Is Bluetooth Still a Threat to 802.11? By Jim Geier
May 21, 2003
As Bluetooth and 802.11 emerged over the past several
years, many people thought that Bluetooth would compete heavily with 802.11.
The introduction of Bluetooth products, however, has been much slower than 802.11
counterparts. Let's see if life still exists in the possibility of Bluetooth
taking over the World.
Bluetooth Basics
The introduction of Bluetooth in May of 1998 was the result of several companies,
such as Ericsson, IBM, Intel,
Nokia, and Toshiba,
working together to create a solution to provide wireless access to computing
devices. The result is considered ideal for small devices, short range, and
low power radio links. This makes Bluetooth a good fit for connecting PCs and
laptop computers, phones, printers, PDAs, and cameras.
IEEE has made Bluetooth the basis for the
802.15 standard for wireless personal area networks (PANs). Bluetooth operates
in the 2.4GHz band, using frequency hopping spread spectrum technology. It constantly
hops over the entire spectrum at a rate of about 1,600 hops per second. Low
power Bluetooth devices have a range of about 30 feet. Higher powered Bluetooth
devices, however, can reach distances of around 300 feet, but this mode is fairly
rare.
One significant downfall of Bluetooth is relatively slow operation. Data rates
are only a couple of megabits-per-second (Mbps), well below that of 802.11a and
802.11b.
802.11 Basics
The 802.11 standard was completed in June of 1997 and is the basis of the Wi-Fi
standard. Since then there have been some additions to the standard, namely
802.11a and 802.11b (with 802.11g pending
ratification). Right now 802.11b is the most popular version, operating in the
2.4GHz spectrum with maximum data rates of 11Mbps and a range of about 300 feet.
802.11a is much faster than 802.11b at 54Mbps but has somewhat less range because
of operation in the higher frequency 5GHz band.
Could Bluetooth replace 802.11?
So is there any significant competition for the market between 802.11 and Bluetooth?
There definitely could be, because higher powered Bluetooth components are capable
of achieving 802.11 ranges. The current Bluetooth products, however, are mostly
low power and focus on wireless PAN functions. In addition, it would be difficult
for any Bluetooth wireless LAN products to gain a strong foothold in the market
because 802.11b products already have widespread adoption.
The place where Bluetooth really falls behind 802.11 is bandwidth. 802.11 components
can reach data rates up to 54Mbps, while Bluetooth lags way behind at around
2Mbps. A network administrator would not think twice about choosing 802.11 over
Bluetooth. Combined with relatively short range, this lower performance doesn't
make Bluetooth feasible for covering larger facilities.
Could 802.11 replace Bluetooth?
This is possible, mostly because 802.11 meets or exceeds nearly all of the
characteristics of Bluetooth. Because widespread adoption of Bluetooth is lacking,
there's still time for 802.11 vendors to get their foot in the door with manufacturers
needing to support needs for wireless PANs.
Some modifications would need to be made, however. The size of 802.11 components
needs to be smaller, but that is becoming more of a reality as semiconductor
companies strive for miniaturization of their 802.11 chipsets. These smaller
components require less power, making them more competitive for devices, such
as mobile phones, that have smaller batteries.
A Combined Solution
If the focus of Bluetooth stays on wireless PANs and 802.11 continues with
only wireless LANs, then they'll both share a happy coexistence. In fact this
is the most likely scenario. Many vendors, such as Intersil, Silicon Wave, and Mobilian, are developing chips that support
both 802.11 and Bluetooth. This enables manufacturers to use either 802.11,
Bluetooth, or both.
Jim Geier provides independent consulting services to companies
developing and deploying wireless network solutions. He is the author of the
book, Wireless LANs and
offers workshops
on deploying wireless LANs.
Got a question for Jim Geier and you're just too shy to post anonymously in our forums?
Join us at the 802.11 Planet Conference
& Expo, June 25 - 27, 2003 at the World Trade Center Boston in Boston, MA.
You can meet Jim in person as he gives his talk called 2.4 GHz or 5GHz? Strategies for Choosing The Right Spectrum .
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