Added arfcn functions

1 files changed, 120 insertions, 0 deletions

diff --git a/python/misc_utils/arfcn.py b/python/misc_utils/arfcn.py
new file mode 100644
index 0000000..2397970
--- /dev/null
+++ b/python/misc_utils/arfcn.py
@@ -0,0 +1,120 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# @file
+# @author Roman Khassraf <rkhassraf@gmail.com>
+# @section LICENSE
+#
+# Gr-gsm is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# Gr-gsm is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with gr-gsm; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+#
+
+# first uplink freq, first arfcn, last arfcn, downlink frequence distance
+__band_conf = {'GSM450': {'first_freq': 450.6e6, 'first_arfcn': 259, 'last_arfcn': 293, 'downlink_dist': 10e6},
+            'GSM480': {'first_freq': 479e6, 'first_arfcn': 306, 'last_arfcn': 340, 'downlink_dist': 10e6},
+            'GSM850': {'first_freq': 824.2e6, 'first_arfcn': 128, 'last_arfcn': 251, 'downlink_dist': 45e6},
+            'P-GSM': {'first_freq': 890.2e6, 'first_arfcn': 1, 'last_arfcn': 124, 'downlink_dist':  45e6},
+            'E-GSM': {'first_freq': 880.2e6, 'first_arfcn': 975, 'last_arfcn': 1023, 'downlink_dist':  45e6},           
+            'R-GSM': {'first_freq': 876.2e6, 'first_arfcn': 955, 'last_arfcn': 1023, 'downlink_dist':  45e6},
+            'DCS1800': {'first_freq': 1710.2e6, 'first_arfcn': 512, 'last_arfcn': 885, 'downlink_dist':  95e6},
+            'PCS1900': {'first_freq': 1850.2e6, 'first_arfcn': 512, 'last_arfcn': 810, 'downlink_dist':  80e6}}
+
+__chan_spacing = 2e5
+
+
+def get_bands():
+    return __band_conf.keys()
+
+
+def is_valid_arfcn(arfcn, band):
+    """
+    Returns True if arfcn is valid in the given band, else False
+    """
+    if band in __band_conf:
+        conf = __band_conf.get(band)
+        first_arfcn = conf['first_arfcn']
+        last_arfcn = conf['last_arfcn']
+        if first_arfcn <= arfcn <= last_arfcn:
+            return True
+    return False
+
+
+def is_valid_uplink(freq, band):
+    """
+    Returns True if the given frequency is a valid uplink frequency in the given band
+    """
+    if band in __band_conf:
+        conf = __band_conf.get(band)
+        first_freq = arfcn2uplink(conf['first_arfcn'], band)
+        last_freq = arfcn2uplink(conf['last_arfcn'], band)
+    if first_freq is None or last_freq is None:
+        return False
+    if first_freq <= freq <= last_freq:
+        return True
+    return False
+
+
+def is_valid_downlink(freq, band):
+    """
+    Returns True if the given frequency is a valid downlink frequency in the given band
+    """
+    if band in __band_conf:
+        conf = __band_conf.get(band)
+        first_freq = arfcn2downlink(conf['first_arfcn'], band)
+        last_freq = arfcn2downlink(conf['last_arfcn'], band)
+    if first_freq is None or last_freq is None:
+        return False
+    if first_freq <= freq <= last_freq:
+        return True
+    return False 
+
+
+def arfcn2uplink(arfcn, band):
+    if band in __band_conf and is_valid_arfcn(arfcn, band):
+
+        conf = __band_conf.get(band)
+        freq_start = conf['first_freq']
+        offset = conf['first_arfcn']
+        # if (band == 'E-GSM' or band == 'R-GSM') and arfcn > 124:
+        #     offset = 1024
+        f = freq_start + (__chan_spacing * (arfcn - offset))
+        return round(f, 1)
+    return None
+
+
+def arfcn2downlink(arfcn, band):
+    if band in __band_conf and is_valid_arfcn(arfcn, band):
+        conf = __band_conf.get(band)
+        distance = conf['downlink_dist']
+        return round(arfcn2uplink(arfcn, band) + distance, 1)
+    return None
+
+
+def uplink2arfcn(freq, band):
+    if band in __band_conf and is_valid_uplink(freq, band):
+        conf = __band_conf.get(band)
+        freq_start = conf['first_freq']
+        offset = conf['first_arfcn']
+        return int(round(offset + ((freq - freq_start) / __chan_spacing), 0))
+    return None
+
+
+def downlink2arfcn(freq, band):
+    if band in __band_conf and is_valid_downlink(freq, band):
+        conf = __band_conf.get(band)
+        distance = conf['downlink_dist']
+        freq_uplink = freq - distance
+        return int(round(uplink2arfcn(freq_uplink, band), 0))
+    return None