Teuku Yuliar Arif

Throughput Estimates for A-MPDU and Block ACK Schemes Using HT-PHY Layer

IEEE 802.11n standard has introduced the new schemes in MAC and HT-PHY layers to improve network throughput. The new schemes in MAC layer are A-MSDU, A-MPDU and Block ACK. In the HT-PHY layer there are MIMO transmission using up to 4 spatial streams, 40 MHz bandwidth channel and 400 ns guard interval. In this paper, we proposed an analytical model that can be used to estimates the throughput of A-MPDU and Block ACK schemes using HT-PHY layer. In our model, there are six different slot types, which are A-MPDU transmission slot, A-MPDU collision slot, A-MPDU sub-frame error slot, BAR error slot and BA error slot. We derive the equations that can be used to calculate the time duration and the probability occurrences of each type slot. Our analytical model also considers the anomalous slot phenomenon in EDCA scheme and frame error probability in HT-PHY. The simulation results using matlab show our analytical model can be used to estimates the throughput of MSDU transmission using A-MPDU and Block ACK schemes. A- MPDU and Block ACK schemes can be used to improve the MAC throughput especially for MSDU size is bigger than 400 bytes. Index Terms—Throughput, A-MPDU, Block ACK, HT- PHY, IEEE 802.11n

DCF and EDCA throughput improvement using Selective Anomalous Slot Avoidance (SASA)

In DCF and EDCA schemes, the number of collisions increased caused the number of anomalous slots also increased. These conditions caused the average duration of collision will be much longer and result in a decreased network throughput. In this paper we have proposed SASA scheme to avoid anomalous slot after the collision. Simulation results show SASA scheme produces higher throughput compare to DCF and EDCA schemes.

Energy Efficiency Opportunity at Same Data Rate and Different MCS in IEEE 802.11n

Currently, the number of Access Point (AP) and mobile station (STA), such as notebooks and smart phones, which supports standard WLAN IEEE 802.11n is increasing. Increasing the number of devices that supports 802.11n standard is implicated in the increased use of energy. Therefore, the necessary efforts so that energy use in WLAN devices in the future can be more efficient. The choice of data rate in 802.11n is ranging from 6.5 to 600 Mbps and indexed by MCS, from MCS-0 to MCS-31. However, there are 10 data rate which is produced by more than one MCS. In this paper, we conducted a simulation to calculate the energy consumption of each MCS that produces the same data rate to determine the MCS which is more energy efficient. Simulations were also conducted to measure the energy efficiency opportunities with the use of appropriate MCS on the use of certain data rate in IEEE 802.11n. This research was carried out by simulation using NS-3. To calculate the energy consumed by each MCS, the simulation performed through three different scenarios. The simulation results show the energy consumption of MCS- 1, MCS-2, MCS-3, MCS-4, MCS-5 and MCS-6 are lower than the MCS-8, MCS-16, MCS-9, MCS-10, MCS-17, MCS-11 and MCS-18.