Home: www.packetnexus.com
Can Bluetooth compete with WLAN? By Mattias Ringqvist and Will Daugherty, McKinsey & Company, Special to ZDNet May 4, 2001 9:49 AM PT URL: http://techupdate.zdnet.com/techupdate/stories/main/0,14179,2715556,00.html COMMENTARY--Much debate is brewing over whether Bluetooth will replace WLAN standards like 802.11b. Yet, how can a technology, initially developed for cable replacement, be seen as a threat to a Wireless LAN technology? Our perspective is that, in most cases, it will not be a threat. In fact, Bluetooth is delayed by at least a year, primarily due to a delay by manufacturers in getting products to market. In the meantime, 802.11b is gaining strong momentum as the WLAN standard. Realistically, the Bluetooth industry should focus on developing applications to take advantage of this superior cable replacement technology that will eventually be embedded in hundreds of millions of handheld devices. Common wisdom in favor of Bluetooth Bluetooth is a low cost, low power, robust wireless connection method with a small footprint that makes it very well suited for millions of handheld devices. Some common early assumptions favoring Bluetooth include: * The price of a Bluetooth chipset, excluding application interface software, is expected to drop from $20 to $5 by 2003. * A Bluetooth chip, designed to communicate in the 10m range, consumes only 1mW of power, compared to an 802.11b chip, which consumes more than 1W. A single Bluetooth chipset is also fairly small, with a size of 8x8mm, compared to the smallest 802.11b at 30x14mm. * Bluetooth and WLAN use the same frequency, 2.4GHz. However, given Bluetooth is designed to be a very robust technology that changes frequency at the speed of 1600 hops/second, it has an advantage over WLAN technologies like 802.11b. * Bluetooth is expected to have a very large reach this year with installation in more than 120 million end user devices, compared to only 4.3 million WLAN products. A somewhat different reality However, not all is what it seems. The predicted price drop for a Bluetooth chipset is driven by aggressive forecasts in volumes shipped. Recently revised volume forecasts of end-user devices shipped with Bluetooth functionality are in fact only 20-30 million units this year. At the same time, the cost of a WLAN chip is now, according to some manufacturers, also expected to fall to around $5 by 2003; competitive with Bluetooth chipsets. In addition, Bluetooth faces interoperability issues, not only on the physical layer between different hardware manufacturers, but also on the application layer, where so far, few profiles have been developed or agreed upon. Several players in the WLAN industry predict a move to 5GHz by 2004, positioning to avoid potential Bluetooth interference and reaching transmission speeds of 24Mbps. Bluetooth only gives a maximum speed of 721kbps for data, compared to 11Mbps for 802.11b. Therefore, streaming video applications, or downloading large quantities of information from the Internet to a laptop or PDA, is more likely to happen over a WLAN connection. Moreover, Bluetooth was never intended to become a network technology, and it holds limited ability to do handoffs between access nodes-an essential feature to ensure mobility. Several manufacturers have solved this for data communication, but real time mobile voice communication is still being developed. Finally, with Bluetooth on every laptop, communic