Belkin Wireless Pre-N Router

By Joseph Moran

November 23, 2004

This is far from being true 802.11n as we will some day know it, but this first commercial product using MIMO technology delivers the goods in speed and distance to any extra-early adopters.

Model: F5D8230-4
Price: $159.99 (MSRP)
Pros: Improved throughput and range, compatible with older 802.11g and b products
Cons: Pricey, upgrade path unknown.

In late 2001 and early 2002, during the roughly six months preceding the final ratification of the 802.11g wireless networking specification, many companies, not satisfied to wait for the formal standard, flooded the market with so-called "draft-g" devices based on preliminary versions of the standard. While this allowed many users to break the performance shackles of 802.11b a bit early and get a taste of the forthcoming higher-speed technology, it also led to a fair number of interoperability issues (both among g products and between g and b devices) as well as seemingly weekly firmware updates designed to expand compatibility, improve performance, or simply fix bugs.

Here we go again—sort of. While the upcoming 802.11n standard is at best in an extremely early form— it's actually a year or more away and there are still many competing proposals on the table— Belkin has recently released it's $159 F5D8230-4, which the company is calling a "Wireless Pre-N Router." This in spite of the fact that, hoping to avoid the draft-G scenario again, the Wi-Fi Alliance is cautioning, (and indeed actively discouraging) wireless vendors from making claims that their products have 802.11n capabilities. (That did not stop the Alliance from giving this product a Wi-Fi Certification for 11g interoperability, however.)

So how does Belkin justify calling the F5D8230-4 a "Pre-N" product? Simply put, because it's based on a new wireless chipset from Airgo Networks, which utilizes a MIMO (Multiple In Multiple Out) smart radio/antenna technology, and MIMO is (almost) guaranteed to be part of the ultimate 802.11n specification.

Using the letter "N" in the product name certainly has the potential to be misleading to a purchaser (Belkin is careful to not use the "IEEE 802.11n" or even just a "802.11n" nomenclature), but it's hardly surprising since the wireless networking segment is so rife with marketing hyperbole it makes political ads look measured and cautious in comparison. In fact, on the product packaging, Belkin claims speeds that are 600% faster and coverage 800% wider than 802.11g.

We'll see.

Just to be clear— though one might (rather dubiously) make the argument that the Belkin Pre-N router is in fact using some progenitor of an eventual 802.11n specification, it's technically not doing so, since there isn't even a working draft of 802.11n just yet. And keep in mind that there's really no iron-clad guarantee that the Belkin product will be upgradeable to 802.11n when it finally arrives.

Finding MIMO

So what exactly is MIMO? Simplified, it's a means by which wireless devices communicate using multiple antennas simultaneously to improve both performance and range. In a conventional radio, a single antenna is used to transmit and receive data streams between wireless devices. (Even devices with dual antennas— known as antenna diversity— only use one antenna to transmit signals; when receiving the antenna with the better signal is utilized while the other is ignored.) In contrast, MIMO takes a single data stream, splits it, and then transmits (and receives) each stream on a separate antenna.

MIMO was designed to exploit what was heretofore considered an impediment to radio transmission— multipath, or the tendency for signals to bounce and reflect off objects, causing them to arrive at an antenna from multiple directions. MIMO uses the multipath effect to transmit and receive multiple slower data streams simultaneously, aggregating the streams at the destination to result in a 108 Mbps connection. MIMO does all it's communication in a single channel, compared to Super G which yields similar performance by using multiple channels.

The Belkin Pre-N router's physical layout departs a bit from the company's previous offerings. The chassis, which is now square instead of rectangular, sports three separate antennas, all in a row on the top of the unit. There are wall mount points. [Corrected from previous statement that the antennas were not adjustable. - Ed.]

Setup

Belkin provides a setup wizard that you can use to automatically configure your computer's network settings prior to physically connecting the router, but I opted to go with the direct method, logging into the routers administrative interface via default IP address.

As a WAN device, the Belkin Pre-N router doesn't offer anything vastly different from the company's previous products, or those from other vendors (this area isn't where the innovation is nowadays, anyway). The device does use Belkin's subscription-based content filtering feature, which is a must if you have any hope of shielding kids from nastiness on the Internet. On the negative site, the unit's logging is pretty weak. The log can't be output to a syslog server, and while you can save it to a text file, doing so usurps your browser window, making it difficult to return to the administration console.

Under wireless settings, you'll find mostly familiar fare as well— you can choose between 802.11g only and 802.11b+g modes (remember, this is still an 802.11g device, albeit with a more sophisticated antenna system). The only settings out of the ordinary are an Auto channel setting which allows the Pre-N router to adjust the channel based on the environment, and the ability to enable 802.11e QoS for when traffic is especially sensitive to latency, like in streaming or VoIP scenarios.

The Wireless Pre-N Router supports both WEP and WPA-PSK encryption, but no AES encryption or RADIUS authentication—so it's not ready for WPA2/802.11i security.

Performance

To test performance of the Wireless Pre-N Router, I used a Dell Latitude Inspiron 300m notebook along with Belkin's companion Pre-N Notebook Network Card (model: F5D8010). Aside from a slightly bulky business end (necessitated by the multiple antennas), the Pre-N card looks and functions like any regular 802.11g card. The company also sells a PCI adapter module that the notebook PC Card will fit into.

Increased throughput was immediately evident using the Pre-N devices. At 10 feet, the throughput between the devices was 39.68 Mbps. Increasing range to 50 feet caused throughput to drop very slightly, down to 38.78, and at 100 feet, throughput suffered only a bit more, measuring 35.72 Mbps.

To compare performance via a pair of conventional 802.11g devices, I also did another round of tests with a Broadcom-based Buffalo WBR-G54 router and the Inspiron's built-in 802.11g/b adapter (also Broadcom-based). With these devices, throughput levels were more or less typical of 802.11g and degraded more rapidly with distance— I obtained 20.29 Mbps of throughput at 10 feet, 15.36 Mbps at 50 feet, and a mere 10.34 Mbps at 100 feet.

Since Belkin claims that the Wireless Pre-N Router will improve the performance even of conventional 802.11g client cards, I also tested the Inspirons' built-in adapter against it. While the throughput at 10 feet was roughly equivalent at 21.08 Mbps, performance did improve rather significantly at the further distances—18.25 Mbps at 50 feet, and 15.97 Mbps at 100 feet, which would seem to validate the claim.

On the subject of signal strength, the Wireless Pre-N router did not seem to provide any increase in actual range. In my test environment, at the point where conventional 802.11g device lost its signal, the Wireless Pre-N device did so as well at roughly the same location. On the other hand, in various areas where a signal was typically weak or tenuous, the Pre-N device pair did maintain a firm bond with each other.

Conclusion

We know that buying the Belkin Wireless Pre-N Router won't make you the first person on your block to able to enjoy early use of a standard that technically doesn't yet exist. Belkin's hyperbolic claims and implications aside however, the Wireless Pre-N Router's innovative MIMO antenna does clearly provide a substantial improvement in throughput and coverage, and that makes it worthy of consideration. Of course, to take full advantage of it you must also have wireless network adapters with MIMO antennas—Centrino's don't count—and the combined street price of a Pre-N Router plus the Cardbus adapter is in excess of $200, about double that of a pair of conventional 802.11g devices these days.

Nevertheless, if you're looking for improved performance, coverage, or both, the Belkin Wireless Pre-N Router will likely serve your needs. Just don't be surprised if you find yourself having to buy a new product when 802.11n finally hits the shelves if you're determined to stay current.



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