networkZONE Products for the week of July 12, 2004

Engim Says…
Wi-Fi Done Right: Engim's New Intelligent Wideband WLAN Chipset Enables All-Services Access Points To Consolidate WLAN Functions And End Overlay Networks
A refined second-generation chip set and two complete reference designs help assure Engim will emerge as a "dominant species" in the still-maturing AP chip set market

Engim, Inc., developers of next-generation silicon technologies that redefines the capacity, security and manageability of wireless LAN infrastructure, introduced the industry's first All Services Access Point (ASAP) processor and a new line of vendor-ready access points that can simultaneously support any combination of current and emerging enterprise Wi-Fi services such as voice, data, security and video. Engim's new EN-3001 Intelligent Wideband Wireless LAN chipset and AP-310 and AP-320 Access Points enable 802.11 equipment manufacturers to rapidly introduce all services solutions with the service flexibility, performance, integrity, and security that can meet or exceed that of today's wired Ethernet enterprise networks. Engim also today announced its selection by Matrx Aerospace Broadband Technologies, developers of in-flight wireless solutions to give airline customers access to enhanced in-flight multi-media services and to provide a wide array of other wireless operational, security and diagnostic services.

With its new generation of solutions, Engim is enabling Wi-Fi equipment manufacturers and IT Managers to re-define their networks' services capacity and functionality, its performance, and its economics. Engim's EN-3001 Wideband Wireless WLAN chipset delivers capacity gains of up to 50 times that of today's single channel APs, making it ideal for today's bandwidth intensive enterprise applications such as converging data, voice and video. In addition, the EN-3001 multi-channel approach enables All-Service Access Points that provide support for any combination of security and intrusion detection, data-voice convergence, enhanced WLAN management and location determination. Additionally, EN-3001-based solutions 'future proof' Wi-Fi networks for large scale client growth, the ongoing addition of new real-time, business-critical applications, and mesh network capability. This ability to provide this multi-service functionality from a single platform eliminates the need for IT Managers to deploy multiple products from multiple vendors, which dramatically reduces WLAN equipment and labor costs and simplifies WLAN administration and management.

Engim's EN-3001 is being incorporated by Matrx Aerospace Broadband Technologies for its delivery of new wireless communications services to commercial aviation passengers, flight crew and command and control staffs. The Matrx Galaxy System is a multi-channel, multi-band system that supports the broad array of cabin and operations services. Among new in-flight passenger services it enables are: multi-media passenger entertainment, Voice over WLAN and internet access. Other important services that the Matrx Galaxy system provides include aircraft health monitoring, security and sub-system control. Such services were previously unattainable due to the capacity limitations, limited services scope, interference issues and instabilities of first generation single-channel 802.11 solutions.

Engim's EN-3001 Intelligent Wideband WLAN Chipset employs Wideband Spectral Processing technology, which provides unprecedented levels of interference mitigation to enable multi-channel capacity and WLAN quality of service with superior manageability and security. EN-3001-based device allow vendors to concurrently support the enterprise's full array of demanding applications including as voice, video, data, security, asset tracking and management. Until now, many of these functions and services required the deployment of expensive separate overlay Wi-Fi equipment. Engim is also delivering the AP-310 All Services Access Point, and the AP-320 Thin All Services Access Point. Each provides all of the multi-channel benefits of the EN-3001 chipset and enables access point manufacturers to design high-function differentiated access point products at very low cost.

The EN-3001's superior WLAN capacity and control advantages include:


analogZONE Says . . .

I first discovered Engim's first multi-channel WiFi chip set a few weeks after they announced it, and have been very disappointed that I never got to chance to review one of the most innovative Wi-Fi products on the market. So when I got wind of the impending release of their updated chip set, I jumped at the chance to take a closer look. Their novel, and extremely powerful wideband architecture has enormous potential in base station applications, and as we'll see, allows it to offer functions and capabilities that single-channel radios can't match.

