The
ral driver supports PCI/CardBus wireless adapters based on the Ralink RT2500, RT2501, and RT2600 chipsets. The
ral driver supports USB 2.0 wireless adapters based on the Ralink RT2500USB chipset.
The RT2500 chipset is the first generation of 802.11b/g adapters from Ralink. It consists of two integrated chips, an RT2560 or RT2570(USB) MAC/BBP and an RT2525 or RT2526(USB) radio transceiver.
The RT2501 chipset is the second generation of 802.11b/g adapters from Ralink. It consists of two integrated chips, an RT2561 MAC/BBP and an RT2527 radio transceiver. This chipset provides support for the IEEE 802.11e standard with multiple hardware transmission queues and allows scatter/gather for efficient DMA operations.
The RT2600 chipset consists of two integrated chips, an RT2661 MAC/BBP and an RT2529 radio transceiver. This chipset uses the MIMO (multiple-input multiple-output) technology with multiple antennas to extend the operating range of the adapter and to achieve higher throughput. MIMO will be the basis of the future IEEE 802.11n standard.
These are the modes the
ral driver can operate in:
BSS mode
Also known as infrastructure mode, this is used when associating with an access point, through which all traffic passes. This mode is the default.
IBSS mode
Also known as IEEE ad-hoc mode or peer-to-peer mode. This is the standardized method of operating without an access point. Stations associate with a service set. However, actual connections between stations are peer-to-peer.
Host AP
In this mode the driver acts as an access point (base station) for other cards.
monitor mode
In this mode the driver is able to receive packets without associating with an access point. This disables the internal receive filter and enables the card to capture packets from networks which it wouldn't normally have access to, or to scan for access points.
ral supports software WEP. Wired Equivalent Privacy (WEP) is the de facto encryption standard for wireless networks. It can be typically configured in one of three modes: no encryption; 40-bit encryption; or 104-bit encryption. Unfortunately, due to serious weaknesses in WEP protocol it is strongly recommended that it not be used as the sole mechanism to secure wireless communication. WEP is not enabled by default.
The transmit speed is user-selectable or can be adapted automatically by the driver depending on the received signal strength and on the number of hardware transmission retries. See
rssadapt(9) for more information.