User's Manual

2
• Intelligent Power Control, Including IEEE 802.11 Power Save
Mode
• Complete Reference Design, the ISL37300P CD is available to
ensure Minimum Time-to-Market
NOTES:
1. Throughout this document, all references to ‘PC Card’, ‘WLAN
adapter’, ‘adapter’, or ‘card’ refer to a card assembly conforming to the
mechanical size specifications of the PC Card.
2. The range will vary in different operating environments due to effects
such as building construction.
3. Atpresent,PTTUsupports Windows95,98and98SE.An upgrade is in
process which will add support for NT.
Functional Overview
The WLAN PC-Card 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 through 14, where permitted
by local regulatory authorities. Radio equipment must be certified in a
country prior to use. Refer to Table 4 for a list of countries and
agencies that have approved the ISL37300P-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 PC-card 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 PC-card 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
• Has a Type II PC Card form factor
A complete Reference Design for the ISL37300P is available to
ensure minimum time-to-market. This information contains details
for manufacturing a PC Card WLAN assembly, including Gerber
PC board files, a Bill of Material with component sourcing,
mechanical drawings, a detailed Radio Description with debug
directions and a test plan.
Related Literature
To learn more about what the IEEE 802.11 is, refer to:
• Tech Brief TB337, Intersil Corporation, “A Brief Tutorial on
Spread Spectrum and Packet Radio”[1].
For a more detailed description of radio operation, please refer to:
• Application Note AN9968, Intersil Corporation, “ISL37300P-
EVAL PRISM 2.5 PCMCIA Wireless LAN Radio Description”
[2]
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
•WEPSecurity
• 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)
• Beacon Generation in an Ad-Hoc Network
• Probe Response Generation in an Ad-Hoc Network
Card Information Structure
The standard Intersil WLAN PC Card will be supplied with
information embedded in the CIS shown in Table 2. It should be
noted that in most systems this information is displayed when the
card is inserted. Customization of the CIS for specific customer
requirements is available upon request, to enable customer
information to be displayed when the card is inserted.
FN8026