| #!/usr/bin/env python |
| # -*- 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 |
| # 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. |
| # |
| # |
| |
| 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([ |
| ('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)]}), |
| ]) |
| |
| |
| def get_bands(): |
| return __band_conf.keys() |
| |
| 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 |
| """ |
| band = arfcn2band(arfcn) |
| if band is not None: |
| conf = __band_conf.get(band) |
| for arfcn_range in conf['ranges']: |
| arfcn_start = arfcn_range[0] |
| arfcn_end = arfcn_range[1] |
| if arfcn_start <= arfcn <= arfcn_end: |
| return True |
| return False |
| |
| |
| def is_valid_uplink(freq): |
| """ |
| Returns True if the given frequency is a valid uplink frequency in the given band |
| """ |
| result = False |
| band = uplink2band(freq) |
| if band is not None: |
| result = True |
| |
| return result |
| |
| def is_valid_downlink(freq): |
| """ |
| Returns True if the given frequency is a valid downlink frequency in the given band |
| """ |
| result = False |
| band = downlink2band(freq) |
| if band is not None: |
| result = True |
| |
| return result |
| |
| def arfcn2uplink(arfcn): |
| band = arfcn2band(arfcn) |
| if band is not None: |
| conf = __band_conf.get(band) |
| f_start = conf['f_start'] |
| 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: |
| 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 = arfcn2band(arfcn) |
| if band is not None: |
| conf = __band_conf.get(band) |
| distance = conf['distance'] |
| return round(arfcn2uplink(arfcn) + distance, 1) |
| return -1 |
| |
| def uplink2arfcn(freq): |
| band = uplink2band(freq) |
| if band is not None: |
| conf = __band_conf.get(band) |
| arfcns_total = 0 |
| for arfcn_range in conf['ranges']: |
| arfcn_start = arfcn_range[0] |
| arfcn_end = arfcn_range[1] |
| 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 = 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), 0)) |
| return -1 |
| |
| |
| def get_arfcn_ranges(band): |
| """ |
| Returns a list of arfcn tuples, each with first and last arfcn of the range. |
| """ |
| result = [] |
| if band in __band_conf: |
| conf = __band_conf.get(band) |
| for arfcn_range in conf['ranges']: |
| arfcn_tuple = (arfcn_range[0], arfcn_range[1]) |
| result.append(arfcn_tuple) |
| return result |
| |