Detente in the Airwaves: 802.11 and Bluetooth Together

By Matthew Peretz

December 07, 2001

Bluetooth and 802.11 are both outstanding technologies for their natural market niches. Concerns over compatibility appeared to give the upper hand to 802.11, but here is one company's solution to interoperability that makes such arguments unnecessary.

U.K.-based Red-M will be demonstrating Genos at the Bluetooth Developers' conference Monday, its cutting-edge software solution for creating a stable, multi-technology network environment that enables both Bluetooth and 802.11-enabled devices to coexist and interoperate successfully. In addition to the Genos architecture, Red-M 's products include the 3000AS access server, 1000AP access point, and Blade PDA expansion modules.

Red-M's product-line manager, Graham Carter, took the time to speak with 802.11-Planet today and explain the company's genesis and its technology solution that serves to reconcile many of the apparent incompatibilities between these two wireless networking technologies.

While 802.11 WLAN technology has been rousingly received and unanimously applauded by the wireless networking industry recently for its applicability to both the enterprise and home markets, Bluetooth seems to have lost its shine. Bluetooth has always enjoyed staunch support from particular segments of the wireless industry, particularly those in the handheld/handset sector who applauded and extolled it as a wireless Personal Area Network technology. The meteoric rise of 802.11 however, seemed to hasten its blue cousins relegation to the sidelines of the wireless wars. After all, people said, Bluetooth is only good for a few feet and around a meg per second of data transfer. Another strike against Bluetooth that people pointed out was that it operates in the same chunk of spectrum, 2.4 GHz, as does 802.11b. That means interference, right? What good is that when you have 802.11b that can propagate a signal hundreds of feet at a healthy 11 Mbps? And then there's 802.11a, and 802.11g, which promise even more phenomenal bandwidth! Good-bye Bluetooth! No. Supporters resoundingly and adamantly looked for a way to create peaceful co-existence.

Well, while 802.11-Planet certainly thinks that 802.11 is the best thing since sliced bread, there isn't and never has been a sound reason to write off Bluetooth. Red-M's Graham Carter firmly agreed with the observation that the two technologies can and do thrive and co-exist when you consider their real world uses.

One example, said Carter, is that in real-world use, PDAs have power constraints that at the present time make them much more suitable to a Bluetooth solution. Of course, he said, one has to consider whether the data transfer requirements are suitable to the technology's capacities. For example, Carter told 802.11-Planet about an installation that the company did in a hospital in Germany in which doctors use Bluetooth-equipped PDAs to transfer data to an SAP database. The devices are used for real-time synchronization from places like patient's bedsides so the Bluetooth solution is perfectly suited for such a task.

Red-M, which was an internal start-up from Madge Networks beginning in 1999, has introduced Genos as what it calls "wirelessware," or rather a type of middleware solution that enables control and management functionality in multi-technology networks, including WLANs, Bluetooth, 3G, and all of their real-world use on laptops, desktops, camcorders, phones, PDAs, and more. Genos enables the provisioning and management of all of these types of devices and routes data to them through the network. Information can even be pushed to devices in an appropriate format.

Genos operates as software that sits on an access server, which, as Carter explained, functions sort of like a subnet and firewall. Carter pointed out that access points, whether they are 802.11 or Bluetooth, increase their security and functionality by connecting through this type of access server arrangement and shouldn't ideally be plugged directly into any network. Genos handles key network management functions such as QoS issues, security, and the authentication and session control of devices on the network.

One of the key reasons that Bluetooth and 802.11 will actually co-exist is that the two technologies have different natural niches. The nature of Bluetooth, with its minimal power consumption requirements and limited bandwidth, makes it more suitable to use in phones and less powerful PDAs. In an office environment, the practical implications of this is that you can set up a completely compatible set of access points and client devices using both 802.11 and Bluetooth. One of the key things that Carter pointed out was that in real trials of exactly such a network setup, there was virtually no practical or significant performance degradation on either side - as long as there was about a meter of space between any two objects employing either technology. Furthermore, Carter said, companies are already making strides towards eliminating even that limitation.

What this all means is that a company will be able to set up an extensive network of mixed technologies and use solutions like Genos to make it all work well. That means that a person walking into an office carrying a Bluetooth-enabled phone will be able to have e-mail transferred without destroying connectivity in the active 802.11 office environment.

Reports by Cahners In-Stat this week seem to support the idea that Bluetooth hasn't lost its bite at all. In fact, the most recent study showed that by volume Bluetooth chip sales will effectively double those of 802.11b chipsets in 2001. While such a statistic is of limited relevance in and of itself, it does show that Bluetooth is back in a big way, supported by many wireless carriers' decisions to deploy public Bluetooth access points.

One interesting aspect that Carter noted when asked about the relative implementation costs of the two technologies is that in analyzing the question, one must consider the fact that 802.11b currently enjoys the benefits of volume-shipping cost reductions that are simply a fact of economies of scale, while Bluetooth as an emerging technology does not. He did note, however, that over time the cost of Bluetooth is expected to be well below 802.11 technology. Volume shipment comparisons would also seem to be of limited use, since the two technologies will increasingly carve out natural niches, rather than competing for the same space.

Matthew Peretz is Managing Editor of 802.11-Planet.com



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