1 / 13

Proposal to Improve Link Margin Function in IEEE 802.11h

This proposal suggests enhancements to the link margin function in IEEE 802.11h, including a new service field format and an example of operation. Benefits include improved transmit power control and flexibility in implementation.

rchadwick
Download Presentation

Proposal to Improve Link Margin Function in IEEE 802.11h

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Proposal to Improve Link Margin Function in IEEE 802.11h Peter Larsson, Ericsson Research, Sweden Peter Larsson, Ericsson Research, Sweden

  2. Overview • Review of other link margin/TPC proposals • A scenario with potential of improvements • Proposal • Format • Example of transmit power determination • Example of basic operation • Benefits • Conclusions Peter Larsson, Ericsson Research, Sweden

  3. Review of Other Link Margin/TPC Proposals: • 01/520: Benefits of TPC request/response element (Joonsuk Kim, Broadcom Corporation) • 01/536: “Proposal to Add Link Margin Field in IEEE 802.11h” (S. Choi and A. Soomro, Philips Research USA) Peter Larsson, Ericsson Research, Sweden

  4. 01/536: Frame Format SERVICE field frame format Range: +9 dB to -5 dB Peter Larsson, Ericsson Research, Sweden

  5. 01/536: Example of Operation AP STA STA sends one MPDU to AP with TX Power field set AP sends ACK with TX powerand Link Margin fields set Adapt TX Power: STA sends next MPDU to APwith adjusted power Adapt TX Power: Optional to adapt ! AP sends ACK with TX powerand Link Margin fields set Peter Larsson, Ericsson Research, Sweden

  6. 01/536 with QoS(+)CF-POLL - DATA -ACK AP STA AP sends one QoS(+)CF-POLL to STA with TX Power field set STA sends DATA with TX powerand Link Margin fields set More important to control transmit power for DATA than for ACK ? + Better to control STA ? Adapt TX Power: AP sends ACK to STAwith adjusted power Peter Larsson, Ericsson Research, Sweden

  7. Proposal: Service Field Format SERVICE field frame format Range: 127 dB, 1 dB steps N.B only 7 bits ! Peter Larsson, Ericsson Research, Sweden

  8. T parameter = T + PTX_MAX - PRX_STA Proposal: Transmit Power ExampleSTA to AP transmission • PTX_STA  INRX_AP + M +PTX + PTX_MAX- PRX_STA= • INRX=Expected Interference + Receiver Noise [dBm] • M= Receive Margin [dB] • PTX= Transmit power [dBm]= PTX +PTX_MAX • PTX=Relative transmit power reduction [dB] • PTX_MAX= Maximum transmit power level for the channel [dBm] • PRX= Receive power [dBm] • N.B. PTX_STA <PTX_MAX Path loss Required RX power Peter Larsson, Ericsson Research, Sweden

  9. Proposal: Example of Operation (QoS(+)CF-POLL - DATA - ACK example) AP STA Set TAP parameter AP sends QoS(+)CF-POLL with TAP parameter set. Adapt TX Power: OL Set TSTA parameter STA sends DATA to AP with adjusted power. TSTA parameter is set Adapt TX Power: OL Adjust TAP parameter AP sends ACK to STA with adjusted power. TAP parameter is adjusted OL = Open Loop CL = Closed Loop Adapt TX Power: CL Adjust TSTA parameter Peter Larsson, Ericsson Research, Sweden

  10. Benefits • A single generic mechanism enabling: • OL control • Acts already at the 2:nd frame. • CL control • Acts on the 4:th frame and onwards and enables more precise control than OL. • Flexibility and optional operation: • Implementors decide whether OL (w/wo RX-interference) or CL is utilized. Peter Larsson, Ericsson Research, Sweden

  11. More Benefits • Minimized use of Service Field bits • Enables additional protection of field if needed Peter Larsson, Ericsson Research, Sweden

  12. Optional/Mandatory Features ? • Two possibilities. • STA 1 generating the T parameter (opt./mand.) • STA 2 using the received T parameter (opt./mand.) • Open for TGh discussion ! • However, we believe that it would be good if at least the T parameter generation is Mandatory. Peter Larsson, Ericsson Research, Sweden

  13. Conclusions • An improved TPC mechanism has been proposed • Provides OL as well as CL capabilities • A new service field format has been proposed • Simpler and more generic than two different fields • Shorter Peter Larsson, Ericsson Research, Sweden

More Related