate company founded in 1995 before being acquired by Cisco in 2003...
) - 125M or 125 High Speed or 125* High Speed (AsusASUSASUSTeK Computer Incorporated is a multinational computer technology and consumer electronics product manufacturer headquartered in Taipei, Taiwan. Its product range includes motherboards, desktops, laptops, monitors, tablet PCs, servers and mobile phones...
) - 125 Mbit/s 802.11g
(It is not the same as "Super-G
Super G (wireless networking)
Super G is Atheros' proprietary frame-bursting, compression and channel bonding technology to improve IEEE 802.11g wireless LAN performance. The throughput transmission speed limit when using Super G is claimed to be up to 40Mbit/s-60Mbit/s at a 108Mbit/s signaling rate, which is achieved through...
" 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
Belkin
Belkin International, Inc., is a Californian manufacturer of computer hardware that specializes in connectivity devices, headquartered in Playa Vista, Los Angeles, California...
, Buffalo Technology, Dell
Dell
Dell, Inc. is an American multinational information technology corporation based in 1 Dell Way, Round Rock, Texas, United States, that develops, sells and supports computers and related products and services. Bearing the name of its founder, Michael Dell, the company is one of the largest...
, Gateway
Gateway, Inc.
Gateway Computer Corporation, is a computer hardware company headquartered in Irvine, California, USA which develops, manufactures, supports, and markets a wide range of personal computers, computer monitors, servers, and computer accessories...
, Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
, Asus
ASUS
ASUSTeK Computer Incorporated is a multinational computer technology and consumer electronics product manufacturer headquartered in Taipei, Taiwan. Its product range includes motherboards, desktops, laptops, monitors, tablet PCs, servers and mobile phones...
, Linksys
Linksys
Linksys by Cisco, commonly known as Linksys, is a brand of home and small office networking products now produced by Cisco Systems, though once a separate company founded in 1995 before being acquired by Cisco in 2003...
(now part of Cisco Systems
Cisco Systems
Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...
), Motorola
Motorola
Motorola, Inc. was an American multinational telecommunications company based in Schaumburg, Illinois, which was eventually divided into two independent public companies, Motorola Mobility and Motorola Solutions on January 4, 2011, after losing $4.3 billion from 2007 to 2009...
, U.S. Robotics
U.S. Robotics
USRobotics Corporation is a company that makes computer modems and related products. It sold high-speed modems in the 1980s, and had a reputation for high quality and compatibility. With the reduced usage of voiceband modems in North America in the early 21st century, USR is now one of the few...
and Netcomm. In general, 125HSM products from different vendors are all interoperable
Interoperability
Interoperability is a property referring to the ability of diverse systems and organizations to work together . The term is often used in a technical systems engineering sense, or alternatively in a broad sense, taking into account social, political, and organizational factors that impact system to...
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
Airgo Networks
Airgo Networks , is a Palo Alto, California-based company specializing in the development of multiple-input multiple-output wireless technology. Founded in 2001, Airgo is a lead proponent of the 802.11n standard....
, Nitro
Nitro (wireless networking)
Nitro from Conexant is a proprietary 802.11g performance enhancement technology introduced in 2003 as part of the PRISM chipset...
from Conexant
Conexant
Conexant Systems, Inc. is an American semiconductor company, formerly the semiconductor division of Rockwell International. Currently it's privately owned by Golden Gate Capital, an equity firm headquartered in San Francisco.-History:...
, and Super G
Super G (wireless networking)
Super G is Atheros' proprietary frame-bursting, compression and channel bonding technology to improve IEEE 802.11g wireless LAN performance. The throughput transmission speed limit when using Super G is claimed to be up to 40Mbit/s-60Mbit/s at a 108Mbit/s signaling rate, which is achieved through...
from Atheros
Atheros
Qualcomm Atheros is a developer of semiconductors for network communications, particularly wireless chipsets. Founded under the name Atheros in 1998 by experts in signal processing from Stanford University, the University of California, Berkeley and the private industry, it became a public company...
. 125HSM can be more successful in radio-dense environments than non-standard channel bonding
Channel bonding
Channel bonding is a computer networking arrangement in which two or more network interfaces on a host computer are combined for redundancy or increased throughput....
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 other ISM band
ISM band
The industrial, scientific and medical radio bands are radio bands reserved internationally for the use of radio frequency energy for industrial, scientific and medical purposes other than communications....
devices—such as neighboring wireless network
Wireless network
Wireless network refers to any type of computer network that is not connected by cables of any kind. It is a method by which homes, telecommunications networks and enterprise installations avoid the costly process of introducing cables into a building, or as a connection between various equipment...
s, cordless telephone
Cordless telephone
A cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...
s, baby monitor
Baby monitor
A baby monitor, also known as a baby alarm, is a radio system used to remotely listen to sounds made by an infant. The transmitter unit, equipped with a microphone, is placed near to the child. It transmits the sounds the baby makes by radio waves to a receiver unit with a speaker carried by, or...
s, and Bluetooth
Bluetooth
Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
devices—can interfere
Interference (communication)
In communications and electronics, especially in telecommunications, interference is anything which alters, modifies, or disrupts a signal as it travels along a channel between a source and a receiver. The term typically refers to the addition of unwanted signals to a useful signal...
with channel bonding at distance
Distance
Distance is a numerical description of how far apart objects are. In physics or everyday discussion, distance may refer to a physical length, or an estimation based on other criteria . In mathematics, a distance function or metric is a generalization of the concept of physical distance...
s of up to 150 feet (45.7 m).
Criticism
- These (and similar) proprietary extensions are incompatible across different wi-fi chips vendors. So to make wi-fi link working in 125 HSM mode, both sides should use chips from same vendor (e.g. Broadcom). In most real-world scenarios such modes are simply useless due to different chips used by different devices.
- Existence of several similar technologies with different branding and incompatible with each other causes massive consumer confusion.
- These technologies are marketed in such a way it is possible to see them as cheating and tricking consumers through technology branding. This type of network will never be able to reach 125 Mbit/s as real data throughput; 125 Mbit/s is the maximum data rate before accounting for overhead. This causes consumer frustration due to failed expectations. For instance, the average consumer would expect a 125 Mbit/s wireless link to outperform a standard 100 Mbit/s wired link while, in fact, 100 Mbit/s wired link will be much faster; a standard wired 100Mbit/s 100BaseT link is approximately three times faster than 125HSM in simplex mode (i.e. transmitting or receiving only) and six times faster than 125HSM in full-duplex mode (i.e. both transmitting and receiving data—which is typical during file transfers between 2 computer connected to the same hub). In other words, even under ideal conditions, 125 HSM mode may only deliver anywhere from a third to one sixth the data transfer speed of a standard 100 Mbit/s wired LAN link.
External links
- Press release announcing 125HSM as Afterburner
- 125 High Speed Mode page within the 54g Wi-Fi technology site
- 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 (formerly Tom's Hardware GuideTom's Hardware GuideTom’s Hardware is an online publication focused on technology that was founded in 1996 by a German medic Dr. Tom Pabst. Tom's Hardware is owned by Bestofmedia Group company, one of the top three online publishers for technology in the world....
) testing 125HSM performance - Short article on various 802.11g boosters