Frame aggregation

About: Frame aggregation is a research topic. Over the lifetime, 487 publications have been published within this topic receiving 14295 citations.

Squeezing 100+ VoIP calls out of 802.11b WLANs

Abstract: To solve the poor bandwidth efficiency problem of VoIP over IEEE 802.11 wireless LANs (WLANs), the literature frequently suggests elongating voice payload size. Such "voice frame aggregation" can be performed (1) over a single call or multiple calls, (2) at the voice source or at the wireless access point (AP), and (3) with additional repacketization delay or without it. This paper shows that over IEEE 802.11 WLANs, voice frame aggregation should better be done at the AP, over a single call, and without additional delay. We demonstrate through simulation and analysis that this particular implementation choice enables us to support far more VoIP calls on 802.11 WLANs than other choices. For one instance, we show that 100 or more G.729 calls are possible on 802.11b within ITU-T recommended delay bounds.

IEEE 802.11 Wireless LAN

Abstract: In recent years, IEEE 802.11 Wireless LAN (WLAN) has emerged as a prevailing technology for the broadband wireless networking. Along with many emerging applications and services over WLANs, the demands for faster and higher-capacity WLANs have been growing fast. However, MAC layer restrains the performance improvement due to its different overhead. We proposed an efficient MAC scheme ‘Frame Aggregation Method’ that would mitigate the overhead inefficiency. The principle of ‘Frame Aggregation Method’ is to aggregate as many as possible packets from the upper layer into large frames. Thus, the frames will be very large as long as there are enough packets to be aggregated. To support various functionalities provided by ‘Frame Aggregation Method’, new MAC frame formats and the corresponding dynamic logic such as queuing mechanisms are designed. The main contribution of this project is the exact calculation of the theoretical maximum throughput for a variety of IEEE 802.11 technologies. This formula is important to researchers as well as system designers. It is a strict barrier that cannot be overcome by any means while remaining standard-compliant.

Improving Performance of QUIC in WiFi

Abstract: QUIC is a new transport protocol under standardization since 2016. Initially developed by Google as an experiment, the protocol is already deployed in large-scale, thanks to its support in Chromium and Google's servers. In this paper we experimentally analyze the performance of QUIC in WiFi networks. We perform experiments using both a controlled WiFi testbed and a production WiFi mesh network. In particular, we study how QUIC interplays with MAC layer features such as IEEE 802.11 frame aggregation. We show that the current implementation of QUIC in Chromium achieves sub-optimal throughput in wireless networks. Indeed, burstiness in modern WiFi standards may improve network performance, and we show that a Bursty QUIC (BQUIC), i.e., a customized version of QUIC that is targeted to increase its burstiness, can achieve better performance in WiFi. BQUIC outperforms the current version of QUIC in WiFi, with throughput gains ranging between 20% to 30%.

QoS-aware adaptive MPDU aggregation of VoIP traffic on IEEE 802.11n WLANs

Abstract: MPDU aggregation is not applied to real-time voice traffic (e.g., VoIP) in currently available IEEE 802.11n WLAN implementations considering the strict upper bounds of end-to-end delay and jitter. As a result, when real-time voice and non-real-time heavy load traffics are intermixed the resource utilization and overall throughput become poor due to the overhead produced by individual voice MPDU transmissions. In this paper, we propose QoS-aware Adaptive MPDU aggregation scheduler which applies aggregation to voice traffic and adaptively adjusts the aggregation size based on time-varying end-to-end delay and WLAN contention, and QoS requirements (e.g. less than 150 ms end-to-end delay). Experimental results of the proposed scheme show that the overall throughput increased by 57% when 10 stations generate 64 Kbps PCM voice traffic on 270 Mbps PHY rate for 2 ms transit delay representing campus network communication. For 120 ms transit delay configuration that represents intercity communication, the throughput enhancement was 45 % compared to the existing scheme1.

Analysis of the downlink saturation throughput of an asymmetric IEEE 802.11n-based WLAN

Abstract: Frame aggregation (FA) mechanisms improve the throughput of WLANs. In this paper, the effect of the FA mechanism on the throughput of wireless local area networks (WLANs) has been investigated. To this end, we propose an analytical model in order to analyze an IEEE 802.11n network comprised of an access point (AP) and several conventional nodes (CNs), all in the coverage area of each other. With respect to the heavier download traffic compared to the upload one, in our scenario, only the AP uses an FA mechanism and the other nodes use the basic IEEE 802.11 standard. In our proposed analytical model, the maximum downlink (DL) throughput is derived. Regarding the asymmetry among nodes, our analytical model consists of two different queueing networks: one for the AP and the other one for CNs. We verify the accuracy of our analytical results by simulations, i.e., less than 5% mismatch between the analytical and simulation results. We show that there is a tradeoff between the DL saturation throughput and performance of CNs. In other words, the FA improves the AP saturation throughput at the cost of a little degradation of the performance for CNs.