<p>Vadim Yanitskiy <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/osmocom-bb/+/18261">View Change</a></p><div style="white-space:pre-wrap">Approvals:
laforge: Looks good to me, approved
pespin: Looks good to me, but someone else must approve
Jenkins Builder: Verified
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">trx_toolkit/gsm_shared.py: implement hopping sequence generation<br><br>Based on firmware/layer1/rfch.c:rfch_hop_seq_gen() by Sylvain Munaut.<br><br>Change-Id: I9ecabfef6f5a4e4180956c6a019c386ccb1c9acd<br>---<br>M src/target/trx_toolkit/gsm_shared.py<br>1 file changed, 73 insertions(+), 2 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/target/trx_toolkit/gsm_shared.py b/src/target/trx_toolkit/gsm_shared.py</span><br><span>index 71f43a7..c8c6b8f 100644</span><br><span>--- a/src/target/trx_toolkit/gsm_shared.py</span><br><span>+++ b/src/target/trx_toolkit/gsm_shared.py</span><br><span>@@ -2,9 +2,10 @@</span><br><span> # -*- coding: utf-8 -*-</span><br><span> </span><br><span> # TRX Toolkit</span><br><span style="color: hsl(0, 100%, 40%);">-# Common GSM constants</span><br><span style="color: hsl(120, 100%, 40%);">+# Common GSM constants and helpers</span><br><span> #</span><br><span style="color: hsl(0, 100%, 40%);">-# (C) 2018-2019 by Vadim Yanitskiy <axilirator@gmail.com></span><br><span style="color: hsl(120, 100%, 40%);">+# (C) 2018-2020 by Vadim Yanitskiy <axilirator@gmail.com></span><br><span style="color: hsl(120, 100%, 40%);">+# Contributions by sysmocom - s.f.m.c. GmbH</span><br><span> #</span><br><span> # All Rights Reserved</span><br><span> #</span><br><span>@@ -106,3 +107,73 @@</span><br><span> return ts</span><br><span> </span><br><span> return None</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+class HoppingParams:</span><br><span style="color: hsl(120, 100%, 40%);">+ """ Hopping sequence generation as per 3GPP TS 45.002, section 6.2.3.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ Based on firmware/layer1/rfch.c:rfch_hop_seq_gen() by Sylvain Munaut.</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ """</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ # Magic numbers for pseudo-random hopping sequence generation</span><br><span style="color: hsl(120, 100%, 40%);">+ RNTABLE = [</span><br><span style="color: hsl(120, 100%, 40%);">+ 48, 98, 63, 1, 36, 95, 78, 102, 94, 73,</span><br><span style="color: hsl(120, 100%, 40%);">+ 0, 64, 25, 81, 76, 59, 124, 23, 104, 100,</span><br><span style="color: hsl(120, 100%, 40%);">+ 101, 47, 118, 85, 18, 56, 96, 86, 54, 2,</span><br><span style="color: hsl(120, 100%, 40%);">+ 80, 34, 127, 13, 6, 89, 57, 103, 12, 74,</span><br><span style="color: hsl(120, 100%, 40%);">+ 55, 111, 75, 38, 109, 71, 112, 29, 11, 88,</span><br><span style="color: hsl(120, 100%, 40%);">+ 87, 19, 3, 68, 110, 26, 33, 31, 8, 45,</span><br><span style="color: hsl(120, 100%, 40%);">+ 82, 58, 40, 107, 32, 5, 106, 92, 62, 67,</span><br><span style="color: hsl(120, 100%, 40%);">+ 77, 108, 122, 37, 60, 66, 121, 42, 51, 126,</span><br><span style="color: hsl(120, 100%, 40%);">+ 117, 114, 4, 90, 43, 52, 53, 113, 120, 72,</span><br><span style="color: hsl(120, 100%, 40%);">+ 16, 49, 7, 79, 119, 61, 22, 84, 9, 97,</span><br><span style="color: hsl(120, 100%, 40%);">+ 91, 15, 21, 24, 46, 39, 93, 105, 65, 70,</span><br><span style="color: hsl(120, 100%, 40%);">+ 125, 99, 17, 123,</span><br><span style="color: hsl(120, 100%, 40%);">+ ]</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ def __init__(self, hsn, maio, ma):</span><br><span style="color: hsl(120, 100%, 40%);">+ # Make sure MA is not empty</span><br><span style="color: hsl(120, 100%, 40%);">+ ma_len = len(ma)</span><br><span style="color: hsl(120, 100%, 40%);">+ if ma_len == 0: # TODO: or rather > 1?