doc.: IEEE 802.19-15/0021r0

Submission Alireza Babaei, CableLabsSlide 1

Discussion of LAA LBT Categories

Notice: This document has been prepared to assist IEEE 802.19. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.

Date: 2015-03-11

Authors:

March 2015

doc.: IEEE 802.19-15/0021r0

Submission Alireza Babaei, CableLabsSlide 2

Abstract

• This document discusses a recent agreement within 3GPP RAN1 regarding LBT (Listen-Before-Talk) categories.

• The purpose of this contribution is to highlight a question that can be asked of 3GPP RAN in a liaison communication to clarify the purpose of the LBT categories.

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

RAN1#80 Agreement Regarding LBT Categories (1 of 2)

At RAN1#80 in February 2015, the following agreement was made and documented in [1]:

Classify the evaluated LBT schemes according to the following categories:

– Category 1: No LBT

– Category 2: LBT without random back-off

– Category 3: LBT with random back-off with fixed size of contention window

– Category 4: LBT with random back-off with variable size of contention window

(continued)

Slide 3 Alireza Babaei, CableLabs

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

RAN1#80 Agreement Regarding LBT Categories (2 of 2)

• Note: Contention window is the maximum possible random back-off value

• Note: Category classification does not restrict a LBT design investigation

• Note: Company is encouraged to evaluate many categories as much as possible

• Illustrative examples– FBE procedure as defined in EN BRAN V1.8.0 belongs to category 2

– LBE procedure with a fixed q for the contention window as defined in EN BRAN V1.8.0 belongs to category 3

– LBE procedure Op A with a variable q for the contention window as defined in EN BRAN V1.8.0 belongs to category 4

Slide 4 Alireza Babaei, CableLabs

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

Presentation from 3GPP [2] at IEEE 802 interim meeting in January 2015 included the following text on Slide 13:

Agreed design targets:

• Single global solution allowing compliance with any regional regulatory requirements

• Effective and fair coexistence with Wi-Fi

• Effective and fair coexistence among LAA networks deployed by different operators

(continued)

LBT Mandatory for 3GPP LAA (1 of 2)

5Alireza Babaei, CableLabsSlide 5

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

Based on the above targets, it was agreed that at least the following functionalities are required for LAA:

1. Listen‐before‐talk (Clear channel assessment)

2. Discontinuous transmission on a carrier with limited maximum transmission duration

3. Dynamic Frequency Selection for radar avoidance in certain bands/regions

4. Carrier selection

5. Transmit Power ControlNote: not all functionalities may have a spec impact; not all functionalities would be mandatory for all LAA eNBs/UEs

LBT Mandatory for 3GPP LAA (2 of 2)

6Alireza Babaei, CableLabsSlide 6

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

Clarification/Explanation Needed

• Given that LBT is considered to be required for 3GPP LAA, clarification/explanation is needed regarding the purpose and intent of Category 1 of the LBT schemes.

• A request of clarification/explanation can be done via a liaison communication from IEEE 802 to 3GPP RAN and 3GPP RAN1.

• IEEE 802 consensus is that LBT is essential to a global LAA solution– IEEE 802 previously sent 3GPP liaison communication [3] that

included the recommendation to evaluate alternatives to the fixed back-off mechanism in LBT (i.e., contention window size not fixed).

Slide 7 Alireza Babaei, CableLabs

March 2015

doc.: IEEE 802.19-15/0021r0

Submission

References

[1] RP-150271, “Status Report to TSG: Study on Licensed-Assisted Access to Unlicensed Spectrum,” 3GPP RAN #67, March 2015

[2] IEEE 802.19-15/0008r0, “3GPP & unlicensed spectrum,” Chairman of 3GPP TSG-RAN, IEEE 802 Interim Session, Jan 11-16, 2015

[3] Liaison to 3GPP TSG RAN, Statement Regarding Coexistence of Licensed Assisted Access (LAA) and IEEE 802 (02-Feb-15)

Slide 8 Alireza Babaei, CableLabs

March 2015