Short Interframe Space

Not to be confused with CIFS.

Short Interframe Space (SIFS), is the amount of time in microseconds required for a wireless interface to process a received frame and to respond with a response frame. It is the difference in time between the first symbol of the response frame in the air and the last symbol of the received frame in the air. A SIFS time consists of the delay in receiver RF, PLCP delay and the MAC processing delay, which depends on the physical layer used. In IEEE 802.11 networks, SIFS is the interframe spacing prior to transmission of an acknowledgment, a Clear To Send (CTS) frame, a block ack frame that is an immediate response to either a block ack request frame or an A-MPDU, the second or subsequent MPDU of a fragment burst, a station responding to any polling a by point coordination function and during contention free periods of point coordination function.[1]

Standard SIFS (μs)[1]
IEEE 802.11-1997 (FHSS) 28
IEEE 802.11-1997 (DSSS) 10
IEEE 802.11b 10
IEEE 802.11a 16
IEEE 802.11g 10
IEEE 802.11n (2.4 GHz) 10
IEEE 802.11n, IEEE 802.11ac (5 GHz), IEEE 802.11ax, IEEE 802.11be, IEEE 802.11bn 16
IEEE 802.11ah (900 MHz) 160
IEEE 802.11ad (60 GHz) 3

Implications for Software Radio

Because most Software-Defined Radios use a host computer for processing, the SIFS imposes a difficult-to-achieve time constraint, as the latency for most SDR systems for the signal to traverse from the radio to the host and back to the radio, and vice versa, exceeds the SIFS requirements.

While in some cases it is possible to achieve SIFS requirements for testing, the practical approach is almost always to leverage the FPGA portion of processors common to many commercial SDRs.

See also

References

  1. ^ a b "IEEE 802.11 - 2012" (PDF). Archived from the original (PDF) on November 19, 2012.

Content Disclaimer

Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.

  1. The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
  2. There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
  3. It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
  4. Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
  5. Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.