Bugzilla – Full Text Bug Listing |
Summary: | Cost231PropagationLossModel is imprecise | ||
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Product: | ns-3 | Reporter: | Tommaso Pecorella <tommaso.pecorella> |
Component: | propagation | Assignee: | Nicola Baldo <nicola> |
Status: | PATCH PENDING --- | ||
Severity: | enhancement | CC: | krotov, ns-bugs, tomh |
Priority: | P5 | ||
Version: | ns-3-dev | ||
Hardware: | All | ||
OS: | All | ||
Bug Depends on: | 2011 | ||
Bug Blocks: | |||
Attachments: |
proposed patch
Proposed patch |
Description
Tommaso Pecorella
2014-10-03 16:27:55 EDT
sorry, I didn't realize the speed of light discussion was here also; opened a separate bug 2011 for the constant value. Let's keep this bug scoped to the Cost231 model, and make the fix of lambda depend on the bug 2011. Created attachment 2613 [details]
proposed patch
Here is a proposed patch addressing the two issues mentioned by Tommaso. I did not test it.
As Tommaso mentioned, the change affects the behavior of the model for all distances, with a non negligible impact in simulation results for typical scenarios.
I am not sure how much this COST 231 model implementation is used, I just recall that LTE simulation typically use OkumuraHataPropagationLossModel, which is in fact an alternative implementation of this model. I've seen just a few examples in the code base that use this model. This considered, how do you feel about pushing this patch?
Created attachment 2718 [details]
Proposed patch
Fixed default value for Lambda attribute so it corresponds to default Frequency.
There's an additional point, raised in the ns-3 users' group: https://groups.google.com/forum/#!topic/ns-3-users/cQpBK9XbpGc The COST 231 model is meant to be used in 1.5-2.0 GHz range, while the default frequency in the model is 2.3 GHz. We should (at least) give a warning when one uses the model outside the normal range and (definitely) not use a default value of 2.3 GHz. |