28 Nov
2014
28 Nov
'14
10:54 p.m.
Hello.
In my phone specs says that it support: UMTS/HSDPA/HSUPA (850, 900, 1900, 2100
MHz).
At the wikipedia, I can read:
Uplink Downlink
GSM-850 824.2 – 849.2 869.2 - 894.2
GSM 900: ------------------------------------------------
P-GSM 900 890,0 - 915,0 935,0 - 960,0
E-GSM 900 880,0 - 890,0 925,0 - 935,0
R-GSM 900 876,0 - 880,0 921,0 - 925,0
GSM1900: ------------------------------------------------
GSM 1900 1850,0 - 1910,0 1930,0 - 1990,0
More clearly(?):
MHZ 1111111111
88888888888888888888999999999999999999990000000000
00112233445566778899001122334455667788990123456789
BAND: 05050505050505050505050505050505050505050505050505
GSM-850 : -----^^^^^----vvvvvv------------------------------
P-GSM 900: ------------------^^^^^^---vvvvvv-----------------
E-GSM 900: ----------------^^^------vvv----------------------
R-GSM 900: ---------------^^-------vv------------------------
(^) means uplink, (v) downlink.
Posible overlap between bands:
SRC Band From To DST Band Hole size
P-GSM 900 ----(890.0 - 894.2)---> GSM-850 | 4.2 MHZ
E-GSM 900 ----(880.0 - 894.2)---> GSM-850 | 14.2 MHZ
R-GSM 900 ----(876.0 - 880.0)---> GSM-850 | 4.0 MHZ
Can a phone, with a modified baseband firmware, transmit data to another phone
directly, without BSS? Or are there any hardware limitation?
From https://gnuradio.org/redmine/attachments/115/all_gsm_channels_arfcn.txt
Source channel:
Channel: 0; Band: EGSM-900 Uplink: 890 MHz, Downlink: 935 MHz
Channel: 1; Band: GSM-900 Uplink: 890.2 MHz, Downlink: 935.2 MHz
...
Channel: 20; Band: GSM-900 Uplink: 894 MHz, Downlink: 939 MHz
Channel: 21; Band: GSM-900 Uplink: 894.2 MHz, Downlink: 939.2 MHz
Destination channel:
Channel: 232; Band: GSM-850 Uplink: 845 MHz, Downlink: 890 MHz
Channel: 233; Band: GSM-850 Uplink: 845.2 MHz, Downlink: 890.2 MHz
...
Channel: 250; Band: GSM-850 Uplink: 848.6 MHz, Downlink: 893.6 MHz
Channel: 251; Band: GSM-850 Uplink: 848.8 MHz, Downlink: 893.8 MHz
For example using a phone on channel 0 (GSM-900 band) to send a packet to a
phone on channel 232 (GSM-850 band), using 890 MHz common frecuency.
I could't get any useful info about that.
Greetings.
Rodrigo.