Summit Knowledge Center
WAITEVENT is a smartBASIC statement that tells the device to wait until a specified conditional becomes true, and to execute a function when it does. The majority of clock time is spent in this low-power state in a smartBASIC application; this is how Bluetooth Low Energy achieves its power optimization. WAITEVENT should never lapse and thereby stop the program. It is always the end and beginning of a continuous loop.
Wake on Wireless (WoW) and Wake on Wireless LAN (WoWLAN) are two terms for the same essential capability: the ability of a wirelessly enabled client device to awake from a sleep mode upon the receipt of a notification from the wireless infrastructure. This capability is intended to minimize the overall amount of current consumed by the client device while, at the same time, allowing the device to awaken and receive time-critical traffic (such as a wireless voice over IP call). By doing this, WoW allows for maximum battery life without a decrease in performance and/or reliability. Currently, there is no set standard for WoW and only limited vendor support.
There are three necessary elements to WoW:
- The infrastructure must send the device a wake up notification. Typically, this notification is a "magic packet" (or a special packet that, when received by the device's radio, causes the radio to notify the host device to wake up).
- The client radio must be capable of maintaining connection to the infrastructure while the client device (into which it is embedded) is asleep. Note that when the host device is asleep it provides the radio with power but no support (such as the host processor and memory); this means that the radio must be self-sufficient to a greater degree than is the case with typical Wi-Fi radios. The radio typically notifies the host device of a wake up event by changing the state of an interface pin to the host.
- The client device must be capable of awakening upon notification from the radio. When present, this capability is typically found in the client device's operating system. The client device must be minimally awake (the process must be running) while in sleep mode to receive the notification and initiate the wakeup process.
With WoW, the client radio must still maintain a connection with the network infrastructure; this implies that the host device must, at minimum, provide power to the client radio. Client devices can typically be placed in power save modes where displays and other power-intensive system components are powered down while the processor and system bus remain operational.
Given the low power consumption of modern microprocessors, the power savings difference between a device in a power save mode and a device that is fully powered down is modest-particularly understanding that in any scenario the client radio must be sufficiently operational to maintain network association and receive a magic packet. The incremental benefit of WoW to a wireless device is a modest, understanding the implementation complexities.
Rather than a full WoW implementation, most client device vendors and network administrators configure their devices for aggressive power save modes. A client device properly configured for power savings can have similar power consumption when compared to a device using WoW.
WEP (Wired Equivalent Privacy) encrypts transmitted data using 64-bit or 128-bit encryption. WEP, which was defined with the original IEEE 802.11 standards, is not recommended because a WEP key can be "broken" in less than an hour using commonly available tools.
Wi-Fi Direct ™ is a means by which one or more Wi-Fi client devices can connect directly to another Wi-Fi client device without joining a Wi-Fi network. The Wi-Fi Alliance, an industry consortium that promotes the use of Wi-Fi, has defined the specification for Wi-Fi Direct as well as a certification test program by which a device can earn the Wi-Fi CERTIFIED Wi-Fi Direct seal.
When a client device supports Wi-Fi Direct, that device can start a Wi-Fi Direct Group and control which other client devices can join the Group. To a client device that does not support Wi-Fi Direct, which the Wi-Fi Alliance calls a legacy client, the Group "leader" appears to be a Wi-Fi infrastructure device such as an access point (AP) and supports AP functionality such as BSS functionality. In other words, a legacy client cannot recognize that it is connecting to another client device instead of to an AP.
When describing Wi-Fi Direct, the Wi-Fi Alliance focuses on the ability of consumer devices such as mobile phones, cameras, printers, and gaming devices to "connect to each other directly to transfer content and share applications quickly and easily". With Wi-Fi Direct, "you do not need an access point or internet connection - your personal Wi-Fi network goes with you wherever you go."
Today, many people want to use their personal devices, such as smartphones and tables, in enterprise settings. When an enterprise client device supports Wi-Fi Direct, personal devices can connect directly to those enterprise client devices without having to connect to the enterprise network. The Wi-Fi Alliance promotes the fact that "all Wi-Fi Direct connections are protected by WPA2T, the latest Wi-Fi security technology."
The version of WPA2 supported for Wi-Fi Direct connections is WPA2-Personal, not WPA2-Enterprise. For connections to Wi-Fi networks, most enterprises rely on WPA2-Enterprise and its 802.1X authentication using an Extensible Authentication Protocol (EAP) type. WPA2-Personal supports not EAP authentication but authentication using a pre-shared key (PSK) or a passphrase that is used to derive a PSK. Many enterprises consider WPA2-Personal insufficient for a connection to an enterprise network
Suppose a client device uses WPA2-Enterprise to connect to an enterprise Wi-Fi network. That device then uses Wi-Fi Direct to define a Group and advertise itself as an AP to the Group. Once a device connects to the Group leader, that device may be able to gain access to the enterprise network through the Group leader. As a result, enterprise network access is secured not by WPA2-Enterprise but by whatever security is configured for Wi-Fi Direct connections to the Group leader.
Consider a hospital that wants to allow doctors to use their personal smartphones or tablets to connect to trusted medical devices such as patient monitors. Those medical devices probably rely on WPA2-Enterprise to connect to the hospital network. If the medical devices support Wi-Fi Direct, then they may allow smartphones and tablets to connect to them. If WPA2-Personal is used for Wi-Fi Direct connections, then the hospital is likely to use the same simple PSK or passphrase on every medical device, or doctors will not be able to connect. Once a doctor's smartphone or tablet is connected, it has access to the monitor as well as the entire hospital network.
