User Manual

2
Functional Overview
The WLAN miniUSB is designed to operate in the 2.4GHz ISM
frequency band, channels 1 to 11, as specified by the FCC in the USA.
The Card will also operate on channels 12 to14, where permitted by
local regulatory authorities. Radio equipment must be certified in a
country prior to use. Refer to Table 3 for a list of countries and
agencies that have approved the ISL37300U-EVAL for operation.
The Intersil PRISM Chip Set allows for high level integration for
reduced size, increased throughput, improved radio performance
and faster time to market. The WLAN miniUSB implements
Direct Sequence Spread Spectrum DSSS technology providing
superior noise and signal jamming immunity including less severe
impact from unintentional radiators such as microwave ovens. The
user can connect the miniUSB in an ad-hoc peer to peer
networking scheme, allowing for instant network setup in any
office environment. By using an access point, the wireless LAN
can be set up to allow for a greater number of users to interconnect,
and to increase the coverage area. With a portal (i.e., Access Point),
the wireless LAN can be easily connected into an existing wired
LAN, allowing for easy expansion of the service.
Compared to the PRISM II chip set, the PRISM 2.5 generation
offers:
• Low loss front end designed for maximum range
• Higher level of chip integration and less peripheral components
to reduce material costs
• Support of optional IEEE 802.11 Short Preamble for
significantly increased data throughput with room for additional
user defined functions.
A complete Reference Design for the ISL37300U is available to
ensure minimum time-to-market. This information contains
detailes for manufacturing a miniUSB WLAN assembly, including
Gerber PC board files, an accurate Bill of Material with
component sourcing and complete mechanical drawings and a
complete Radio Description and test plan.
Related Literature
• Tech Brief TB337, Intersil Corporation, “A Brief Tutorial on
Spread Spectrum and Packet Radio”[1].
• Application Note ANxxxx, Intersil Corporation, “ISL37300U-
EVAL PRISM 2.5 11 Mb miniUSB Wireless LAN Radio
Description” [2]
• Tech Brief TB337, Intersil Corporation, “A Brief Tutorial on
Spread Spectrum and Packet Radio” [3]
• Tech Brief TB382, Intersil Corporation, “Measurement of
WLAN Receiver Sensitivity” [4]
• Application Note AN9850, Intersil Corporation,
“Complementary Code Keying Made Simple” [5]
• Application Note AN9829, Intersil Corporation, “Brief Tutorial
on IEEE 802.11 Wireless LANs” [6]
• Application Note AN9820, Intersil Corporation, “A Condensed
Review of Spread Spectrum Techniques for ISM Band Systems”
[7]
The ISL3873 Media Access Controller (MAC)
Protocol Handler
The ISL3873 MAC/Baseband Processor and its firmware are
responsible for running the IEEE 802.11 protocol in the WLAN
card. This section describes the features of IEEE 802.11 that are
implemented.
The functions supported by the STA (station) Firmware are:
• CSMA/CA (Carrier Sense Multiple Access with Collision
Avoidance) with Random Backoff
•WEP Security
• Short/Long Preamble with multirate
• RTS/CTS Handshake (Ready To Send/Clear To Send) and NAV
Management (Network Allocation Vector)
• MAC Level Acknowledgments (Media Access Control)
• Re-Transmission of Unacknowledged Frames
• Duplicate Detection and Rejection
• Broadcast and Multicast Frames
• Fragmentation and Re-Assembly
• Power Management (Planned)
• Timestamp Synchronization
• DCF (Distributed Coordination Function)
• PCF (Point Coordination Function)
• Beacon Generation in an Ad-Hoc Network
• Probe Response Generation in an Ad-Hoc Network
Card Information Structure
The standard Intersil WLAN miniUSB will be supplied with
information embedded in the Plug and Play (PnP) shown in Table
2. It should be noted that in most systems this information is
displayed when the card is inserted. Customization of the PnP for
specific customer requirements is available upon request, to enable
customer information to be displayed when the card is inserted.
TABLE 2. PnP EMBEDDED INFORMATION
FUNCTION NAME CONTENT
Manufacturer’s ID 00
Function ID Network Adapter
Product Revision 1
Manufacturer Intersil Corporation
Product 12603873
PROG
LOT
FN8022