A Powerful Architecture
In case you have not taken a look at the original product, it's a three-chip 802.11b/g wideband transceiver, capable of supporting up to three simultaneous channels of full-rate traffic on any channel. Without going into painful detail, the chip set consists of a SiGe wideband radio IC, a SiGe "analog" chip that does the ADC/DAC conversion of the wideband signal, and a CMOS baseband/MAC chip that does all the signal processing architecture (See the block diagram). With an additional 5 GHz radio, it can also support full 802.11a operation.

The unconventional architecture processes the full Wi-Fi spectrum, and then digitally extracts the three channels of interest. Likewise, the transmit side generates three separate channels and then combines them digitally before generating a baseband waveform that is sent to the transmitter as a single signal. The cool thing here is that this allows the Engim chip set to support simultaneous transmission, or reception, on any combination of channels with little (or as Engim claims) or none of the degradation in capacity or range that accompanies solutions using discrete co-located radios.

One of the most vexing (but non-obvious) problems that people discover when trying to simply co-locate multiple one-channel radios is that that the energy from each transmitter's side lobes spreads out across the spectrum onto adjacent channels. This will degrade, and in some cases completely swamp a signal you're trying to receive. And this does not even factor in the RF leakage that can infiltrate a radio's innards when it's in close proximity to another transmitter. Only one other company (Synad, recently acquired by STMicroelectronics) gets around this by carefully interleaving its transmissions, and taking advantage of some loopholes in the 802.11 timing standard to "spoof" the protocol into supporting its slightly-modified way of dishing out frames to multiple terminals. It works, and works rather well, but is still subject to some of the limitations of a single-channel radio.

Engim's wideband architecture solves this problem more elegantly by subtracting out the adjacent channel interference in several places. The RF section subtracts out its self-induced transmit interferers before the receiver even sees it, and then the baseband digitally estimates, and suppresses the side lobe components of incoming traffic on adjacent channels. The result is that the chip set supports three independent channels that can operate at will across the entire spectrum.

Engim's Updates
The EN3001 reviewed here is the second incarnation of the chip set, which has updates to the RF and digital baseband/MAC chips while the analog section remains the unchanged. The wideband SiGE RF front end chip now sports the RF cancellation I mentioned earlier that significantly improves performance during simultaneous transmission and reception.

The new digital baseband/MAC chip has added a pair of on-chip 10/100 Ethernet MACs, a nice feature the cuts BOM cost for many applications, and eliminates traffic bottlenecks across the host system's PCI bus. Having built-in Ethernet makes the chip "thin AP-ready" with only a few other components required. While less apparent, the DSP elements of the chip also have some algorithmic tweaks that improve interference mitigation -- something that translates into better reach and rates under "normal" conditions, and better operational margins in more challenging environments. Interestingly, the analog section remains unchanged, with more than enough linearity, resolution (10 "true" bits at full speed), and sampling speed (over 200 Msample/s) to deliver full throughput on all channels.

Powerful Applications
While unnecessarily complex (and expensive) for most (but not all) terminal applications, the multi-channel system affords an access point many capabilities that are much more costly, less effective, and in some cases, downright impossible to implement using three separate transceivers. The radio, combined with some clever reference software allows you to construct what Engim calls an ASAP an "all services access point". This means an access point that will deliver any service, on any channel, with no ifs, ands, or buts.

This ability to deploy three channels with a single box allows you to do things like dedicate one channel to slower carrying 802.11b traffic to keep it from dropping the capacity of the adjacent channel that assigned to the faster 802.11g traffic. Meanwhile, you could use the third channel to carry latency-sensitive VoIP traffic. Engim's ability to sequester traffic on dedicated channels according to speed, priority, or type of service will be essential in both public and institutional infrastructures where high subscriber density requires efficient use of limited bandwidth.

Another intriguing option is to use the third channel as a "rover" channel to monitor the band for both willful intrusion, and accidental interference. Besides simply looking for other unauthorized Wi-Fi sources, the chip's DSP section has built-in FFT spectral analysis capabilities which can continuously analyze the spectral content and energy levels of any RF emitter. This gives the Engim system a distinct advantage over single-radio APs which must periodically interrupt their service to scan the airwaves, or employ separate "overlay" systems which use separate "air monitor" boxes.

