Tips for Setting up Routers for 802.11b/g Use
The purpose of this section is to describe the settings for the most typical AP configurable parameters to enable compatibility with the Microchip MRF24WB0M / MRF24WG0M devices :
- DHCP Settings - For DHCP on LAN side (where AP is DHCP server), set Router to Enable DHCP server. Set Client Lease time to be longer than the typical off time of the station to ensure that the IP address provided doesn’t change each time the station is powered up. If an option for Always Broadcast is present for DHCP setup (broadcasts all DHCP responses to all clients), it should be disabled.
- Data Rate Settings - Ensure that service rates include 802.11b. 802.11g or 802.11n only rates (green field) should be avoided, but mixed settings are usually acceptable. If a Basic Rate setting is defined, it should be set to 1 and 2MBPS only.
- SSID Broadcast - Should typically be enabled so that the AP sends beacon frames containing the SSID. If disabled, ensure that Microchip Stack is set for Active Scanning.
- Channel Selection - For debug purposes, it is typical to use a fixed channel instead of Auto Channel Selection. If a fixed channel has been selected for the MRF24 Station, select the corresponding channel for the AP.
- Multicast Passthrough - If using multicast features (ZeroConfig for instance) ensure that the Router is configured to enable forwarding of Multicast packets.
- Beacon Interval - Set the value for the time interval between AP beacons, typical is 100msec. For lower power, this can be set to a smaller value, say 30mS, if the DTIM interval is correspondingly increased.
- RTS Threshold - Set the value for the frame size above which RTS/CTS will be used, typical is 2347.
- Fragmentation Threshold - Set the value for the frame size above which packets will be fragmented, typical is 2346.
- DTIM Interval - Set the value for Delivery Traffic Indication Message Interval, typical is 3 if the Beacon Interval is set for 100mSec. For lower power with the MRF24WB0M / MRF24WG0M, if the Beacon Interval is set to 30mS, then the DTIM should be set to 100 to allow 300mS DTIM Interval.
- WLAN Partition (or AP Isolation)- Prevents AP clients from communicating to each other, typically disabled.
- WMM Enable - Allows wireless multimedia traffic, disable unless necessary for other AP services.
- Short Guard Interval (GI) - Lowers the guard interval between frames, disable unless necessary for other AP services.
- WiFi Protected Setup (WPS) - Enables WPS device discovery, disable unless necessary for other AP services.
- Frame Burst - Enables higher wireless packet throughput, disable unless necessary for other AP services. This may be called turbo, or other marketing terms.
- CTS Protection Mode – Improves reliability of 802.11g traffic, disable unless necessary for other AP services.
- Key Entry – Security can be entered with either a numerical key or an ASCII passphrase. Ensure you enter what the AP expects. If just starting, it is best to have another station like a laptop to validate what the AP is expecting.
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