function [E_up,E_down] = evalPBO(PBO,Att_mtr,start_node,stop_node,Ref_Att,Ref_Noise);
%% ===========================================================================
% evalPBO - Calculates PBO for up (and downstream)
%
% INPUT
% -----
% PBOmethod : PBO struct (method and param)
% tot_Att : matrix with Attenuation in dB/km
% start_node: Start node for PBO modem
% stop_node : Stop node for PBO modem
% Ref_Att : Reference Attenuation for PBO calculation
% Ref_Noise : Reference Noise for PBO method
% Tx : Transmitted signal from far end without PBO
% Rx : Recieved signal at our end without PBO (not available?)
%
% OUTPUT
% ------
% E_up : Scaling of transmit upstream PSD
% E_down : Scaling of transmit downstream PSD
%
% Algorithmic details:
%
% Reference:
% [1] ETSI Document TS 101 270-2, Transmission and Multiplexing
% (TM); Access transmission systems on metal access cables; Very
% high-speed Digital Subscriber Line (VDSL); Part 1: Tranceiver
% Specification; V0.1.2 (2000-03)
% [2] FSAN xDSL simulation tool manual
% [3] FSAN VDSL working group, "Power-backoff methods for VDSL",
% ETSI TM6 983T17A0, Lulea, Sweden June 1998
% [4] ITU Q4/15 FI-102, Fiji 2000
% [5] ITU Q4/15 FI-114, Fiji 2000
% [6] ITU Q4/15 D.815, Geneva 2000
%% ===========================================================================
%% ===========================================================================
% Copyright (C):
% 1998-1999 by Telia Research AB, Lulea, Sweden;
% 2000 by Forschungszentrum Telekommunikation Wien, Austria;
% All rights reserved.
% Project : FSAN duplex model
% Author(s) : Tomas Nordstrom (Tomas.Nordstrom@FTW.at)
% : Daniel Bengtsson (Daniel.J.Bengtsson@Telia.se)
%
% CVS: $Id: evalPBO.m,v 1.11 2000/04/04 08:26:45 tono Exp $
%% ===========================================================================
% Change History
% 1998-12-16 (DaB) Created
% 1998-12-22 (ToNo) Added and updated comments
% 1999-02-04 (DaB) Modified to allowmultiple cables
% 1999-03-10 (DaB) Added new PBO methods
% 1999-03-11 (DaB) New input arguments
% 1999-08-11 (DaB) Rewritten for new structure
% 1999-09-30 (DaB) Rewritten for new ex struct
% 1999-11-16 (ToNo) Implementing the multiple reference length method
% 2000-03-23 (ToNo) Implementing the multiple reference freq method
% 2000-04-04 (ToNo) Implementing a number of multiple constant PBO methods
%% ===========================================================================
global ex;
f=ex.param.frequency.f; % Frequency axis
switch PBO.method
%% ===========================================================================
case 'None',
% No PBO method
E_up=ones(1,length(f));
%% ===========================================================================
case 'RefLen',
% Reference length method
att=Att_mtr{start_node,stop_node};
tmp=Ref_Att.*(PBO.param.len(1)./1000)-att;
tmp=min(tmp,zeros(size(f)));
E_up=ones(1,length(f)).*10.^(tmp/10);
case 'RefLenM',
% Reference length method with multiple references
att=Att_mtr{start_node,stop_node};
high=PBO.param.plan.up.fc+PBO.param.plan.up.bw/2;
low =PBO.param.plan.up.fc-PBO.param.plan.up.bw/2;
E_up=ones(1,length(f));
for band=1:length(PBO.param.len),
tmp=Ref_Att.*(PBO.param.len(band)./1000)-att;
tmp=min(tmp,zeros(size(f)));
ix=find(f<high(band) & f>low(band));
E_up(ix)=10.^(tmp(ix)/10);
end;
case 'RefFEXT',
% Reference FEXT method
l_ref=PBO.param.len(1);
att=Att_mtr{start_node,stop_node};
len_att=sumLen(start_node,stop_node);
tmp=Ref_Att.*(l_ref./1000)+10*log10(l_ref) ...
