Saturation throughput analysis of IEEE 802.11g (ERP-OFDM) networks

Abstract

This paper presents the saturation throughput analysis of IEEE 802.11g (ERP-OFDM) networks. The presented work is based on the Markov model previously introduced and validated by the authors in Szczypiorski and

A performance analysis of HICCUPS—a steganographic system for WLAN

“…The analysis is similar to effort done for the 802.11 CSMA/CA networks in [2][3][4][5]7]. Figure 1 illustrates four states of the channel that could occur during the corrupted frame mode.…”

“…In this mode all 802.11 frames have incorrect value of CRC-32 code deliberately set in the FCS field (Frame Checksum Control). Thus, there are no positive acknowledgments through ACK (ACKnowledgment) frames, and therefore "ACK error" state is omitted [2][3][4][5]7]. The "success" of the transmission in the HICCUPS, not defined in the same way as for the 802.11 network, means that during transmission there were no collisions and no data errors.…”

“…2.2 Probability of frame transmission in the corrupted frame mode-τ H Based on the model presented and evaluated in [2][3][4][5]7] let us consider a model of the 802.11 CSMA/CA backoff procedure in corrupted frame mode. From a WLAN perspective of the HICCUPS, communication always fails, because of absence of proper checksums.…”

“…From a WLAN perspective of the HICCUPS, communication always fails, because of absence of proper checksums. Hence transmission of steganograms is performed in every step of the backoff procedure, so we could describe the HICCUPS behaviour with the Markov chain-based model as presented in [2][3][4][5]7] with probability of the failure p f = 1 (means "always failure").…”

“…For the purpose of this analysis the Markov chain-based model was used which is dedicated for 802.11 CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance; [2][3][4][5]7]). The cost of system usage (κ) is defined as a decline of WLAN throughput that results from the HICCUPS operating in the corrupted frame mode [6].…”