| Common Wireless Connection Terms | |
| Jitter |
Jitter is the deviation in or displacement of some aspect of the pulses in a high-frequency digital signal. As the name suggests, jitter can be thought of as shaky pulses. The deviation can be in terms of amplitude, phase timing, or the width of the signal pulse. Another definition is that it is "the period frequency displacement of the signal from its ideal location." Among the causes of jitter are electromagnetic interference (EMI) and crosstalk with other signals. Jitter can cause a display monitor to flicker; affect the ability of the processor in a personal computer to perform as intended; introduce clicks or other undesired effects in audio signals, and loss of transmitted data between network devices. The amount of allowable jitter depends greatly on the application. |
| RSSI |
According to 802.11-1999, Received Strength Signal Indicator (RSSI) is a PHY layer measure of the energy observed by the antenna used to receive the current PPDU - in other words, the relative strength of the physical RF carrier signal, as communicated to the MAC layer. To learn more about how RSSI is used, visit the IEEE website and follow links to the wireless zone and 802.11 standards. |
| MPDU |
According to the IEEE 802.11-1999 standard, RTS Threshold indicates "the number of octets in an MPDU below which an RTS/CTS handshake will not be performed." MPDU is the MAC Protocol Data Unit, which is the sequence of fields generated by the MAC sublayer for submission to the PHY layer for transmission over a physical interface. In other words, an MPDU does not include the PHY Preamble or Header, and it's the PHY Header that contains the CRC. In addition, that standard says that "the length of the MPDU shall never be larger than the aFragmentationThreshold unless WEP is invoked [in which case} the MPDU shall be expanded by the IV [initialization vector] and ICV [integrity check value]... this may result in a fragment larger than the aFragmentationThreshold."
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| PHY | The phyisical layer. |