root/vic/branches/cc/cc/formula.h @ 4855

Revision 4855, 2.5 KB (checked in by soohyunc, 4 years ago)

TFRC's max rate is bounded by 50 Mbytes/sec.

This means that IPI can go as fast as 20 usec - it is roughly same speed over
window-based TFWC when cwnd allows sehding them. This will mean that Vic is
unlikely send packets faster than this speed.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Rev URL
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1/*
2 * Copyright (c) 2010 University College London
3 * All rights reserved.
4 *
5 * AUTHOR: Soo-Hyun Choi <s.choi@.cs.ucl.ac.uk>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor of the Laboratory may be used
16 *    to endorse or promote products derived from this software without
17 *    specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $Id$
32 */
33
34#ifndef vic_cc_formula_h
35#define vic_cc_formula_h
36
37#define MAXRATE 50000000.0
38#define SAMLLFLOAT 0.0000001
39
40/*
41 * This takes as input the packet drop rate, and outputs the sending
42 *   rate in bytes per second.
43 */
44static double p_to_b(double p, double rtt, double tzero, int psize, int bval)
45{
46        double tmp1, tmp2, res;
47
48        if (p < 0 || rtt < 0) {
49                return MAXRATE ;
50        }
51        res = rtt * sqrt(2.0*bval*p/3.0);
52        tmp1 = 3.0 * sqrt(3.0*bval*p/8.0);
53
54        if (tmp1>1.0) tmp1=1.0;
55
56        tmp2 = tzero * p * (1.0+32.0 * p * p);
57        res += tmp1 * tmp2;
58
59        // At this point, 1/res gives the sending rate in pps:
60        // 1/(rtt*sqrt(2*bval*p/3) + 3*sqrt(3*bval*p/8)*tzero*p*(1+32*p*p))
61        if (res < SAMLLFLOAT) {
62                res=MAXRATE;
63        } else {
64                // change from 1/pps to Bps.
65                res=psize/res;
66        }
67        if (res > MAXRATE) {
68                res = MAXRATE ;
69        }
70
71        // the unit of rate is (bits/sec)
72        //double brate = 8.0 * res;
73
74        return res;
75}
76
77#endif /* vic_cc_formula_h */
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