At the Next Generation Network Ventures Conference today, start-up Atheros Communications, Inc., proposed enhancements to the IEEE and ETSI wireless Local-Area-Network (WLAN) standards to enable a wide range of devices, including real-time multimedia devices, to communicate under a single unified protocol in either a home or an enterprise.
Atheros' proposal for a 5-GHz Unified Protocol (5-UPTM) would permit cost-effective designs in which everything from cordless phones to high-definition televisions and personal computers could communicate in a single wireless multimedia network with speeds up to 108 Mbps. The existing standard specifications support high data rate devices up to 54 Mbps. The proposed Atheros enhancements would support interoperability with the existing standards, while allowing for higher speeds and scalability down to low-cost, low-power, low data rate devices.
"Having a scalable protocol that can cost-effectively enable low-speed devices to interoperate with high-speed devices results in a single multipurpose network," said Richard A. Redelfs, president and CEO of Atheros. "The Internet is a perfect example of the value a unified network delivers versus independent single-function networks."
Today's wireless Local- and Personal-Area Network solutions operate primarily in the 2.4-GHz spectrum using separate protocols or standards for different applications. In addition, many new cordless telephones use this spectrum. These solutions operate independently, all competing for the same 85 MHz of radio spectrum using incompatible protocols -- which can often lead to interference, reduced performance and dissatisfied users.
The 5-GHz spectrum addresses these issues and is ideal for next-generation wireless LANs for several reasons: (1) Regulatory bodies in the United States and Europe have allocated a broad 200-MHz of radio spectrum, enabling higher data throughput. (2) The spectrum receives minimal interference from microwave ovens. (3) And like the 2.4-GHz spectrum, it does not require a license throughout much of the world. Because the 5-GHz spectrum allocation is relatively new, competing protocols for different applications do not yet exist.
"Mobile computer users in enterprises are rapidly embracing wireless local and personal area networking," said J. Gerry Purdy, president of market research firm Mobile Insights. "With current technology, the notebook PC has to switch between different technologies. A mobile professional needs a seamless wireless connection to interoperate with his/her personal devices and the ability to stay connected using a wireless system in the office, at home and on the road. A single wireless technology that provides interoperability between each of these usage models while remaining competitive in terms of cost and power consumption would amount to a major industry breakthrough."
Atheros envisions the following requirements for a unified protocol to support business and home applications:
-- Reliable high-speed support (100 Mbps)
-- Multimedia traffic support (for example, guaranteed bandwidth)
-- Ad hoc network support
-- Efficient spectrum (bandwidth) usage
-- Support for low data rate devices that trade data rate for lower cost and power consumption
-- Cooperation among all devices sharing the spectrum
-- Interoperability at the least-common-denominator bandwidth between any two devices
Enabling the Wireless Future
The 5-GHz Unified Protocol enhancements will enable a single network to support both multimedia and "bursty" network traffic, while also providing interoperability between low and high data rate devices. Next-generation wireless technology based on 5-UP will also enable new applications and services that either are not feasible or are difficult to implement using wired connections. Examples include integrated wireless monitoring and security systems, personal email pads, portable electronic newspapers and books, portable music and video-on-demand, cordless Internet telephony and utility meter readings.
"We see a future where the cable coming into the home can deliver TV and PC content as well as offer phone service," said Adam Grosser, president of Subscriber Networks for Excite@Home. "Wireless distribution can dramatically reduce the deployment costs of these services within the home. Atheros' proposal would allow a single radio, located where the cable comes into the home, to communicate with TVs, PCs and cordless phones."
How the Technology Works
Both the international IEEE 802.11a and European ETSI HiperLAN II specifications are for high-speed local-area-networks operating in the 5.15- to 5.35-GHz band. At this time, no products are shipping in accordance with these new specifications. Atheros' proposal is to enhance these protocols and provide backward interoperability to products that comply only with the specifications as they exist, while also enabling new capabilities.
With 802.11a and HiperLAN II, the allocated radio spectrum is divided into eight separate network segments or channels of 20-MHz. Each channel supports a certain number of devices, and individual devices can roam across network segments just as a mobile phone gets handed from one base-station to another as the user drives across town. This 20-MHz spectrum for a network segment supports 54 Mbps of throughput, shared among the devices on the segment at any given point in time.
Within a channel, the 20-MHz spectrum is divided into 52 "narrow-band carriers" -- each about 300 kHz -- based on a technology called Orthogonal Frequency Division Multiplexing (OFDM). The existing specifications allow only one device on the network segment to "speak" at a time, using all 52 carriers.
Atheros' proposed 5-UP enhancements will allow
-- Carriers to be dynamically and individually assigned, enabling scalable and simultaneous communications
-- Carriers to be reserved, enabling guaranteed bandwidth for multimedia
-- 40-Mhz channels in environments where eight separate channel are not needed, enabling 2x54, or 108 Mbps, of throughput
The open 5-GHz spectrum offers an opportunity for the industry to develop the proposed enhancements to existing 5-GHz wireless LAN standards and benefit from a single distributed communications platform that enables a wide range of implementations and opportunities for new applications.
[ Home | Contact | MobiChat | Experts database | Let's do it ]
Comments to the content of this page can be posted on the MobiChat discussion group