An Adaptive Common Control Channel MAC with Transmission Opportunity in IEEE 802.11ac

Spectral utilization is a major challenge in wireless ad hoc networks due in part to using limited network resources. For ad hoc networks, the bandwidth is shared among stations that can transmit data at any point in time. It  is important to maximize the throughput to enhance the network service. In this paper, we propose an adaptive multi-channel access with transmission opportunity protocol for multi-channel ad hoc networks, called AMCA-TXOP. For the purpose of coordination, the proposed protocol uses an adaptive common control channel over which the stations negotiate their channel selection based on the entire available bandwidth and then switch to the negotiated channel. AMCA-TXOP requires a single radio interface so that each station can listen to the control channel, which can overhear all agreements made by the other stations. This allows parallel transmission to multiple stations over various channels, prioritizing data traffic to achieve the quality-of-service requirements. The proposed approach can work with the 802.11ac protocol, which has expanded the bandwidth to 160 MHz by channel bonding. Simulations were conducted to demonstrate the throughput gains that can be achieved using the AMCA-TXOP protocol. Moreover, we compared our protocol with  the IEEE 802.11ac standard protocols

Modeling, Implementation and Evaluation of IEEE 802.11ac in Enterprise Networks

Simulation studies are today an important tool in the development of new networks. For this purpose the NS-3 network simulator can be used. The focus of this thesis work lies on 802.11ac, the latest version of the Wi-Fi standard. NS-3 does not support the IEEE 802.11ac standard and the goal was to implement features for this. Different deployment scenarios were modeled in various conditions and the result evaluated. The thesis work describes the changes made to the existing network simulator NS-3, and also evaluations of different simulations. The most extensive simulation result is from the IEEE 802.11ax scenario document were there is four different scenarios. The selected scenario to model was the enterprise where various 802.11ac simulations were carried out. Support for wider channels were implemented and also bit-error calculation for 256-QAM. Simulation results concluded that increasing the number of nodes from 64 to 256 in an enterprise network will yield 17% lower average throughput to each AP and, several APs on the same channel will create unreliable networks with some stations getting high throughput and some not able to send at all. Also that aggregation makes the peak throughput close to the upper bound

Impact of cell load on 5GHz IEEE 802.11 WLAN

We have conducted an empirical study of the latest 5GHz IEEE 802.11 wireless LAN (WLAN) variants of 802.11n (5GHz) and 802.11ac (Wave 1), under different cell load conditions. We have considered typical configurations of both protocols on a Linux testbed. Under light load,there is no clear difference between 802.11n and 802.11ac in terms of performance and energy consumption. However, in some cases of high cell load, we have found that there may be a small advantage with 802.11ac. Overall, we conclude that there may be little benefit in upgrading from 802.11n (5GHz) to 802.11ac in its current offering, as the benefits may be too small.Postprin

IEEE 802.11ac MU-MIMO Wireless LAN cells with legacy clients

We provide an empirical evaluation of an IEEE 802.11ac Wireless LocalArea Network (WLAN) cell with Multiple User Multiple Input MultipleOutput (MU-MIMO) technology. We conducted our experiments on a testbed comprising consumer equipment under different office scenarios using 40MHz and 80MHz channels. This is the first performance study of MU-MIMO with 802.11ac in an operational scenario using a commercial access point. We find that, for clients that do not support MU-MIMO,operating in a cell that has MU-MIMO enabled may result in reduced performance.Postprin