Both of these single-radio methods work, but have significant limitations -- the most important being that they are "blind" to non-802.11 traffic. Engim's on-chip spectrum analysis capabilities allows a user to "see" non-Wi-Fi RF presences, like microwave ovens, PCS and cordless phones, Bluetooth radios, as well as motor noise from appliances, and to select channels that best avoid the interference.

Interestingly, this ability to closely monitor all available frequencies, can also be used to support smooth hand-offs between APs -- a critical capability for the emerging Wi-Fi phone market. A VoWLAN-enabled AP could use Engim's spectrum analysis capability to monitor a hand set's signal strength even if it's not "talking" to it at the moment. This allows it to "see" all the handsets in the area, and predict signal strength trends. With this knowledge, it can more easily coordinate hand-offs with other APs over a back channel with much less likelihood of a dropped call.

There are lots of other interesting possibilities when you have more than one radio to play with, but one of the most intriguing is enhancing the throughput of wireless mesh networks. Thanks to their ease of lower installation costs and OSPF-like capacity utilization abilities, meshed wireless infrastructures are gaining in popularity -- even in enterprise applications. The biggest challenge for deploying mesh networks using single-radio APs is that overall capacity must be shared between talking to wireless terminals and back-hauling data from other network nodes. Engim relives this bottleneck by dedicating one or two channels to back haul tasks, freeing up the access channel's full capacity.

Chips Or Boards -- Your Choice
The new chip set's introduction is accompanied by a pair of really nice AP development platforms based on production-ready reference designs (including a complete BOM & Gerber files) for completely operational "thick" and "thin" access points. The AP-310 is a traditional "thick" AP platform which employs a discrete PowerQUICC I I (Freescale's 8247) as its host processor (although the chip set can work with other chips, including the Intel IXP425). The other ref design (AP-320) is a "thin" architecture, which takes advantage of the chip set's processor to do packet processing, encapsulation (CAP/WAP or other protocol) and forwarding to a centralized controller.Both reference designs also include Engim's extensive collection of pre-developed modules software that can be used as-is, or used for building a custom solution. These include the RF monitoring application I mentioned earlier that uses on-chip FFT to look for interferers and intruders, and a programmable list of actions to be taken upon their discovery. Another module allows you to quickly implement the "intelligent channel association" function that identifies traffic types in terms of data rate, and application, and moves it into the appropriate channel. Whether you're simply tweaking the reference code and slapping your label on the case, or doing a ground-up custom design, Engim gives you the tools to get your product off the lab bench and into production fast.

Both the availability of these development tools, and some solid design wins I discussed privately as background for this story are great news. I've always thought Engim's technology was among the best in the industry, and offered unique advantages, but have worried that their late entry into the game might hurt their chances for gaining a critical market share. But given the longer-than-anticipated maturation of the AP market, their timing might not be so bad after all. The timely arrival of a fully-refined 2nd-generation chip set, along with a pair of excellent quick-turn reference designs are important factors in assuring that Engim will emerge as a "dominant species" in the still-maturing AP chip set market.

The EN-3001 chip set and related system developer kits are in production. While Engim is reluctant to discuss pricing details, they did say that their reference designs will allow a manufacturer to create a "thick" AP with a complete BOM of $120, and a "thin" AP (without a separate host controller) with a complete BOM of under $100: and that's complete, including power supply, case, antennas, and all other incidentals.

Because they have a working chip set, and have been very candid about the operation, and limitations of their technology, Engim gets a respectably low Saltshaker rating. They would have scored even lower (ie better), but I do have some concerns about the challenges of a single-chip wideband RF section. Not having actually seen the chip running in a lab where I could check performance parameters adds a half-saltshaker, but still keeps the rating well within the bounds of credulity.

Data Sheet

Lee's Saltshaker Rating

   


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