Performance Analysis of Downlink MU-TXOP Sharing in IEEE 802.11ac

The 802.11ac version of the popular IEEE 802.11 protocol aims to boost performance by increasing the channel bandwidth and allowing downlink multiuser multiple-input multiple-output (MIMO)—i.e., simultaneous transmission to multiple clients in the downlink direction. In this paper, we evaluate the performance improvements of multiuser Transmission Opportunity (MU-TXOP) sharing in this scenario under nonsaturated load and non-ideal channel condition, using a novel analytical model based on discrete Markov chain and E-limited M/G/1 queuing model. Our results show that MU-TXOP sharing achieves up to 105% gain in throughput compared to the case without MU-TXOP sharing. Moreover, the low-priority traffic benefits most from MU-TXOP sharing, with up to 150% throughput gain at low traffic intensity due to availability of additional transmission opportunities for secondary ACs.

[1]  Chiu Ngo,et al.  MAC enhancements for downlink multi-user MIMO transmission in next generation WLAN , 2012, 2012 IEEE Consumer Communications and Networking Conference (CCNC).

[2]  Jaume Barceló,et al.  On the Performance of Packet Aggregation in IEEE 802.11ac MU-MIMO WLANs , 2012, IEEE Communications Letters.

[3]  Chulho Chung,et al.  Saturation throughput analysis of IEEE 802.11ac TXOP sharing mode , 2015 .

[4]  Zhaoxing Li,et al.  Modeling the TXOP Sharing Mechanism of IEEE 802.11ac Enhanced Distributed Channel Access in Non-Saturated Conditions , 2015, IEEE Communications Letters.

[5]  Adlen Ksentini,et al.  Performance Analysis of the TXOP Sharing Mechanism in the VHT IEEE 802.11ac WLANs , 2014, IEEE Communications Letters.

[6]  Kurosaki Masayuki,et al.  Performance Evaluation for Multi-User MIMO IEEE 802.11ac Wireless LAN System , 2011 .

[7]  Boris Bellalta,et al.  A space-time batch-service queueing model for multi-user MIMO communication systems , 2009, MSWiM '09.

[8]  Zheng Chang,et al.  IEEE 802.11ac: Enhancements for very high throughput WLANs , 2011, 2011 IEEE 22nd International Symposium on Personal, Indoor and Mobile Radio Communications.

[9]  A. Girotra,et al.  Performance Analysis of the IEEE 802 . 11 Distributed Coordination Function , 2005 .

[10]  Jelena V. Misic,et al.  Analysis of Impact of TXOP Allocation on IEEE 802.11e EDCA under Variable Network Load , 2012, IEEE Transactions on Parallel and Distributed Systems.

[11]  Youngsoo Kim,et al.  Enhancing WLAN backoff procedures for downlink MU-MIMO support , 2013, 2013 IEEE Wireless Communications and Networking Conference (WCNC).