ParkerVision SignalMax Wireless

By Joseph Moran

December 09, 2004

What's more important, throughput speed or a solid signal in all locations? These products bet on the latter, using standard 802.11b data rates but filing in holes where other products can't.

Price: $99 (Router model WR1500); $79 (Cardbus or USB adapter)
Pros: Range claims to be met.
Cons: 802.11b only, no support for WPA encryption

When shopping for WLAN equipment for a home or office, buyers are often fixated on a product's throughput claims. However, equally important to many purchasers (either from the start or once the products are bought and installed) is whether a WLAN will cover all the areas necessary to enable users to operate wireless devices wherever they wish.

Unlike many other WLAN vendors, Parkervision doesn't make any throughput claims at all for its SignalMax line of products. Instead, it aims focus on the issue of wireless coverage, by utilizing a technology the company calls Direct to Data (D2D). D2D uses a method of transmitting and receiving called RF Energy Sampling that samples much larger parts of the wireless signal than a conventional radio. Parkervision says this makes the signal less susceptible to interference and makes extracting data from it more efficient, greatly increasing signal range. (The technology is applicable to any product that uses RF; the company also makes a D2D-based cordless phone.)

Considering the prevalence of large, multistory homes, expansive yards, and the many sources of potential interference (both active and passive) a WLAN signal must contend with, chances are that a good percentage of WLAN users experience some kind of signal problem, either in the form of dead spots or weak areas where the signal is too tenuous to be used reliably. Sometimes, these coverage issues can be mitigated by simply adjusting (and adjusting, and adjusting again) the position or location of the access point. In many cases though, buyers must resort to the use of high-gain antennas, repeaters, or additional access points, which inevitably results in increased cost and complexity when setting up a network. ParkerVision promises to solve WLAN coverage problems with the D2D radio technology, obviating the need for these extra devices.

The company boasts that its SignalMax products—the WR1500 router with access point and WLAN1500 Cardbus adapter (a USB adapter is also available)—can achieve signal distance of one mile in an open field. (That's certainly impressive and may even be true, but how many of us live or work in an open field?) Nevertheless, the company is confident enough in its products that it guarantees that the hardware will cover an entire home and offers a 30-day refund if any dead spots are encountered.

It's important to note that both the WR1500 and the WLAN1500 are 11 Mbps 802.11b-only devices. ParkerVision says a follow-on 802.11g product incorporating the D2D radio technology will be released early in 2005. Interestingly enough, ParkerVision chose not to have either product's packaging indicate this fact, perhaps presuming that prospective buyers will consider the SignalMax products inferior to 802.11g devices (an argument than can be made if you consider potential throughput as the sole criterion). The box flap does indicate the devices are compatible with both b and g products, which they of course are (in the case of the WLAN1500 card though, only provided that the wireless network is operating in mixed mode).

The WR1500 certainly won't win any awards for exterior design— the router is a conventional-looking and fairly large black slab that sits flat on a desk, with a pair of adjustable dipole antennas coming out the back. The unit can also be wall mounted.

Looking at the WR1500's administrative interface, I noticed that it seemed vaguely familiar. A bit of investigation revealed that the administrative UI is nearly identical to that used by ZyXEL on many of its ZyAIR WLAN products, and sure enough a check of the WR1500's system status page indicated that the device is in fact running on ZyNOS. It turns out that ParkerVision sources some components and software from ZyXEL, but the D2D radio was developed in-house.

Notwithstanding the WR1500's unique radio technology, the unit's wireless configuration settings are similar to those in most 802.11b products. Two notable exceptions are that in addition to setting the channel manually, you can also click a "Scan" button that will search the spectrum and automatically select the channel with the least interference. There is also area that will sniff out existing wireless networks and display the SSID, mode, and signal strength of each, along with the channel being used.

The WR-1500 provides only WEP encryption and doesn't offer any WPA support. The unit can interface with an 802.x/RADIUS server, and like the ZyXEL products on which it is based, can maintain a local database of 32 users that can be authenticated via MD5. The WR-1500 also has excellent logging capabilities with the ability to record a number of different events, as well as send the logs (or an instant alert) to an administrator via e-mail. Syslog is also supported.

To gauge the coverage potential of the SignalMax WR1500, I tested it with the WLAN1500 Cardbus card installed in a Dell Inspiron 300m notebook. I began by running some tests with a Buffalo AirStation G54 access point (set to 11b-only mode) and the Dell's built-in WLAN adapter (both Broadcom chipset-based). This resulted in throughput scores of 5.88 Mbps at 10 feet, 5.23 at 50 feet, 5.13 at 100 feet, and 4.4 Mbps at 150 feet. Beyond that point, the client could not obtain a signal.

I then re-ran the tests with the WR1500 access point and the WLAN1500 card installed in the Inspiron. (Incidentally, the WLAN1500 card takes after the access point and is bulky compared to a conventional WLAN Cardbus card—it protrudes out of the slot about an extra = inch.) The pair of SignalMax devices transferred roughly the same amount of data as the first pair up to 100 feet— 5.3 Mpbs at 10 feet, 5.09 at 50 feet, and 4.92 at 100 feet. Interestingly, at 150 feet the SignalMax product mustered only 1.71 Mbps, but on the other hand at 200 feet, a point at which the previous products could not communicate, the SignalMax pair managed a solid connection, albeit at a mere .35 Mbps.

In ad-hoc testing for signal strength at various points around my building—which is large with concrete block construction (including many interior walls), and thus not particularly RF-friendly— I found that the SignalMax WR1500 and WLAN1500 were often (but not always) able to communicate reliably in areas where conventional b or g hardware could not.

The D2D-based SignalMax products certainly seem to have the potential to provide improved range in large or otherwise challenging environments. If high throughput is as important to you as range though, a powerful 802.11g access point and/or a high gain antenna may be a better choice, at least until Parkervision releases its 802.11g version, especially since at $100 for the access point and $80 for the card (street prices), the SignalMax products are more expensive than a typical pair of standard 802.11g devices. But if wireless range is your paramount concern, the Parkervision SignalMax products are worth a look.



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