</span><br><span style="color: hsl(120, 100%, 40%);">+ raise ValueError("Mobile Allocation is empty")</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ self.hsn = hsn</span><br><span style="color: hsl(120, 100%, 40%);">+ self.maio = maio</span><br><span style="color: hsl(120, 100%, 40%);">+ self.ma = ma</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ # Pre-calculate 2 ** NBIN in advance</span><br><span style="color: hsl(120, 100%, 40%);">+ self._pnm = (ma_len >> 0) | (ma_len >> 1) \</span><br><span style="color: hsl(120, 100%, 40%);">+ | (ma_len >> 2) | (ma_len >> 3) \</span><br><span style="color: hsl(120, 100%, 40%);">+ | (ma_len >> 4) | (ma_len >> 5) \</span><br><span style="color: hsl(120, 100%, 40%);">+ | (ma_len >> 6)</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ def __str__(self):</span><br><span style="color: hsl(120, 100%, 40%);">+ fmt = "hsn=%u, maio=%u, ma_len=%u"</span><br><span style="color: hsl(120, 100%, 40%);">+ return fmt % (self.hsn, self.maio, len(self.ma))</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ @staticmethod</span><br><span style="color: hsl(120, 100%, 40%);">+ def fn2gsm_time(fn):</span><br><span style="color: hsl(120, 100%, 40%);">+ t1 = fn // (26 * 51)</span><br><span style="color: hsl(120, 100%, 40%);">+ t2 = fn % 26</span><br><span style="color: hsl(120, 100%, 40%);">+ t3 = fn % 51</span><br><span style="color: hsl(120, 100%, 40%);">+ tc = (fn // 51) % 8</span><br><span style="color: hsl(120, 100%, 40%);">+ return (t1, t2, t3, tc)</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ # Resolve current ARFCN using the given TDMA frame number</span><br><span style="color: hsl(120, 100%, 40%);">+ def resolve(self, fn):</span><br><span style="color: hsl(120, 100%, 40%);">+ # Cyclic hopping</span><br><span style="color: hsl(120, 100%, 40%);">+ if self.hsn == 0:</span><br><span style="color: hsl(120, 100%, 40%);">+ mai = (fn + self.maio) % len(self.ma)</span><br><span style="color: hsl(120, 100%, 40%);">+ return self.ma[mai]</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ # Pseudo random hopping</span><br><span style="color: hsl(120, 100%, 40%);">+ (t1, t2, t3, tc) = self.fn2gsm_time(fn)</span><br><span style="color: hsl(120, 100%, 40%);">+ ma_len = len(self.ma)</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ rn_idx = (self.hsn ^ (t1 & 63)) + t3</span><br><span style="color: hsl(120, 100%, 40%);">+ m = t2 + self.RNTABLE[rn_idx]</span><br><span style="color: hsl(120, 100%, 40%);">+ mp = m & self._pnm</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ s = mp if mp < ma_len else (mp + t3 & self._pnm) % ma_len</span><br><span style="color: hsl(120, 100%, 40%);">+ mai = (s + self.maio) % ma_len</span><br><span style="color: hsl(120, 100%, 40%);">+ return self.ma[mai]</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmocom-bb/+/18261">change 18261</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/osmocom-bb/+/18261"/><meta itemprop="name" content="View Change"/></div></div>
<div style="display:none"> Gerrit-Project: osmocom-bb </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I9ecabfef6f5a4e4180956c6a019c386ccb1c9acd </div>
<div style="display:none"> Gerrit-Change-Number: 18261 </div>
<div style="display:none"> Gerrit-PatchSet: 2 </div>
<div style="display:none"> Gerrit-Owner: Vadim Yanitskiy <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: Vadim Yanitskiy <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>