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IEEE 802.11 Model C (modified) plug-in

Introduction

The IEEE 802.11 (Model C) [1] was used in the developemnt of the ECC Report 131Annex 2 [2] to characterise all TS-TS radio propagation in the Monte Carlo studies.

The SEAMCAT plugin (.java, .jar and .class) can be found in the section below.

Note: the “modified” term to the plugin refers to the fact that the algorithm has been implemented to ensure the user to set most of the input parameters.

Download and testing of the plugins

The plugins are available in a .zip file containing the source code .java and the executable .class)

Name Model_C_IEEE_802_11_rev2
Date 17/10/2012
Download (.java) download here
Download (.jar) download here (for embbedement)
Download (.class) download here
Testing The condition on the frees space loss has been corrected.
Use of the new SEAMCAT 4 interface
Compatibility SEAMCAT 4.0.0 and onward (previous SEAMCAT versions do not support this version)

Assumptions

Measurements results reported in the literature indicate that the presence of people across the propagation link between a transmitter and a receiver could cause additional loss (of up to 20 to 30dB), as a result of body loss or multi-path interference due to body scattering.

In circumstances where the spatial density of TSs is high (as in the geometries investigated in ECC Report 131), the probability of TS-TS path blocking is also high, and hence the TS-TS path can no longer be treated as line-of-sight. Consequently, a path loss model with a greater exponent is more suitable than the free space path loss model for the characterisation of TS-TS links in dense hotspots.

In ECC Report 131, the mean path loss is characterised by a dual-slope model with a break point at 5 m. The proposed plugin as the flexibility to allow the user to set the distance break point as input to Parameter 1.

In addition, the log-normal distributed shadowing with standard deviations of 3 dB and 4 dB is assumed in ECC Report 131 for separations of less than 5 metres and greater than 5 metres respectively. The proposed plugin as the flexibility to allow the user to set the lognormal value before and after the breakpoint as Parameter 2 and Parameter 3 respectively.

Where the calculated path loss is less than free space attenuation for the same distance, the free space attenuation is used instead.

Equation

The mean path loss is characterised by a dual-slope model with a break point dBP, an exponent of 2 for all distances less than dBP, and an exponent of 3.5 otherwise. In short, the mean path loss, L, in dB is



where d is the separation between the transmitter and receiver in kilometres, dBP = 0.005 is the break-point in km (i.e. 5 m), and LFS is free space path loss.



where hTx and hRx are the height of the transmitter (Tx) and receiver (Rx) respectively and are expressed in m. d is the distance between the Tx and Rx and is expressed in km. f is the frequency and is expressed in MHz.

The log-normal distributed shadowing with standard deviations as defined by the user is applied to the pathloss calculated.

This propagation model is used to calculate terminal-terminal interference and takes account of shadowing losses due to objects between the two terminals, but does not explicitly account for any loss from near-field objects, such as the person carrying the equipment.

How to load the plugins

Load the .class file or the .jar file (to allow embeddement) on your SEAMCAT plugin folders (see plugin section with embeddement)

How to use the plugin

Select “plugin” from the propagation model drop down list. Note that if the name of the model is tuncated you can put your cursor on the field and a tooltip with full name will appear.

  1. Variation. You can select it if you want the Log-normal shadowing effect to be simulated.
  2. Distance to break point, dBP (in m)
  3. Log-normal shadowing standard deviation before the dBP (in dB)
  4. log-normal shadowing standard deviation after the dBP (in dB)
  5. you can reset all the input fields to their pre-initial values



Archive

version history

Below is the history of the various version made available. These versions can be considered as obsolete.

Name 802.11_model_C_modified_rev1
Date 17/10/2012
Download (.java+.class) download here - Plugin obsolete
Compatibility SEAMCAT 3.0.0 and backward

Note on the old (obsolete) plugin interface (Ver. 3 and backward)

Note on usage

  1. Select “plugin” from the propagation model selection (contrary from a built in model)
  2. Select the plugin to use (i.e. IEEE_802_11_Model_C_modified)
  3. Select the environment: Rural/suburban/urban (not in use)
  4. Parameter 1: distance break point, dBP (in km)
  5. Parameter 2: log-normal shadowing standard deviation before the dBP (in dB)
  6. Parameter 3: log-normal shadowing standard deviation after the dBP (in dB)



References

[1] “TGn Channel Models (IEEE 802.11-03/940r2),” High Throughput Task Group, IEEE P802.11, 15 March 2004.
[2] ECC Report 131, Derivation of a Block Edge Mask (BEM) for terminal stations in the 2.6 GHz frequency band (2500-2690 MHz)  www.ecodocdb.dk

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