...and while we're at it, how long is a piece of string?

July 8, 2004

3 Min Read
WiMax: How Far?  How Fast?

One of the big questions about WiMax is exactly what kind of data transfer speeds and range the products -- based on the 802.16d fixed wireless standard -- will actually offer.

WiMax is a metropolitan area networking technology, which is seen by some as the savior of the fixed wireless industry, because it will allow them to reduce costs, by sourcing standardized components from vendors, and offer carriers interoperable infrastructure kit.

The initial fixed wireless 802.16d WiMax spec has just been ratified (see WiMax Spec Ratified). A mobile variant, called (surprise!) 802.16e, is expected to be ratified in 2005.

According to the coming edition of our monthly paid research report, Unstrung Insider, the answer is still a moving target, but performance may in fact lag behind the proprietary systems currently offered by vendors of broadband wireless access (BWA -- a.k.a. fixed wireless).

"The term WiMax is a catch-all phrase that hides a huge range of applications and variations in how the spec is implemented," says Gabriel Brown, chief analyst for Unstrung Insider. "So asking a vendor how their WiMax system will perform is like asking, 'How long is a piece of string?' "Nevertheless, Brown has dug up a chart from Intel Corp. (Nasdaq: INTC) that attempts to offer some of the speeds-and-feeds questions about WiMax performance:

Table 1: WiMax System Performance

Range

< 4 miles

4-6 miles

> 6 miles

Base-station cost (�04 pricing)

$5k - $20k for WISP class $20k+ for carrier

same

same

CPE price

< $300

same

same

Adaptive modulation scheme

64 QAM

16 QAM

� QPSK up to 16 QAM

Data throughput (20 MHz channel*)

75 Mbit/s

50 Mbit/s

17 Mbit/s to 50 Mbit/s depending on link quality

No. of business users (T1 level) 1

206

138

46 to 138

No. of residential users (512 kbit/s) 2

1,552

1,035

345 to 1,035

Source: Intel
Assumes two 10MHz bands in the base station as benchmark for comparison purposes. Over-subscription rate is 5x for business and 12.5x for residential. Also takes into account overhead (efficiency), which for 802.16 is 85% independent of number of users.



But -- even as the general industry is backing WiMax -- some vendors are claiming that the standard won't be able to offer the kind of performance that their proprietary systems can.

Allan Klein, vice president of technology at SR Telecom Inc. (Toronto: SRX), says in the Insider report: "“We’ve been saying for sometime that basic WiMax won’t do the trick. To get the performance in non-line-of-site that we get today, you’ll have to implement the optional extensions in WiMax that aren’t part of the basic profiles."— Dan Jones, Site Editor, Unstrung

WiMax: Going the Distance will soon be available as part of an annual subscription (12 monthly issues) to Unstrung Insider, priced at $1,350. Individual reports are available for $900.

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