Dear All, If a stronger frame (P1) arrive during the reception of a weaker frame (P2) by a certain threshold (dB), a MAC (802.11) in NS2 will decide it as a collision.
However in hardware implementation for e.g in Prism chipset, P1 can still be captured if it arrives within P2's preamble time (Preamble Capture) and in Atheros chipset, P1 can be captured even if it arrives after P2's preamble time (Frame Body Capture) [1]. Settings in [2], MAC = IEEE 802.11p Preamble Capture Threshold = 5dB Frame Body Capture Threshold = 10dB Settings in [3], MAC = IEEE 802.11p Preamble Capture Threshold = 4dB Frame Body Capture Threshold = 10dB Settings in [4], MAC = IEEE 802.11a (5.9GHz) Preamble Capture Threshold = 4dB Frame Body Capture Threshold = 10dB These capture thresholds very much dependent on the datarate, chipset manufacturer's parameter setting etc. It is not defined by the standard. Anyone aware the optimal/chipset manufacturer setting for IEEE 802.11b (e.g 11Mbps) for Preamble and Frame Body Capture Threshold ? Would appreciate if you could point me to some papers or web URL's for my further reading. My search have not been fruitful thus far. rgds Saravanan K Reference: [1] Jiho Ryu, Jeongkeun Lee, Sung-Ju Lee, and Taekyoung Kwon, "Revamping the IEEE 802.11a PHY simulation models", in Proceedings of the 11th international symposium on Modeling, analysis and simulation of wireless and mobile systems (MSWiM '08), pp 28-36, New York, USA [2] Hannes Hartenstein, Kenneth Laberteaux, "VANET: Vehicular Applications and Inter-Networking Technologies", Wiley, [3] Moritz Killat* and Hannes Hartenstein, "An Empirical Model for Probability of Packet Reception in Vehicular Ad Hoc Networks", EURASIP Journal on Wireless Communications and Networking, 2009 [4] Byungjin Cho, "A Simulation study on Interference in CSMA/CA Ad-Hoc Networks using Point Process", Masters Thesis, Aaltoo University, 2010