802.11a FAQ
By Chris De Herrera, Copyright 2002
 Version 1.00  Revised 7/20/2002

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Introduction

Recently, I have been asked more and more about 802.11a and how to use it with your Pocket PC.  This FAQ covers the current state of 802.11a as it relates to the Pocket PC and it's capabilities.

802.11a is a standard for communicating between multiple devices using wireless.  802.11a communicates at 54 megabits per second. It is similar to 802.11b however they are not interoperable.

 The Current State of 802.11a

Currently 802.11a is available for access points and PC Cards. Atheros is the first vendor to offer an 802.11a chipset.  The PC Cards that support 802.11a use a high performance standard called Cardbus.  Right now there are no 802.11a implementations for 16 bit PC Cards or CompactFlash Cards.

In order for your Pocket PC to use 802.11a, it needs to support Cardbus PC Cards.  At this time, none of the Pocket PCs support Cardbus PC Cards.  This is due to the design of the StrongARM and XScale chipsets from Intel that only support PC Card, CompactFlash or Secure Digital peripherals.  Also, the existing Pocket PCs do not offer high performance communications.  Based on my personal experience with 100 megabit Ethernet cards, the Pocket PC communicates at peak of approximately 400 k bytes per second.  Currently this is much slower than the maximum speed of Ethernet, 100 megabit Ethernet, 802.11a and 802.11b.

At this time, Intel needs to add support for Cardbus PC Cards in order for Pocket PCs to use high speed peripherals efficiently.  Also, Microsoft needs to improve the performance of the TCP/IP stack.  Of course, higher clock speeds of new CPUs will help the overall performance of the system.  I hope at some point in the future we will see a smaller high speed connector that is similar to the CompactFlash slot so we can take advantage of high speed communications like 802.11a.