GSM: Channel Release

asked 2020-05-29 10:17:01 +0000

Nalin gravatar image

updated 2020-05-29 10:20:40 +0000

Guy Harris gravatar image

Hello Sir,

I found that wireshark is not able to decode below RAW data correctly. Problem is with "Cell Selection Indicator after Release of all TCH and SDCCH IE --> E-UTRAN Description struct" decoding

RAW data: 06 0d 00 73 04 01 00 00 00 c1 77 1b 70 51 4d 84 38 1a e1 94 0c d8 65 34 b6 19 60 0d 86 5a 43 61 98 26 d8 67 fa 36 00

Actual EARFCN list is below: 1300/3590/37900/38098/38400/38544/38950/40936

But decode is only 2 EARFCN: 1300 and 19297

It decodes

        Cell Selection Indicator after Release of all TCH and SDCCH
            Element ID: 0x77
            Length: 27
            E-UTRAN Description
                ...1 .... = Repeating E-UTRAN Description struct: Present
                .... 0000  0101 0001  0100 .... = EARFCN: 1300
                .... 1... = Measurement Bandwidth: Present
                .... .101 = Measurement Bandwidth: NRB = 100 (5)
                1... .... = Repeated E-UTRAN Not Allowed Cells: Present
                E-UTRAN Not Allowed Cells
                    .0.. .... = Repeated PCID: Not Present
                    ..0. .... = PCID Bitmap Group: Not Present
                    ...0 .... = PCID Pattern: Not Present
                    .... 0... = Repeated E-UTRAN Frequency Index: Not Present <-- This must be 0 | 1 < TARGET_PCID : bit (9) > };
                .... .1.. = Repeated E-UTRAN Not Allowed Cells: Present <-- { 1 <E-UTRAN Description : < E-UTRAN Description struct >> } ** 0 };
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