A hacker may figure out the simplistic PSK or passphrase in a short amount of time. Once the hacker has the PSK or passphrase, he or she can enter the trusted hospital network through any medical device for which Wi-Fi Direct is configured and active.
A more secure approach is to centralize information from medical devices and provide clinicians with an application that enables them to access information from the network itself instead of through individual medical devices.
Wireless Zero Configuration (WZC) is a Microsoft Windows (XP and later) wireless connection management utility. WZC dynamically selects a wireless network with which to connect based on a user's preferences and various default settings. This service can be used instead of (or in the absence of) a manufacturer's wireless network utility.
A wireless intrusion prevention system (WIPS) on a computer network is a device designed to mitigate unauthorized access points or other wireless devices perceived as potentially malicious. If a WIPS device detects a device that appears threatening, it may take steps to prevent the device from intruding into the network.
A wireless device specifically defined by the FCC for transmission of biotelemetry data, or data related to a patient's health. WMTS was defined in 200 because of intereference issues that arose with the increased use of digital television. WMTS frequency bands are 608-614 MHz, 1395-1400 MHz, and 1427-1432 MHz. Because there is not agreement on how to use these bands outside the U.S., WMTS devices cannot be marketed or used freely outside the U.S.
WLAN, or a wireless local area network, links multiple devices using a wireless method (such as OFDM). WLAN typically provides a connection through an access point to the Internet and allows users to move around within the local coverage area while remaining connected to the network.
WMM (SCU Global Setting)
WMM is an SCU Global setting that enables or disables the use of WMM extensions.
Note: If you change the WMM global setting in SCU, you must do a power cycle or suspend/resume on the device to cause the change to take effect.
A 10-Series, 20-Series, or 22-Series Summit radio programmed for the WorldWide domain supports not only 802.11d, but also a "world mode" capability. When the radio is within range of APs that are not configured for 802.11d, the radio identifies the channels that the APs support and automatically adapts the radio's channel set to the channels supported by the APs. The world mode feature applies to all 14 channels at 2.4 GHz but only to the UNII-1 channels at 5 GHz.
Notes: Summit 30 Series radios and Summit 15N radios support 802.11d but do not support the special Summit "world mode" capability.
Both WPA and WPA2 include three security elements: authentication, encryption, and encryption key management. WPA and WPA2 support the same authentication methods and similar key management methods. The primary difference between the two is in the area of encryption: WPA defines TKIP as the primary encryption method; WPA2 defines AES-CCMP as the primary encryption method.
Both WPA and WPA2 include a Personal version and an Enterprise version. With WPA-Personal and WPA2-Personal, which SCU refers to as WPA-PSK and WPA2-PSK, authentication is done through a pre-shared key (PSK) or passphrase that is statically configured on every client device and infrastructure device. With WPA-Enterprise and WPA2-Enterprise, authentication is IEEE 802.1X, which uses an EAP type. WPA2-Enterprise is the equivalent of IEEE 802.11i, the ratified standard for Wi-Fi security.
A setting on Cisco access points that enables both WPA and non-WPA stations to associate to an access point using the same SSID, provided that the access point is configured for Migration Mode (WPA optional with TKIP+WEP128 or TKIP+WEP40 cipher). In other words, WPA Migration Mode means WPA key management with TKIP for the pairwise cipher and TKIP, 128-bit WEP, or 40-bit WEP for the group cipher. When WPA Migration Mode is in use, you can select WPA TKIP or WEP EAP for your Summit radio encryption type.
There are some security risks in using WPA Migration Mode. When supporting both static or dynamic WEP stations and WPA stations, security operates at the least-secure level common to all devices. Although WPA key authentication, per-packet keying, and message integrity are enabled in Migration Mode, they are not enforced for all stations. As a result, a passive WEP key attack could be launched against WEP users. Additionally, the broadcast WEP key rotation (Group Key rotation) may not be employed for static WEP stations. WPA Migration Mode should only be used as a temporary transition mode.
WPA-PSK and WPA2-PSK, the SCU terms for WPA-Personal and WPA2-Personal, are designed for small networks with very few clients and infrastructure devices. Authentication is done through a pre-shared key (PSK) of up to 256 bits (entered as a string of up to 64 hexadecimal digits) or a passphrase of 8 to 63 ASCII characters (from which a PSK is derived).
Note: Note: PSK can be vulnerable if the user relies on a weak passphrase for protection.
Note: See WPA/WPA2 for additional information.
- Compatible with older hardware
- Uses a 128-bit encryption key
- Changes the key used for each packet
See AES - Advanced Encryption Standard for more information.
Enables both WPA and WPA2 stations to associate to an access point using the same SSID. WPA2 Mixed Mode is defined by the Wi-Fi Alliance, and support for the feature is a part of Wi-Fi certification testing. When WPA2 Mixed Mode is configured, the access point advertises the encryption ciphers (TKIP, CCMP, other) that are available for use. The station selects an encryption cipher which is then used for encryption between the station and access point. The access point must support WPA2 Mixed Mode in order for this option to work.
In other words, WPA Mixed Mode means WPA key management with AES for the pairwise cipher and AES or TKIP for the group cipher. When WPA2 Mixed Mode is in use, you can select WPA2 AES or WPA TKIP for your Summit radio encryption type.