Channel occupancy estimation method for Wireless LAN

Abstract

Channel occupancy is key information to realize efficient operation of the wireless system. Channel occupancy can be defined as the time occupancy ratio in the case of Wireless LAN (WLAN). We propose a novel passive method to estimate the time occupancy ratio of WLAN. The proposed method produces greater improvement in estimation accuracy compared with that of conventional methods. In this paper, we introduce the definition of the time occupancy ratio as the utilization index of a WLAN radio resource. Then, details of the proposal are introduced. Finally, the excellent evaluation results executed on an experimental system are introduced even when many loss packets exist.

Nulls in the Air: Passive and Low-Complexity QoS Estimation Method for a Large-Scale Wi-Fi Network Based on Null Function Data Frames

“…Specifically, the beacon-based method of [14] requires four equa- tions for calculating the potential bandwidth, while the control-frame-based method of [15] requires 18 equations for calculating the saturation throughput. The COR-based method of [18] requires only three equations, which is the simplest among the conventional methods. Additionally, the retransmission-ratio-based method of [20] requires 14 equations for calculating the available bandwidth.…”

“…Additionally, the retransmission-ratio-based method of [20] requires 14 equations for calculating the available bandwidth. Different from these sophisticated methods [14], [15], [18], [20], the proposed method requires one equation for calculating the NFDF retry ratio, where only two variables N r and N t are used. This simple structure enables a low-cost implementation, as detailed in the following subsection.…”

“…The authors first considered the use of retransmitted frames, instead of the collision probability [26], because the frame retry is caused mainly by collisions. Similar to other passive estimation methods [14], [15], [18], this proposed scheme imposes no complexity on the UE. Moreover, it avoids additional interference.…”

“…Fukuhara et al [18] proposed a sophisticated passive estimation method for the time occupancy ratio of a specific Wi-Fi channel, which is defined as ''channel occupancy ratio (COR).'' Specifically, an independent analyzer, which supports the proposed method, collects the inter-frame space, the average of random backoff, the data packet duration, and the ACK packet duration for all the received packets.…”

Novel TCP method to suppress the time delay effect in heterogeneous radio systems

“…Various approaches are used to achieve the cognitive radio system in communication services [2][3][4][5][6][7][8]. Our approach adopts a scheme involving the cooperative use of the radio resources of multiple and different communication systems co-existing in some frequency bands, which is generally called the heterogeneous radio system [9].…”