Making arfcn<->freq conversions more robust and uptading apps depending on it

1 files changed, 88 insertions, 66 deletions

diff --git a/python/misc_utils/arfcn.py b/python/misc_utils/arfcn.py
index 86d379d..349e8ce 100644..100755
--- a/python/misc_utils/arfcn.py
+++ b/python/misc_utils/arfcn.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 # @file
 # @author (C) 2015 by Roman Khassraf <rkhassraf@gmail.com>
+#         (C) 2017 by Piotr Krysik <ptrkrysik@gmail.com>
 # @section LICENSE
 #
 # Gr-gsm is free software; you can redistribute it and/or modify
@@ -23,32 +24,66 @@
 
 import collections
 
+__chan_spacing = 2e5
+__arfcn_pcs = 0x8000
+
 # first uplink freq, distance between uplink/downlink frequency, list of range tuple
 # each tuple in a range tuple contains: first arfcn of the range, last arfcn of the range, offset of the range
 # entries are ordered by relevance
 __band_conf = collections.OrderedDict([
-    ('P-GSM', {'f_start': 890.0e6, 'distance': 45e6, 'ranges': [(1, 124, 0)]}),
-    ('DCS1800', {'f_start': 1710.2e6, 'distance': 95e6, 'ranges': [(512, 885, 512)]}),
-    ('PCS1900', {'f_start': 1850.2e6, 'distance': 80e6, 'ranges': [(512, 810, 512)]}),
-    ('E-GSM', {'f_start': 890.0e6, 'distance': 45e6, 'ranges': [(0, 124, 0), (975, 1023, 1024)]}),
-    ('R-GSM', {'f_start': 890.0e6, 'distance': 45e6, 'ranges': [(0, 124, 0), (955, 1023, 1024)]}),
-    ('GSM450', {'f_start': 450.6e6, 'distance': 10e6, 'ranges': [(259, 293, 259)]}),
-    ('GSM480', {'f_start': 479e6, 'distance': 10e6, 'ranges': [(306, 340, 306)]}),
-    ('GSM850', {'f_start': 824.2e6, 'distance': 45e6, 'ranges': [(128, 251, 128)]}),
+    ('GSM900', {'f_start': 880.2e6, 'distance': 45e6, 'ranges': [(975, 1023), (0, 124)]}),
+    ('DCS1800', {'f_start': 1710.2e6, 'distance': 95e6, 'ranges': [(512, 885)]}),
+    ('GSM850', {'f_start': 824.2e6, 'distance': 45e6, 'ranges': [(128, 251)]}),
+    ('PCS1900', {'f_start': 1850.2e6, 'distance': 80e6, 'ranges': [(512+__arfcn_pcs, 810+__arfcn_pcs)]}), #PCS band is "special" as its channel number range overlap with DCS1800
+    ('GSM450', {'f_start': 450.6e6, 'distance': 10e6, 'ranges': [(259, 293)]}),
+    ('GSM480', {'f_start': 479e6, 'distance': 10e6, 'ranges': [(306, 340)]}),
+    ('GSM-R', {'f_start': 876.2e6, 'distance': 45e6, 'ranges': [(955, 1023), (0, 124)]}),
 ])
 
-__chan_spacing = 2e5
-
 
 def get_bands():
     return __band_conf.keys()
 
-
-def is_valid_arfcn(arfcn, band):
+def arfcn2band(arfcn):
+    for band_name,band_desc in __band_conf.items():
+        for arfcns_range in band_desc["ranges"]:
+            arfcn_start = arfcns_range[0]
+            arfcn_stop  = arfcns_range[1]
+            if arfcn_start <= arfcn <= arfcn_stop:
+                return band_name
+    return None
+    
+def freq2band(freq, downlink=False):
+    for band_name,band_desc in __band_conf.items():
+        chans_total = 0
+        #count total number of channels in the range
+        for arfcns_range in band_desc["ranges"]:
+            arfcn_start = arfcns_range[0]
+            arfcn_stop  = arfcns_range[1]
+            chans_in_range = arfcn_stop - arfcn_start + 1
+            chans_total = chans_total + chans_in_range
+
+        first_freq = band_desc["f_start"]
+        if downlink:
+            first_freq = first_freq + band_desc["distance"]
+        last_freq  = first_freq + (chans_total - 1) * __chan_spacing
+        
+        if first_freq <= freq <= last_freq:
+            return band_name
+    return None
+
+def uplink2band(freq):
+    return freq2band(freq, False)
+
+def downlink2band(freq):
+    return freq2band(freq, True)
+    
+def is_valid_arfcn(arfcn):
     """
     Returns True if arfcn is valid in the given band, else False
     """
-    if band in __band_conf:
+    band = arfcn2band(arfcn)
+    if band is not None:
         conf = __band_conf.get(band)
         for arfcn_range in conf['ranges']:
             arfcn_start = arfcn_range[0]
@@ -58,92 +93,78 @@ def is_valid_arfcn(arfcn, band):
     return False
 
