function theMargin = marginEval(xlen)
%% ===========================================================================
% Copyright (C):
%       2005-2009 by Forschungszentrum Telekommunikation Wien, Austria;
%                                                         All rights reserved.
% Description   : ETSI SpM performance simulations
%
% Project       : BANG, FTW
% Author(s)     : Tomas Nordstrom (Tomas.Nordstrom@FTW.at)
%
% Usage:
%   %   Compact scenario description, suitable for TTsetup
%   ntt = {{'ETSI-SDSL-sym-1024',20,-1}{'ETSI-ADSL-FDDoverPOTS',20,-1}};
%   ex.param.modemlist=str2mat(ntt{1}{1}); % Considered modem
%
%   %  Set up parameters for marginEval
%   ex.ms.ntt    = ntt;                 % Scenario to consider
%   ex.ms.resrow = 1;                   % Row for result should match modemlist
%   ex.ms.cable  = 'ETSI-SDSL-PE04';    % Cable to use
%                    
%   % Do the search
%   [reach,fval,exitflag,output]=fzero(@marginEval,[250,8000]);
%
% CVS:       $Id: marginEval.m,v 1.2 2005/01/04 10:25:12 tono Exp $
%% ===========================================================================

%% ===========================================================================
% Change History
%      2005-04-25 (ToNo) Created as a separate evaluator function
%                        useful for search with fzero (cf. ExSDSLreach_v2.m)
%% ===========================================================================
global ex;

ex.tt=TTsetup(ex.ms.ntt,xlen,ex.ms.cable);
result = evalExperiment;
[bitrate_LT, bitrate_NT, margin_LT, margin_NT] = calcXDSLresult(ex,result);
theMargin = min(margin_LT(ex.ms.resrow),margin_NT(ex.ms.resrow));