1. July 2010
doc.: IEEE /0xxxr0
Revised shorter presentation to TGax relating to coexistence efforts in Coexistence SC
12 Sept 2017
Authors:
Name
Company
Phone
Andrew Myles
Cisco
Andrew Myles, Cisco
Andrew Myles, Cisco

2. Work is required in ETSI BRAN (& maybe 3GPP) is required to ensure 802
Work is required in ETSI BRAN (& maybe 3GPP) is required to ensure achieves its potential
Situation
Problem
Solution
IEEE 802 has been working with 3GPP on Wi-Fi/LAA coexistence for the last few years …
… but IEEE 802 has probably achieved as much as is possible for the moment
… although there may be a possibility for IEEE 802 to reengage with 3GPP in the future
In parallel, ETSI BRAN has been defining EN , which will impact coexistence with Wi-Fi globally …
… but the current version of EN is problematic for ax performance & spatial reuse
… although the planned revision of EN provides an opportunity to better enable ax features
Call to action: please actively participate in the Coexistence SC to ensure ax can achieve its potential!
Andrew Myles, Cisco

3. IEEE 802 has been working with 3GPP on Wi-Fi/LAA coexistence for the last few years …
IEEE 802 has been collaborating with 3GPP for the last few years, with a goal of good coexistence between Wi-Fi & LAA (and its variants)
There is now some consensus in the Coexistence SC that the collaboration has probably gone as far as it can at this time …
…with many points of agreement leading to good LAA refinements
… but a few remaining points of disagreement
The main open issues, as documented in the last two Liaison Statements from IEEE 802 to 3GPP, are:
What are appropriate PD/ED thresholds?
Should a device be allowed to transmit energy for primary purpose of blocking the transmissions of other devices?
Should LAA implementations be subject to mandatory testing to validate claims made about LAA/Wi-Fi coexistence?
The move of LTE into unlicensed spectrum requires coordination for continued “fair” & “efficient” access
IEEE 802 has been working with 3GPP on these issues since 2014 and has been partially successful
The IEEE Coexistence SC has now decided to pivot to focus mainly on ETSI BRAN rather than 3GPP, using EN to:
Allow any technology to use ’s dual threshold option
Enable innovation based on spatial reuse
Restrict the inappropriate use of blocking energy
Call to action: please participate in the Coexistence SC’s work if you are interested in coexistence issues!
… but IEEE 802 has probably achieved as much as is possible for the moment
Andrew Myles, Cisco

4. In parallel, ETSI BRAN has been defining EN , which will impact coexistence with Wi-Fi globally
For the last two years, ETSI BRAN has been revising the EN Harmonised Standard to align it with the RE-Directive in Europe, particularly Article 3.2:
Radio equipment shall be so constructed that it both effectively uses and supports the efficient use of radio spectrum in order to avoid harmful interference
The latest version of EN is now in operation, and enforces coexistence between multiple technologies by defining:
LBT similar to EDCA …
… and TxOPs similar to EDCA
… with an ED-only mechanism
… or a PD/ED-mechanism as defined by the IEEE standard
The impact of EN is not just limited to Europe, with many countries adopting the European rules
Andrew Myles, Cisco

5. The current version of EN 301 893 is problematic for 802
The current version of EN is problematic for ax performance & spatial reuse
The current version of EN will probably result in good coexistence between ac and LAA
However, EN has some potential serious problems in the context of ax
Some people believe EN ’s PD/ED requirements mean that ax will have less performance than ac (& LAA)
802.11ax is required to use an ED of -72 dBm (roughly)
Whereas ac can use an ED of -62 dBm
EN ’s PD/ED requirements mean that ax will be unable to use its new colour based spatial reuse mechanism
There are no exceptions to the rule for a PD of -82 dBm
Andrew Myles, Cisco

6. The upcoming revision of EN 301 893 provides an opportunity to better enable 802.11ax features
ETSI BRAN has just adopted a WI to revise EN , with anything related to Article 3.2 of the RE-Directive within scope
The revision provides 802 with an excellent opportunity to propose refinements to make EN more compatible with ax features … and established 802 positions
WG has already asked ETSI BRAN to allow ax to use the same ED/PD mechanisms as ac, thus solving the performance issue
Coex SC has started discussing ways to enable spatial re-use without diminishing the “fair” coexistence enforced by EN
WG could ask ETSI BRAN to enforce restrictions on the transmission of energy with a primary purpose of blocking others from transmitting
Alternatively, IEEE 802 could ask ETSI BRAN to significantly loosen the requirements in EN , with a bias to enabling innovation rather than ensuring coexistence
This approach is preferred by some Coex SC participants
Andrew Myles, Cisco

7. Call to action: please participate in Coexistence SC to ensure 802
Call to action: please participate in Coexistence SC to ensure ax can achieve its potential
Please participate in Coexistence SC if you are …
Interested in promoting “fair” coexistence with Wi-Fi (particularly ax) in a multi-technology environment
Interested in engaging with ETSI BRAN on EN , to either:
Refine the rules to enable ax features, with a “fair” coexistence bias
Loosen the rules to enable ax features, with an innovation bias
Interested in any re-engagement with 3GPP on coexistence issues
eg for LAA, eLAA, feLAA, NR
Interested in engagement with other organisations on coexistence issues
eg MulteFire Alliance
If IEEE 802 does not address these issues there is a risk ax will not achieve its potential as the basis of the next generation of Wi-Fi
Andrew Myles, Cisco