-att-10*log10(len_att);
tmp=min(tmp,zeros(size(f)));
E_up=ones(1,length(f)).*10.^(tmp/10);
%% ===========================================================================
case {'RefFreq' , 'Constant'}
% Reference frequency method (Constant power)
att=Att_mtr{start_node,stop_node};
f_ref=PBO.param.freq(1); %find the constant
f_index=max(find(f<=f_ref));
tmp=Ref_Att(f_index).*PBO.param.maxlen/1000-att(f_index);
tmp=min(tmp,zeros(size(f)));
E_up=ones(1,length(f)).*(10.^(tmp/10));
case {'RefFreqM', 'ConstantM'}
% Reference frequency (Constant) method with multiple references
att=Att_mtr{start_node,stop_node};
high=PBO.param.plan.up.fc+PBO.param.plan.up.bw/2;
low =PBO.param.plan.up.fc-PBO.param.plan.up.bw/2;
E_up=ones(1,length(f));
for band=1:length(PBO.param.freq),
f_ref=PBO.param.freq(band); %find the constant
f_index=max(find(f<=f_ref));
tmp=Ref_Att(f_index).*PBO.param.maxlen/1000-att(f_index);
tmp=min(tmp,zeros(size(f)));
ix=find(f<high(band) & f>low(band));
E_up(ix)=10.^(tmp(ix)/10);
end;
case 'ConstantRefFEXTM'
% Flat spectrum reference FEXT (ITU FI-114)
att=Att_mtr{start_node,stop_node};
len_att=sumLen(start_node,stop_node);
high=PBO.param.plan.up.fc+PBO.param.plan.up.bw/2;
low =PBO.param.plan.up.fc-PBO.param.plan.up.bw/2;
E_up=ones(1,length(f));
for band=1:length(PBO.param.len),
l_ref=PBO.param.len(band);
f_ref=PBO.param.freq(band); % find the level at the reference frequency
f_index=max(find(f<=f_ref));
tmp=Ref_Att(f_index).*(l_ref./1000)+10*log10(l_ref) ...
-att(f_index)-10*log10(len_att);
tmp=min(tmp,zeros(size(f)));
ix=find(f<high(band) & f>low(band));
E_up(ix)=10.^(tmp(ix)/10);
end;
case 'ConstantAvgLogM' % NOTE/WARNING - This is not ready yet!
% Flat spectrum constant average log method (ITU Q4/15 D.815, Geneva 2000)
Tx=-60*ones(1,length(f)); % ToDo: Get correct values for Tx and Rx!
Rx=-60*ones(1,length(f));
high=PBO.param.plan.up.fc+PBO.param.plan.up.bw/2;
low =PBO.param.plan.up.fc-PBO.param.plan.up.bw/2;
E_up=ones(1,length(f));
for band=1:length(PBO.param.k),
k_ref=PBO.param.k(band);
ix=find(f<high(band) & f>low(band));
k=trapz(f(ix),log2(Rx(ix)));
level=2^((k_ref-k)/(high(band)-low(band))); %%% Should this be 10*log10 ?
E_up(ix)=level*Tx(ix);
end;
case 'ConstantRefNoiseM'
% Flat spectrum reference noise (ITU Q4/15 FI-114, Fiji 2000)
att=Att_mtr{start_node,stop_node};
high=PBO.param.plan.up.fc+PBO.param.plan.up.bw/2;
low =PBO.param.plan.up.fc-PBO.param.plan.up.bw/2;
E_up=ones(1,length(f));
len_att=sumLen(start_node,stop_node)./1000;
for band=1:length(PBO.param.freq),
q_ref=PBO.param.q(band); % get the boosting parameter
f_ref=PBO.param.freq(band); % find the level at the reference frequency
f_index=max(find(f<=f_ref));
tmp=10*log10(q_ref)+10*log10(Ref_Noise) ...
-att(f_index)-20*log10(f_ref./1e6)-10*log10(len_att)-ex.param.XTlevel.FEXT;
tmp=min(tmp,zeros(size(f)));
ix=find(f<high(band) & f>low(band));
E_up(ix)=10.^(tmp(ix)/10);
end;
%% ===========================================================================
case 'RefNoise'
% Reference Noise method
att=Att_mtr{start_node,stop_node};
len_att=sumLen(start_node,stop_node)./1000;
tmp=10*log10(Ref_Noise)-att-20*log10(f./1e6)-10*log10(len_att)-ex.param.XTlevel.FEXT;
tmp=min(tmp,zeros(size(f)));
E_up=ones(1,length(f)).*(10.^(tmp/10));
%% ===========================================================================
otherwise
sprintf('Unknown PBO method: %s',PBO.method)
end; %switch
E_down=ones(1,length(f)); % Downstream PBO not implemented !!!!!!!
function len=sumLen(startno,stopno)
global ex;
len=0;
for nodeno=startno+1:stopno,
len=len+ex.tt.topology{nodeno,1};
end;