 
-def is_valid_uplink(freq, band):
+def is_valid_uplink(freq):
     """
     Returns True if the given frequency is a valid uplink frequency in the given band
     """
-    result = None
-    if band in __band_conf:
-        conf = __band_conf.get(band)
-        result = False
-        for arfcn_range in conf['ranges']:
-            arfcn_start = arfcn_range[0]
-            arfcn_end = arfcn_range[1]
-            first_freq = arfcn2uplink(arfcn_start, band)
-            last_freq = arfcn2uplink(arfcn_end, band)
-            if first_freq is None or last_freq is None:
-                result = False
-            elif first_freq <= freq <= last_freq:
-                result = True
+    result = False
+    band = uplink2band(freq)
+    if band is not None:
+        result = True
+        
     return result
 
-
-def is_valid_downlink(freq, band):
+def is_valid_downlink(freq):
     """
     Returns True if the given frequency is a valid downlink frequency in the given band
     """
-    result = None
-    if band in __band_conf:
-        conf = __band_conf.get(band)
-        result = False
-        for arfcn_range in conf['ranges']:
-            arfcn_start = arfcn_range[0]
-            arfcn_end = arfcn_range[1]
-            first_freq = arfcn2downlink(arfcn_start, band)
-            last_freq = arfcn2downlink(arfcn_end, band)
-            if first_freq is None or last_freq is None:
-                result = False
-            elif first_freq <= freq <= last_freq:
-                result = True
+    result = False
+    band = downlink2band(freq)
+    if band is not None:
+        result = True
+        
     return result
 
-
-def arfcn2uplink(arfcn, band):
-    if band in __band_conf and is_valid_arfcn(arfcn, band):
+def arfcn2uplink(arfcn):
+    band = arfcn2band(arfcn)
+    if band is not None:
         conf = __band_conf.get(band)
         f_start = conf['f_start']
-        offset = None
+        arfcns_total = 0
         for arfcn_range in conf['ranges']:
             arfcn_start = arfcn_range[0]
             arfcn_end = arfcn_range[1]
-            if arfcn_start <= arfcn <= arfcn_end:
-                offset = arfcn_range[2]
 
-        if offset is not None:
-            f = f_start + (__chan_spacing * (arfcn - offset))
-            return round(f, 1)
+            if arfcn_start <= arfcn <= arfcn_end:
+                f = f_start + (__chan_spacing * (arfcn - arfcn_start + arfcns_total))
+                return round(f, 1)
+            arfcns_total = arfcn_end - arfcn_start + 1
     return -1
 
 
-def arfcn2downlink(arfcn, band):
-    if band in __band_conf and is_valid_arfcn(arfcn, band):
+def arfcn2downlink(arfcn):
+    band = arfcn2band(arfcn)
+    if band is not None:
         conf = __band_conf.get(band)
         distance = conf['distance']
-        return round(arfcn2uplink(arfcn, band) + distance, 1)
+        return round(arfcn2uplink(arfcn) + distance, 1)
     return -1
 
-
-def uplink2arfcn(freq, band):
-    if band in __band_conf and is_valid_uplink(freq, band):
+def uplink2arfcn(freq):
+    band = uplink2band(freq)
+    if band is not None:
         conf = __band_conf.get(band)
-        f_start = conf['f_start']
-        offset = None
+        arfcns_total = 0
         for arfcn_range in conf['ranges']:
             arfcn_start = arfcn_range[0]
             arfcn_end = arfcn_range[1]
-            offset = arfcn_range[2]
-            arfcn = int(round(offset + ((freq - f_start) / __chan_spacing), 0))
-            if arfcn_start <= arfcn <= arfcn_end:
+            arfcns_in_range = arfcn_end - arfcn_start + 1
+           
+            freq_start = conf['f_start'] + arfcns_total * __chan_spacing
+            freq_end = freq_start + (arfcns_in_range - 1) * __chan_spacing 
+            if freq_start <= freq <= freq_end:
+                arfcn = int(round(arfcn_start + ((freq - freq_start) / __chan_spacing), 0))
                 return arfcn
+            arfcns_total = arfcns_total + arfcns_in_range
     return -1
 
-
-def downlink2arfcn(freq, band):
-    if band in __band_conf and is_valid_downlink(freq, band):
+def downlink2arfcn(freq):
+    band = downlink2band(freq)
+    if band is not None:
         conf = __band_conf.get(band)
         distance = conf['distance']
         freq_uplink = freq - distance
-        return int(round(uplink2arfcn(freq_uplink, band), 0))
+        return int(round(uplink2arfcn(freq_uplink), 0))
     return -1
 
 
@@ -158,3 +179,4 @@ def get_arfcn_ranges(band):
             arfcn_tuple = (arfcn_range[0], arfcn_range[1])
             result.append(arfcn_tuple)
     return result
+