What's New in 802.11 Model Suite as in latest ns2.33 Distribution
Tuesday, 25. November 2008, 02:03:14
What's New in 802.11 Model Suite as in latest ns2.33 Distribution
<伊落丹> illidan.modeler [at] gmail.com
Northern Capital, Pandaren Empire
New features have been added to physical layer (PHY), such as modulation, fading, interference. PHY tries to deliver a transparent bit stream through the communication channel. The indication for quality of delivery is always the bit error ratio (BER). To calculate BER to a fairly accurately level, we might need to model fading, pathloss, modulation and other factors. For network simulations at a packet level (what we are doing with ns2), a PHY modeling with higher fidelity will affect higher layer protocols with more details. In usual cases this is what we expect, since we're studying network protocols and techniques in a given PHY environment.
There are also enhancements introduced to layer-2 and management plane, including infrastructure mode support, roaming, etc.
I summarize features of the new model suites below as well as those of the legacy one.
Legacy model in ns2 main distro: 802.11 DCF (by CMU)
Features:
* RTS/CTS/DATA/ACK frame sequence
* physical and virtual sensing
Extension to legacy 802.11 DCF model: 802.11 infrastructure mode (by Univ. of Washington)
Features:
* infrastructure mode
* STA handoff process: scanning-authenticating-association
* passive and active scanning
* inter-AP communications
Replacement to legacy 802.11 DCF model: 802.11Ext
Features:
* Management plane: transmission, reception, transmission coordination, reception coordination, backoff manager, and channel state monitor
* Cumulative SINR computation
* Multiple modulation scheme
* Packet drop tracing at the PHY layer
* Nakagami fading model
Replacement to legacy 802.11 DCF model: dei80211mr
Features:
* different transmission rates, modulation and coding schemes
* SINR-based packet level error model
For more details, refer to ns2 Manual（Nov 2008）, Section 16.3.
<伊落丹> illidan.modeler [at] gmail.com
Northern Capital, Pandaren Empire
New features have been added to physical layer (PHY), such as modulation, fading, interference. PHY tries to deliver a transparent bit stream through the communication channel. The indication for quality of delivery is always the bit error ratio (BER). To calculate BER to a fairly accurately level, we might need to model fading, pathloss, modulation and other factors. For network simulations at a packet level (what we are doing with ns2), a PHY modeling with higher fidelity will affect higher layer protocols with more details. In usual cases this is what we expect, since we're studying network protocols and techniques in a given PHY environment.
There are also enhancements introduced to layer-2 and management plane, including infrastructure mode support, roaming, etc.
I summarize features of the new model suites below as well as those of the legacy one.
Legacy model in ns2 main distro: 802.11 DCF (by CMU)
Features:
* RTS/CTS/DATA/ACK frame sequence
* physical and virtual sensing
Extension to legacy 802.11 DCF model: 802.11 infrastructure mode (by Univ. of Washington)
Features:
* infrastructure mode
* STA handoff process: scanning-authenticating-association
* passive and active scanning
* inter-AP communications
Replacement to legacy 802.11 DCF model: 802.11Ext
Features:
* Management plane: transmission, reception, transmission coordination, reception coordination, backoff manager, and channel state monitor
* Cumulative SINR computation
* Multiple modulation scheme
* Packet drop tracing at the PHY layer
* Nakagami fading model
Replacement to legacy 802.11 DCF model: dei80211mr
Features:
* different transmission rates, modulation and coding schemes
* SINR-based packet level error model
For more details, refer to ns2 Manual（Nov 2008）, Section 16.3.
WIDGETIZE