Investigating Impact of ACK in Non-beacon Enabled Slotted IEEE 802.15.4

IEEE 802.15.4 standard is gaining attention of researchers day by day due to its wide application arena. Till now numerous studies have conducted and yet lot more is in progress for understanding and rounding off sharp edges of this standard. This study briefly describes the standard i.e. IEEE 802.15.4 and explicitly non-beacon enabled slotted CSMA/CA. In slotted or non-beacon enabled CSMA/CA there are further two flavors. One deals with transmission of an extra control packet (ACK frame) on successfully reception of data packet however, other flavor do not transmit any control packet representing successful transmission. In later part of this paper, extensive simulations are conducted in comparison with these two flavors. Our studies imply to use non-ACK mode in low scalable environment ensuring high probability of getting channel access, low delay and better good put.